Figure 2: The performance of signal segmentation for three ROIs after ICA. The spatial segmentation of ROIs was listed in (a)–(e) along different CNRs. The area symbols for artery, surrounding tissue, and tissue are denoted as I, II, and III, respectively. The performance in signal segmentation is summarized in (f). The solid line denotes the true rate of selected region located in the ROI and the dash line is the false rate outside ROI.