This study is designed to investigate whether filling the rectum with high density barium prior to a magnetic resonance spectroscopy (MRS)exam of the prostate improves the quality of the acquired spectrum. It is expected that the dense substance should help prevent air from entering the rectum and thus susceptibility artifacts in the obtained MRS data should be reduced. Ten patients with localized prostate cancer will be recruited for this study. There will be no change in treatment planning based on MRS study. Patient will receive standard radiation treatment prescribed by radiation oncologist.