Fahmi Rachid, Eck Brendan L, Vembar Mani, Bezerra Hiram G, Wilson David L
Biomedical Engineering Department, Case Western Reserve University, Cleveland, OH, 44106, USA.
Philips Healthcare, Cleveland, OH, 44143, USA.
Proc SPIE Int Soc Opt Eng. 2014 Feb;9038. doi: 10.1117/12.2043800. Epub 2014 Mar 13.
Dynamic cardiac CT perfusion (CTP) is a high resolution, non-invasive technique for assessing myocardial blood flow (MBF), which in concert with coronary CT angiography enable CT to provide a unique, comprehensive, fast analysis of both coronary anatomy and functional flow. We assessed perfusion in a porcine model with and without coronary occlusion. To induce occlusion, each animal underwent left anterior descending (LAD) stent implantation and angioplasty balloon insertion. Normal flow condition was obtained with balloon completely deflated. Partial occlusion was induced by balloon inflation against the stent with FFR used to assess the extent of occlusion. Prospective ECG-triggered partial scan images were acquired at end systole (45% R-R) using a multi-detector CT (MDCT) scanner. Images were reconstructed using FBP and a hybrid iterative reconstruction ( , Philips Healthcare). Processing included: beam hardening (BH) correction, registration of image volumes using 3D cubic B-spline normalized mutual-information, and spatio-temporal bilateral filtering to reduce partial scan artifacts and noise variation. Absolute blood flow was calculated with a deconvolution-based approach using singular value decomposition (SVD). Arterial input function was estimated from the left ventricle (LV) cavity. Regions of interest (ROIs) were identified in healthy and ischemic myocardium and compared in normal and occluded conditions. Under-perfusion was detected in the correct LAD territory and flow reduction agreed well with FFR measurements. Flow was reduced, on average, in LAD territories by 54%.
动态心脏CT灌注成像（CTP）是一种用于评估心肌血流（MBF）的高分辨率无创技术，它与冠状动脉CT血管造影相结合，使CT能够对冠状动脉解剖结构和功能血流进行独特、全面且快速的分析。我们在有或无冠状动脉闭塞的猪模型中评估了灌注情况。为诱导闭塞，每只动物均接受左前降支（LAD）支架植入和血管成形术球囊插入。球囊完全放气时获得正常血流状态。通过球囊抵住支架充气诱导部分闭塞，使用血流储备分数（FFR）评估闭塞程度。使用多探测器CT（MDCT）扫描仪在收缩末期（R-R间期的45%）采集前瞻性心电图触发的部分扫描图像。使用滤波反投影（FBP）和混合迭代重建（ ，飞利浦医疗）对图像进行重建。处理过程包括：束硬化（BH）校正、使用三维立方B样条归一化互信息对图像体积进行配准，以及时空双边滤波以减少部分扫描伪影和噪声变化。使用基于奇异值分解（SVD）的去卷积方法计算绝对血流。从左心室（LV）腔估计动脉输入函数。在健康心肌和缺血心肌中识别感兴趣区域（ROI），并在正常和闭塞状态下进行比较。在正确的LAD区域检测到灌注不足，血流减少与FFR测量结果高度一致。LAD区域的血流平均减少了54%。
