The goal of this study was to use a dual-agent, 13C-pyruvate and 13C-urea, HP 13C MRSI approach to investigate changes in tumor perfusion and metabolism during prostate cancer development, progression from low- to high-grade disease and metastases, and after Ldha knock-out in order to assess the functional importance of lactate metabolism in this common and often lethal cancer. The gene discussed is LDHA; the disease is neoplasm.