The main goal was to compare DR and IR, on both<i>within-subject</i>and<i>between-subject</i>variability.<i>Approach.</i>This work evaluated the Parametric motion-compensation OSEM List-mode algorithm for resolution-recovery-1T DR method, using multiple scans of Parkinson's disease patients with [<sup>11</sup>C]UCB-J, a radioligand for synaptic vesicle glycoprotein 2A (SV2A), a marker for synaptic density. This evidence concerns the gene SV2A and Parkinson disease.