项目编号NVKP_16-1-2016-0017（"国家心脏计划"）已在匈牙利国家研究，发展和创新基金的支持下实施，该基金由NVKP_16资助计划资助。该研究由匈牙利创新和技术部的专题卓越计划（2020-4.1.1.-TKP2020）资助，在塞梅尔威斯大学的治疗开发和生物成像主题计划的框架内。

该协议遵循塞梅尔威斯大学科学与研究伦理区域和机构委员会的指导方针。本协议适用于特定供应商。尽管无论使用超声机和后处理软件，某些步骤仍然有效，但如果使用其他供应商的解决方案，则可能存在重要差异。
1. 技术要求
<ol><li>利用能够进行3D成像的超声心动图机。</li>
	<li>连接具有 3D 经胸超声心动图功能的相控阵换能器。</li>
	<li>应用超声系统的内置3导联心电图，使系统能够将记录和分析同步到心脏周期。</li>
</ol>2. 采集3D超声心动图图像
<ol><li>将患者置于左侧侧卧位（患者躺在左侧，左臂伸展到头顶上方）。</li>
	<li>确保屏幕上的心电图追踪质量良好。 注意:这是后处理的先决条件，因为软件将根据ECG信号检测心脏周期的不同点。</li>
	<li>解冻图像，并开始用换能器检查患者。可视化传统的顶点四腔视图。</li>
	<li>通过将扇区宽度调整为左心宽，降低深度以截断左心房以及使用轻微的过度加气来优化图像质量。 注意:确保整个左心室内膜和心外膜表面可见。</li>
	<li>按 4D 按钮切换到 3D 模式。 注意:通过按触摸屏上的" 多切片..." 按钮，将有四个选项（5、7、8、12 切片）使用标准的短轴和长轴切割来概览 3D 数据集。如果需要，可以校正探头定位，以确保将整个左心室壁厚度从顶端到二尖瓣水平纳入金字塔3D数据集。建议使用 12 个切片（具有 9 个可调节的短轴视图）。</li>
	<li>使用多拍或单拍模式采集 3D 图像。<ol>
<li>使用 Multi Beat 模式实现更高的空间和时间分辨率，其中数据集将从 2、3、4 或 6 个心脏周期重建（可在屏幕上设置） - 患者呼气结束呼吸和稳定的换能器定位，以最大限度地减少拼接伪影。 注: 单拍 采集的空间和时间分辨率较低。然而，大多数现代传感器具有更好的质量，因此可用于获取适当的3D数据集，而无需重建以进行进一步分析。作为一般建议，建议使用每秒超过 15 卷的音量率进行进一步分析。</li>
		<li>当从子卷重建全卷并且整个LV可见时，冻结图像。使用"周期选择"和"循环次数"旋钮，选择获得最佳获得的心脏周期，然后按"图像存储"。 注:拼接伪像在空间上或暂时未对齐的子卷彼此相邻。具有显著左心室壁凹陷或具有拼接伪影的数据集通常不适合进一步分析。可以使用多切片模式仔细检查已获取的 3D 数据集的质量。</li>
	</ol>
</li>
</ol>3. 后处理以量化左心室形态和功能
<ol><li>选择适合进一步分析的 3D 数据集。 注意:该协议的这一部分需要先前获取和保存的高质量3D图像，并且可以在超声机器和单独的工作站上执行。</li>
	<li>单击" 测量|音量，然后选择 "4D 自动 LVQ"。</li>
	<li>在四屏（三个顶面视图:四个、两个和三个腔室视图，以及一个短轴视图，后者可以通过长轴视图上的水平平面进行调整）上，软件会要求 修改顶点切片与标准视图的对齐方式。如果需要，通过倾斜和旋转手动校正顶点视图以显示相应的标准视图，从而消除透视收缩。设置倾斜以通过在长轴视图上拖动和移动卡钳来将卡钳与LV的长轴对齐。通过机床上相应的或 "全部旋转" 旋钮或通过调整短轴图像上的卡钳来设置旋转。 注:可通过按下 "自动对齐 "按钮重置软件建议。</li>
	<li>完成视图对齐后，单击下一步 EDV。舒张末期 （ED） 帧使用心电图信号自动检测，但如有必要，可以手动校正。</li>
	<li>左心室内膜和心外膜表面的半自动检测<ol><li>在任何顶点视图上手动选取两个地标点。首先，在任何顶点视图中识别左心室顶点，然后确定左心室基底的中间（二尖瓣环空水平）。该算法将自动勾勒整个左心室的心内膜边界。 注意:还有两个选项: 手动，这意味着在每个顶点视图中应设置两个基础和一个顶点，以及 自动初始化，它将自动勾勒左心室轮廓，而无需任何用户交互。</li>
		<li>检查三个顶点视图、三个不同级别的短轴视图和第四个用户控制的短轴中的等值线可信度，以便对检测到的表面进行视觉验证。通过手动添加点，可以进行等值线校正，然后将这些点合并到等值线中。 注意:使用 "撤消"时，可以删除以前添加的点。 "重置 "按钮可重置轮廓，以从头开始整个部分。可以调整轮廓可见性，以便在灰度图像上欣赏心内膜表面。心内膜和心外膜轮廓应以准确和一致的方式进行。有关详细建议，请查看以下参考资料6。</li>
		<li>选择下一步，即 ESV。</li>
		<li>重复上述相同的程序（3.5.1-3.5.2），以识别和纠正收缩末期框架上的心内膜轮廓。 注:收缩末期（ES）框架使用ECG信号自动检测，但如有必要，可以手动校正。舒张末期体积 （EDV）、收缩末期体积 （ESV）、射血分数 （EF）、心率 （HR）、每搏量 （SV）、心输出量 （CO） 和球形指数 （SpI） 的值已显示在屏幕上。</li>
		<li>按 音量波形 进行下一步。该软件显示左心室的动态3D模型以及时间体积曲线，因为它在整个心脏周期中逐帧跟踪心内膜表面（图1）。 注意:在这里，可以在任何帧处编辑心内膜边界。</li>
		<li>对于下一步，按 左心室质量。该软件自动勾勒舒张末期框架上的左心室外膜轮廓，并计算左心室肿块（EDMass）。 注意:如有必要，通过添加点以在任何短轴或长轴平面中包括（与前面描述的方法相同）来编辑心外膜表面的轮廓。可以选择要调整的轮廓:Endo，Epi或Endo + Epi。</li>
		<li>按 4D 应变 ROI 进行下一步。该软件自动勾勒收缩末期框架上的左心室外膜轮廓，并计算左心室收缩末期质量（ESMass）。 注意:如有必要，编辑心外膜表面的收缩末期轮廓，方法是添加点以在任何短轴或长轴平面中包括（与前面描述的方法相同）。ESMass 应具有与 EDMass 相似的价值。此步骤对于通过斑点跟踪计算 3D 应变值至关重要。</li>
		<li>按 4D 应变结果 进行下一步。该软件可逐帧可视化多个短轴和长轴平面上的 3D 心肌跟踪，以及整个心脏周期中 17 个标准左心室段的相应应变值。还显示了时间应变曲线和牛眼图。计算并可以演示以下参数:纵向应变，圆周应变，径向应变，面积应变，旋转和扭转。 注意:如果通过对图像的目视观察或基于时间应变曲线认为特定左心室段具有低跟踪质量，则有可能将其从分析中排除。但是，默认情况下，软件建议在段批准或拒绝时进行审批或拒绝。通过更改"布局"，可以在LV的动态3D模型上可视化颜色编码的应变值。</li>
	</ol></li>
	<li>要终止分析，请按 批准并退出。</li>
</ol>

<ol>
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左心室形态学和功能测量是心脏病诊断、管理和随访的基石。此外，它们是结果的强大预测因素。通常，现行实践指南建议对左心室进行基于二维超声心动图的评估。然而，3D超声心动图已被证明更准确，因为它没有关于LV形状的几何假设7，8。通过斑点跟踪进行变形成像是评估心肌应变不同方向的可靠方法，可以更灵敏地量化壁运动异常5<...

评估左心室 （LV） 形态和功能是心脏病学中一般甚至更具体检查的主要目的1。广泛可用的无创经胸超声心动图（TTE）可以提供大量信息，是方便，快速且具有成本效益的评估的首选方法。
低压质量、容量和随后的射血分数的测量具有重要的诊断价值和预后价值2。给定的度量值越准确，其值就越高。与金标准心脏磁共振（CMR）成像衍生值更好的相关性是对超声心动图技术的持续追逐。通常，临床实践指南推荐双平面辛普森方法测量左心室体积和射血分数3。然而，左心室是一种三维（3D）结构，其形状通常不规则，因此，在某些临床场景中，几个断层扫描平面无疑无法准确描绘左心室形态和功能。超声波硬件和软件技术的最新进展允许实时3D成像的发展，这彻底改变了超声心动图方案。
此外，需要对壁运动异常进行定量方法，导致变形成像的兴起4。应变和应变速率参数可以通过使用标准灰度图像的斑点跟踪来计算。3D 超声心动图还可以克服二维应变评估的几个缺点5。从昂贵的科学工具，3D超声心动图开始成为日常临床实践中使用的一种强大技术，而LV的定量无疑是这一突破的第一线。
本文旨在通过提供提示和技巧以及强调潜在的陷阱来引导读者通过详细的3D协议，以促进有关LV的这一重要技术的广泛但技术上合理的使用。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3V-D/4V-D/4Vc-D</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>ultrasound probe</td>
		</tr>
		<tr>
			<td>4D Auto LVQ</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>software for analysis</td>
		</tr>
		<tr>
			<td>E9/E95</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>ultrasound machine</td>
		</tr>
		<tr>
			<td>EchoPac v203</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>software for analysis</td>
		</tr>
	</tbody>
</table>

evaluation of left ventricular structure and function using 3d echocardiography

左心室 （LV） 的三维 （3D） 定量在诊断准确性和各种心脏疾病的精确风险分层方面提供了显著的附加值。最近，3D超声心动图在常规心脏病学实践中变得可用;然而，高质量的图像采集和后续分析具有陡峭的学习曲线。本文旨在通过提供提示和技巧以及强调潜在的陷阱来引导读者通过详细的3D协议，以促进有关LV的这一重要技术的广泛但技术上合理的使用。首先，我们展示了以最佳空间和时间分辨率获取的高质量3D数据集。然后，我们通过使用应用最广泛的内置软件之一，介绍了对LV进行详细定量的分析步骤。我们将通过测量射血分数和心肌变形（纵向和圆周应变）来量化左心室体积，球形度，质量和收缩功能。我们将讨论并提供临床示例，说明强烈建议从传统的超声心动图方法过渡到基于3D的定量的基本场景。

左心室的 3D 分析在大多数患者中是可行的。病例1是一名健康的志愿者，心室容积和功能正常（图1）。病例 2（图 2）是一名 64 岁男性患者，伴有扩张型心肌病和宽 QRS 复合体（160 ms）左束支传导阻滞形态。黄金标准CMR测量值如下:舒张末期体积:243 mL，收缩末期体积:160 mL，射血分数:34%，左心室质量:163g。传统的线性超声心动图测...

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Evaluation of Left Ventricular Structure and Function using 3D Echocardiography

在本文中，我们为通过3D超声心动图对左心室进行容量评估和斑点跟踪分析提供了分步采集和分析方案，特别关注最大化该技术可行性的实用方面。

使用3D超声心动图评估左心室结构和功能

Three-dimensional (3D) quantification of the left ventricle (LV) provides significant added value in terms of diagnostic accuracy and precise risk ...

evaluation-left-ventricular-structure-function-using-3d

Research

JoVE Journal

Bioengineering

3.8K 次观看.  Semmelweis University. 在本文中，我们为通过3D超声心动图对左心室进行容量评估和斑点跟踪分析提供了分步采集和分析方案，特别关注最大化该技术可行性的实用方面。

视频: Evaluation of Left Ventricular Structure and Function using 3D Echocardiography

Measuring Left Ventricular Pressure in Late Embryonic and Neonatal Mice

Blood pressure increases significantly during embryonic and postnatal development in vertebrate animals. In the mouse, blood flow is first detectable around embryonic day (E) 8.51. Systolic left ventricular (LV) pressure is 2 mmHg at E9.5 and 11 mmHg at E14.52. At these mid-embryonic stages, the LV is clearly visible through the chest wall for invasive pressure measurements because the ribs and skin are not fully developed. Between E14.5 and birth (approximately E21) imaging methods must be used to view the LV. After birth, mean arterial pressure increases from 30 - 70 mmHg from postnatal day (P) 2 - 353. Beyond P20, arterial pressure can be measured with solid-state catheters (i.e. Millar or Scisense). Before P20, these catheters are too big for developing mouse arteries and arterial pressure must be measured with custom pulled plastic catheters attached to fluid-filled pressure transducers3 or glass micropipettes attached to servo null pressure transducers4.
Our recent work has shown that the greatest increase in blood pressure occurs during the late embryonic to early postnatal period in mice5-7. This large increase in blood pressure may influence smooth muscle cell (SMC) phenotype in developing arteries and trigger important mechanotransduction events. In human disease, where the mechanical properties of developing arteries are compromised by defects in extracellular matrix proteins (i.e. Marfan's Syndrome8 and Supravalvular Aortic Stenosis9) the rapid changes in blood pressure during this period may contribute to disease phenotype and severity through alterations in mechanotransduction signals. Therefore, it is important to be able to measure blood pressure changes during late embryonic and neonatal periods in mouse models of human disease.
We describe a method for measuring LV pressure in late embryonic (E18) and early postnatal (P1 - 20) mice. A needle attached to a fluid-filled pressure transducer is inserted into the LV under ultrasound guidance. Care is taken to maintain normal cardiac function during the experimental protocol, especially for the embryonic mice. Representative data are presented and limitations of the protocol are discussed.

Measuring left ventricular pressure (LV) in embryonic and neonatal mice is described. Pressure is measured by inserting a needle connected to a fluid-filled transducer into the LV under ultrasound guidance. Care must be taken to maintain normal cardiac function during the experimental protocol.

测量中晚期胚胎和新生小鼠左心室压力

Blood pressure increases significantly during embryonic and postnatal development in vertebrate animals. In the mouse, blood flow is first detectable ...

科研

生物工程

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD).

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

This method outlines the use of Quantum Micro-Computed Tomography (MicroCT) to assess cardiac morphology, function, perfusion, metabolism and viability with iodinated contrast agent in mice with experimentally-induced myocardial ischemia. The technique can be applied for non-destructive high-throughput longitudinal in vivo imaging of various animal models of human heart disease.

在心肌结构，功能的体内定量评估，灌注与活力使用心脏微型计算机断层扫描

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that ...

Bioprinting of Cartilage and Skin Tissue Analogs Utilizing a Novel Passive Mixing Unit Technique for Bioink Precellularization

Bioprinting is a powerful technique for the rapid and reproducible fabrication of constructs for tissue engineering applications. In this study, both cartilage and skin analogs were fabricated after bioink pre-cellularization utilizing a novel passive mixing unit technique. This technique was developed with the aim to simplify the steps involved in the mixing of a cell suspension into a highly viscous bioink. The resolution of filaments deposited through bioprinting necessitates the assurance of uniformity in cell distribution prior to printing to avoid the deposition of regions without cells or retention of large cell clumps that can clog the needle. We demonstrate the ability to rapidly blend a cell suspension with a bioink prior to bioprinting of both cartilage and skin analogs. Both tissue analogs could be cultured for up to 4 weeks. Histological analysis demonstrated both cell viability and deposition of tissue specific extracellular matrix (ECM) markers such as glycosaminoglycans (GAGs) and collagen I respectively.

Cartilage and skin analogs were bioprinted using a nanocellulose-alginate based bioink. The bioinks were cellularized prior to printing via a single step passive mixing unit. The constructs were demonstrated to be uniformly cellularized, have high viability, and exhibit favorable markers of differentiation.

Bioink Precellularization 无源混合装置打印软骨及皮肤组织类似物的应用

Bioprinting is a powerful technique for the rapid and reproducible fabrication of constructs for tissue engineering applications. In this study, both ...

Purification and Analytics of a Monoclonal Antibody from Chinese Hamster Ovary Cells Using an Automated Microbioreactor System

Monoclonal antibodies (mAbs) are one of the most popular and well-characterized biological products manufactured today. Most commonly produced using Chinese hamster ovary (CHO) cells, culture and process conditions must be optimized to maximize antibody titers and achieve target quality profiles. Typically, this optimization uses automated microscale bioreactors (15 mL) to screen multiple process conditions in parallel. Optimization criteria include culture performance and the critical quality attributes (CQAs) of the monoclonal antibody (mAb) product, which may impact its efficacy and safety. Culture performance metrics include cell growth and nutrient consumption, while the CQAs include the mAb's N-glycosylation and aggregation profiles, charge variants, and molecular weight. This detailed protocol describes how to purify and subsequently analyze HCCF samples produced by an automated microbioreactor system to gain valuable performance metrics and outputs. First, an automated protein A fast protein liquid chromatography (FPLC) method is used to purify the mAb from harvested cell culture samples. Once concentrated, the glycan profiles are analyzed by mass spectrometry using a specific platform (refer to the Table of Materials). Antibody molecular weights and aggregation profiles are determined using size exclusion chromatography-multiple angle light scattering (SEC-MALS), while charge variants are analyzed using microchip capillary zone electrophoresis (mCZE). In addition to the culture performance metrics captured during the bioreactor process (i.e., culture viability, cell counts, and common metabolites including glutamine, glucose, lactate, and ammonia), spent media is analyzed to identify limiting nutrients to improve the feeding strategies and overall process design. Therefore, a detailed protocol for the absolute quantification of amino acids by liquid chromatography-mass spectrometry (LC-MS) of spent media is also described. The methods used in this protocol take advantage of high-throughput platforms that are compatible for large numbers of small-volume samples.

A detailed protocol for the purification and subsequent analysis of a monoclonal antibody from harvested cell culture fluid (HCCF) of automated microbioreactors has been described. Use of analytics to determine critical quality attributes (CQAs) and maximizing limited sample volume to extract vital information is also presented.

使用自动微生物反应器系统从中国仓鼠卵巢细胞中纯化和分析单克隆抗体

Monoclonal antibodies (mAbs) are one of the most popular and well-characterized biological products manufactured today. Most commonly produced using ...

Four-Dimensional CT Analysis Using Sequential 3D-3D Registration

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data remains difficult because segmentation in all volumetric frames is time-consuming. We aimed to analyze joint kinematics using a sequential 3D-3D registration technique to provide the kinematics of the moving bone with respect to the fixed bone semiautomatically using 4DCT DICOM data and existing software. Surface data of the source bones are reconstructed from 3DCT. The trimmed surface data are respectively matched with surface data from the first frame in 4DCT. These trimmed surfaces are sequentially matched until the last frame. These processes provide positional information for target bones in all frames of the 4DCT. Once the coordinate systems of the target bones are decided, translation and rotation angles between any two bones can be calculated. This 4DCT analysis offers advantages in kinematic analyses of complex structures such as carpal or tarsal bones. However, fast or large-scale motions cannot be traced because of motion artifacts.

We analyzed joint kinematics from four-dimensional computed tomography data. The sequential 3D-3D registration method semiautomatically provides the kinematics of the moving bone with respect to the subject bone from four-dimensional computed tomography data.

使用顺序 3D-3D 注册进行四维 CT 分析

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data ...

Optical Imaging of Isolated Murine Ventricular Myocytes

The ability to isolate adult cardiac myocytes has permitted researchers to study a variety of cardiac pathologies at the single cell level. While advances in calcium sensitive dyes have permitted the robust optical recording of single cell calcium dynamics, recording of robust transmembrane optical voltage signals has remained difficult. Arguably, this is because of the low single to noise ratio, phototoxicity, and photobleaching of traditional potentiometric dyes. Therefore, single cell voltage measurements have long been confined to the patch clamp technique which while the gold standard, is technically demanding and low throughput. However, with the development of novel potentiometric dyes, large, fast optical responses to changes in voltage can be obtained with little to no phototoxicity and photobleaching. This protocol describes in detail how to isolate adult murine myocytes which can be used for cellular shortening, calcium, and optical voltage measurements. Specifically, the protocol describes how to use a ratiometric calcium dye, a single-excitation calcium dye, and a single excitation voltage dye. This approach can be used to assess the cardiotoxicity and arrhythmogenicity of various chemical agents. While phototoxicity is still an issue at the single cell level, methodology is discussed on how to reduce it.

We present the methodology for the isolation of murine myocytes and how to obtain voltage or calcium traces simultaneously with sarcomere shortening traces using fluorescence photometry with simultaneous digital cell geometry measurements.

分离的月毛心室肌细胞的光学成像

The ability to isolate adult cardiac myocytes has permitted researchers to study a variety of cardiac pathologies at the single cell level. While advances ...

Primary Clarification of CHO Harvested Cell Culture Fluid using an Acoustic Separator

Primary clarification is an essential step in a biomanufacturing process for the initial removal of cells from therapeutic products within the harvested cell culture fluid. While traditional methods like centrifugation or filtration are widely implemented for cell removal, the equipment for these processes have large footprints and operation can involve contamination risks and filter fouling. Additionally, traditional methods may not be ideal for continuous bioprocessing schemes for primary clarification. Thus, an alternate application using acoustic (sound) waves was investigated to continuously separate cells from the cell culture fluid. Presented in this study is a detailed protocol for using a bench-scale acoustic wave separator (AWS) for the primary separation of culture fluid containing a monoclonal IgG1 antibody from a CHO cell bioreactor harvest. Representative data are presented from the AWS and demonstrate how to achieve effective cell clarification and product recovery. Finally, potential applications for AWS in continuous bioprocessing are discussed. Overall, this study provides a practical and general protocol for the implementation of AWS in primary clarification for CHO cell cultures and further describes its application potential in continuous bioprocessing.

Presented here is a protocol for the primary clarification of CHO cell culture using an acoustic separator. This protocol can be used for the primary clarification of shake flask cultures or bioreactor harvests and has the potential application for continuous clarification of the cell bleed material during perfusion bioreactor operations.

使用声学分离器对CHO收获的细胞培养液进行初步澄清

Primary clarification is an essential step in a biomanufacturing process for the initial removal of cells from therapeutic products within the harvested ...

Quantification of Mouse Heart Left Ventricular Function, Myocardial Strain, and Hemodynamic Forces by Cardiovascular Magnetic Resonance Imaging

Mouse models have contributed significantly to understanding genetic and physiological factors involved in healthy cardiac function, how perturbations result in pathology, and how myocardial diseases may be treated. Cardiovascular magnetic resonance imaging (CMR) has become an indispensable tool for a comprehensive in vivo assessment of cardiac anatomy and function. This protocol shows detailed measurements of mouse heart left ventricular function, myocardial strain, and hemodynamic forces using 7-Tesla CMR. First, animal preparation and positioning in the scanner are demonstrated. Survey scans are performed for planning imaging slices in various short- and long-axis views. A series of prospective ECG-triggered short-axis (SA) movies (or CINE images) are acquired covering the heart from apex to base, capturing end-systolic and end-diastolic phases. Subsequently, single-slice, retrospectively gated CINE images are acquired in a midventricular SA view, and in 2-, 3-, and 4-chamber views, to be reconstructed into high-temporal resolution CINE images using custom-built and open-source software. CINE images are subsequently analyzed using dedicated CMR image analysis software.
Delineating endomyocardial and epicardial borders in SA end-systolic and end-diastolic CINE images allows for the calculation of end-systolic and end-diastolic volumes, ejection fraction, and cardiac output. The midventricular SA CINE images are delineated for all cardiac time frames to extract a detailed volume-time curve. Its time derivative allows for the calculation of the diastolic function as the ratio of the early filling and atrial contraction waves. Finally, left ventricular endocardial walls in the 2-, 3-, and 4-chamber views are delineated using feature-tracking, from which longitudinal myocardial strain parameters and left ventricular hemodynamic forces are calculated. In conclusion, this protocol provides detailed in vivo quantification of the mouse cardiac parameters, which can be used to study temporal alterations in cardiac function in various mouse models of heart disease.

This study describes a comprehensive cardiovascular magnetic resonance imaging (CMR) protocol to quantify the left ventricular functional parameters of the mouse heart. The protocol describes the acquisition, post-processing, and analysis of the CMR images as well as assessment of different cardiac functional parameters.

通过心血管磁共振成像定量小鼠心脏左心室功能、心肌劳损和血流动力学力

Mouse models have contributed significantly to understanding genetic and physiological factors involved in healthy cardiac function, how perturbations ...

A Large Animal Model for Pulmonary Hypertension and Right Ventricular Failure: Left Pulmonary Artery Ligation and Progressive Main Pulmonary Artery Banding in Sheep

Decompensated right ventricular failure (RVF) in pulmonary hypertension (PH) is fatal, with limited medical treatment options. Developing and testing novel therapeutics for PH requires a clinically relevant large animal model of increased pulmonary vascular resistance and RVF. This manuscript discusses the latest development of the previously published ovine PH-RVF model that utilizes left pulmonary artery (PA) ligation and main PA occlusion. This model of PH-RVF is a versatile platform to control not only the disease severity but also the RV&#39;s phenotypic response.
Adult sheep (60-80 kg) underwent left PA (LPA) ligation, placement of main PA cuff, and insertion of RV pressure monitor. PA cuff and RV pressure monitor were connected to subcutaneous ports. Subjects underwent progressive PA banding twice per week for 9 weeks with sequential measures of RV pressure, PA cuff pressures, and mixed venous blood gas (SvO2). At the initiation and endpoint of this model, ventricular function and dimensions were assessed using echocardiography. In a representative group of 12 animal subjects, RV mean and systolic pressure increased from 28 &#177; 5 and 57 &#177; 7 mmHg at week 1, respectively, to 44 &#177; 7 and 93 &#177; 18 mmHg (mean &#177; standard deviation) by week 9. Echocardiography demonstrated characteristic findings of PH-RVF, notably RV dilation, increased wall thickness, and septal bowing. The longitudinal trend of SvO2 and PA cuff pressure demonstrates that the rate of PA banding can be titrated to elicit varying RV phenotypes. A faster PA banding strategy led to a precipitous decline in SvO2 &#60; 65%, indicating RV decompensation, whereas a slower, more paced strategy led to the maintenance of physiologic SvO2 at 70%-80%. One animal that experienced the accelerated strategy developed several liters of pleural effusion and ascites by week 9. This chronic PH-RVF model provides a valuable tool for studying molecular mechanisms, developing diagnostic biomarkers, and enabling therapeutic innovation to manage RV adaptation and maladaptation from PH.

This manuscript describes the surgical technique and experimental approach to develop severe right ventricular pressure overload to model their adaptive and maladaptive phenotypes.

肺动脉高压与右心室衰竭的大型动物模型:绵羊左肺动脉结扎与进行性主肺动脉束带

Decompensated right ventricular failure (RVF) in pulmonary hypertension (PH) is fatal, with limited medical treatment options. Developing and testing ...

安装猪主动脉瓣流体动力学特性的评价

An Ex Vivo Porcine Model for Hydrodynamic Testing of Experimental Aortic Valve Procedures and Novel Medical Devices

The options for testing new cardiac procedures and investigative medical devices prior to use in an animal model are limited. In this study, we present a method for mounting a porcine aortic valve in a pulse duplicator to evaluate its hydrodynamic properties. These properties can then be evaluated before and after the procedure under investigation is performed and/or the investigative medical device is applied. Securing the inflow segment presents some difficulty owing to the lack of circumferential myocardium in the left ventricular outflow tract. This method addresses that issue by securing the inflow segment using the anterior leaflet of the mitral valve and then suturing the left ventricular free wall around the inflow fixture. The outflow segment is secured simply by inserting the fixture into an incision in the superior aspect of the aortic arch. We found that specimens had significantly different hydrodynamic properties before and after tissue fixation. This finding induced us to use fresh specimens in our testing and should be considered when using this method. In our work, we used this method to test novel intracardiac patch materials for use in the valvular position by performing an aortic valve neocuspidization procedure (Ozaki procedure) on the mounted porcine aortic valves. These valves were tested before and after the procedure to assess the change in hydrodynamic properties in comparison to the native valve. Herein, we report a platform for hydrodynamic testing of experimental aortic valve procedures that enables comparison with the native valve and between different devices and techniques used for the procedure under investigation.

作者聚焦:在开始大型动物研究之前推进心脏手术测试 

We present a method for mounting a porcine aortic valve on a pulse duplicator to test its hydrodynamic properties. This method can be used to determine the change in hydrodynamics after the application of an experimental procedure or novel medical device prior to use in a large animal model.

用于实验性主动脉瓣手术和新型医疗设备流体动力学测试的 离体 猪模型

The options for testing new cardiac procedures and investigative medical devices prior to use in an animal model are limited. In this study, we present a ...