Modular miniPET: A comparison between 10 and 12 detector modules

By means of computer simulations, scatter fraction, spatial resolution and sensitivity of two 10-detector-module small-animal PET (r77-miniPET and r106-miniPET), are analyzed and compared to the performance of the 12-detector-module PET scanner miniPET II [1]. All simulations have been performed with the well validated Geant4 Application for Emission Tomography (GATE) [2]. Sensitivity and scatter fraction speak in favor of the 10-module scanner: a clear improvement in count rate and scatter fraction was found. Moreover, steeper slopes of noise equivalent count rate curves at low levels of activity was found. Spatial resolution instead was found to be better in the 12-module scanner. The encouraging results here presented particularly refer to r77-miniPET: all things considered, the 10-detector design behaves better than miniPET II if there are no gaps between detector modules. Preliminary trials performed with 8 detector modules in a ring are even more encouraging and need further assessment.