Correction for the random coincidences in dual head gamma camera imaging

Planar large field of view gamma-camera detectors in coincidence imaging are characterized by a high count rate, leading to a high acquired random coincidence rate. The authors propose and compare two methods to correct for the random coincidences that account for the variation of the random count rate during the detector rotation. One method consists in using an uniform random distribution and the other method consists in using the single photon distribution (SPD) on each detector. The latter method also accounts for the variation of the spatial distribution of the random coincidences. The uniform distribution method leads to an underestimation of the random coincidences inside the object and an overestimation of the random coincidences outside the object. The distribution of the random coincidences is better estimated from the spatial distribution of the single photons. The SPD correction allows to recover contrast values close to the original ones