FIGURE 2.

SROC curve of ¹¹C-PIB-PET for predicting conversion to AD in patients with MCI. A weighted symmetric SROC curve with a 95% CI was computed with the Moses-Shapiro-Littenberg method, and the quantitative value of the AUC ± SE was 0.8773 ± 0.0287. We calculated the maximum joint sensitivity and specificity as point Q∗ on a symmetric ROC curve (0.8078 ± 0.0288), which is a global measure of test accuracy. Summary ROC plots display the results of individual studies in ROC space; each study is plotted as a single sensitivity–specificity circular point. The size of points in the plot is proportional to their sample sizes. ¹¹C-PIB-PET = ¹¹C-Pittsburgh compound B positron emission tomography, 95% CI = 95% confidence interval, AD = Alzheimer disease, AUC = area under curve, MCI = mild cognitive impairment, ROC = receiver-operating characteristic, SE = standard error, SROC = summary receiver operating characteristic.