Diffuse Peripheral Zone T2 Hypointensity

Objective Evaluate the accuracy of an obscured surgical capsule (OSC) for detecting diffuse prostate cancer (PCa) in the setting of diffusely T2 hypointense peripheral zones (PZs) on prostate magnetic resonance imaging. Methods Axial T2-weighted sequences of prostate magnetic resonance imaging performed on July 1, 2015, to August 1, 2017, were blindly assessed for diffusely T2 hypointense PZs, OSC, and focal diffusion abnormalities by 2 radiologists. Diffuse PCa was defined by the presence of bilateral PCa on at least 4 contiguous biopsy cores involving 2/3 levels. Interobserver agreement and multivariate analysis were performed. Results Seven (10%) of 70 patients had diffuse PCa. There was weak interreader agreement for OSC (κ coefficient = 0.58). Obscured surgical capsule was 57% sensitive and 89% specific for the presence of diffuse PCa and was associated with it (odds ratio, 17.6; P = 0.0008). Multivariate logistic regression demonstrated that OSC was the only significant predictor for the presence of diffuse PCa. Conclusion Obscured surgical capsule is a strong independent predictor for diffuse PCa in T2 hypointense PZs.