Prostate Assessment with Restriction Spectrum Imaging (RSI) MRI

Participants will undergo prostate MRI using a range of b-values and echo times. 40 participants will be invited to complete two such scans within 30 days of each other to evaluate reliability across time. Several advanced MRI models will be applied to the data, and the models will be assessed for accurate prediction of grade group ≥2 prostate cancer on histopathology, obtained through routine clinical care. We hypothesize that advanced, multi-compartment dMRI will yield a reliable, quantitative metric that is superior to standard ADC for detection of csPCa. RSI is a multicompartment model of diffusion MRI that uses data acquired at multiple b-values to distinguish varied diffusion speeds (restricted intracellular, hindered extracellular, and approximately free diffusion). The relative contributions of each compartment are estimated for each voxel in the imaging field of view. RSI cellularity index is a normalized parameter reflecting the contribution of very slow diffusion that is associated with tumor cellularity.