This is a prospective single arm study. 120 patients at risk for significant occult prostate cancer on an active surveillance program will undergo MS3TMRI followed by a standard TRUSBx and additional biopsies guided by the MS3TMRI results. The positive predictive value (PPV) of MS3TMRI-TRUSBx for cancer requiring consideration of therapy will be compared to the PPV of TRUSBx alone. MS3TMRI consists of T2, diffusion-weighted imaging (DWI), dynamic contrast enhanced MRI (DCEMRI), proton MR spectroscopy (MRS) interpreted by a radiologist and by CAD methods validated on whole mount prostate specimens.