RecruitingPhase 2Drug trialHyperpolarized Pyruvate (13C) MR Imaging in Monitoring Patients With Prostate Cancer on Active SurveillanceThis phase II trial studies the side how well hyperpolarized carbon C 13 pyruvate (HP C-13 pyruvate) magnetic resonance imaging (MRI) works in monitoring patients with prostate cancer on active surveillance who have not received treatment. Diagnostic procedures, such as MRI, may help visualize HP C-13 pyruvate uptake and breakdown in tumor cells.