Inclusion Criteria:
* Biopsy-proven adenocarcinoma of the prostate. Biopsy may be performed outside of University of California, San Francisco (UCSF), if detailed results of sextant biopsy are available. For Cohort A only, a minimum of 20 participants out of a planned enrollment of 50 patients must have high-risk disease as defined by primary Gleason score of 4 or 5 on prior prostate biopsy.
* Cohort A only: Planned radical prostatectomy at UCSF within 12 weeks following protocol MRI/MRSI.
* Cohort B only: HIFU focal therapy completed within 18 months of protocol MRI/MRSI, and planned systematic and MR-guided biopsy at UCSF within 12 weeks following protocol MRI/MRSI.
* The participant is able and willing to comply with study procedures and provide signed and dated informed consent
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
* Absolute neutrophil count (ANC) \>= 1500 cells/microliter (uL)
* Hemoglobin \>= 9.0 mg/dL
* Platelets \>= 75,000 cells/uL
* Estimated creatinine clearance \>= 50 mL/min (by the Cockcroft Gault equation)
* Bilirubin \< 1.5 x upper limit of normal (ULN) (unless Gilbert's is suspected)
* Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \< 1.5 x ULN
Exclusion Criteria:
* Participants who because of age less than 18 years old, general medical or psychiatric condition, or physiologic status cannot give valid informed consent.
* Participants unwilling or unable to undergo MR imaging, including patients with contraindications to MRI, such as cardiac pacemakers or non-compatible intracranial vascular clips.
* Participants who cannot tolerate or have contra-indications to endorectal coil insertion; for example, participants with a prior abdominoperineal resection of the rectum or latex allergy.
* Patients with contra-indications to injection of gadolinium contrast; for example patients with prior documented allergy or those with inadequate renal function.
* Metallic hip implant or any other metallic implant or device that distorts local magnetic field and compromises the quality of MR imaging.
* Cryosurgery, surgery for prostate cancer, prostatic or pelvic radiotherapy prior to study enrollment. For Cohort B, HIFU focal therapy is allowed. No limit on number of prior prostate biopsies; prior transurethral prostatic resection (TURP) is not allowed.
* Current or prior androgen deprivation therapy. For Cohort A, a history of use of a 5-alpha reductase inhibitor is allowed, provided it was discontinued at least one month prior to study entry. For cohort B, a history of use of 5-α reductase inhibitor is allowed, provided it is discontinued at least 14 days to protocol MRI/MRSI.
* Poorly controlled hypertension, with blood pressure at study entry \> 160/100; the addition of anti-hypertensives to control blood pressure is allowed for eligibility determination.
* Congestive heart failure or New York Heart Association (NYHA) status \>= 2.
* A history of clinically significant electrocardiography (EKG) abnormalities, including QT prolongation, a family history of prolonged QT interval syndrome, or myocardial infarction (MI) within 6 months of study entry; patients with rate-controlled atrial fibrillation/flutter will be allowed on study.
