OBJECTIVE. The purpose of this study is to evaluate the utility of T2-weighted imaging, dynamic contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI) for detecting prostate cancer in patients with total serum prostate-specific antigen (PSA) levels of 4–10 ng/mL, which is referred to as the “gray zone.” MATERIALS AND METHODS. Fifty patients with gray-zone PSA levels underwent MRI before biopsy. According to the sites of biopsy, the prostate was divided into eight regions on MRI scans. These regions were evaluated individually for the following features: detectability of prostate cancer on per-region and per-patient bases, and relationship between tumor size and positive or negative MRI findings for tumor detection. RESULTS. On a per-region basis, the sensitivity and specificity of tumor detection were 36% and 97% for T2-weighted imaging, 43% and 95% for DCE-MRI, 38% and 96% for DWI, and 53% and 93% for the combined method of MRI, respectively. The sensitivity of combined MRI to detect tumor...

OBJECTIVE. The aim of this retrospective study was to assess the enhancement patterns of hepatic hemangiomas on gadoxetate disodium.MATERIALS AND METHODS. A total of 22 patients with 32 hepatic hemangiomas (23 typical type and nine high-flow type) in normal liver underwent gadoxetate disodium–enhanced MRI. Contrast-enhanced images were obtained before and after contrast injection, including arterial phase, portal phase, equilibrium phase, and three hepatobiliary phases (10, 15 and 20 minutes). Signal-to-phantom ratios of hemangiomas and the portal vein as well as lesion-to-liver contrast-to-phantom ratios were assessed.RESULTS. Mean signal-to-phantom ratios of all 32 hemangiomas showed the highest value on the arterial phase and subsequently decreased over time (p = 0.029 to p < 0.001). Mean lesion-to-liver contrast-to-phantom ratios of all 32 hemangiomas showed a positive value during the arterial phase and increasingly negative values at later time points (p = 0.001 to p < 0.001). The enhancement patter...