Department of Radiology, Erasmus MC, Universitair Medisch Centrum, Thoraxcenter, Ba 585, 's-Gravendijkwal 230, 3015 CE Rotterdam, the Netherlands.
Acad Radiol. 2011 Dec;18(12):1529-36. doi: 10.1016/j.acra.2011.08.002.
To compare two semiautomated methods for measurement of infarcted myocardium area on delayed contrast enhanced magnetic resonance imaging, with histopathology findings as standard of reference.
Percentage area of myocardial infarction was measured in 10 Yorkshire landrace pigs manually and using two semiautomated methods. The first (standard deviation method) used two operator-selected regions of interest (ROIs) and nine different cutoff values (one to nine times the standard deviation of signal intensity in normal myocardium) to identify infarction. The second (threshold method) used threshold values based on percentages of maximum signal intensity to identify infarction. Results were compared with histopathology findings.
Difference between percentage area of infarction obtained with standard deviation method and autopsy specimens was in the range: -13.5% to +13.2%. With threshold method (thresholds from 30% to 90% of signal intensity), difference was -15% to +23%. Manual contouring underestimated infarcted area by 2% comparing to autopsy results. The best agreement between histopathology and semi-automated software was achieved for 4 standard deviations with standard deviation method: difference -0.45%, and for a percentage threshold of 70% (difference +0.67%) with threshold method. However, with standard deviation method, there was statistically significant difference between ROIs based on their location in viable myocardium: mean difference 1.7 ± 4%, P < .0001.
Semiautomated measurement of myocardial infarcted area on delayed enhanced magnetic resonance images performs well compared to autopsy. The threshold method, based on percentages of maximum signal intensity is preferable over standard deviation method, which is more susceptible to variability from location of ROIs within viable myocardium.
比较两种半自动化方法在延迟对比增强磁共振成像上测量梗死心肌面积，以组织病理学发现为标准。
手动和使用两种半自动方法测量 10 头约克郡兰德瑞斯猪的心肌梗死百分比面积。第一种（标准差方法）使用两个操作员选择的感兴趣区（ROI）和九个不同的截止值（正常心肌信号强度标准差的 1 到 9 倍）来识别梗死。第二种（阈值方法）使用基于信号强度最大百分比的阈值来识别梗死。结果与组织病理学发现进行比较。
标准差方法获得的梗死面积百分比与尸检标本之间的差异在 -13.5%至+13.2%之间。使用阈值方法（信号强度的 30%至 90%的阈值），差异为-15%至+23%。手动轮廓描记术与尸检结果相比低估了梗死面积 2%。标准差方法的 4 个标准差与组织病理学具有最佳一致性：差异为-0.45%，阈值方法的 70%的百分比阈值（差异为+0.67%）具有最佳一致性。然而，对于标准差方法，基于其在存活心肌中的位置的 ROI 之间存在统计学上显著差异：平均差异 1.7±4%，P<0.0001。
与尸检相比，延迟增强磁共振图像上的心肌梗死面积半自动测量表现良好。基于最大信号强度百分比的阈值方法优于标准差方法，后者更容易受到存活心肌中 ROI 位置变化的影响。
