Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, 165 Cambridge St, Suite 400, Boston, MA 02114.
Acad Radiol. 2013 Oct;20(10):1301-5. doi: 10.1016/j.acra.2013.07.004.
Cardiac computed tomography (CT) has emerged as a robust modality for imaging coronary stenosis and has recently been used to evaluate myocardial abnormalities such as ischemic perfusion defects and infarction. We developed a new image analysis algorithm for the semiautomatic and quantitative assessment of myocardial perfusion by CT.
The algorithm semiautomatically segments two-dimensional short-axis reformatted DICOM images of the left ventricle into regions of interest (ROIs) in accordance with American Heart Association (AHA) standards and is capable of creating nine further ROI subsegments. This includes separate endocardial, mid-ventricle, and epicardial layers. Image intensity values (Hounsfield unit) and relative myocardial thickness are quantitatively reported for each ROI and segment.
The algorithm allows comparison of the HU values at the same ROI locations between rest and stress. The reproducibility is very good; ICC 0.89 for rest images, 0.83 for stress images. The mean time for generating ROIs for the entire heart was 11 minutes versus 22 minutes for manual tracing.
The algorithm reports parameters relevant for evaluation of stress perfusion CT studies and will allow more accurate and reproducible analysis in cardiac CT research.
心脏计算机断层扫描（CT）已成为一种强大的冠状动脉狭窄成像方法，最近还被用于评估心肌异常，如缺血性灌注缺损和梗死。我们开发了一种新的 CT 心肌灌注半自动化定量分析算法。
该算法根据美国心脏协会（AHA）标准半自动分割二维短轴 DICOM 图像的左心室感兴趣区（ROI），并能够进一步创建九个 ROI 子区域。这包括单独的心内膜、心室中部和心外膜层。为每个 ROI 和节段定量报告图像强度值（Hounsfield 单位）和相对心肌厚度。
该算法允许在静息和应激状态下比较同一 ROI 位置的 HU 值。可重复性非常好；静息图像的 ICC 为 0.89，应激图像的 ICC 为 0.83。生成整个心脏 ROI 的平均时间为 11 分钟，而手动追踪的时间为 22 分钟。
该算法报告了评估应激灌注 CT 研究的相关参数，并将允许在心脏 CT 研究中进行更准确和可重复的分析。
