这项工作得到了国立卫生研究院的支持 [1TL1TR001997-01, 2016-2017]。

本议定书遵循肯塔基大学机构审查委员会和人类专题研究议定书规定的指导方针。
1. 打开图像查看器
<ol><li>打开在进行研究的机构中使用的图像查看器。双击桌面图标以打开查看器。</li>
	<li>使用机构用户名和密码登录。</li>
</ol>2. 确定适当的病人
<ol><li>单击工具栏中的 "学习列表" 图标。</li>
	<li>在 "搜索条件" 下拉列表中, 选择标记为 "患者 ID 等于" 的选项。</li>
	<li>输入病人的医院标识号。</li>
	<li>在 "模式" 下, 单击所有模式以取消选择所有成像模式。<ol>
<li>点击CT选择此模式。</li>
	</ol>
</li>
	<li>在正文区域下, 将默认值保留到所有正文区域。</li>
	<li>然后, 在 "查找" 中单击鼠标。</li>
</ol>3. 确定最佳研究
<ol><li>单击 "执行时间" 按学习日期组织列表。</li>
	<li>然后, 点击兴趣研究。 注: 最佳的研究是 CT 胸部 (无论是有或不对比)。当有多种研究可用时, 使用 ct 扫描, 可以可视化整个冠状动脉树最接近指数时间点 (回顾性数据分析) 或最近的 CT 扫描 (为临床目的)。</li>
</ol>4. 识别最佳图像系列
<ol><li>单击屏幕右上角的 "平铺" 图标上的鼠标, 并突出显示单个平铺。单击此处, 使屏幕成为单个窗格。</li>
	<li>悬停在图像顶端行上的系列图标上, 以标识具有3毫米切片厚度 (或最接近3毫米) 的系列。</li>
	<li>单击并按住鼠标左键, 将此图标拖动到查看屏幕的中心, 然后松开鼠标左键。</li>
	<li>使用中心鼠标滚动条 (或者, 或者, 按住鼠标左键并向右拖动) 可以滚动图像并确保对冠状动脉树进行充分的可视化。</li>
</ol>5. 优化图像以突出钙化
<ol><li>滚动图像, 直到一个图像, 其中一个冠状动脉的可视化。</li>
	<li>右键单击并选择"窗口/级别" 选项。</li>
	<li>点击交互式 W/L。</li>
	<li>作为起始点, 在 W (窗口) 字段中键入500 。</li>
	<li>作为起始点, 请在 L (级别) 字段中键入150 。 注意: 调整窗口和水平设置的目的是优化心外膜脂肪 (通常是心脏剪影中最低的 Hounsfield 单位 (胡))、心脏室、钙化或金属结构 (通常是最高的胡) 之间的对比。CT 扫描的对比, 使用较低的 kV 往往需要最高水平 (通常 > 250 胡) 和最大的窗口 (经常 > 1000 胡)。对于 "低剂量" CT 扫描 (低 mAs) 没有对比, 将使用一个稍低的水平 (0-150 胡)。</li>
	<li>通过按住水平滑动条上的鼠标左键并将其向右和向左移动来手动调整窗口 (将滚动条向右移动会增加窗口)。</li>
	<li>通过按住垂直滑动条上的鼠标左键并上下移动 (向上移动滚动条以提高级别), 手动调整级别。 注: 目标是调整窗口和水平以达到以下目的: 脂肪, 包括心外膜脂肪, 应暗灰色到黑色;心肌应稍浅灰色;钙和金属应该是白色的。</li>
	<li>单击 "关闭" 关闭窗口和级别框, 然后开始查看图像。</li>
</ol>6. 识别冠状动脉钙化
<ol><li>使用鼠标的中心滚动球滚动和向下的一系列图像, 一次看一个冠状动脉。</li>
	<li>标记 (在单独的文档, 电子表格等) 是否有冠状动脉钙化存在或缺席的四个主要的心外膜冠状动脉 (图 1)。 注: 如果在血管本身或其分支中可见, CAC 在左前降动脉 (童子)、左旋动脉 (LCx) 或右冠状动脉 (RCA) 中被视为存在。</li>
</ol>7. 鉴别细微钙化区的技术
<ol><li>找出可疑的冠状动脉钙化区。</li>
	<li>在屏幕上右键单击以弹出菜单。</li>
	<li>单击批注。</li>
	<li>然后, 单击椭圆 ROI。</li>
	<li>单击并按住在钙化区的鼠标左键, 并将其向下移动并向右创建一个圆形或椭圆形, 足以覆盖钙化区。 注意: 确保感兴趣的区域 (ROI) 足够大, 足以覆盖潜在钙化和一些心外膜脂肪的整个区域, 但体积小到不能包括其他分室 (尤其是那些有对比度的)。该软件将提供最低, 最大, 和平均面积的胡在该地区没有兴趣区域。<ol>
<li>点击并按住鼠标左键在感兴趣的区域中心移动, 如果有必要。</li>
		<li>单击并按住鼠标左键, 在感兴趣区域的拐角处调整大小 (如果需要)。</li>
	</ol>
</li>
	<li>重复步骤 7.5-7.5.2 创建另一个感兴趣的区域在胸骨上, 在屏幕顶部明亮的骨结构。</li>
	<li>重复步骤 7.5-7.5.2, 以创建另一个感兴趣的区域的上升主动脉。</li>
	<li>将潜在钙化区的最大胡与上升主动脉和胸骨中最大的胡进行比较。 注: 如果距离升主动脉的最大胡差超过2标准, 则将一个区域归类为冠状动脉钙化。冠脉钙化应与胸骨最大的胡, 比升主动脉中的最大胡更接近 (图 2)。</li>
</ol>8. 鉴别冠状动脉钙化与其他钙化源的区别
<ol><li>要打开后处理软件, 请左键单击 Windows 的开始按钮, 然后单击后处理软件。现在, 使用机构用户名和密码登录。</li>
	<li>要打开研究和系列, 请在屏幕右上方的搜索选项中的相应字段中键入患者 ID或患者姓名。然后, 取消选择日期 1。<ol>
<li>现在, 点击更新学习列表, 然后在屏幕左上方的结果列表中对所需的研究进行一次单击。</li>
		<li>在下面的系列列表中, 单击标签中具有 3 mm 切片厚度的系列。</li>
	</ol>
</li>
	<li>单击并按住鼠标滚动条上的一个图像, 并移动鼠标放大, 使动脉可以很好地可视化。</li>
	<li>单击并按住鼠标左键在每个十字线的中心, 移动他们在有关钙化区的中心。</li>
	<li>单击并按住十字线上标记上的鼠标左键, 可以旋转其他两个图像。继续观看其他两个图像, 直到相邻的兴趣结构被良好的可视化。 注: 3 最常被混淆为冠状动脉钙化的地区包括主动脉壁钙化, 如 RCA 或左主干 (LM) 钙化, 二尖瓣环状钙化 (误认为 LCx 钙化) 或三尖瓣环形钙化 (误认为 RCA 钙化) 和心包钙化。冠状动脉周围有心外膜脂肪, 而这些相邻的结构不是。</li>
</ol>

<ol><li>Douglas, P., et al. <a target="_blank" href="https://www.ncbi.nlm.nih.gov/pubmed/25773919">Outcomes of anatomical versus function testing for coronary artery disease.</a> The New England Journal of Medicine. 372 (14), 1291-1300 (2015).</li>
<li>Detrano, R., et al. <a target="_blank" href="https://www.nejm.org/doi/full/10.1056/NEJMoa072100">Coronary calcium as a predictor of coronary events in four racial or ethnic groups.</a> The New England Journal of Medicine. 358, 1336-1345 (2008).</li>
<li>Sarma, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Radiation+and+chest+CT+scan+examinations%3A+what+do+we+know%5BTitle%5D)+AND+%22CHEST%22%5BJournal%5D)">Radiation and chest CT scan examinations: what do we know.</a> CHEST. 142, 750-760 (2012).</li>
<li>Winkler, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Identification+of+coronary+artery+calcification+and+diagnosis+of+coronary+artery+disease+by+abdominal+CT%3A+A+resident+education+continuous+quality+improvement+project%5BTitle%5D)+AND+%22Academic+Radiology%22%5BJournal%5D)">Identification of coronary artery calcification and diagnosis of coronary artery disease by abdominal CT: A resident education continuous quality improvement project.</a> Academic Radiology. 22 (6), 704-707 (2015).</li>
<li>Budoff, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Coronary+artery+and+thoracic+calcium+on+noncontrast+thoracic+CT+scans%3A+comparison+of+ungated+and+gated+examinations+in+patients+from+the+COPD+Gene+cohort%5BTitle%5D)+AND+%22Journal+of+Cardiovascular+Computed+Tomography%22%5BJournal%5D)">Coronary artery and thoracic calcium on noncontrast thoracic CT scans: comparison of ungated and gated examinations in patients from the COPD Gene cohort.</a> Journal of Cardiovascular Computed Tomography. 5, 113-118 (2011).</li>
<li>Einstein, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Agreement+of+visual+estimation+of+coronary+artery+calcium+from+low-dose+CT+attenuation+correction+scans+in+hybrid+PET%2F+CT+and+SPECT%2FCT+with+standard+Agatston+score%5BTitle%5D)+AND+%22JACC%3A+Journal+of+the+American+College+of+Cardiology%22%5BJournal%5D)">Agreement of visual estimation of coronary artery calcium from low-dose CT attenuation correction scans in hybrid PET/ CT and SPECT/CT with standard Agatston score.</a> JACC: Journal of the American College of Cardiology. 56, 1914-1921 (2010).</li>
<li>Kim, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Coronary+calcium+screening+using+low-dose+lung+cancer+screening%3A+effectiveness+of+MDCT+with+retrospective+reconstruction%5BTitle%5D)+AND+%22AJR.+American+Journal+of+Roentgenology%22%5BJournal%5D)">Coronary calcium screening using low-dose lung cancer screening: effectiveness of MDCT with retrospective reconstruction.</a> AJR. American Journal of Roentgenology. 190, 917-922 (2008).</li>
<li>Kirsch, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Detection+of+coronary+calcium+during+standard+chest+computed+tomography+correlates+with+multi-detector+computed+tomography+coronary+artery+calcium+score%5BTitle%5D)+AND+%22The+International+Journal+of+Cardiovascular+Imaging%22%5BJournal%5D)">Detection of coronary calcium during standard chest computed tomography correlates with multi-detector computed tomography coronary artery calcium score.</a> The International Journal of Cardiovascular Imaging. 28, 1249-1256 (2012).</li>
<li>Wu, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Coronary+arterial+calcification+on+low-dose+ungated+MDCT+for+lung+cancer+screening%3A+concordance+study+with+dedicated+cardiac+CT%5BTitle%5D)+AND+%22AJR.+American+Journal+of+Roentgenology%22%5BJournal%5D)">Coronary arterial calcification on low-dose ungated MDCT for lung cancer screening: concordance study with dedicated cardiac CT.</a> AJR. American Journal of Roentgenology. 190, 923-928 (2008).</li>
<li>Xie, X., et al. <a target="_blank" href="https://www.ncbi.nlm.nih.gov/pubmed/23756678">Validation and prognosis of coronary artery calcium scoring in non-triggered thoracic computed tomography: systematic review and meta-analysis.</a> Circulation: Cardiovascular Imaging. 6, 514-521 (2013).</li>
<li>Itani, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Coronary+artery+calcification+detected+by+a+mobile+helical+computed+tomography+unit+and+future+cardiovascular+death%3A+4-year+follow-up+of+6120+asymptomatic+Japanese%5BTitle%5D)+AND+%22Heart+and+Vessels%22%5BJournal%5D)">Coronary artery calcification detected by a mobile helical computed tomography unit and future cardiovascular death: 4-year follow-up of 6120 asymptomatic Japanese.</a> Heart and Vessels. 19, 161-163 (2004).</li>
<li>Hughes-Austin, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Relationship+of+coronary+calcium+on+standard+chest+CT+scans+with+mortality%5BTitle%5D)+AND+%22JACC%3A+Cardiovascular+Imaging%22%5BJournal%5D)">Relationship of coronary calcium on standard chest CT scans with mortality.</a> JACC: Cardiovascular Imaging. 9, 152-159 (2016).</li>
<li>Shemesh, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Ordinal+scoring+of+coronary+artery+calcifications+on+low-dose+CT+scans+of+the+chest+is+predictive+of+death+from+cardiovascular+disease%5BTitle%5D)+AND+%22Radiology%22%5BJournal%5D)">Ordinal scoring of coronary artery calcifications on low-dose CT scans of the chest is predictive of death from cardiovascular disease.</a> Radiology. 257, 541-548 (2010).</li>
<li>Sarwar, A., et al. <a target="_blank" href="https://www.ncbi.nlm.nih.gov/pubmed/19520336">Diagnostic and prognostic value of absence of coronary artery calcification.</a> JACC: Cardiovascular Imaging. 2, 675-688 (2009).</li>
<li>Gupta, V. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Coronary+artery+calcification+predicts+cardiovascular+complications+after+sepsis%5BTitle%5D)+AND+%22Journal+of+Critical+Care%22%5BJournal%5D)">Coronary artery calcification predicts cardiovascular complications after sepsis.</a> Journal of Critical Care. 44, 261-266 (2017).</li>
<li>Takx, R. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Automated+coronary+artery+calcification+scoring+in+non-gated+chest+CT%3A+agreement+and+reliability%5BTitle%5D)+AND+%22PLoS+One%22%5BJournal%5D)">Automated coronary artery calcification scoring in non-gated chest CT: agreement and reliability.</a> PLoS One. 9 (3), 91239(2014).</li>
<li>Hecht, H. S., et al. <a target="_blank" href="https://www.ncbi.nlm.nih.gov/pubmed/28832417">2016 SCCT/STR guidelines for coronary artery calcium scoring of noncontrast noncardiac chest CT scans: A report of the Society of Cardiovascular Computed Tomography and Society of Thoracic Radiology.</a> Journal of Cardiovascular Computed Tomography. 11 (1), 74-84 (2016).</li>
<li>Erbel, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Progression+of+coronary+artery+calcification+seems+to+be+inevitable%2C+but+predictable+-+results+of+the+Heinz+Nixdorf+recall+%28HNR%29+study%5BTitle%5D)+AND+%22European+Heart+Journal%22%5BJournal%5D)">Progression of coronary artery calcification seems to be inevitable, but predictable - results of the Heinz Nixdorf recall (HNR) study.</a> European Heart Journal. 35 (42), 2960-2971 (2014).</li>
<li>Blaha, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Improving+the+CAC+score+by+addition+of+regional+measures+of+calcium+distribution%5BTitle%5D)+AND+%22JACC%3A+Cardiovascular+Imaging%22%5BJournal%5D)">Improving the CAC score by addition of regional measures of calcium distribution.</a> JACC: Cardiovascular Imaging. 9, 1407-1416 (2016).</li>
</ol>

作者没有什么可透露的。

CAC 的识别是一个非常强大的预后工具, 越来越多的文献支持它在许多不同的临床情况下使用。大多数文献集中在门控心脏 ct 扫描, 以确定 cac, 但有有力的证据表明, cac 的相关性, 非门控 CT 扫描, 以及预后的能力, 这一发现。考虑到美国的 ct 扫描利用情况, 以及对辐射暴露的越来越多的关注, 从已经获得的 ct 扫描中提取 CAC 信息的能力似乎提供了额外的价值 (即, 提高质量最低限度到无需额外费...

冠状动脉疾病是主要的不良心血管事件的预测因素。CT 扫描为冠状动脉疾病提供了客观证据, 可以识别以前未确诊的患者。此外, CAC 具有重要的预后价值。具体来说, 在门控心脏 CT 扫描中没有 CAC, 确定了在许多不同的病人中, 包括患有心脏病症状的病人, 以及无症状的患者, 在随后的心血管事件中有低风险的患者人数。患者1,2。7000万的 ct 扫描在美国进行, 使用率上升, 其中大约 11-1200万的扫描是胸部 CT 扫描, 在许多患者中发现 CAC 的可能性仍然很高3。然而, 大多数的 CT 扫描的胸部进行的分析, 不是专门的心脏 CT 扫描。专用的心脏 CT 扫描有标准化的切片厚度, 采集协议, 心电图 (ECG) 门, 以尽量减少心脏运动, 和重建协议。还有一个标准化定量的门控心脏 CT 扫描使用 Agatston 评分。Agatston 评分系统已得到良好的验证, 并与临床结果1,2。
CAC 可以很容易地识别这些非门控 CT 扫描, 但往往被忽视4。在非门控 ct 扫描和从门控 ct 扫描获得的 Agatston 评分之间有良好的相关性 (> 90% 在联合分析中)5、6、7、8、9 ,10。在非门控 CT 扫描中, CAC 的存在与更糟糕的临床结局有关;然而, 这种缺席与发病率和死亡率的好处有关,10,11,12,13,14,15。
虽然不同的研究观察了 cac 对非门控研究的预后, 但已发表的关于如何最好地确定 cac 的公布数据有限。有人试图确定一种自动的方法来识别在低剂量 CT 胸部扫描为肺癌筛查目的的 CAC;然而, 对其他研究协议的翻译是非常有限的16。采用差分 CT 扫描仪、协议和对比 (定时和数量) 限制了这种自动方法的应用。心血管计算机断层扫描学会和胸腔放射学会的尝试, 以促进对所有 CT 胸腔的 CAC 标准报告已达到17混合结果。虽然在本指南文件中提供了一个总体框架, 但确定冠状动脉钙化的具体细节, 特别是对于那些不经常可视化冠状动脉解剖的提供者来说, 是有限的。此外, 针对腹部 CT 扫描、对比研究和裁决具有挑战性的病例的策略没有得到解决。许多研究公布了它们自己所使用的协议的内部和观察者的重复性;然而, 在不同的研究中没有使用标准方法。
在这些非门控 CT 扫描中持续可靠地识别 cac 的能力, 允许对 cac 在许多不同情况下预测心血管结局的回顾和前瞻性观察研究。然而, 需要有一个标准的方法来识别非门控 CT 扫描的 CAC, 以确保结果的重现性, 以及在训练中的一致性, 以帮助临床实践。

<table><tbody><tr><td>Microsoft Windows Server 2012 R2 Standard</td><td>PowerEdge R730</td><td>8F8KFB2</td><td>Server specifications for post-processing software: Intel(R) Xeon(R) CPU E5-2609 v3 @ 1.90GHz Intel(R) Xeon&amp;reg;CPU E5-2609 v3 @ 1.90GHz</td></tr><tr><td>Intuition</td><td>Terarecon</td><td>4.4.12.xxx</td><td>Post-processing software</td></tr><tr><td>McKesson Radiology Viewing Station</td><td>McKesson</td><td>Station Lite Version 1.0.0.182</td><td>IP version 8.0.31.0</td></tr><tr><td>Computer Desktop and Monitor: Optiplex 9030 AIO</td><td>Dell</td><td>Optiplex 9030 AIO</td><td>Processor: Intel&amp;nbsp; Core i5-4590S CPU @ 3.00 GHz, 3001Mhz, 4 Cores, 4 Logical Processors</td></tr></tbody></table>

identifying coronary artery calcification on non-gated computed tomography scans

冠状动脉钙化 (CAC) 是一种客观的冠状动脉疾病测量方法, 可以在非门控计算机断层扫描 (CT) 检查中发现, 与门控心脏 CT 扫描有很高的相关性。这个标准化的协议采取了一个步骤明智的方法, 不仅优化图像的钙化鉴别, 而且还区分 CAC 与其他常见的原因钙化的心脏剪影。在非门控 CT 扫描中对 CAC 的识别有助于确定一个非常强大的预后因素, 可以影响治疗干预或下游诊断测试, 而不需要进行门控心脏扫描。这些非门控的 CT 扫描通常是作为病人例行护理的一部分获得的, 而这一数据在没有另一剂量电离辐射的情况下是容易得到的。该协议允许准确准确地提取这些数据, 用于临床研究研究的回顾性数据分析, 也可用于患者的临床评估和管理。

如上文所述, 冠状动脉解剖在大多数患者中是相对可预测的。在大多数患者中, 评估这些血管的典型地点也很容易被发现 (图 1)。使用所述方法, 在84% 的患者中可以可靠地确定 CAC 的存在或缺失 (267 的317例可能的患者)15。绝大多数被排除的患者没有 ct 扫描在指定的时间框架内, 或有腹部 ct 扫描, 其中完全冠状动脉血管没有看到, 并没有...

Watch this Scientific Journal Video about Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans at JoVE.com

Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans

在这里, 我们提出了一个协议, 以可靠和系统地识别冠状动脉钙化 (CAC) 的非门控计算机断层扫描 (CT) 的胸部或腹部。CAC 为研究和临床目的提供了一种客观的冠状动脉疾病测量方法。

非门控断层扫描的冠状动脉钙化识别

Coronary artery calcification (CAC) provides an objective measure of coronary artery disease and can readily be identified on non-gated computed ...

identifying-coronary-artery-calcification-on-non-gated-computed

Research

JoVE Journal

Medicine

15.1K 次观看.  University of Kentucky. 在这里, 我们提出了一个协议, 以可靠和系统地识别冠状动脉钙化 (CAC) 的非门控计算机断层扫描 (CT) 的胸部或腹部。CAC 为研究和临床目的提供了一种客观的冠状动脉疾病测量方法。

视频: Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans

Use of a Hanging Weight System for Coronary Artery Occlusion in Mice

Murine studies of acute injury are an area of intense investigation, as knockout mice for different genes are becoming increasingly available 1-38. Cardioprotection by ischemic preconditioning (IP) remains an area of intense investigation. To further elucidate its molecular basis, the use of knockout mouse studies is particularly important 7, 14, 30, 39. Despite the fact that previous studies have already successfully performed cardiac ischemia and reperfusion in mice, this model is technically very challenging. Particularly, visual identification of the coronary artery, placement of the suture around the vessel and coronary occlusion by tying off the vessel with a supported knot is technically difficult. In addition, re-opening the knot for intermittent reperfusion of the coronary artery during IP without causing surgical trauma adds additional challenge. Moreover, if the knot is not tied down strong enough, inadvertent reperfusion due to imperfect occlusion of the coronary may affect the results. In fact, this can easily occur due to the movement of the beating heart.
Based on potential problems associated with using a knotted coronary occlusion system, we adopted a previously published model of chronic cardiomyopathy based on a hanging weight system for intermittent coronary artery occlusion during IP 39. In fact, coronary artery occlusion can thus be achieved without having to occlude the coronary by a knot. Moreover, reperfusion of the vessel can be easily achieved by supporting the hanging weights which are in a remote localization from cardiac tissues.
We tested this system systematically, including variation of ischemia and reperfusion times, preconditioning regiments, body temperature and genetic backgrounds39. In addition to infarct staining, we tested cardiac troponin I (cTnI)
as a marker of myocardial infarction in this model. In fact, plasma levels of cTnI correlated with infarct sizes (R2=0.8). Finally, we could show in several studies that this technique yields highly reproducible infarct sizes during murine IP and myocardial infarction6, 8, 30, 40, 41. Therefore, this technique may be helpful for researchers who pursue molecular mechanisms involved in cardioprotection by IP using a genetic approach in mice with targeted gene deletion. Further studies on cardiac IP using transgenic mice may consider this technique.

A murine model for myocardial ischemia and ischemic preconditioning is an important tool study cardioprotective mechanisms in vivo. Here, we report an easy applicable in situ model for cardiac IP using a hanging-weight system for coronary artery occlusion.

悬重系统的使用在小鼠冠状动脉闭塞

Murine studies of acute injury are an area of intense investigation, as knockout mice for different genes are becoming increasingly available 1-38. ...

科研

医学

Coronary Artery Ligation and Intramyocardial Injection in a Murine Model of Infarction

Mouse models are a valuable tool for studying acute injury and chronic remodeling of the myocardium in vivo. With the advent of genetic modifications to the whole organism or the myocardium and an array of biological and/or synthetic materials, there is great potential for any combination of these to assuage the extent of acute ischemic injury and impede the onset of heart failure pursuant to myocardial remodeling. 
Here we present the methods and materials used to reliably perform this microsurgery and the modifications involved for temporary (with reperfusion) or permanent coronary artery occlusion studies as well as intramyocardial injections. The effects on the heart that can be seen during the procedure and at the termination of the experiment in addition to histological evaluation will verify efficacy. 
Briefly, surgical preparation involves anesthetizing the mice, removing the fur on the chest, and then disinfecting the surgical area. Intratracheal intubation is achieved by transesophageal illumination using a fiber optic light. The tubing is then connected to a ventilator. An incision made on the chest exposes the pectoral muscles which will be cut to view the ribs. For ischemia/reperfusion studies, a 1 cm piece of PE tubing placed over the heart is used to tie the ligature to so that occlusion/reperfusion can be customized. For intramyocardial injections, a Hamilton syringe with sterile 30gauge beveled needle is used. When the myocardial manipulations are complete, the rib cage, the pectoral muscles, and the skin are closed sequentially. Line block analgesia is effected by 0.25% marcaine in sterile saline which is applied to muscle layer prior to closure of the skin. The mice are given a subcutaneous injection of saline and placed in a warming chamber until they are sternally recumbent. They are then returned to the vivarium and housed under standard conditions until the time of tissue collection. At the time of sacrifice, the mice are anesthetized, the heart is arrested in diastole with KCl or BDM, rinsed with saline, and immersed in fixative. Subsequently, routine procedures for processing, embedding, sectioning, and histological staining are performed. 
Nonsurgical intubation of a mouse and the microsurgical manipulations described make this a technically challenging model to learn and achieve reproducibility. These procedures, combined with the difficulty in performing consistent manipulations of the ligature for timed occlusion(s) and reperfusion or intramyocardial injections, can also affect the survival rate so optimization and consistency are critical.

Numerous genetic manipulations and/or intramyocardial injections of genes, proteins, cells, and/or biomaterials are superimposed upon the dimension of time in studies of acute ischemia/ reperfusion injury and chronic remodeling in mice. This video illustrates the microsurgical procedures for ischemia/reperfusion, permanent coronary artery ligation, and intramyocardial injection studies.

结扎冠状动脉内注射在小鼠模型梗死

Mouse models are a valuable tool for studying acute injury and chronic remodeling of the myocardium in vivo.  With the advent of genetic modifications to ...

Modified Technique for Coronary Artery Ligation in Mice

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI we need better knowledge about pathophysiology of myocardial ischemia. This knowledge may be valuable to define new therapeutic targets for innovative cardiovascular therapies4. Experimental MI model in mice is an increasingly popular small-animal model in preclinical research in which MI is induced by means of permanent or temporary ligation of left coronary artery (LCA)5. In this video, we describe the step-by-step method of how to induce experimental MI in mice.
The animal is first anesthetized with 2% isoflurane. The unconscious mouse is then intubated and connected to a ventilator for artificial ventilation. The left chest is shaved and 1.5 cm incision along mid-axillary line is made in the skin. The left pectoralis major muscle is bluntly dissociated until the ribs are exposed. The muscle layers are pulled aside and fixed with an eyelid-retractor. After these preparations, left thoracotomy is performed between the third and fourth ribs in order to visualize the anterior surface of the heart and left lung. The proximal segment of LCA artery is then ligated with a 7-0 ethilon suture which typically induces an infarct size ~40% of left ventricle. At the end, the chest is closed and the animals receive postoperative analgesia (Temgesic, 0.3 mg/50 ml, ip). The animals are kept in a warm cage until spontaneous recovery.

The surgical procedure used to induce experimental myocardial infarction in mice begins with left thoracotomy between the third and the fourth ribs in order to visualize the anterior surface of the heart and left lung. The left coronary artery is ligated, the chest is closed and the mouse is allowed to recover spontaneously.

改性技术在小鼠冠状动脉结扎

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI ...

Retrograde Perfusion and Filling of Mouse Coronary Vasculature as Preparation for Micro Computed Tomography Imaging

Visualization of the vasculature is becoming increasingly important for understanding many different disease states. While several techniques exist for imaging vasculature, few are able to visualize the vascular network as a whole while extending to a resolution that includes the smaller vessels1,2. Additionally, many vascular casting techniques destroy the surrounding tissue, preventing further analysis of the sample3-5. One method which circumvents these issues is micro-Computed Tomography (&mu;CT). &mu;CT imaging can scan at resolutions &lt;10 microns, is capable of producing 3D reconstructions of the vascular network, and leaves the tissue intact for subsequent analysis (e.g., histology and morphometry)6-11. However, imaging vessels by ex vivo &mu;CT methods requires that the vessels be filled with a radiopaque compound. As such, the accurate representation of vasculature produced by &mu;CT imaging is contingent upon reliable and complete filling of the vessels. In this protocol, we describe a technique for filling mouse coronary vessels in preparation for &mu;CT imaging.
Two predominate techniques exist for filling the coronary vasculature: in vivo via cannulation and retrograde perfusion of the aorta (or a branch off the aortic arch) 12-14, or ex vivo via a Langendorff perfusion system 15-17. Here we describe an in vivo aortic cannulation method which has been specifically designed to ensure filling of all vessels. We use a low viscosity radiopaque compound called Microfil which can perfuse through the smallest vessels to fill all the capillaries, as well as both the arterial and venous sides of the vascular network. Vessels are perfused with buffer using a pressurized perfusion system, and then filled with Microfil. To ensure that Microfil fills the small higher resistance vessels, we ligate the large branches emanating from the aorta, which diverts the Microfil into the coronaries. Once filling is complete, to prevent the elastic nature of cardiac tissue from squeezing Microfil out of some vessels, we ligate accessible major vascular exit points immediately after filling. Therefore, our technique is optimized for complete filling and maximum retention of the filling agent, enabling visualization of the complete coronary vascular network &#x2013; arteries, capillaries, and veins alike.

Visualization of the coronary vessels is critical to advancing our understanding of cardiovascular diseases. Here we describe a method for perfusing murine coronary vasculature with a radiopaque silicone rubber (Microfil), in preparation for micro-Computed Tomography (&mu;CT) imaging.

微型计算机断层扫描成像制备小鼠冠状动脉血管逆行灌注和灌装

Visualization of the vasculature is becoming increasingly important for understanding many different disease states. While several techniques exist for ...

Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT)

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC)1 and carotid intimal medial thickness (C-IMT)2 provide information about the burden of disease. However, despite multiple validation studies of CAC3-5, and C-IMT2,6, these modalities do not accurately assess plaque characteristics7,8, and the composition and inflammatory state of the plaque determine its stability and, therefore, the risk of clinical events9-13.
[18F]-2-fluoro-2-deoxy-D-glucose (FDG) imaging using positron-emission tomography (PET)/computed tomography (CT) has been extensively studied in oncologic metabolism14,15. Studies using animal models and immunohistochemistry in humans show that FDG-PET/CT is exquisitely sensitive for detecting macrophage activity16, an important source of cellular inflammation in vessel walls. More recently, we17,18 and others have shown that FDG-PET/CT enables highly precise, novel measurements of inflammatory activity of activity of atherosclerotic plaques in large and medium-sized arteries9,16,19,20. FDG-PET/CT studies have many advantages over other imaging modalities: 1) high contrast resolution; 2) quantification of plaque volume and metabolic activity allowing for multi-modal atherosclerotic plaque quantification; 3) dynamic, real-time, in vivo imaging; 4) minimal operator dependence. Finally, vascular inflammation detected by FDG-PET/CT has been shown to predict cardiovascular (CV) events independent of traditional risk factors21,22 and is also highly associated with overall burden of atherosclerosis23. Plaque activity by FDG-PET/CT is modulated by known beneficial CV interventions such as short term (12 week) statin therapy24 as well as longer term therapeutic lifestyle changes (16 months)25.
The current methodology for quantification of FDG uptake in atherosclerotic plaque involves measurement of the standardized uptake value (SUV) of an artery of interest and of the venous blood pool in order to calculate a target to background ratio (TBR), which is calculated by dividing the arterial SUV by the venous blood pool SUV. This method has shown to represent a stable, reproducible phenotype over time, has a high sensitivity for detection of vascular inflammation, and also has high inter-and intra-reader reliability26. Here we present our methodology for patient preparation, image acquisition, and quantification of atherosclerotic plaque activity and vascular inflammation using SUV, TBR, and a global parameter called the metabolic volumetric product (MVP). These approaches may be applied to assess vascular inflammation in various study samples of interest in a consistent fashion as we have shown in several prior publications.9,20,27,28

Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography FDG-PET/CT

There is great need to identify atherosclerosis non-invasively, and here we demonstrate how FDG-PET/CT can be used to detect and quantify atherosclerotic plaque activity and vascular inflammation.

动脉粥样硬化斑块的活动和血管炎症的定量使用[18 F]，氟正电子发射断层扫描/电脑断层扫描（FDG-PET/CT）

Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC)1 and carotid intimal medial thickness (C-IMT)2 ...

A Semi-Automated and Reproducible Biological-Based Method to Quantify Calcium Deposition In Vitro

Vascular calcification involves a series of degenerative pathologies, including inflammation, changes to cellular phenotype, cell death, and the absence of calcification inhibitors, that concomitantly lead to a loss of vessel elasticity and function. Vascular calcification is an important contributor to morbidity and mortality in many pathologies, including chronic kidney disease, diabetes mellitus, and atherosclerosis. Current research models to study vascular calcification are limited and are only viable at the late stages of calcification development in vivo. In vitro tools for studying vascular calcification use end-point measurements, increasing the demands on biological material and risking the introduction of variability to research studies. We demonstrate the application of a novel fluorescently labeled probe that binds to in vitro calcification development on human vascular smooth muscle cells and determines the real-time development of in vitro calcification. In this protocol, we describe the application of our newly developed calcification assay, a novel tool in disease modeling that has potential translational applications. We envisage this assay to be relevant in a broader spectrum of mineral deposition research, including applications in bone, cartilage, or dental research.

A Semi-Automated and Reproducible Biological-Based Method to Quantify Calcium Deposition In Vitro

Cardiovascular disease is the leading cause of death worldwide. Vascular calcification contributes substantially to the burden of cardiovascular morbidity and mortality. This protocol describes a simple method to quantify vascular smooth muscle cell-mediated calcium precipitation in vitro by fluorescent imaging.

一种半自动且可重现的基于生物学的体外定量钙沉积的方法

Vascular calcification involves a series of degenerative pathologies, including inflammation, changes to cellular phenotype, cell death, and the absence ...

生物化学

使用 SWCS 工具改进冠状动脉钙化评估

Semi-Automatic Graphical Tool for Measuring Coronary Artery Spatially Weighted Calcium Score from Gated Cardiac Computed Tomography Images

The current standard for measuring coronary artery calcification to determine the extent of atherosclerosis is by calculating the Agatston score from computed tomography (CT). However, the Agatston score disregards pixel values less than 130 Hounsfield Units (HU) and calcium regions less than 1 mm2. Due to this thresholding, the score is not sensitive to small, weakly attenuating regions of calcium deposition and may not detect nascent micro-calcification. A recently proposed metric called the spatially weighted calcium score (SWCS) also utilizes CT but does not include a threshold for HU and does not require elevated signals in contiguous pixels. Thus, the SWCS is sensitive to weakly attenuating, smaller calcium deposits and may improve the measurement of coronary heart disease risk. Currently, the SWCS is underutilized owing to the added computational complexity. To promote translation of the SWCS into clinical research and reliable, repeatable computation of the score, the aim of this study was to develop a semi-automatic graphical tool that calculates both the SWCS and the Agatston score. The program requires gated cardiac CT scans with a calcium hydroxyapatite phantom in the field of view. The phantom allows for deriving a weighting function, from which each pixel&#39;s weight is adjusted, allowing for the mitigation of signal variations and variability between scans. With all three anatomical views visible simultaneously, the user traces the course of the four main coronary arteries by placing points or regions of interest. Features such as scroll-to-zoom, double-click to delete, and brightness/contrast adjustment, along with written guidance at every step, make the program user-friendly and easy to use. Once tracing the arteries is complete, the program generates reports, which include the scores and snapshots of any visible calcium. The SWCS may reveal the presence of subclinical disease, which may be used for early intervention and lifestyle changes.

作者聚焦:推进心血管成像 - 引入用于早期疾病检测的空间加权钙评分 

This video demonstrates the use of a novel graphical tool for measuring the spatially weighted calcium score (SWCS), an alternative to the Agatston score, for quantifying coronary artery calcification. The graphical tool computes SWCS based on image data from gated cardiac computed tomography and user-defined paths of the coronary arteries.

用于从门控心脏计算机断层扫描图像测量冠状动脉空间加权钙评分的半自动图形工具

The current standard for measuring coronary artery calcification to determine the extent of atherosclerosis is by calculating the Agatston score from ...

生物工程

<meta charset="utf8"></head><body>用于冠状动脉疾病评估的无创即时检测

Signal Acquisition, Score Interpretation, and Economics of a Non-Invasive Point-of-Care Test for Coronary Artery Disease

A point-of-care non-invasive test for Coronary Artery Disease (CAD) (POC-CAD) has been previously developed and validated. The test requires the simultaneous acquisition of orthogonal voltage gradient (OVG) and photoplethysmogram signals, which is the primary methodology described in this paper. The acquisition of the OVG, a biopotential signal, necessitates the placement of electrodes on the prepared skin of the patient&#39;s thorax (arranged similarly to the Frank lead configuration, comprising six bipolar electrodes and a reference electrode) and a hemodynamic sensor on the finger (using a standard transmission modality). The signal is uploaded to a cloud-based system, where engineered features are extracted from the signal and supplied to a machine-learned algorithm to yield the CAD Score. The physician must then interpret the value of the CAD Score in the context of their patient&#39;s pre-test probability of CAD, resulting in a post-test probability of CAD. This interpretation can be performed at the level of test positivity and test negativity or at a finer level of granularity; methodologies for each are proposed here based on likelihood ratios. Using the post-test probability, the physician must determine the appropriate next step in the treatment of their patient; several scenarios are used to illustrate this process. Test adoption is only feasible if economically viable; a discussion of the integration of the test into the CAD diagnostic flow and the resultant cost savings to the healthcare system is provided. The economic model demonstrates that cost savings to the healthcare system can be achieved by preventing delayed treatment, which, if left unaddressed, results in disease progression requiring more advanced (and expensive) care.

<meta charset="utf8"></head><body>冠状动脉疾病无创即时检测的信号采集、评分解释和经济性

The methodology to acquire the physiological signal for a Coronary Artery Disease (CAD) test is presented. A method is proposed to interpret the CAD score concerning test positivity and negativity, including the granularities of each. The economics of the test are discussed in the context of the current standard of care.

非门控断层扫描的冠状动脉钙化识别

摘要

探索更多视频

悬重系统的使用在小鼠冠状动脉闭塞

结扎冠状动脉内注射在小鼠模型梗死

改性技术在小鼠冠状动脉结扎

微型计算机断层扫描成像制备小鼠冠状动脉血管逆行灌注和灌装

动脉粥样硬化斑块的活动和血管炎症的定量使用[18 F]，氟正电子发射断层扫描/电脑断层扫描（FDG-PET/CT）

一种半自动且可重现的基于生物学的体外定量钙沉积的方法

用于从门控心脏计算机断层扫描图像测量冠状动脉空间加权钙评分的半自动图形工具

用于从门控心脏计算机断层扫描图像测量冠状动脉空间加权钙评分的半自动图形工具

用于从门控心脏计算机断层扫描图像测量冠状动脉空间加权钙评分的半自动图形工具

冠状动脉疾病无创即时检测的信号采集、评分解释和经济性