Fig. 4

FROC analysis (a) and AFROC analysis (b) for detection sensitivity on prostate cancer lesions. The number of false positives (x-axis) of Fig. 4a is shown in log-scale. According to the FROC curves, for a detection sensitivity > 0.1, using z-DWI shows a lower rate of false-positive detections per patient. The AFROC curves (b) show that compared with using f-DWI, using z-DWI can result in higher AUC in terms of PCa lesion detections per patient (0.855 [95%CI:0.825-0.883] vs. 0.760 [95%CI:0.714-0.799]). FROC=Free-response receiver operating characteristics analysis. AFROC = alternative free-response receiver operating characteristics. FPF = false positive fraction