FIGURE 1. Accuracy curves showing agreement between PERFEX and nuclear medicine physicians. Curves show accuracy for PERFEX as a function of CF shift level, using clinical interpretation of myocardial perfusion SPECT studies by nuclear medicine physicians as gold standard. For this population, 0.10 shift level results in optimal accuracy for localizing disease to LAD and RCA vascular territories and 0.20 level for LCX territory.
FIGURE 2. ROC curves showing agreement between PERFEX and nuclear medicine physicians. ROC curves are plotted for overall detection of CAD (A) and for localization to LAD (B), LCX (C), and RCA (D) vascular territories. Points shown on ROC curves are generated from different CF shift levels. Level corresponding to 0.15 CF shift level was deemed to be average optimal input certainty factor from comparison of accuracy at different levels (Fig. 1).
FIGURE 3. ROC curves showing agreement between PERFEX and coronary angiography. ROC curves are plotted for overall detection of CAD (A) and for localization to LAD (B), LCX (C), and RCA (D) vascular territories. Points shown on ROC curves are generated from different CF shift levels. *Results obtained from nuclear medicine physicians using coronary angiography as gold standard.
FIGURE 4. Detection and localization of CAD: PERFEX vs. nuclear medicine physicians. Bar graphs show sensitivity and specificity values for PERFEX and nuclear medicine physicians (expert) at 3 different CF shift levels using coronary angiography as gold standard. For 0.15 CF shift level, there are no statistically significant differences in 5 of 8 criteria tested and PERFEX provides statistically better results in 1 of 3 criteria for which there are differences.