https://echopedia.org/api.php?action=feedcontributions&user=Vdbilt&feedformat=atomEchopedia - User contributions [en]2024-03-29T00:53:58ZUser contributionsMediaWiki 1.39.5https://echopedia.org/index.php?title=File:Swingingheart.avi&diff=6585File:Swingingheart.avi2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:Swingingheart.avi</p>
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<div>Apical 4 Cjaner view of a swinging heart. Note the pericardial effusion.</div>Vdbilthttps://echopedia.org/index.php?title=File:PulsusAlternans.png&diff=6578File:PulsusAlternans.png2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:PulsusAlternans.png</p>
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<div>An ECG of a 40 year old man with Kahlers' disease and tamponade. Note the electrical alternans in the precordial leads and the microvoltages in the extremity leads</div>Vdbilthttps://echopedia.org/index.php?title=File:MVThrombus.avi&diff=6574File:MVThrombus.avi2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:MVThrombus.avi</p>
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<div></div>Vdbilthttps://echopedia.org/index.php?title=File:A4CTTS.avi&diff=6568File:A4CTTS.avi2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:A4CTTS.avi</p>
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<div>Apical 4 chamber view of a Takotsubo cardiomyopathy</div>Vdbilthttps://echopedia.org/index.php?title=File:FirstEchoCor.png&diff=6562File:FirstEchoCor.png2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:FirstEchoCor.png</p>
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<div>The first echocardiogram made by Inge Edler and Hellmuth Hertz in 1953</div>Vdbilthttps://echopedia.org/index.php?title=File:EdlerHertz.png&diff=6560File:EdlerHertz.png2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:EdlerHertz.png</p>
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<div>Inge Edler and Hellmuth Hertz in 1977 in the University Hospital in Lund.</div>Vdbilthttps://echopedia.org/index.php?title=File:Torso.png&diff=6557File:Torso.png2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:Torso.png</p>
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<div>Torso Schematic</div>Vdbilthttps://echopedia.org/index.php?title=File:PLAXLynch.png&diff=6555File:PLAXLynch.png2023-10-17T16:33:17Z<p>Vdbilt: Vdbilt uploaded File:PLAXLynch.png</p>
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<div>Parasternal long axis view</div>Vdbilthttps://echopedia.org/index.php?title=File:A4C_normal.avi&diff=6547File:A4C normal.avi2023-10-17T16:33:16Z<p>Vdbilt: Vdbilt uploaded File:A4C normal.avi</p>
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<div>Apical 4 Chamber view of a normal heart</div>Vdbilthttps://echopedia.org/index.php?title=File:SuprasternalNormal.avi&diff=6537File:SuprasternalNormal.avi2023-10-17T16:33:16Z<p>Vdbilt: Vdbilt uploaded File:SuprasternalNormal.avi</p>
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<div>Suprasternal view of a normal heart</div>Vdbilthttps://echopedia.org/index.php?title=File:Subcostal_normal.avi&diff=6528File:Subcostal normal.avi2023-10-17T16:33:16Z<p>Vdbilt: Vdbilt uploaded File:Subcostal normal.avi</p>
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<div>Subcostal view of a normal heart</div>Vdbilthttps://echopedia.org/index.php?title=File:SAXPAP_normal.avi&diff=6525File:SAXPAP normal.avi2023-10-17T16:33:16Z<p>Vdbilt: Vdbilt uploaded File:SAXPAP normal.avi</p>
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<div>A parasternal short axis view on level of the papillary muscle</div>Vdbilthttps://echopedia.org/index.php?title=File:SAXAP_normal.avi&diff=6513File:SAXAP normal.avi2023-10-17T16:33:16Z<p>Vdbilt: Vdbilt uploaded File:SAXAP normal.avi</p>
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<div>A parasternal short axis on apical level</div>Vdbilthttps://echopedia.org/index.php?title=File:PLAXnormal.avi&diff=6508File:PLAXnormal.avi2023-10-17T16:33:15Z<p>Vdbilt: Vdbilt uploaded File:PLAXnormal.avi</p>
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<div>Parasternal long axis view of a normal heart</div>Vdbilthttps://echopedia.org/index.php?title=File:A3Cnormal.avi&diff=6474File:A3Cnormal.avi2023-10-17T16:33:14Z<p>Vdbilt: Vdbilt uploaded File:A3Cnormal.avi</p>
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<div>Apical 3 chamber view of a normal heart</div>Vdbilthttps://echopedia.org/index.php?title=File:A2Cnormal.avi&diff=6470File:A2Cnormal.avi2023-10-17T16:33:14Z<p>Vdbilt: Vdbilt uploaded File:A2Cnormal.avi</p>
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<div>Apical 2 chamber view of a normal heart</div>Vdbilthttps://echopedia.org/index.php?title=File:A5Cnormal.avi&diff=6446File:A5Cnormal.avi2023-10-17T16:33:14Z<p>Vdbilt: Vdbilt uploaded File:A5Cnormal.avi</p>
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<div>A 5 chamber view</div>Vdbilthttps://echopedia.org/index.php?title=File:Heart_apical_2c_myocardial_regions.svg&diff=6400File:Heart apical 2c myocardial regions.svg2023-10-17T16:33:12Z<p>Vdbilt: Vdbilt uploaded File:Heart apical 2c myocardial regions.svg</p>
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<div>== Summary ==<br />
{{Information<br />
|Description = Heart apical two-chamber view myocardial regions<br />
|Source = Patrick J. Lynch, medical illustrator<br />
|Date = December 23, 2006<br />
|Author = Patrick J. Lynch, medical illustrator<br />
|Permission = Creative Commons Attribution 2.5 License 2006<br />
|other_versions = None<br />
}}<br />
<br />
Patrick J. Lynch; illustrator; C. Carl Jaffe; MD; cardiologist<br />
Yale University Center for Advanced Instructional Media<br />
Medical Illustrations by Patrick Lynch, generated for multimedia teaching projects by the Yale University School of Medicine, Center for Advanced Instructional Media, 1987-2000.<br />
Patrick J. Lynch, http://patricklynch.net<br />
Creative Commons Attribution 2.5 License 2006; no usage restrictions except please preserve our creative credits: Patrick J. Lynch, medical illustrator; C. Carl Jaffe, MD, cardiologist.<br />
http://creativecommons.org/licenses/by/2.5/<br />
<br />
<br />
[[Category:Echocardiography]] [[Category:Anatomical plates and drawings of the Heart]] [[Category:Patrick Lynch]]<br />
== Licensing ==<br />
{{cc-by-2.5}}</div>Vdbilthttps://echopedia.org/index.php?title=File:Printvoorbeeld.png&diff=6335File:Printvoorbeeld.png2023-10-17T16:33:11Z<p>Vdbilt: Vdbilt uploaded File:Printvoorbeeld.png</p>
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<div></div>Vdbilthttps://echopedia.org/index.php?title=User:Vdbilt&diff=6307User:Vdbilt2014-12-11T08:51:32Z<p>Vdbilt: </p>
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<div>Ivo van der Bilt is a Cardiologist in the Haga Heart Center in the Haga Teaching Hospital in The Hague in the Netherlands. <br />
<br />
He is co-founder of [http://www.ecgpedia.org ECGpedia.org], [http://www.echopedia.org ECHOpedia.org], [http://www.cardionetworks.org Cardionetworks.org], and is secretary of the Cardionetworks foundation.<br />
<br />
[[Special:Emailuser/Vdbilt|Contact I.A.C. van der Bilt]]</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6326Auscultation2014-12-11T08:49:52Z<p>Vdbilt: </p>
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<div>__NOTOC__<br />
<!-- BANNER ACROSS TOP OF PAGE --><br />
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| style="width:56%; color:#000;" |<br />
<!-- "WELKOM BIJ DE ONLINE AUSCULTATIE PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welkom bij de online auscultatie cursus </div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Auteurs]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introductie in auscultatie van het hart</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|<br />
* [[Introductie in cardiale auscultatie]]<br />
Open deze Powerpoint presentatie over cardiale auscultatie<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Casus en Voorbeelden</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Leer van deze casus en voorbeelden<br />
*[[Aorta Klep Stenose]]<br />
*[[Mitralis Klep Stenose]]<br />
*[[Aorta Klep Insufficiëntie]]<br />
*[[Mitralis Klep Insufficiëntie]]<br />
*[[Gespleten Tweede Harttoon]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiale Auscultatie en Echocardiografie</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultatie en Echocardiografie|Auscultatie en Echocardiografie<br />
*[[Introductie|Introductie]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Lees de sectie met [[Frequently Asked Questions]] voor meer informatie.<br />
*[[Authors|Deze mensen]] hebben bijgedragen aan de Auscultatie cursus. Deze cursus is mede mogelijk gemaakt door een Grassroots beurs van het Academisch Medisch Centrum<br />
*Lees ook hoe jij kan [[Contributing to ECGpedia|bijdragen]]!<br />
*Algemene [[References]] en online bronnen<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6325Auscultation2014-12-11T08:38:09Z<p>Vdbilt: </p>
<hr />
<div>__NOTOC__<br />
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{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
| style="width:56%; color:#000;" |<br />
<!-- "WELKOM BIJ DE ONLINE AUSCULTATIE PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welkom bij de online auscultatie cursus </div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Auteurs]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introductie in auscultatie van het hart</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|<br />
* [[Introductie in cardiale auscultatie]]<br />
Open deze Powerpoint presentatie over cardiale auscultatie<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Leer van deze casus en voorbeelden<br />
*[[Aorta Klep Stenose]]<br />
*[[Mitralis Klep Stenose]]<br />
*[[Aorta Klep Insufficiëntie]]<br />
*[[Mitralis Klep Insufficiëntie]]<br />
*[[Gespleten Tweede Harttoon]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiale Auscultatie en Echocardiografie</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultatie en Echocardiografie|Auscultatie en Echocardiografie<br />
*[[Introductie|Introductie]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Lees de sectie met [[Frequently Asked Questions]] voor meer informatie.<br />
*[[Authors|Deze mensen]] hebben bijgedragen aan de Auscultatie cursus. Deze cursus is mede mogelijk gemaakt door een Grassroots beurs van het Academisch Medisch Centrum<br />
*Lees ook hoe jij kan [[Contributing to ECGpedia|bijdragen]]!<br />
*Algemene [[References]] en online bronnen<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6324Auscultation2014-12-11T08:36:55Z<p>Vdbilt: </p>
<hr />
<div>__NOTOC__<br />
<!-- BANNER ACROSS TOP OF PAGE --><br />
{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
| style="width:56%; color:#000;" |<br />
<!-- "WELKOM BIJ DE ONLINE AUSCULTATIE PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welkom bij de online auscultatie cursus </div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Auteurs]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introductie in auscultatie van het hart</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|<br />
* [[Introductie in cardiale auscultatie]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Leer van deze casus en voorbeelden<br />
*[[Aorta Klep Stenose]]<br />
*[[Mitralis Klep Stenose]]<br />
*[[Aorta Klep Insufficiëntie]]<br />
*[[Mitralis Klep Insufficiëntie]]<br />
*[[Gespleten Tweede Harttoon]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiale Auscultatie en Echocardiografie</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultatie en Echocardiografie|Auscultatie en Echocardiografie<br />
*[[Introductie|Introductie]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Lees de sectie met [[Frequently Asked Questions]] voor meer informatie.<br />
*[[Authors|Deze mensen]] hebben bijgedragen aan de Auscultatie cursus. Deze cursus is mede mogelijk gemaakt door een Grassroots beurs van het Academisch Medisch Centrum<br />
*Lees ook hoe jij kan [[Contributing to ECGpedia|bijdragen]]!<br />
*Algemene [[References]] en online bronnen<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6323Auscultation2014-12-11T08:35:29Z<p>Vdbilt: </p>
<hr />
<div>__NOTOC__<br />
<!-- BANNER ACROSS TOP OF PAGE --><br />
{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
| style="width:56%; color:#000;" |<br />
<!-- "WELKOM BIJ DE ONLINE AUSCULTATIE PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welkom bij de online auscultatie cursus </div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Auteurs]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introductie in auscultatie van het hart</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|<br />
* [[Introductie in cardiale auscultatie]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Leer van deze casus en voorbeelden<br />
*[[Aorta Klep Stenose]]<br />
*[[Mitralis Klep Stenose]]<br />
*[[Aorta Klep Insufficiëntie]]<br />
*[[Mitralis Klep Insufficiëntie]]<br />
*[[Gespleten Tweede Harttoon]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultatie en Echocardiografie|Auscultatie en Echocardiografie<br />
*[[Introductie|Introductie]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Lees de sectie met [[Frequently Asked Questions]] voor meer informatie.<br />
*[[Authors|Deze mensen]] hebben bijgedragen aan de Auscultatie cursus. Deze cursus is mede mogelijk gemaakt door een Grassroots beurs van het Academisch Medisch Centrum<br />
*Lees ook hoe jij kan [[Contributing to ECGpedia|bijdragen]]!<br />
*Algemene [[References]] en online bronnen<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Introductie_in_cardiale_auscultatie&diff=6328Introductie in cardiale auscultatie2014-12-10T14:20:05Z<p>Vdbilt: </p>
<hr />
<div>De bloedsomloop werd voor het eerst beschreven in de 17de eeuw door Harvey in zijn befaamde werk “De Motu Cordis”. <br />
Aanvankelijk beoefende men de “directe” auscultatie (men “ legde letterlijk zijn oor te luisteren”). Aangezien de hygienische omstandigheden destijds niet bijster goed waren en directe auscultatie van een vrouw door een man eigenlijk onbetamelijk was luisterde hij met een papieren koker, die later werd uitgevoerd in hout.<br />
René Laënnec (1781-1826), een Franse arts, vond de stehoscoop uit in 1816. <br />
Het duurde na uitvinding van de stethososcoop bijna 100 jaar voordat alle tonen en geruisen van het hart juist geinterpreteerd werden.<br />
De stethoscoop bestaat uit een slang (die zo kort mogelijk dient te zijn om de afstand tussen de geluidsbron en het oor zo kort mogelijk tehouden) en een kop.<br />
De “ kop” van de stetoscoop bestaat uit een “ klok” (voor beluistering van laag frequente geluiden) en een “membraan” (voor beluistering van hoogfrequente geluiden). De klok mag niet te stevig aangedrukt worden, anders spant de huid onder de klok zich op en functioneert al seen membraan waardoor men de laagfrequente tonen en geruisen “ wegdrukt”. <br />
Auscultatie dient altijd te gebeuren in combinatie met beoordeling algehele<br />
klinische toestand (ademfrequentie, cyanose, polsfrequentie en kwaliteit, voelen van de acra). Zoeken naar tekenen van hartfalen (CVD, palpatie ictus cordis, lever, auscultatie longen, beoordeling oedeem), beoordeling perifere arteriële pulsaties.<br />
Auscultatie is niet moeilijk als men gevoel voor ritme en muziek heeft, weet hoe het hart in de thorax ligt en hoe het hart werkt. Cruciaal bij de interpretatie van harttonen en souffles is dat de systole korter duurt dan de diastole (dit geldt voor<br />
hartfrequenties < 120/min).<br />
Regel 1: luister selectief (eerst alleen naar 1-ste toon dan naar 2-de toon, vervolgens<br />
alleen naar systole en alleen naar diastole).<br />
Regel 2 : Luister systematisch (steeds in dezelfde volgorde bijv. 2R, 2L, LSR, apex) en<br />
in verschillende posities (rugligging, linkerzijligging, zittend in exspiratie op 4L).<br />
<br />
Eerste harttoon (sluiting van mitralis- en tricuspidalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de mitralisklep en tricuspidalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen. Men kan het geluid vergelijken met het klappen van een opbollend zeil als dat wind vangt. Het geluid wordt NIET veroorzaakt door het tegen elkaar slaan van de kleprandjes, want deze zijn zeer dun. De sluiting van de mitralisklep is veel luider dan die van de tricuspidalisklep, omdat de druk in de linker hartshelft 5-6 maal hoger is dan in de rechter hartshelft. De 1ste toon wordt dan ook vooral veroorzaakt door sluiting van de mitralisklep en wordt het best gehoord op de apex. <br />
<br />
Tweede toon (sluiting van de aorta- en pulmonalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de aorta- en mitralisklep en is het best hoorbaar aan de hartbasis want daar liggen de aorta- en pulmonalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen.<br />
<br />
Beoordeling van de luidheid van de 1ste en 2de toon<br />
Beoordeling van de luidheid van de 1ste en 2de toon berust op het principe dat<br />
de 1ste toon luider is dan de 2de toon aan de apex, terwijl de 2de toon luider is dan de 1ste toon aan de hartbasis. Immers de mitralisklep ligt dicht bij de apex en de aorta- en pulmonalisklep liggen bij de hartbasis (zie tekening).<br />
De 1ste toon is zacht o.a. bij een slechte systolische LV<br />
functie (denk maar aan een deur die openstaat: als hij met kracht dichtgeslagen wordt hoor je een hard geluid en als hij met geringe kracht woordt dichtgeslagen hoor je een zacht geluid).<br />
De 2de toon is zacht bij een ernstige gecalcificeerde aortaklepstenose (denk maar aan een zeil “ wat in gips gedoopt is”, de wind kan nog zo hard blazen maar je hoort geen klap want het zeil bolt niet op).</div>Vdbilthttps://echopedia.org/index.php?title=Introductie_in_cardiale_auscultatie&diff=6327Introductie in cardiale auscultatie2014-12-10T14:19:49Z<p>Vdbilt: Created page with "Inleiding De bloedsomloop werd voor het eerst beschreven in de 17de eeuw door Harvey in zijn befaamde werk “De Motu Cordis”. Aanvankelijk beoefende men de “directe” a..."</p>
<hr />
<div>Inleiding<br />
De bloedsomloop werd voor het eerst beschreven in de 17de eeuw door Harvey in zijn befaamde werk “De Motu Cordis”. <br />
Aanvankelijk beoefende men de “directe” auscultatie (men “ legde letterlijk zijn oor te luisteren”). Aangezien de hygienische omstandigheden destijds niet bijster goed waren en directe auscultatie van een vrouw door een man eigenlijk onbetamelijk was luisterde hij met een papieren koker, die later werd uitgevoerd in hout.<br />
René Laënnec (1781-1826), een Franse arts, vond de stehoscoop uit in 1816. <br />
Het duurde na uitvinding van de stethososcoop bijna 100 jaar voordat alle tonen en geruisen van het hart juist geinterpreteerd werden.<br />
De stethoscoop bestaat uit een slang (die zo kort mogelijk dient te zijn om de afstand tussen de geluidsbron en het oor zo kort mogelijk tehouden) en een kop.<br />
De “ kop” van de stetoscoop bestaat uit een “ klok” (voor beluistering van laag frequente geluiden) en een “membraan” (voor beluistering van hoogfrequente geluiden). De klok mag niet te stevig aangedrukt worden, anders spant de huid onder de klok zich op en functioneert al seen membraan waardoor men de laagfrequente tonen en geruisen “ wegdrukt”. <br />
Auscultatie dient altijd te gebeuren in combinatie met beoordeling algehele<br />
klinische toestand (ademfrequentie, cyanose, polsfrequentie en kwaliteit, voelen van de acra). Zoeken naar tekenen van hartfalen (CVD, palpatie ictus cordis, lever, auscultatie longen, beoordeling oedeem), beoordeling perifere arteriële pulsaties.<br />
Auscultatie is niet moeilijk als men gevoel voor ritme en muziek heeft, weet hoe het hart in de thorax ligt en hoe het hart werkt. Cruciaal bij de interpretatie van harttonen en souffles is dat de systole korter duurt dan de diastole (dit geldt voor<br />
hartfrequenties < 120/min).<br />
Regel 1: luister selectief (eerst alleen naar 1-ste toon dan naar 2-de toon, vervolgens<br />
alleen naar systole en alleen naar diastole).<br />
Regel 2 : Luister systematisch (steeds in dezelfde volgorde bijv. 2R, 2L, LSR, apex) en<br />
in verschillende posities (rugligging, linkerzijligging, zittend in exspiratie op 4L).<br />
<br />
Eerste harttoon (sluiting van mitralis- en tricuspidalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de mitralisklep en tricuspidalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen. Men kan het geluid vergelijken met het klappen van een opbollend zeil als dat wind vangt. Het geluid wordt NIET veroorzaakt door het tegen elkaar slaan van de kleprandjes, want deze zijn zeer dun. De sluiting van de mitralisklep is veel luider dan die van de tricuspidalisklep, omdat de druk in de linker hartshelft 5-6 maal hoger is dan in de rechter hartshelft. De 1ste toon wordt dan ook vooral veroorzaakt door sluiting van de mitralisklep en wordt het best gehoord op de apex. <br />
<br />
Tweede toon (sluiting van de aorta- en pulmonalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de aorta- en mitralisklep en is het best hoorbaar aan de hartbasis want daar liggen de aorta- en pulmonalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen.<br />
<br />
Beoordeling van de luidheid van de 1ste en 2de toon<br />
Beoordeling van de luidheid van de 1ste en 2de toon berust op het principe dat<br />
de 1ste toon luider is dan de 2de toon aan de apex, terwijl de 2de toon luider is dan de 1ste toon aan de hartbasis. Immers de mitralisklep ligt dicht bij de apex en de aorta- en pulmonalisklep liggen bij de hartbasis (zie tekening).<br />
De 1ste toon is zacht o.a. bij een slechte systolische LV<br />
functie (denk maar aan een deur die openstaat: als hij met kracht dichtgeslagen wordt hoor je een hard geluid en als hij met geringe kracht woordt dichtgeslagen hoor je een zacht geluid).<br />
De 2de toon is zacht bij een ernstige gecalcificeerde aortaklepstenose (denk maar aan een zeil “ wat in gips gedoopt is”, de wind kan nog zo hard blazen maar je hoort geen klap want het zeil bolt niet op).</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6322Auscultation2014-12-10T14:19:20Z<p>Vdbilt: </p>
<hr />
<div>__NOTOC__<br />
<!-- BANNER ACROSS TOP OF PAGE --><br />
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<!-- "WELKOM BIJ DE ONLINE AUSCULTATIE PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welkom bij de online auscultatie cursus </div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Auteurs]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introductie in auscultatie van het hart</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|<br />
* [[Introductie in cardiale auscultatie]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Leer van deze [[Cases and Examples|casus en voorbeelden]]<br />
*[[Aorta Klep Stenose]]<br />
*[[Mitralis Klep Stenose]]<br />
*[[Aorta Klep Insufficiëntie]]<br />
*[[Mitralis Klep Insufficiëntie]]<br />
*[[Gespleten Tweede Harttoon]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Introduction_to_cardiac_auscultation&diff=6330Introduction to cardiac auscultation2014-12-10T13:58:22Z<p>Vdbilt: </p>
<hr />
<div>Inleiding<br />
De bloedsomloop werd voor het eerst beschreven in de 17de eeuw door Harvey in zijn befaamde werk “De Motu Cordis”. <br />
Aanvankelijk beoefende men de “directe” auscultatie (men “ legde letterlijk zijn oor te luisteren”). Aangezien de hygienische omstandigheden destijds niet bijster goed waren en directe auscultatie van een vrouw door een man eigenlijk onbetamelijk was luisterde hij met een papieren koker, die later werd uitgevoerd in hout.<br />
René Laënnec (1781-1826), een Franse arts, vond de stehoscoop uit in 1816. <br />
Het duurde na uitvinding van de stethososcoop bijna 100 jaar voordat alle tonen en geruisen van het hart juist geinterpreteerd werden.<br />
De stethoscoop bestaat uit een slang (die zo kort mogelijk dient te zijn om de afstand tussen de geluidsbron en het oor zo kort mogelijk tehouden) en een kop.<br />
De “ kop” van de stetoscoop bestaat uit een “ klok” (voor beluistering van laag frequente geluiden) en een “membraan” (voor beluistering van hoogfrequente geluiden). De klok mag niet te stevig aangedrukt worden, anders spant de huid onder de klok zich op en functioneert al seen membraan waardoor men de laagfrequente tonen en geruisen “ wegdrukt”. <br />
Auscultatie dient altijd te gebeuren in combinatie met beoordeling algehele<br />
klinische toestand (ademfrequentie, cyanose, polsfrequentie en kwaliteit, voelen van de acra). Zoeken naar tekenen van hartfalen (CVD, palpatie ictus cordis, lever, auscultatie longen, beoordeling oedeem), beoordeling perifere arteriële pulsaties.<br />
Auscultatie is niet moeilijk als men gevoel voor ritme en muziek heeft, weet hoe het hart in de thorax ligt en hoe het hart werkt. Cruciaal bij de interpretatie van harttonen en souffles is dat de systole korter duurt dan de diastole (dit geldt voor<br />
hartfrequenties < 120/min).<br />
Regel 1: luister selectief (eerst alleen naar 1-ste toon dan naar 2-de toon, vervolgens<br />
alleen naar systole en alleen naar diastole).<br />
Regel 2 : Luister systematisch (steeds in dezelfde volgorde bijv. 2R, 2L, LSR, apex) en<br />
in verschillende posities (rugligging, linkerzijligging, zittend in exspiratie op 4L).<br />
<br />
Eerste harttoon (sluiting van mitralis- en tricuspidalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de mitralisklep en tricuspidalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen. Men kan het geluid vergelijken met het klappen van een opbollend zeil als dat wind vangt. Het geluid wordt NIET veroorzaakt door het tegen elkaar slaan van de kleprandjes, want deze zijn zeer dun. De sluiting van de mitralisklep is veel luider dan die van de tricuspidalisklep, omdat de druk in de linker hartshelft 5-6 maal hoger is dan in de rechter hartshelft. De 1ste toon wordt dan ook vooral veroorzaakt door sluiting van de mitralisklep en wordt het best gehoord op de apex. <br />
<br />
Tweede toon (sluiting van de aorta- en pulmonalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de aorta- en mitralisklep en is het best hoorbaar aan de hartbasis want daar liggen de aorta- en pulmonalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen.<br />
<br />
Beoordeling van de luidheid van de 1ste en 2de toon<br />
Beoordeling van de luidheid van de 1ste en 2de toon berust op het principe dat<br />
de 1ste toon luider is dan de 2de toon aan de apex, terwijl de 2de toon luider is dan de 1ste toon aan de hartbasis. Immers de mitralisklep ligt dicht bij de apex en de aorta- en pulmonalisklep liggen bij de hartbasis (zie tekening).<br />
De 1ste toon is zacht o.a. bij een slechte systolische LV<br />
functie (denk maar aan een deur die openstaat: als hij met kracht dichtgeslagen wordt hoor je een hard geluid en als hij met geringe kracht woordt dichtgeslagen hoor je een zacht geluid).<br />
De 2de toon is zacht bij een ernstige gecalcificeerde aortaklepstenose (denk maar aan een zeil “ wat in gips gedoopt is”, de wind kan nog zo hard blazen maar je hoort geen klap want het zeil bolt niet op).</div>Vdbilthttps://echopedia.org/index.php?title=Introduction_to_cardiac_auscultation&diff=6329Introduction to cardiac auscultation2014-12-10T13:56:30Z<p>Vdbilt: Created page with "Inleiding De bloedsomloop werd voor het eerst beschreven in de 17de eeuw door Harvey in zijn befaamde werk “De Motu Cordis”. Aanvankelijk beoefende men de “directe” a..."</p>
<hr />
<div>Inleiding<br />
De bloedsomloop werd voor het eerst beschreven in de 17de eeuw door Harvey in zijn befaamde werk “De Motu Cordis”. <br />
Aanvankelijk beoefende men de “directe” auscultatie (men “ legde letterlijk zijn oor te luisteren”). Aangezien de hygienische omstandigheden destijds niet bijster goed waren en directe auscultatie van een vrouw door een man eigenlijk onbetamelijk was luisterde hij met een papieren koker, die later werd uitgevoerd in hout.<br />
René Laënnec (1781-1826), een Franse arts, vond de stehoscoop uit in 1816. <br />
Het duurde na uitvinding van de stethososcoop bijna 100 jaar voordat alle tonen en geruisen van het hart juist geinterpreteerd werden.<br />
De stethoscoop bestaat uit een slang (die zo kort mogelijk dient te zijn om de afstand tussen de geluidsbron en het oor zo kort mogelijk tehouden) en een kop.<br />
De “ kop” van de stetoscoop bestaat uit een “ klok” (voor beluistering van laag frequente geluiden) en een “membraan” (voor beluistering van hoogfrequente geluiden). De klok mag niet te stevig aangedrukt worden, anders spant de huid onder de klok zich op en functioneert al seen membraan waardoor men de laagfrequente tonen en geruisen “ wegdrukt”. <br />
Auscultatie dient altijd te gebeuren in combinatie met beoordeling algehele<br />
klinische toestand (ademfrequentie, cyanose, polsfrequentie en kwaliteit, voelen van de acra). Zoeken naar tekenen van hartfalen (CVD, palpatie ictus cordis, lever, auscultatie longen, beoordeling oedeem), beoordeling perifere arteriële pulsaties.<br />
Auscultatie is niet moeilijk als men gevoel voor ritme en muziek heeft, weet hoe het hart in de thorax ligt en hoe het hart werkt. Cruciaal bij de interpretatie van harttonen en souffles is dat de systole korter duurt dan de diastole (dit geldt voor<br />
hartfrequenties < 120/min).<br />
Regel 1: luister selectief (eerst alleen naar 1-ste toon dan naar 2-de toon, vervolgens<br />
alleen naar systole en alleen naar diastole).<br />
Regel 2 : Luister systematisch (steeds in dezelfde volgorde bijv. 2R, 2L, LSR, apex) en<br />
in verschillende posities (rugligging, linkerzijligging, zittend in exspiratie op 4L).<br />
<br />
Eerste harttoon (sluiting van mitralis- en tricuspidalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de mitralisklep en tricuspidalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen. Men kan het geluid vergelijken met het klappen van een opbollend zeil als dat wind vangt. Het geluid wordt NIET veroorzaakt door het tegen elkaar slaan van de kleprandjes, want deze zijn zeer dun. De sluiting van de mitralisklep is veel luider dan die van de tricuspidalisklep, omdat de druk in de linker hartshelft 5-6 maal hoger is dan in de rechter hartshelft. De 1ste toon wordt dan ook vooral veroorzaakt door sluiting van de mitralisklep en wordt het best gehoord op de apex. <br />
<br />
Tweede toon (sluiting van de aorta- en pulmonalisklep)<br />
Deze wordt veroorzaakt door het sluiten van de aorta- en mitralisklep en is het best hoorbaar aan de hartbasis want daar liggen de aorta- en pulmonalisklep. Het geluid wordt veroorzaakt door het opspannen van de klepslippen.<br />
<br />
Beoordeling van de luidheid van de 1ste en 2de toon<br />
Beoordeling van de luidheid van de 1ste en 2de toon berust op het principe dat<br />
de 1ste toon luider is dan de 2de toon aan de apex, terwijl de 2de toon luider is dan de 1ste toon aan de hartbasis. Immers de mitralisklep ligt dicht bij de apex en de aorta- en pulmonalisklep liggen bij de hartbasis (zie tekening).<br />
De 1ste toon is zacht o.a. bij een slechte systolische LV<br />
functie (denk maar aan een deur die openstaat: als hij met kracht dichtgeslagen wordt hoor je een hard geluid en als hij met geringe kracht woordt dichtgeslagen hoor je een zacht geluid).<br />
De 2de toon is zacht bij een ernstige gecalcificeerde aortaklepstenose (denk maar aan een zeil “ wat in gips gedoopt is”, de wind kan nog zo hard blazen maar je hoort geen klap want het zeil bolt niet op).</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6321Auscultation2014-12-10T13:54:56Z<p>Vdbilt: </p>
<hr />
<div>__NOTOC__<br />
<!-- BANNER ACROSS TOP OF PAGE --><br />
{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
| style="width:56%; color:#000;" |<br />
<!-- "WELCOME TO THE ONLINE AUSCULATATION PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, <br />
Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|<br />
* [[Introduction to cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
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{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
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<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6320Auscultation2014-12-10T13:54:30Z<p>Vdbilt: Undo revision 8354 by Vdbilt (talk)</p>
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<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
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|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
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[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, <br />
Van Den Brink<br />
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{|<br />
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! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction*|Auscultation Textbook]]<br />
* [[Introduction to cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
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!<br />
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<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
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{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6319Auscultation2014-12-10T13:53:52Z<p>Vdbilt: </p>
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| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, <br />
Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
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! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
* [[Introduction to cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
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{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
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{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6318Auscultation2014-12-09T18:44:26Z<p>Vdbilt: </p>
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{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, <br />
Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
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! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction*|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
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<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6317Auscultation2014-12-09T18:43:28Z<p>Vdbilt: </p>
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{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
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{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:15%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, <br />
Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
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{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
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<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6316Auscultation2014-12-09T18:43:12Z<p>Vdbilt: </p>
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{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:20%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, <br />
Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
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<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6315Auscultation2014-12-09T18:42:51Z<p>Vdbilt: </p>
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{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
| style="width:56%; color:#000;" |<br />
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{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:20%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
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<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6314Auscultation2014-12-09T18:41:32Z<p>Vdbilt: </p>
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<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
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| style="width:40%; font-size:95%;" |<br />
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[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:50%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cardiac Auscultation and Echocardiography</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
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{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6313Auscultation2014-12-09T17:57:48Z<p>Vdbilt: </p>
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<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
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|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:30%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:40%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Trans Thoracic Echo</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Auscultation and Echocardiography|Auscultation and Echocardiography<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6312Auscultation2014-12-09T17:56:18Z<p>Vdbilt: </p>
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<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:30%; font-size:95%;" |<br />
| style="width:30%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:30%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Auscultation Textbook]]<br />
* [[Introduction into cardiac auscultation]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
*[[Split Second Heart Sound]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Trans Thoracic Echo</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Transthoracic Echocardiography|Transthoracic Echocardiography (TTE)<br />
*[[Introduction|Introduction]]<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to the Auscultation course.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to Cardionetworks]]!<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6311Auscultation2014-12-09T17:49:37Z<p>Vdbilt: </p>
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<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
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<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:20%; font-size:95%;" |<br />
| style="width:20%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:20%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Ausciltation Textbook]]<br />
* [[Introduction]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Trans Thoracic Echo</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Transthoracic Echocardiography|Transthoracic Echocardiography (TTE)<br />
*[[Introduction|Introduction]]<br />
<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Transesophagal Echo</h2><br />
|-<br />
|[[Image:Transesophageal_echocardiography_diagram.svg|100px|link=|center]]<br />
|- <br />
|Transesophageal Echocardiography|Transesophageal Echocardiography<br />
*[[Introduction|Introduction]]<br />
*[[TEE_-_standard_imaging_views|TEE - standard imaging views]]<br />
<br />
<br />
|}<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
*ECHOpedia.org is part of [http://www.cardionetworks.org Cardionetworks]<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to ECHOpedia.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to ECHOpedia]]!<br />
*Follow the [[Timeline|development of ECHOpedia]]<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6310Auscultation2014-12-09T17:46:38Z<p>Vdbilt: </p>
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| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course</div><br />
<br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:11%; font-size:95%;" |<br />
| style="width:11%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van Der Bilt, Boink, Van Den Brink<br />
| style="width:11%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Introduction in Auscultation</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Introduction|Ausciltation Textbook]]<br />
* [[Introduction]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Aortic Valve Stenosis]]<br />
*[[Mitral Valve stenosis]]<br />
*[[Aortic Valve Regurgitation]]<br />
*[[Mitral Valve Regurgitation]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Trans Thoracic Echo</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Transthoracic Echocardiography|Transthoracic Echocardiography (TTE)<br />
*[[Introduction|Introduction]]<br />
<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Transesophagal Echo</h2><br />
|-<br />
|[[Image:Transesophageal_echocardiography_diagram.svg|100px|link=|center]]<br />
|- <br />
|Transesophageal Echocardiography|Transesophageal Echocardiography<br />
*[[Introduction|Introduction]]<br />
*[[TEE_-_standard_imaging_views|TEE - standard imaging views]]<br />
<br />
<br />
|}<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
*ECHOpedia.org is part of [http://www.cardionetworks.org Cardionetworks]<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to ECHOpedia.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to ECHOpedia]]!<br />
*Follow the [[Timeline|development of ECHOpedia]]<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Auscultation&diff=6309Auscultation2014-12-09T17:37:50Z<p>Vdbilt: Jonas, dit is een test site voor een Grass root beurs met Geert en Renee. Later haal ik het weer weg. groeten, Ivo</p>
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<!-- "WELCOME TO THE ONOLINE AUSCULATATION PORTAL" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to the online auscultation course,</div><br />
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|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:11%; font-size:95%;" |<br />
* [[Textbook|Echo textbook]]<br />
* [[Cases and Examples|Cases]]<br />
* [http://www.echopedia.org/Echo_reference_card_2011.pdf '''Reference card''']<br />
| style="width:11%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van der Bilt, De Jong, Landzaat, Riezebos, Van den Brink<br />
| style="width:11%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">The ECHO Textbook</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Textbook|ECHO Textbook]]<br />
* [[Introduction]]<br />
* [[Standard imaging Views]]<br />
* [[Advanced Echocardiographic techniques]]<br />
* [[Assessment of function]]<br />
* [[Valves]]<br />
* [[The normal echocardiogram]]<br />
* [[Aquired heart disease]]<br />
* [[Cardiomyopathies]]<br />
* [[Congenital heart disease]]<br />
* [[Miscellaneous]]<br />
* [[Normal Values of TTE]]<br />
* [[Normal Values of TEE]]<br />
* [[Classification of valve stenosis and regurgitation]]<br />
* [[Normal measurements of aortic valve protheses]]<br />
* [[Normal measurements of mitral valve protheses]]<br />
* [[Guidelines]]<br />
<br />
<h2 style="margin:0px;margin-bottom:15px;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Reference Card</h2><br />
*'''!!NEW!!''' Download and print our '''[http://www.echopedia.org/Echo_reference_card_2011.pdf Echo Reference Card as PDF]''', read the [[printing instructions]])<br />
*You can now also [http://www.cardionetworks.org/contact/echocard/ order a reference card].<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Diseases of the Aortic Valve]]<br />
*[[Diseases of the Mitral Valve]]<br />
*[[Diseases of the Tricuspid Valve]]<br />
*[[Diseases of the Pulmonic Valve]]<br />
*[[Cardiomyopathies]]<br />
*[[Acquired Heart Disease]]<br />
*[[Pericardial Disease]]<br />
*[[Surgery]]<br />
*[[Congenital Heart Disease]]<br />
*[[Miscellaneous]]<br />
*[[Auscultation]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Trans Thoracic Echo</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Transthoracic Echocardiography|Transthoracic Echocardiography (TTE)<br />
*[[Introduction|Introduction]]<br />
* [[Standard imaging Views]]<br />
*[[Coronary Artery Disease]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Transesophagal Echo</h2><br />
|-<br />
|[[Image:Transesophageal_echocardiography_diagram.svg|100px|link=|center]]<br />
|- <br />
|Transesophageal Echocardiography|Transesophageal Echocardiography<br />
*[[Introduction|Introduction]]<br />
*[[TEE_-_standard_imaging_views|TEE - standard imaging views]]<br />
<br />
<br />
|}<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
*ECHOpedia.org is part of [http://www.cardionetworks.org Cardionetworks]<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to ECHOpedia.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to ECHOpedia]]!<br />
*Follow the [[Timeline|development of ECHOpedia]]<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=Main_Page&diff=388Main Page2014-12-09T17:34:24Z<p>Vdbilt: </p>
<hr />
<div>__NOTOC__<br />
<!-- BANNER ACROSS TOP OF PAGE --><br />
{| id="mp-topbanner" style="width:100%; background:#fcfcfc; margin-top:-1em; margin-bottom:.5em; border:1px solid #ccc;"<br />
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<!-- "WELCOME TO ECGPEDIA" AND ARTICLE COUNT --><br />
{| style="width:280px; border:none; background:none;"<br />
| style="width:280px; text-align:center; white-space:nowrap; color:#000;" |<br />
<div style="font-size:162%; border:none; margin:0; padding:.1em; color:#000;">Welcome to ECHOpedia,</div><br />
<div style="top:+0.2em; font-size:95%;">a free echocardiography textbook, designed for medical professionals <br />such as cardiologists and echocardiography technicians.</div><br />
|}<br />
<br />
<!-- PORTAL LIST ON RIGHT-HAND SIDE --><br />
| style="width:11%; font-size:95%;" |<br />
* [[Textbook|Echo textbook]]<br />
* [[Cases and Examples|Cases]]<br />
* [http://www.echopedia.org/Echo_reference_card_2011.pdf '''Reference card''']<br />
| style="width:11%; font-size:95%;" |<br />
[[Authors|Main authors]]: <br />
Van der Bilt, De Jong, Landzaat, Riezebos, Van den Brink<br />
| style="width:11%; font-size:95%;" |<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
! <h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">The ECHO Textbook</h2><br />
|-<br />
|[[Image:book.jpg|100px|link=|center]]<br />
|-<br />
|Browse the illustrated [[Textbook|ECHO Textbook]]<br />
* [[Introduction]]<br />
* [[Standard imaging Views]]<br />
* [[Advanced Echocardiographic techniques]]<br />
* [[Assessment of function]]<br />
* [[Valves]]<br />
* [[The normal echocardiogram]]<br />
* [[Aquired heart disease]]<br />
* [[Cardiomyopathies]]<br />
* [[Congenital heart disease]]<br />
* [[Miscellaneous]]<br />
* [[Normal Values of TTE]]<br />
* [[Normal Values of TEE]]<br />
* [[Classification of valve stenosis and regurgitation]]<br />
* [[Normal measurements of aortic valve protheses]]<br />
* [[Normal measurements of mitral valve protheses]]<br />
* [[Guidelines]]<br />
<br />
<h2 style="margin:0px;margin-bottom:15px;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Reference Card</h2><br />
*'''!!NEW!!''' Download and print our '''[http://www.echopedia.org/Echo_reference_card_2011.pdf Echo Reference Card as PDF]''', read the [[printing instructions]])<br />
*You can now also [http://www.cardionetworks.org/contact/echocard/ order a reference card].<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Cases and Examples</h2><br />
|-<br />
|[[Image:cases.jpg|100px|link=|center]]<br />
|- <br />
|Learn from these [[Cases and Examples|cases and examples]]<br />
*[[Diseases of the Aortic Valve]]<br />
*[[Diseases of the Mitral Valve]]<br />
*[[Diseases of the Tricuspid Valve]]<br />
*[[Diseases of the Pulmonic Valve]]<br />
*[[Cardiomyopathies]]<br />
*[[Acquired Heart Disease]]<br />
*[[Pericardial Disease]]<br />
*[[Surgery]]<br />
*[[Congenital Heart Disease]]<br />
*[[Miscellaneous]]<br />
*[[Auscultation]]<br />
<br />
|}<!-- Start of right-column --><br />
|style="width:25%;border:1px solid #E2ACB1;background-color:#FFF5F5;vertical-align:top;color:#000"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#FFF5F5"<br />
!<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Trans Thoracic Echo</h2><br />
|-<br />
|[[File:TTE.jpeg|115px|link=|center]]<br />
|- <br />
|Transthoracic Echocardiography|Transthoracic Echocardiography (TTE)<br />
*[[Introduction|Introduction]]<br />
* [[Standard imaging Views]]<br />
*[[Coronary Artery Disease]]<br />
<br />
<h2 style="margin:0;background-color:#D1DAEB;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:center;color:#000;padding:0.2em 0.4em;">Transesophagal Echo</h2><br />
|-<br />
|[[Image:Transesophageal_echocardiography_diagram.svg|100px|link=|center]]<br />
|- <br />
|Transesophageal Echocardiography|Transesophageal Echocardiography<br />
*[[Introduction|Introduction]]<br />
*[[TEE_-_standard_imaging_views|TEE - standard imaging views]]<br />
<br />
<br />
|}<br />
|}<br />
<br />
{|<br />
| style="width:25%;border:1px solid #E2ACB1;background-color:#fcfcfc;vertical-align:top"|<br />
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#fcfcfc"<br />
*ECHOpedia.org is part of [http://www.cardionetworks.org Cardionetworks]<br />
*Read the section with [[Frequently Asked Questions]] for more information.<br />
*[[Authors|These people]] have contributed to ECHOpedia.<br />
*Also read how you can [[Contributing to ECGpedia|contribute to ECHOpedia]]!<br />
*Follow the [[Timeline|development of ECHOpedia]]<br />
*General [[References]] and online resources<br />
|-<br />
|}</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=165The principle of ultrasound2012-11-16T12:10:29Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Teun|C.C. van der Pijl - Teunisse]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
==Exploring the heart through ultrasound==<br />
<br />
*''Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions''<br />
<br />
*''Image acquisition is highly operator dependent''<br />
<br />
*''Knowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis''<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
==The general principles of echocardiography==<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
*Frequency (f = 1/s = s -1 = Hz)<br />
*Wavelength (λ = m)<br />
*Amplitude (dB)<br />
<br />
''Frequency (f)'' = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
*v = f x λ (m/s)<br />
<br />
''Propagation velocity'' is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
The ''wavelength'' determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
<br />
''Amplitude and intensity'' drop as ultrasound travels through tissues. This phenomenon is called '''attenuation''' (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the ''acoustic impedance'' of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of ''specular reflection''. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – ''refraction'' – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
<br />
The ''intensity'' increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
<br />
An estimate of peak intensity is given by the '''mechanical index (MI)''' calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
==Imaging principles of ultrasound==<br />
==Transducers==<br />
==References==<br />
==Image quality optimization==<br />
<br />
'''WIL JE DAT IK DIT WEGHAAL?'''<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
<br />
Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
<br />
<br />
DOPPLER PRINCIPLES<br />
<br />
Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
<br />
<br />
The mathematical formula is: <br />
<br />
<br />
<br />
<br />
The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
<br />
Doppler Instrumentation:<br />
<br />
Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
<br />
If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
<br />
Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
<br />
<br />
<br />
Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
<br />
<br />
Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
<br />
Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
<br />
High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
<br />
Doppler Displays:<br />
<br />
The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
<br />
<br />
<br />
Doppler Controls:<br />
<br />
Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
<br />
Color Flow Imaging:<br />
<br />
Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
<br />
<br />
<br />
<br />
<br />
Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
<br />
<br />
Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=164The principle of ultrasound2012-11-15T22:21:33Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Teun|C.C. van der Pijl - Teunisse]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
==Exploring the heart through ultrasound==<br />
<br />
*''Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions''<br />
<br />
*''Image acquisition is highly operator dependent''<br />
<br />
*''Knowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis''<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
==The general principles of echocardiography==<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
*Frequency (f = 1/s = s -1 = Hz)<br />
*Wavelength (λ = m)<br />
*Amplitude (dB)<br />
<br />
''Frequency (f)'' = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
*v = f x λ (m/s)<br />
<br />
''Propagation velocity'' is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
The ''wavelength'' determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
<br />
''Amplitude and intensity'' drop as ultrasound travels through tissues. This phenomenon is called '''attenuation''' (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the ''acoustic impedance'' of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of ''specular reflection''. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – ''refraction'' – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
<br />
The ''intensity'' increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
<br />
An estimate of peak intensity is given by the '''mechanical index (MI)''' calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
<br />
'''WIL JE DAT IK DIT WEGHAAL?'''<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
<br />
Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
<br />
<br />
DOPPLER PRINCIPLES<br />
<br />
Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
<br />
<br />
The mathematical formula is: <br />
<br />
<br />
<br />
<br />
The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
<br />
Doppler Instrumentation:<br />
<br />
Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
<br />
If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
<br />
Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
<br />
<br />
<br />
Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
<br />
<br />
Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
<br />
Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
<br />
High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
<br />
Doppler Displays:<br />
<br />
The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
<br />
<br />
<br />
Doppler Controls:<br />
<br />
Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
<br />
Color Flow Imaging:<br />
<br />
Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
<br />
<br />
<br />
<br />
<br />
Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
<br />
<br />
Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=163The principle of ultrasound2012-11-15T22:21:01Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Teun|C.J. Teunisse]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
==Exploring the heart through ultrasound==<br />
<br />
*''Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions''<br />
<br />
*''Image acquisition is highly operator dependent''<br />
<br />
*''Knowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis''<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
==The general principles of echocardiography==<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
*Frequency (f = 1/s = s -1 = Hz)<br />
*Wavelength (λ = m)<br />
*Amplitude (dB)<br />
<br />
''Frequency (f)'' = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
*v = f x λ (m/s)<br />
<br />
''Propagation velocity'' is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
The ''wavelength'' determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
<br />
''Amplitude and intensity'' drop as ultrasound travels through tissues. This phenomenon is called '''attenuation''' (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the ''acoustic impedance'' of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of ''specular reflection''. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – ''refraction'' – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
<br />
The ''intensity'' increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
<br />
An estimate of peak intensity is given by the '''mechanical index (MI)''' calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
<br />
'''WIL JE DAT IK DIT WEGHAAL?'''<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
<br />
Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
<br />
<br />
DOPPLER PRINCIPLES<br />
<br />
Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
<br />
<br />
The mathematical formula is: <br />
<br />
<br />
<br />
<br />
The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
<br />
Doppler Instrumentation:<br />
<br />
Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
<br />
If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
<br />
Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
<br />
<br />
<br />
Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
<br />
<br />
Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
<br />
Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
<br />
High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
<br />
Doppler Displays:<br />
<br />
The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
<br />
<br />
<br />
Doppler Controls:<br />
<br />
Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
<br />
Color Flow Imaging:<br />
<br />
Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
<br />
<br />
<br />
<br />
<br />
Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
<br />
<br />
Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=162The principle of ultrasound2012-11-15T22:19:45Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
==Exploring the heart through ultrasound==<br />
<br />
*''Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions''<br />
<br />
*''Image acquisition is highly operator dependent''<br />
<br />
*''Knowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis''<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
==The general principles of echocardiography==<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
*Frequency (f = 1/s = s -1 = Hz)<br />
*Wavelength (λ = m)<br />
*Amplitude (dB)<br />
<br />
''Frequency (f)'' = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
*v = f x λ (m/s)<br />
<br />
''Propagation velocity'' is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
The ''wavelength'' determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
<br />
''Amplitude and intensity'' drop as ultrasound travels through tissues. This phenomenon is called '''attenuation''' (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the ''acoustic impedance'' of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of ''specular reflection''. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – ''refraction'' – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
<br />
The ''intensity'' increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
<br />
An estimate of peak intensity is given by the '''mechanical index (MI)''' calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
<br />
'''WIL JE DAT IK DIT WEGHAAL?'''<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
<br />
Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
<br />
<br />
DOPPLER PRINCIPLES<br />
<br />
Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
<br />
<br />
The mathematical formula is: <br />
<br />
<br />
<br />
<br />
The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
<br />
Doppler Instrumentation:<br />
<br />
Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
<br />
If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
<br />
Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
<br />
<br />
<br />
Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
<br />
<br />
Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
<br />
Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
<br />
High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
<br />
Doppler Displays:<br />
<br />
The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
<br />
<br />
<br />
Doppler Controls:<br />
<br />
Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
<br />
Color Flow Imaging:<br />
<br />
Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
<br />
<br />
<br />
<br />
<br />
Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
<br />
<br />
Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=161The principle of ultrasound2012-11-15T22:12:40Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
==Exploring the heart through ultrasound==<br />
<br />
*Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions<br />
<br />
*Image acquisition is highly operator dependent<br />
<br />
*Knowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
==The general principles of echocardiography==<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
*Frequency (f = 1/s = s -1 = Hz)<br />
*Wavelength (λ = m)<br />
*Amplitude (dB)<br />
<br />
Frequency (f) = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
*v = f x λ (m/s)<br />
<br />
Propagation velocity is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
The wavelength determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
Amplitude and intensity drop as ultrasound travels through tissues. This phenomenon is called attenuation (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the acoustic impedance of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of specular reflection. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – refraction – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
The intensity increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
An estimate of peak intensity is given by the mechanical index (MI) calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
<br />
<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
<br />
Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
<br />
<br />
DOPPLER PRINCIPLES<br />
<br />
Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
<br />
<br />
The mathematical formula is: <br />
<br />
<br />
<br />
<br />
The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
<br />
Doppler Instrumentation:<br />
<br />
Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
<br />
If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
<br />
Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
<br />
<br />
<br />
Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
<br />
<br />
Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
<br />
Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
<br />
High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
<br />
Doppler Displays:<br />
<br />
The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
<br />
<br />
<br />
Doppler Controls:<br />
<br />
Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
<br />
Color Flow Imaging:<br />
<br />
Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
<br />
<br />
<br />
<br />
<br />
Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
<br />
<br />
Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=160The principle of ultrasound2012-11-15T22:11:15Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
==Exploring the heart through ultrasound==<br />
<br />
*Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions<br />
<br />
*Image acquisition is highly operator dependent<br />
<br />
*Knowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
==CHAPTER 1 the general principles of echocardiography==<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
*Frequency (f = 1/s = s -1 = Hz)<br />
*Wavelength (λ = m)<br />
*Amplitude (dB)<br />
<br />
Frequency (f) = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
v = f x λ (m/s)<br />
<br />
Propagation velocity is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
<br />
The wavelength determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
Amplitude and intensity drop as ultrasound travels through tissues. This phenomenon is called attenuation (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the acoustic impedance of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of specular reflection. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – refraction – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
The intensity increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
An estimate of peak intensity is given by the mechanical index (MI) calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
<br />
Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
<br />
<br />
DOPPLER PRINCIPLES<br />
<br />
Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
<br />
<br />
The mathematical formula is: <br />
<br />
<br />
<br />
<br />
The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
<br />
Doppler Instrumentation:<br />
<br />
Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
<br />
If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
<br />
Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
<br />
<br />
<br />
Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
<br />
<br />
Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
<br />
Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
<br />
High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
<br />
Doppler Displays:<br />
<br />
The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
<br />
<br />
<br />
Doppler Controls:<br />
<br />
Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
<br />
Color Flow Imaging:<br />
<br />
Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
<br />
<br />
<br />
<br />
<br />
Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
<br />
<br />
Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilthttps://echopedia.org/index.php?title=The_principle_of_ultrasound&diff=159The principle of ultrasound2012-11-15T22:07:30Z<p>Vdbilt: </p>
<hr />
<div>{{DevelopmentPhase}}<br />
{{auteurs|<br />
|mainauthor= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|moderator= [[user:Vdbilt|I.A.C. van der Bilt]]<br />
|supervisor=<br />
}}<br />
<br />
=Exploring the heart through ultrasound.=<br />
<br />
Basic knowledge of ultrasound physics is vital to the correct application of ultrasound for diagnostic and therapeutic interventions<br />
<br />
Image acquisition is highly operator dependent<br />
<br />
Kowledge of the physical attributes of ultrasound waves and image generation is critical to recognition of artefacts and prevention of misdiagnosis<br />
<br />
Ultrasound has been used in medicine since the beginning of the 20th century.<br />
<br />
Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. <br />
<br />
Ultrasound waves are sound waves with a higher than audible frequency. The audible frequency range is 20 hertz (Hz) to 20,000Hz (20kHz). Cardiac imaging applications use an ultrasound frequency range of 1–20MHz (MegaHertz) (1.000.000 – 20.000.000 Hz).<br />
<br />
CHAPTER 1 the general principles of echocardiography<br />
To understand ultrasound it is important to understand sound (waves).<br />
Sound is a sequence of waves of pressure that propagate through compressible media such as air or water.<br />
Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions, respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.<br />
Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave.<br />
<br />
<br />
<br />
http://www.physicsclassroom.com/class/sound/u11l1c.cfm<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
<br />
Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. We won’t go into transverse waves in this chapter about cardiac ultrasound.<br />
Sound waves are characterized by different generic properties:<br />
▪ Frequency (f = 1/s = s -1 = Hz)<br />
▪ Wavelength (λ = m)<br />
▪ Amplitude (dB)<br />
<br />
Frequency (f) = is the number of wavelengths that pass per unit time. It is measured as cycles (or wavelengths) per second and the unit is hertz (Hz).<br />
Wavelength (λ) = the distance between two areas of maximal compression (or rarefaction). The importance of wavelength is that the penetration of the ultrasound wave is proportional to wavelength and image resolution is no more than 1-2 wavelengths.<br />
Propagation velocity = frequency x wavelength<br />
<br />
v = f x λ (m/s)<br />
<br />
Propagation velocity is dependent of physical properties of a medium (eg. density, temperature or pressure). Frequency is not dependent of the medium, the wavelength is.<br />
Propagation dependens on acoustic impedance of the tissue and the angle of incidence (insonation angle) with the interface. <br />
<br />
<br />
The wavelength determines imaging resolution. In echocardiography, adequate resolution is obtained with wavelengths less than 1mm. A shorter wavelength corresponds to a higher frequency, and vice versa.<br />
In soft tissue propagation velocity is relatively constant at 1540 m/sec and this is the value assumed by ultrasound machines for all human tissue. <br />
Current echocardiography uses intermittent repetitive generation of ultrasound pulses consisting of a few cycles each.<br />
Amplitude and intensity drop as ultrasound travels through tissues. This phenomenon is called attenuation (measured in decibels, dB). Sources of attenuation are: specular reflection, scattering and absorption. Attenuation increases with travelled distance and ultrasound frequency.<br />
The ultrasound waves enter the tissue, are transmitted through the tissues and are reflected back from tissues based on the acoustic impedance of the tissue. Acoustic impedance of a tissue is its density times the velocity at which sound travels through the tissue. The greater the mismatch in acoustic impedance between two adjacent tissues, the greater the amount of ultrasound reflected back to the transducer. Bone/tissue and air/tissue interfaces are highly reflective due to the large mismatch in their acoustic impedances of adjacent tissues. Bone has a very high acoustic impedance and air has a very low acoustic impedance relative to soft tissue. Thus, when the ultrasound beam intersects a bony structure or air-filled interface, the ultrasound beam is reflected back to the transducer, preventing imaging of deeper structures. Therefore, echocardiography must be performed in the intercostal spaces within the cardiac windows (where the heart is against the thorax, without intervening lung) or from subcostal windows. The high mismatch at air/soft tissue interfaces explains the need of using ultrasound gel as a coupling medium during examination.<br />
<br />
Encountering an interface, the ultrasound partially returns towards the source and is partially transmitted. At a smooth and large interface the ultrasound obeys rules of specular reflection. The reflected ultrasound returns to the source in cases of perpendicular incidence, but does not return to the source in cases of an oblique incidence. Transmission of ultrasound occurs with a change in direction – refraction – in cases of oblique incidence. At a rough interface or when encountering small structures (with dimensions in the range of the wavelength) the ultrasound suffers scattering, returning towards the source and being transmitted in many directions. The proportion of ultrasound returning to the source (backscatter) is independent of insonation angle. Scatter reflections allow generation of an image of examined structures instead of a mirror (specular) image of the transducer. The backscatter is higher with higher ultrasound frequency and depends on scatterer size. A point scatterer sends ultrasound homogenously in all directions. The backscatter from the multitude of scatterers encountered by the ultrasound wave interfere enhancing (constructive interference) or neutralizing each other (destructive interference). This explains why the image of tissues contains speckles and apparent free spaces instead of having homogeneous appearance.<br />
<br />
Hier moeten we een mooie tekening voor laten maken…..<br />
Ultrasound is a form of energy, travelling in a beam. The energy transferred in the unit of time defines the power, measured in milliwatts (mW). The power per unit of beam cross-sectional area represents the average intensity (mW/cm2). Power and intensity are proportional with the square of the wave amplitude.<br />
The intensity increases with power increase or cross-sectional area decrease by focusing the ultrasound beam. The intensity varies across the beam, being highest in the centre and lower towards the edges.<br />
An estimate of peak intensity is given by the mechanical index (MI) calculated from the peak negative pressure (MPa) divided by the square root of transmitted frequency (MHz). The mechanical index (an estimate of the maximum amplitude of the pressure pulse in tissue) can be used as an estimate for the degree of bio-effects a given set of ultrasound parameters will induce. A higher mechanical index means a larger bio-effect. Currently the FDA stipulates that diagnostic ultrasound scanners cannot exceed a mechanical index of 1.9.<br />
<br />
<br />
<br />
Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. The definition of Ultrasound(US)is sound with a frequency > 20kHz. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.<br />
<br />
The Four Acoustic Variables:<br />
Pressure - the amount of force over a given area. <br />
Distance - particle displacement with the wave <br />
Temperature - <br />
Density <br />
<br />
Reflection and Propagation:<br />
<br />
Effect of propagation through gaseous zones - poor propagation, inadequate imaging.<br />
Effect of propagation through dense zones - nearly all of the US is reflected. Structures below dense zones are poorly imaged.<br />
Examples of dense materials - bone, calcium, metal.<br />
<br />
<br />
Material Speed of Propagation <br />
bone 4080 m/s <br />
blood 1570 m/s <br />
tissue 1540 m/s <br />
fat 1450 m/s <br />
air 330 m/s <br />
<br />
Definitions:<br />
Cycle - the combination of one rarefaction and one compression equals one cycle.<br />
Amplitude - the maximum displacement of a particle or pressure wave. <br />
Intensity - the amount of force or energy of sound. <br />
Decibel (dB) - a numerical expression of the relative loudness of sound. <br />
Wavelength - the distance between the onset of peak compression or cycle to the next.<br />
Velocity - the velocity is the speed at which sound waves travel through a particular medium. Velocity is equal to the frequency x wavelength. The velocity of US through human soft tissue is 1540 meters per second.<br />
<br />
Frequency - the number of cycles per unit of time. Frequency and wavelength are inversely related. The higher the frequency the smaller the wavelength.<br />
<br />
Acoustic Impedance - simply put, acoustic impedance is dependent on the density of the material in which sound is propagated through. The greater the impedance the more dense the material.<br />
<br />
Reflection - the portion of a sound that is returned from the boundary of a medium. (echo) The angle of incidence influences the reflected and refracted waves. <br />
<br />
Refraction - the change of sound direction on passing from one medium to another.<br />
<br />
Acoustic Mismatch - the boundary between two different media where reflection and refraction occurs.<br />
<br />
Attenuation - the decrease in amplitude and intensity as a sound wave travels through a medium.<br />
<br />
Types of Echoes:<br />
<br />
Specular - echoes originating from relatively large, regularly shaped objects with smooth surfaces. These echoes are relatively intense and angle dependent. (i.e. IVS, valves)<br />
<br />
Scattered - echoes originating from relatively small, weakly reflective, irregularly shaped objects are less angle dependant and less intense. (ie. blood cells)<br />
<br />
<br />
<br />
Scattering: Reflection and Refraction are affected by the material being imaged. <br />
<br />
Frequencies:<br />
<br />
Frequencies for adult imaging - 2.0mHz to 3.0mHz.<br />
<br />
Frequencies for pediatric imaging - 5.0mHz to 7.5mHz to 12mHz.<br />
<br />
Effect of higher frequencies on penetration - the higher the frequency the less penetration, the lower the frequency the greater the penetration.<br />
<br />
<br />
Artifacts:<br />
<br />
Acoustic Shadowing - the loss of information below an object because the greater portion of the sound energy was reflected back by the object. This occurs in objects like prosthetic valves.<br />
<br />
<br />
<br />
Enhancement - the increase in relection amplitude from objects that lie behind a weakly attenuating structure. Enhancement may occur in structures below a cyst.<br />
<br />
Reverberation - the unsuitable reflections generated when the sound wave strikes a highly reflective object creating artifacts that degrade the image. The peak of the sector scan window is usually filled with reverberations due to the initial transmission of sound energy reflecting off of the chest wall and being reflected off the transducer face in a repetitious fashion. Reverberations may occur in more internal structures like the diaphragm or from dense objects such as a mechanical valve prothesis. Mirroring may occur as sound energy is reflected off dense structures and displayed on the screen as a double image. <br />
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Side-Lobe - produced from the side lobes of the ultrasound beam. This artifact appears as false structures in the scan plane.<br />
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DOPPLER PRINCIPLES<br />
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Christian Johann Doppler described the effect of motion of sound sources and its effect on the frequency of the sound to the observer. In medical applications we find that the frequency of the reflected signal is modified by the velocity and direction of blood flow. If blood cells are moving towards the transducer, they increase the frequency of the returning signal. As cells move away from the transducer, the frequency of the returning signal decreases.<br />
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The mathematical formula is: <br />
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The frequency difference is equal to the reflected frequency minus the originating frequency. If the resulting frequency is higher then there is a positive Doppler shift and the object is moving toward the transducer and if the resulting frequency is lower, there is a negative Doppler shift and it is moving away from the transducer.The angle theta, cos D component is the angle of incidence of the beam upon the object. For the most accurate determination of flow, the beam should be parallel to the flow of blood where the angle theta is zero. If the angle of incidence is greater, the results are less reliable. It is generally accepted that results from the Doppler shift where the angle theta is greater than 20 degrees is not used for calculation.<br />
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Doppler Instrumentation:<br />
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Doppler techniques are dependent on the transducers used. The transducer operating in continuous wave mode utilizes one half of the element(s) and are continuously sending sound energy while the other half is continuously receiving the reflected signals. <br />
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If the transducer is being used in a pulsed wave mode, the whole transducer is used to send and then receive the returning signals.<br />
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Comparing the two modes of Doppler techniques describes the advantages and disadvantages.<br />
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Advantages Disadvantages <br />
Continuous Wave <br />
Accurately measures high velocity flows Lacks range resolution <br />
Pulsed wave Ability to measure velocities at a specific location (range resolution) Aliasing of velocities above the Nyquist limit (inability to measure high velocities accurately) <br />
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Pulsed wave techniques have proven to be very valuable in blood flow studies. The technique allows the accurate measurement of blood flow at a specific area in the heart and detection of both velocity and direction. Measurement is performed by timing the reception of the returning signals giving a view of flows at specific depths. The region where flow velocities are measured is called the sample volume. Errors in the accuracy of the information arise if the velocities exceed a certain speed. The highest velocity accurately measured is called the Nyquist limit.<br />
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Nyquist Limit - defined as ½ the Pulse Repetition Frequency (the number of pulses per second.) If the velocity of flow exceeds the Nyquist limit, the direction and velocity are inaccurately displayed and, in fact, appear to change direction. Color flow Doppler capitalizes on this effect allowing us to detect flow disturbances from laminar to turbulent flow.<br />
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High PRF - a Doppler technique that attempts to overcome the effects of the Nyquist limit. This technique may be seen as a compromise of pulsed wave and continuous wave properties and involves the use of multiple sample volumes thereby increasing the accuracy of velocity measurements at the cost of range ambiguity.<br />
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Doppler Displays:<br />
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The display of Doppler velocity data is the Doppler frequency shifts versus time. Included in the display are the Doppler settings such as frequency, calibration, range, and timing markers.<br />
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Doppler Controls:<br />
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Controls used during the Doppler examination are dependent on manufacturers specifications and the modes available. Controls for the cursor, sample volume length and depth, angle correction, gain, filters, and spectral averaging are typically included.<br />
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Color Flow Imaging:<br />
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Sampling methods - CFI is based on pulsed Doppler technology where multiple sample volumes among multiple planes are detected and displayed utilizing color mapping for direction and velocity flow data. Common mapping formats are BART (Blue Away, Red Towards ) or RABT, and enhanced or variance flow maps where saturations and intensities indicate higher velocities and turbulence or acceleration, respectively. Some maps utilize a third color, green, to indicate accelerating velocities and turbulence.<br />
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Artifacts - aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow. Other artifacts associated with CFI and spectral Doppler are artifacts due to gain set too high, "ghosting" from improperly set wall filters (low frequency), mirroring, crying/talking artifacts, and signal loss from data sharing. <br />
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Limitations of CFI - CFI is a "qualitative" examination and has not yet been "quantified", that is, results cannot be measured to give discrete numbers for diagnosis. Qualitative assessment gives comment on the overall view or quality of the results as in flow conditions and jet direction, velocity, and pattern. Quantitative results are those measured and given discrete numbers used in calculations. There are some current semi-quantitative results given as ratios of jet length by jet width to determine the degree of regurgitation given as mild, moderate or severe.</div>Vdbilt