This study will evaluate the feasibility of identifying changes in diffusion MRI characteristics of bone that correlates with response to therapy in men with metastatic prostate cancer.

This study will evaluate a special type of MRI (magnetic resonance imaging) scan that measures the movement of water molecules through tissue called diffusion MRI. Researchers are using this new MRI technology to track the diffusion, or movement, of water through tumor tissue, and map these changes as a cancer patient undergoes treatment. Early research seems to indicate that tumor cells restrict the movement of water, so as tumor cells die, the movement of water changes within the tumor. These changes in the movement (diffusion) of water may help doctors determine earlier than traditional tests whether a patient's cancer is responding (getting better) to treatment. This study will evaluate the feasibility of identifying changes in diffusion MRI characteristics of bone that correlates with response to therapy in men with metastatic prostate cancer.

Inclusion Criteria:

• Diagnosis of prostate cancer.
• Evidence of metastatic disease by bone scan.
• Patients must be initiating systemic therapy for metastatic disease.
• New D2 disease beginning therapy with androgen deprivation.
• CRPC (Castration Resistant Prostate Cancer) beginning systemic non hormonal therapy.
• Patients must be willing to provide the blood samples for the correlative markers.
• Patients must be able to lie flat in an MRI (Magnetic Resonance Imaging) magnet for 30-60 minutes.
• Life expectancy of 12 weeks or greater.
• All patients must be informed of the investigational nature of this study and must sign an informed consent in accordance with institutional and federal guidelines.

Exclusion Criteria:

• Contraindication to MRI imaging.
• Patients who require sedation with general anesthesia to undergo MRI imaging.
• Weight greater than 275 pounds.