Vos P H, Vossepoel A M, Hermans J, Pauwels E K
Eur J Nucl Med. 1982;7(4):174-80. doi: 10.1007/BF00443927.
Experimental studies have been made of the lesion detectability in myocardial perfusion studies using thallium-201. A series of images (AP-view) was generated using a convolution of a mathematical model of the left ventricular myocardium and an experimentally determined point spread function. Background was added. Images were simulated with 100 k, 200 k, and 300 k counts for the complete image. Each image contained a lesion with either 0% or 50% of the normal tracer concentration. All images were interpreted by five experienced observers, independently of each other. Their interpretations were analysed using the Kolmogorov-Smirnov two sample test. The true positive fraction (TPF) was hardly affected by changes in count density. The TPF decreased significantly if the lesion tracer concentration changed from 0% to 50% of the normal myocardial tracer concentration. The decrease was independent of the count density. The false positive fraction (FPF) decreased significantly if the count density increased; no difference in FPF was found for a change in lesion tracer concentration. In addition, plots were generated with the TPF versus lesion volume. The TPF was lowest for locations far from the camera; FPF was high for these segments. Increase of the count density mainly improved the FPF in these segments. Small lesion were more difficult to detect.
已经对使用铊 - 201进行心肌灌注研究时病变的可检测性进行了实验研究。使用左心室心肌的数学模型与实验确定的点扩散函数进行卷积生成了一系列图像（前后位视图）。添加了背景。对完整图像分别用100k、200k和300k计数进行图像模拟。每张图像都包含一个病变，其示踪剂浓度为正常浓度的0%或50%。所有图像由五名经验丰富的观察者独立解读。使用柯尔莫哥洛夫 - 斯米尔诺夫双样本检验分析他们的解读结果。真阳性率（TPF）几乎不受计数密度变化的影响。如果病变示踪剂浓度从正常心肌示踪剂浓度的0%变为50%，真阳性率会显著降低。这种降低与计数密度无关。如果计数密度增加，假阳性率（FPF）会显著降低；病变示踪剂浓度变化时，假阳性率没有差异。此外，还绘制了真阳性率与病变体积的关系图。离相机较远位置的真阳性率最低；这些节段的假阳性率较高。计数密度的增加主要改善了这些节段的假阳性率。小病变更难检测。
