Multiparametric Magnetic Resonance Imaging of Prostate Cancer: Association of Quantitative Magnetic Resonance Parameters with Histopathologic Findings

Background: Prostate cancer continues to be diagnosed with increasing frequency. Multiparametric magnetic resonance imaging (MP-MRI) has a favorable correlation with prostatectomy histopathology findings. These advanced functional imaging techniques may help increase the sensitivity of prostate cancer detection and the accuracy of predicting the Gleason score (GS), which is a measure of cancer aggressiveness. Objectives: The purpose of this study was to determine associations between MP-MRI parameter and whole-mount pathological finding as reference standard. Patients and Methods: Twenty-four consecutive prostate cancer patients who underwent an MRI exam followed by radical prostatectomy were incorporated in this study. The average time between MRI and prostatectomy was 40 days (7 - 100 days). All patients had biopsy proven adenocarcinoma of the prostate and the mean GS was 6.7 (median, 7; range 6 - 9). Results: The mean age was 59 +/- 7 years. The mean serum prostate specific antigen (PSA) was 7.81 +/- 5.73 ng/mL. The GS ranged from 6 to 9 and most patients (79%) had a GS of 7. MRI data were correlated to biopsy results. Pearson correlation analysis revealed a significant negative correlation between GS and apparent diffusion coefficient (ADC) measurements (r = -0.926, P = 0. 01), and a strong positive correlation between Gleason scores and MRS measurements (r = 0.965, P = 0.01). No significant correlation was observed between any of the dynamic contrast enhanced MRI (DCE-MRI) parameters and GS. Conclusion: Combining anatomical and functional MRI significantly improves prostate cancer localization. It is a useful tool in the diagnosis and management of prostate cancer as well as a valid tool for assessing men on active surveillance. However, it should not be seen as a replacement for tissue biopsy.