Fig. 4

CT of NEMA body phantom placed on patient bed with different gamma camera orbits. The orange contour illustrates the original NEMA detector orbit, which is used for the simulations of all activity distributions in the dataset. The green and the red contours represent two expanded versions of the NEMA detector orbit, used for analyzing the influence of deviations in detector orbit between training and input data on the u-net performance. The blue and purple contours represent the mean and the maximum (maximum distance for every angle) patient detector orbits for all 436 SPECT/CT scans