Additional file 1: of Quantitative performance and optimal regularization parameter in block sequential regularized expectation maximization reconstructions in clinical 68Ga-PSMA PET/MR

Figure S1. Box and whisker plots showing tumor-to-background ratio distributions obtained from lesions in 25 patients. The top panel (a) shows the group with small size and low-uptake lesions (N = 8), the middle panel (b) shows the group with medium size and medium uptake lesions (N = 15), the lower panel (c) shows the group with large size or high-uptake lesions (N = 17). Each subplot shows from left to right the results of the TOF OSEM reconstructions with 28 subsets and 2 and 3 iterations, followed by TOF BSREM reconstructions with regularization parameter β = 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 700, 800, 900, 1000, and 1200. The tumor-to-background is defined as the SUVmax of the lesion devided by the SUVmean of the background. TOF = time-of-flight, SUV = standardized uptake value, SUVmax = the average of the hottest 5 voxels in the lesion, SUVmean = the average value of the voxels in the background ROI, OSEM = ordered subset expectation maximization, and BSREM = block sequential regularized expectation maximization. (DOCX 174 kb