Fig. 3

Representative planar mask projection images from measurement (left) and simulation (right) with 0.1 mm isotropic pixels and without uniformity correction. The measured image agrees well with the simulation and demonstrates the minimal distortion and superior resolution of SiPMs. The Derenzo patterns are fully resolved, and the FWHM of PSFs produced by the 0.7 mm-diameter holes was consistent with a limiting intrinsic resolution of 0.85 mm. The images shown are for demonstrative purposes as the detector’s FOV is not large enough to include the full extent of all line profiles and Derenzo patterns, which resulted in clipping of the line profiles shown at \(y=7\) mm. Therefore, when analyzing the intrinsic spatial resolution and linearity from all line profiles, the central line profiles were placed across the center of the detector as instructed by the NEMA protocol, thereby clipping the Derenzo pattern at \(y=97\) mm (not shown)