Pahk Kisoo, Oh Sun Young, Jeong Eugene, Lee Sung Ho, Woo Sang Keun, Yu Jung Woo, Choe Jae Gol, Cheon Gi Jeong
Department of Nuclear Medicine, Korea University Anam Hospital, 126-1, Anam-Dong 5-Ga, Seongbuk-Gu, Seoul, 136-705 South Korea.
Department of Cardiovascular Surgery, Korea University Anam Hospital, Seoul, South Korea.
Nucl Med Mol Imaging. 2013 Jun;47(2):104-14. doi: 10.1007/s13139-013-0206-8. Epub 2013 May 8.
To evaluate the reliability of quantitation of myocardial viability on cardiac F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scans with three different methods of visual scoring system, autoquantitation using commercially available autoquantitation software, and infarct-size measurement using histogram-based maximum pixel threshold identification on polar-map in rat hearts.
A myocardial infarct (MI) model was made by left anterior descending artery (LAD) ligation in rat hearts. Eighteen MI rats underwent cardiac FDG-PET-computed tomography (CT) twice within a 4-week interval. Myocardium was partitioned into 20 segments for the comparison, and then we quantitated non-viable myocardium on cardiac FDG PET-CT with three different methods: method A-infarct-size measurement using histogram-based maximum pixel threshold identification on polar-map; method B-summed MI score (SMS) by a four-point visual scoring system; method C-metabolic non-viable values by commercially available autoquantitation software. Changes of non-viable myocardium on serial PET-CT scans with three different methods were calculated by the change of each parameter. Correlation and reproducibility were evaluated between the different methods.
Infarct-size measurement, visual SMS, and non-viable values by autoquantitation software presented proportional relationship to each other. All the parameters of methods A, B, and C showed relatively good correlation between each other. Among them, infarct-size measurement (method A) and autoquantitation software (method C) showed the best correlation (r = 0.87, p < 0.001). When we evaluated the changes of non-viable myocardium on the serial FDG-PET-CT- however, autoquantitation program showed less correlation with the other methods. Visual assessment (method B) and those of infarct size (method A) showed the best correlation (r = 0.54, p = 0.02) for the assessment of interval changes.
Commercially available quantitation software could be applied to measure the myocardial viability on small animal cardiac FDG-PET-CT scan. This kind of quantitation showed good correlation with infarct size measurement by histogram-based maximum pixel threshold identification. However, this method showed the weak correlation when applied in the measuring the changes of non-viable myocardium on the serial scans, which means that the caution will be needed to evaluate the changes on the serial monitoring.
采用三种不同的视觉评分系统、使用市售自动定量软件进行自动定量以及在大鼠心脏极坐标图上基于直方图的最大像素阈值识别来测量梗死面积的方法，评估心脏F-18氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）上心肌存活定量的可靠性。
通过结扎大鼠心脏的左前降支动脉制作心肌梗死（MI）模型。18只MI大鼠在4周内接受两次心脏FDG-PET计算机断层扫描（CT）。将心肌分为20个节段进行比较，然后我们用三种不同方法在心脏FDG PET-CT上对无活力心肌进行定量：方法A——在极坐标图上基于直方图的最大像素阈值识别来测量梗死面积；方法B——通过四点视觉评分系统计算梗死总和评分（SMS）；方法C——使用市售自动定量软件得出代谢无活力值。用每个参数的变化计算三种不同方法在系列PET-CT扫描上无活力心肌的变化。评估不同方法之间的相关性和可重复性。
梗死面积测量、视觉SMS和自动定量软件得出的无活力值相互之间呈比例关系。方法A、B和C的所有参数相互之间显示出相对良好的相关性。其中，梗死面积测量（方法A）和自动定量软件（方法C）显示出最佳相关性（r = 0.87，p < 0.001）。然而，当我们评估系列FDG-PET-CT上无活力心肌的变化时，自动定量程序与其他方法的相关性较低。视觉评估（方法B）和梗死面积评估（方法A）在评估间期变化时显示出最佳相关性（r = 0.54，p = 0.02）。
市售定量软件可用于测量小动物心脏FDG-PET-CT扫描上的心肌存活情况。这种定量与基于直方图的最大像素阈值识别测量梗死面积显示出良好的相关性。然而，该方法在测量系列扫描上无活力心肌的变化时显示出较弱的相关性，这意味着在评估系列监测的变化时需要谨慎。
