High risk prostate cancer patients will undergo C11-Choline PET/MR whole body fusion scan and pelvic mpMRI for accurate staging. The PET/MR imaging findings, including the primary lesion with the prostate bed and pelvic lymph nodes, will be correlated with the histopathologic result. Researchers aim to provide accurate one-stop shopping opportunity in diagnosis and staging of high risk prostate cancer using the C11-choline PET/MR scan.