Diagnostic Performance of Multiparametric MR Imaging at 3.0 Tesla in Discriminating Prostate Cancer from Prostatitis: A Histopathologic Correlation.

Objective: To investigate the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI) in differentiating prostate cancer (PCa) from prostatitis foci.

Materials and Methods: This retrospective analysis included 81 biopsy-proven lesions (44 prostatitis and 37 PCa). Normalized T2-signal intensity (nT2SI) and SI on diffusion-weighted imaging (b=1000 and 2000 mm2 /s), apparent diffusion coefficient (ADC) values, peak SI, SI at the end of the dynamic curves, mean peak time, mean enhancement percentage, and washout percentage obtained from dynamic contrast-enhanced imaging (DCEI) were measured.

Results: nT2SI (3.8 vs. 3.2, p=0.003) and ADC values (0.685×10-3 mm2 /s vs. 0.874×10-3 mm2 /s, p<0.001) were significantly higher in the prostatitis group than in the PCa group. The washout percentage was the only DCEI parameter that was significantly different between the two groups (12% vs. 4%, respectively, p=0.003). The ADC values alone showed higher sensitivity (80.5%) and specificity (75%) than all of the single criteria and most of the combined criteria. The combination of nT2SI, ADC values, and washout percentage (at least two positive criteria were sufficient for a diagnosis of PCa) yielded the highest sensitivity (77.7%) and specificity (85.7%) among all combinations.

Conclusion: PCa and prostatitis can be discriminated using mpMRI with high sensitivity and specificity.