우리는 하버드 의과 대학 / 브리검 및 여성 병원 심장 혈관 생리학 핵심 연구소에서 제공하는 자원에 감사드립니다. 이 작품은 국립 보건원 보조금 HL088533, HL071775, HL093148 및 HL099073 (RL)의 자금 조달에 의해 부분적으로 지원되었다. MB는 미국 심장협회 창립자 계열사 인후친교상을 수상했다. KU는 미국 심장 협회 설립자 제휴 박사 후 펠로우십 어워드의 수상자입니다. SC는 엘리슨 재단의 상을 받았습니다.

1. 분석을 위한 이미지 준비
<ol><li>무두질 긴 축 보기에서 뮤린 또는 인간 심초음파 B 모드 이미지를 가져옵니다. 전송 초점의 시간 이득 보상 설정 및 배치를 조정하여 일반적인 연습에 따라 PARAsternal 보기에서 LV 및 기타 심장 구조의 시각화를 최적화합니다. 모든 이미지가 DICOM 파일 형식으로 저장되었는지 확인합니다. 표준화된 이미지 뷰는 프레임 의 베이스에 열성 좌심실 벽을 배치합니다. 프레임은 왼쪽 심실 심근과 심낭의 전체를 표시해야합니다. 해상도는 왼쪽 심실의 심근 테두리, 심근 벽 및 내내심 테두리를 해비할 만큼 충분히 높아야 합니다. 과도한 중퇴 또는 이미지 아티팩트가 있는 이미지를 삭제합니다.</li>
	<li>이미지를 분석하기 위한 이미지 파일을 이미지J 소프트웨어 플랫폼 v1.46으로 DICOM 파일로 가져옵니다. 파일을 8비트 이미지 파일로 변환합니다.</li>
	<li>적절한 품질 최종 확장기 프레임에 도달 할 때까지 심장 주기의 연속 프레임을 스크롤합니다. 또는 심초음파 보기 프로그램에서 최종 확장기 프레임을 선택한 다음 ImageJ에서 사용할 고해상도 .jpg 파일 형식으로 내보냅니다. 심전도 추적의 R 파를 사용하여 엔드 디아스톨에 가장 가까운 프레임을 식별한 다음 최대 내부 차원으로 LV를 캡처하는 단일 최상의 프레임을 식별합니다. 이 단일 프레임을 최종 확장기 프레임을 고려하십시오.</li>
	<li>관심 있는 지역을 선택할 때 사용자가 피사체 ID에 눈이 멀어질 것을 권장합니다.</li>
</ol>2. ROI 샘플링
<ol><li>심근 참조 선택. 관심의 심근 영역을 선택할 때 (ROI), 심근 조직의 이질성을 캡처하는 것을 목표로. 필요에 따라 분석 결과에 영향을 주지 않으면서 이미지 밝기와 콘트라스트가 필요에 따라 ROI 선택을 위해 조정할 수 있습니다.<ol>
<li>ImageJ의 직사각형 드로잉 도구를 사용하여 기저 비열성 심근 벽의 중간 3분의 1을 근사화하는 길이의 사각형을 선택합니다.</li>
		<li>직사각형 ROI의 크기를 조정하여 ROI 크기 조정 도구를 사용하여 심낭의 폭을 가로지르게 합니다.</li>
		<li>IMAGEJ의 회전 도구를 사용하여 ROI를 회전하여 심근 영역 내에 놓습니다.</li>
		<li>심근 ROI의 모서리에 필요한 조정을 합니다. 심근 벽의 중간 3분의 1 내에 있는 최종 심근 영역을 캡처하고 심근 또는 심장 외영역으로 확장하지 않고 심근벽의 폭을 포함한다. 주어진 연구에서 이루어진 모든 조치에 대해 동일한 상대 적 위치와 총 심근 영역의 비율을 캡처하는 것을 목표로합니다.</li>
		<li>ImageJ 분석 도구를 통해 선택 영역에 알고리즘을 적용합니다(섹션 3 참조).</li>
	</ol>
</li>
	<li>심근 선택. 다시 한번, 기저 비열성 심근벽의 중간 3분의 1 내에서 심근 조직의 이질성을 포착하는 것을 목표로 한다. 필요에 따라 분석 결과에 영향을 주지 않으면서 이미지 밝기와 콘트라스트가 필요에 따라 ROI 선택을 위해 조정할 수 있습니다.<ol>
<li>심근 벽의 너비에 걸쳐 있는 사각형을 선택합니다., 심근 및 에피카르듐을 제외. 심근 선택이 심근 선택과 동일한 테타 각도에 인접한지 확인합니다. 선택 영역 내에 유두 근육 영역을 포함하지 마십시오.</li>
		<li>심근 ROI를 회전하여 심근 선택과 평행하게 놓습니다.</li>
		<li>심근 ROI의 모서리에 필요한 조정을 합니다. 심근벽의 3분의 1 에 속하는 최종 심근 영역을 분리하고 심근 또는 내루마 영역으로 확장하지 않고 벽의 폭을 포착합니다.</li>
		<li>ImageJ 매크로를 통해 선택 영역에 알고리즘을 적용합니다.</li>
	</ol>
</li>
</ol>3. 데이터 분석 및 처리
<ol><li>"getTogramValue.txt"라는 ImageJ 매크로를 설치합니다.</li>
	<li>ImageJ 히스토그램 분석 도구를 사용하여 ROI 내에서 신호 강도 값의 분포를 미리 봅니다(심근 선택 및 심근 선택에 대해 이 단계를 수행하십시오).</li>
	<li>ImageJ 매크로를 사용하여 ROI에 대한 이러한 신호 밀도 값을 기록합니다(심근 선택 및 심근 선택에 대해 이 단계를 수행).<ol>
<li>강도 값을 0(가장 어둡게)에서 255(가장 밝은) 단위로 선택 영역 내의 각 픽셀에 할당합니다.</li>
		<li>강도 값을 강도 증가 순서로 계층적으로 정렬하여 신호 강도의 분포를 생성합니다.</li>
		<li>분포에 대한 다음 백분위수 값을 선택하고 보고합니다: 20번째 백분위수, 50번째 백분위수(중앙값), 및 80번째 백분위수.</li>
	</ol>
</li>
	<li>심근 참조를 사용하여 심근 강도를 정규화합니다.<ol>
<li>강도의 심근 백분위수 값을 강도12의해당 심근 백분위수 값으로 나누거나강도(13)의심근 백분위수 값으로부터 강도의 심근 백분위수 값을 공제하여 정규화한다.</li>
		<li>4가지 분석 방법에 대한 값을 보고합니다:20번째 백분위수,50번째 백분위수(중앙값) 및80번째 백분위수 값에 대한 심근-심근-심근 값의 정규화.</li>
	</ol>
</li>
</ol>4. 주기적 가변성 정량화
<ol><li>DICOM 파일의 연속 프레임을 통해 심근 선택에 알고리즘을 적용하여 심장 주기를 통과합니다. 프레임 간의 강도 분포의 차이를 최종 수축기 및 끝 확장기 프레임에 주의를 기울입니다. 위에서 설명한 모든 이미지 분석은 이전에 획득하고 디지털 방식으로 DICOM 형식으로 저장되었던 비침습적 심초음파 이미지에서 오프라인으로 수행됩니다. 모든 연구 프로토콜은 브리검 과 여성의 기관 검토 위원회와 하버드 의료 지역 서 기관 동물 관리 및 사용 위원회에 의해 승인되었다.</li>
</ol>

<ol>
	<li>Yamada, S., Komuro, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrated+backscatter+for+the+assessment+of+myocardial+viability.">Integrated backscatter for the assessment of myocardial viability.</a> Curr. Opin. Cardiol. 21, 433-437 (2006).</li><li>Mimbs, J. W., O'Donnell, M., Bauwens, D., Miller, J. W., Sobel, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dependence+of+ultrasonic+attenuation+and+backscatter+on+collagen+content+in+dog+and+rabbit+hearts.">The dependence of ultrasonic attenuation and backscatter on collagen content in dog and rabbit hearts.</a> Circ. Res. 47, 49-58 (1980).</li><li>Picano, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+quantitative+ultrasonic+evaluation+of+myocardial+fibrosis+in+humans.">In vivo quantitative ultrasonic evaluation of myocardial fibrosis in humans.</a> Circulation. 81, 58-64 (1990).</li><li>Mizuno, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myocardial+ultrasonic+tissue+characterization+for+estimating+histological+abnormalities+in+hypertrophic+cardiomyopathy:+comparison+with+endomyocardial+biopsy+findings.">Myocardial ultrasonic tissue characterization for estimating histological abnormalities in hypertrophic cardiomyopathy: comparison with endomyocardial biopsy findings.</a> Cardiology. 96, 16-23 (2001).</li><li>Mizuno, R., Fujimoto, S., Saito, Y., Nakamura, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+quantitation+of+myocardial+fibrosis+using+combined+tissue+harmonic+imaging+and+integrated+backscatter+analysis+in+dilated+cardiomyopathy.">Non-invasive quantitation of myocardial fibrosis using combined tissue harmonic imaging and integrated backscatter analysis in dilated cardiomyopathy.</a> Cardiology. 108, 11-17 (2007).</li><li>Marini, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+variation+in+myocardial+gray+level+as+a+marker+of+viability+in+man.+A+videodensitometric+study.">Cyclic variation in myocardial gray level as a marker of viability in man. A videodensitometric study.</a> Eur. Heart. J. 17, 472-479 (1996).</li><li>Komuro, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensitive+detection+of+myocardial+viability+in+chronic+coronary+artery+disease+by+ultrasonic+integrated+backscatter+analysis.">Sensitive detection of myocardial viability in chronic coronary artery disease by ultrasonic integrated backscatter analysis.</a> J. Am. Soc. Echocardiogr. 18, 26-31 (2005).</li><li>Ciulla, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+patterns+of+myocardial+fibrosis+in+hypertensive+patients:+endomyocardial+biopsy+versus+ultrasonic+tissue+characterization.">Echocardiographic patterns of myocardial fibrosis in hypertensive patients: endomyocardial biopsy versus ultrasonic tissue characterization.</a> J. Am. Soc. Echocardiogr. 10, 657-664 (1997).</li><li>Maceira, A. M., Barba, J., Varo, N., Beloqui, O., Diez, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonic+backscatter+and+serum+marker+of+cardiac+fibrosis+in+hypertensives.">Ultrasonic backscatter and serum marker of cardiac fibrosis in hypertensives.</a> Hypertension. 39, 923-928 (2002).</li><li>D'Hooge, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+frame+rate+myocardial+integrated+backscatter.+Does+this+change+our+understanding+of+this+acoustic+parameter.">High frame rate myocardial integrated backscatter. Does this change our understanding of this acoustic parameter.</a> Eur. J. Echocardiogr. 1, 32-41 (2000).</li><li>Finch-Johnston, A. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+variation+of+integrated+backscatter:+dependence+of+time+delay+on+the+echocardiographic+view+used+and+the+myocardial+segment+analyzed.">Cyclic variation of integrated backscatter: dependence of time delay on the echocardiographic view used and the myocardial segment analyzed.</a> J. Am. Soc. Echocardiogr. 13, 9-17 (2000).</li><li>Di Bello, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+echodensity+of+myocardial+wall+in+the+diabetic+heart:+an+ultrasound+tissue+characterization+study.">Increased echodensity of myocardial wall in the diabetic heart: an ultrasound tissue characterization study.</a> J. Am. Coll. Cardiol. 25, 1408-1415 (1995).</li><li>Takiuchi, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+ultrasonic+tissue+characterization+can+identify+high-risk+atherosclerotic+alteration+in+human+carotid+arteries.">Quantitative ultrasonic tissue characterization can identify high-risk atherosclerotic alteration in human carotid arteries.</a> Circulation. 102, 766-770 (2000).</li><li>Querejeta, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum+carboxy-terminal+propeptide+of+procollagen+type+I+is+a+marker+of+myocardial+fibrosis+in+hypertensive+heart+disease.">Serum carboxy-terminal propeptide of procollagen type I is a marker of myocardial fibrosis in hypertensive heart disease.</a> Circulation. 101, 1729-1735 (2000).</li></ol>

이해 상충이 선언되지 않았습니다.

초음파 신호 강도 분포를 정량화하는 이미지 분석 알고리즘의 프로토콜을 설명하고, 차례로 심근 미세 구조의 대리 측정을 제공합니다. ROI 및 참조 영역의 선택, 크기 조정 및 위치 지정을 포함한 프로토콜의 표준화된 기능은 사용자 및 주체 기반 가변성을 최소화합니다. 우리는 최종 확장기 단일 프레임 심초음파 이미지에 적용 할 때 알고리즘이 적당히 후부하 스트레스에 노출 된 심근과 정상적...

에코카르디오그래피는 일반적으로 비침습적으로 심장 구조와 기능의 변화를 특성화하고 정량화하는 데 사용되는 널리 접근 가능한 이미징 양식입니다. 심장 조직의 초음파 평가는 한 번에 관심의 주어진 영역 내에서 백스캐터 신호 강도의 분석을 포함 할 수 있습니다, 뿐만 아니라 심장 주기의 과정을 통해. 이전 연구는 초음파 신호 강도의 측정이 심근 섬유 혼란의 근본적인 존재를 식별 할 수 있음을 제안했다, 생존 대 실행 가능한 심근 조직, 및 간질 섬유증1-3. 우리는 심근 '미세 구조'를 총 크기와 형태학의 선형 측정을 넘어 초음파 분석을 사용하여 특성화 할 수있는 조직 아키텍처로 지칭합니다. 이에 따라, 초음파 신호 강도의 분석은 비대및 확장된 심근병증4,5,만성 관상동맥질환6,7,고혈압 심장질환8,9의설정에서 심근 조직의 미세구조적 변화를 평가하는 데 사용되어 왔다. 그러나, 이전에 확립된 기술은 백스캐터 신호 강도의 통합 또는 평균 값에 주로 의존해 왔으며, 이는 랜덤 노이즈5,낮은 프레임속도(10)의별칭 데이터, 순환변동(11)에기초한 알고리즘에 대한 시간 지연으로부터의 가변성에 취약할 수 있다.
본명, 이전 방법으로부터 확장되는 초음파 기반 이미지 분석 알고리즘을 사용하는 방법을 설명한다. 이 알고리즘은 이미지 분석을 위한 단일 종횡확장프레임에 중점을 두고 주어진 심근 샘플에서 파생된 신호 강도 값의 전체 분포를 설명합니다. 심낭을 인프레임 참조12,13으로사용하여, 알고리즘은 초음파 신호 강도 분포의 변동을 재재현하고 심근 미세 구조의 향상된 대리 측정을 제공한다. 단계별 프로토콜에서는 사용하기 위한 이미지 준비, 관심 영역 샘플링 및 관심 있는 영역 내에서 데이터를 처리하는 방법을 설명합니다. 우리는 또한 좌심실에 후부하 응력에 가변 노출을 가진 마우스와 인간에게서 취득한 심초음파 심초음파 심상에 알고리즘을 적용에서 대표적인 결과를 보여줍니다.

<table border="0" cellpadding="0" cellspacing="0" width="770">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">ImageJ v 1.46</td>
			<td style="width:268px;">NIH (Bethesda, MD)</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">open access software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Power ShowCase</td>
			<td style="width:268px;">Trillium Technology (Ann Arbor, MI)</td>
			<td style="width:119px;"></td>
			<td>commercial software</td>
		</tr>
	</tbody>
</table>

ultrasonic assessment of myocardial microstructure

에코카르디오그래피는 일반적으로 비침습적으로 심장 구조와 기능의 변화를 특성화하고 정량화하는 데 사용되는 널리 접근 가능한 이미징 양식입니다. 심장 조직의 초음파 평가는 관심의 주어진 지역 내에서 백스캐터 신호 강도의 분석을 포함 할 수 있습니다. 이전에 확립된 기술은 주로 백스캐터 신호 강도의 통합 또는 평균 값에 의존해 왔으며, 이는 순환 변동에 기초한 알고리즘에 대한 낮은 프레임 속도 및 시간 지연에서 별칭 데이터로부터 가변성에 취약할 수 있습니다. 본 명세서에서, 우리는 이전 방법으로부터 확장되는 초음파 기반 이미징 알고리즘을 설명하고, 단일 이미지 프레임에 적용될 수 있으며 주어진 심근 샘플로부터 유래된 신호 강도 값의 전체 분포를 설명한다. 대표적인 마우스 및 인간 이미징 데이터에 적용하면 알고리즘은 만성 후하중 저항에 노출되지 않고 피사체를 구별합니다. 이 알고리즘은 심근 미세 구조의 향상된 대리 측정을 제공하며 개방형 이미지 분석 소프트웨어를 사용하여 수행할 수 있습니다.

신호 강도 분석은 4개의 주요 단계(도 1)에서 수행된다(그림1)포함: 1) 이미지 선택 및 서식, 2) 샘플링 ROI 및 기준 영역, 3) 알고리즘 응용 프로그램, 및 4) 심근-심근 강도 비율을 산출하기 위해 최종 값을 처리한다. ROI의 선택 및 크기는 인터사용자뿐만 아니라 인트라우더가 변성을 제한하도록 표준화된다(그림2). 각 ROI의 위치는 또한 각 피사체의 해부학 적 구조와 관련하여 ...

Watch this Scientific Journal Video about Ultrasonic Assessment of Myocardial Microstructure at JoVE.com

Ultrasonic Assessment of Myocardial Microstructure

에코카르디오그래피는 일반적으로 비침습적으로 심장 구조와 기능의 변화를 특성화하고 정량화하는 데 사용됩니다. 당사는 심근 미세 구조의 향상된 대리 측정을 제공하고 오픈 액세스 이미지 분석 소프트웨어를 사용하여 수행 할 수있는 초음파 기반 이미징 알고리즘을 설명합니다.

심근 미세 구조의 초음파 평가

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and ...

ultrasonic-assessment-of-myocardial-microstructure

Research

JoVE Journal

Medicine

5.4K 조회수.  Harvard Medical School. 에코카르디오그래피는 일반적으로 비침습적으로 심장 구조와 기능의 변화를 특성화하고 정량화하는 데 사용됩니다. 당사는 심근 미세 구조의 향상된 대리 측정을 제공하고 오픈 액세스 이미지 분석 소프트웨어를 사용하여 수행 할 수있는 초음파 기반 이미징 알고리즘을 설명합니다.

비디오: Ultrasonic Assessment of Myocardial Microstructure

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

기능 추적을 사용하여 자기 공명이 유래 심근 스트레인 평가

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

연구

의학

Acute Myocardial Infarction in Rats

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial infarction (AMI). This model is also referred to as an acute ischemic cardiomyopathy or ischemia followed by reperfusion (IR); which is induced by an acute 30-minute period of ischemia by ligation of the left anterior descending artery (LAD) followed by reperfusion of the tissue by releasing the LAD ligation (Vasilyev and McConnell). This protocol will focus on assessment of the infarct size and the area-at-risk (AAR) by Evan's blue dye and triphenyl tetrazolium chloride (TTC) following 4-hours of reperfusion; additional comments toward the evaluation of cardiac function and remodeling by modifying the duration of reperfusion, is also presented. Overall, this AMI rat animal model is useful for studying the consequence of a myocardial infarction on cardiac pathophysiological and physiological function.

The rat model of acute myocardial infarction (AMI) is useful to study the consequence of a MI on cardiac pathophysiological and physiological function.

고양이에서 급성 심근 경색

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular ...

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery (SALLI) MRI in Rats

Small animal magnetic resonance imaging is an important tool to study cardiac function and changes in myocardial tissue. The high heart rates of small animals (200 to 600 beats/min) have previously limited the role of CMR imaging. Small animal Look-Locker inversion recovery (SALLI) is a T1 mapping sequence for small animals to overcome this problem 1. T1 maps provide quantitative information about tissue alterations and contrast agent kinetics. It is also possible to detect diffuse myocardial processes such as interstitial fibrosis or edema 1-6. Furthermore, from a single set of image data, it is possible to examine heart function and myocardial scarring by generating cine and inversion recovery-prepared late gadolinium enhancement-type MR images 1.
	The presented video shows step-by-step the procedures to perform small animal CMR imaging. Here it is presented with a healthy Sprague-Dawley rat, however naturally it can be extended to different cardiac small animal models.

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

Contrast enhanced cardiac magnetic resonance (CMR) imaging allows comprehensive in vivo assessment of the heart in small animal models of cardiovascular disease. Here we detail the procedures to perform CMR imaging, reconstruction and analysis using Small Animal Lock-Locker Inversion Recovery (SALLI) in rats.

작은 동물 룩 로커 반전 복구 (SALLI) 쥐의 MRI를 사용하여 심장 기능 및 심근 형태학의 평가

Small animal magnetic resonance  imaging is an important tool to study cardiac function and changes in myocardial  tissue. The high heart rates of small ...

Myocardial Infarction and Functional Outcome Assessment in Pigs

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One important prerequisite is a good understanding of all safety and efficacy aspects obtained in a large animal model that validly reflect the human scenario of myocardial infarction (MI). Pigs are widely used in this regard since their cardiac size, hemodynamics, and coronary anatomy are close to that of humans. Here, we present an effective protocol for using the porcine MI model using a closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. This approach is based on 90 min of myocardial ischemia, inducing large left ventricle infarction of the anterior, septal and inferoseptal walls. Furthermore, we present protocols for various measures of outcome that provide a wide range of information on the heart, such as cardiac systolic and diastolic function, hemodynamics, coronary flow velocity, microvascular resistance, and infarct size. This protocol can be easily tailored to meet study specific requirements for the validation of novel cardioregenerative biologics at different stages (i.e. directly after the acute ischemic insult, in the subacute setting or even in the chronic MI once scar formation has been completed). This model therefore provides a useful translational tool to study MI, subsequent adverse remodeling, and the potential of novel cardioregenerative agents.

This protocol describes the porcine myocardial infarction (MI) model using a 90 min closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. Furthermore, the protocol for several outcome parameters, such as cardiac function, hemodynamics, microvascular resistance, and infarct size, are also presented.

돼지의 심근 경색 및 기능적 결과의 평가

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One ...

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

급성 심근 경색의 돼지 모델의 주요 결과 평가

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the examiners&#39; expertise. Speckle tracking Echocardiography (STE) is a promising but technically challenging method that can be used to quantitatively assess regional and global systolic and diastolic myocardial performance. Myocardial strain and strain rate can be measured in all three dimensions&#160;&#8212; radial, circumferential, longitudinal &#8212; of myocardial deformation. Standard cross-sectional two-dimensional B-mode images are recorded and subsequently postprocessed by automated continuous frame-by-frame tracking and motion analysis of speckles within the myocardium. Images are recorded as digital loops and synchronized to a 3-lead EKG for timing purposes. Longitudinal deformation is assessed in the apical 4-, 3-, and 2-chamber views. Circumferential and radial deformation are measured in the parasternal short axis plane.
Optimal image quality and accurate tissue tracking are paramount for the correct determination of myocardial performance parameters. Utilizing transthoracic STE in a healthy volunteer, the present article is a detailed outline of the essential steps and potential pitfalls of quantitative echocardiographic myocardial deformation analysis.

Speckle tracking echocardiography is an emerging diagnostic imaging technique for the quantitative assessment of global and regional myocardial performance. Standard view echocardiographic motion images are recorded and deformation parameters are subsequently measured by automated continuous frame-by-frame tracking and motion analysis of speckles within the B-mode images of the myocardium.

좌심실 심근 변형의 정량적 평가를위한 흉부 얼룩 추적 심 초음파

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the ...

Histological Quantification of Chronic Myocardial Infarct in Rats

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ischemic injury. Following the initial acute phase, chronic remodeling of the left ventricle (LV) modifies the structure and function of the heart. Permanent coronary ligation in small animals has been widely used as a reference model for a chronic model of MI. Thinning of the infarcted wall progressively develops to transmural fibrosis. Histological assessment of infarct size is commonly performed; nevertheless, a standardization of the methods for quantification is missing. Indeed, important methodological aspects, such as the number of sections analyzed and the sampling and quantification methods, are usually not described and therefore preclude comparison across investigations. Too often, quantification is performed on a single section obtained at the level of the papillary muscles. Because novel strategies aimed at reducing infarct expansion and remodeling are under investigation, there is an important need for the standardization of accurate heart sampling protocols. We describe an accurate method to quantify the infarct size using a systematic sampling of harvested rat heart and image analyses of trichromatic stained histological sections obtained from base to apex. We also provide evidence that calculating the expansion index (EI) allowed for infarct size assessment, taking into account changes of the left ventricle throughout the remodeling.

The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections.

쥐의 만성 심근 경색의 조직 학적 정량

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ...

3D Whole-heart Myocardial Tissue Analysis

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other biologicals that enhance angio- or vasculogenesis into the infarct border zone (IBZ), tissue perfusion is improved, and the myocardium can be protected from further damage. For maximum therapeutic effect, it is hypothesized that the regenerative substance is best delivered to the IBZ. This requires accurate injections and has led to the development of new injection techniques. To validate these new techniques, we have designed a validation protocol based on myocardial tissue analysis. This protocol includes whole-heart myocardial tissue processing that enables detailed two-dimensional (2D) and three-dimensional (3D) analysis of the cardiac anatomy and intramyocardial injections. In a pig, myocardial infarction was created by a 90-min occlusion of the left anterior descending coronary artery. Four weeks later, a mixture of a hydrogel with superparamagnetic iron oxide particles (SPIOs) and fluorescent beads was injected in the IBZ using a minimally-invasive endocardial approach. 1 h after the injection procedure, the pig was euthanized, and the heart was excised and embedded in agarose (agar). After the solidification of the agar, magnetic resonance imaging (MRI), slicing of the heart, and fluorescence imaging were performed. After image post-processing, 3D analysis was performed to assess the IBZ targeting accuracy. This protocol provides a structured and reproducible method for the assessment of the targeting accuracy of intramyocardial injections into the IBZ. The protocol can be easily used when the processing of scar tissue and/or validation of the injection accuracy of the whole heart is desired.

This protocol describes a novel method for the 3D comparison of whole-heart myocardial tissue with MRI. This is designed for the accurate assessment of intramyocardial injections in the infarct border zone of a chronic porcine model of myocardial infarction.

3D 전체 심장 심근 조직 분석

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other ...

Ultrasonic-augmented Primary Adult Fibroblast Isolation

Primary adult fibroblasts have become an important tool to study fibrosis, fibroblast interactions and inflammation in all body tissues. Since primary fibroblasts cannot divide indefinitely due to myofibroblast differentiation or senescence induction, new cultures must be established regularly. However, there are several obstacles to overcome during the processes of developing a reliable isolation protocol and primary fibroblast isolation itself: the method&#8217;s degree of difficulty (especially for beginners), the risk of bacterial contamination, the required time until primary fibroblasts can be used for experiments, and subsequent cell quality and viability. In this study, a fast, reliable and easy-to-learn protocol to isolate and culture primary adult fibroblasts from mouse heart, lung, liver and kidney combining enzymatic digestion and ultrasonic agitation is provided.

We present a protocol to isolate primary adult fibroblasts in an easy, fast and reliable way, performable by beginners (e.g., students). The procedure combines enzymatic tissue digestion and mechanical agitation with ultrasonic waves to obtain primary fibroblasts. The protocol can easily be adapted to specific experimental requirements (e.g., human tissue).

초음파 증강 원발성 섬유아세포 분리

Primary adult fibroblasts have become an important tool to study fibrosis, fibroblast interactions and inflammation in all body tissues. Since primary ...

Semi-Minimal Invasive Method to Induce Myocardial Infarction in Rats and the Assessment of Cardiac Function by an Isolated Working Heart System

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily and highly reproducible MI induction procedure is required to obtain further insight and better understanding of the underlying pathological changes. This procedure can also be used to evaluate the effects or potency of new and promising treatments (as drugs or interventions) in acute MI, subsequent remodeling and heart failure (HF). After intubation and pre-operative preparation of the animal, an anesthetic protocol with isoflurane was performed, and the surgical procedure was conducted&#160;quickly. Using a minimally invasive approach, the left anterior descending artery (LAD) was located and occluded by a ligature. The occlusion can be performed acutely for subsequent reperfusion (ischemia/reperfusion injury). Alternatively, the vessel can be ligated permanently to investigate the development of chronic MI, remodeling or HF. Despite common pitfalls, the drop-out rates are minimal. Various treatments such as remote ischemic conditioning can be examined for their cardioprotective potential pre-, peri- and post-operatively. The post-operative recovery was quick as the anesthesia was precisely controlled and the duration of the operation was short. Post-operative analgesia was administered for three days. The minimally invasive procedure reduces the risk of infection and inflammation. Furthermore, it facilitates rapid recovery. The &#8220;working heart&#8221; measurements were performed ex vivo and enabled precise control of preload, afterload and flow. This procedure requires specific equipment and training for adequate performance. This manuscript provides a detailed step-by-step introduction for conducting these measurements.

This article presents an efficient method to perform myocardial ischemia and subsequent chronic reperfusion in rats using a minimally invasive approach. In addition, left ventricular hemodynamic function of rats is assessed by echocardiography and isolated working heart methods.&#160;

쥐의 심근 경색과 격리 된 작업 심장 시스템에 의한 심장 기능 평가를 유도하는 반 최소 침습 적 방법

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily ...