Combined quantitative dynamic contrast-enhanced MR imaging and 1H MR spectroscopic imaging of human prostate cancer

Purpose: To differentiate prostate carcinoma from healthy peripheral zone and central gland using quantitative dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and two-dimensional H-1 MR spectroscopic imaging (MRSI) combined into one clinical protocol. Materials and Methods: Twenty-three prostate cancer patients were studied with a combined DCE-MRI and MRSI protocol. Cancer regions were localized by histopathology of whole mount sections after radical prostatectomy. Pharmacokinetic modeling parameters, K-trans and k(ep), as well as the relative levels of the prostate metabolites citrate, choline, and creatine, were determined in cancer, healthy peripheral zone (PZ), and in central gland (CG). Results: K-trans and k(ep) were higher (P < 0.05) in cancer and in CG than in normal PZ. The (choline + creatine)/citrate ratio was elevated in cancer compared to the PZ and CG (P < 0.05). While a (choline + creatine)/citrate ratio above 0.68 was found to be a reliable indicator of cancer, elevated K-trans was only a reliable cancer indicator in the diagnosis of individual patients. K-trans and (choline + creatine)/citrate ratios in cancer were poorly correlated (Pearson r(2) = 0.07), and thus microvascular and metabolic abnormalities may have complementary value in cancer diagnosis. Conclusion: The combination of high-resolution spatiovascular information from dynamic MRI and metabolic information from MRSI has excellent potential for improved localization and characterization of prostate cancer in a clinical setting.