Comparison of Early Submucosal Enhancement and Tumor Stalk in Staging Bladder Urothelial Carcinoma.

OBJECTIVE. The purpose of this study was to compare the efficacy of submucosal enhancement on dynamic contrast-enhanced MRI (DCE-MRI) and detection of a stalk on DWI for differentiating stage T1 from stage T2 bladder urothelial carcinoma. SUBJECTS AND METHODS. Our prospective study was approved by the institutional medical ethics committee and informed consent was obtained from all patients. Fifty-nine patients (92 tumors in total) with urothelial bladder cancer underwent MRI within 2 weeks before surgery. Two image sets of T2-weighted MRI with DWI and T2-weighted with DCE-MRI were interpreted independently at 2-week intervals by two uroradiologists without any knowledge of the surgical or histologic findings. The tumor was categorized as stage T1 or lower when a stalk was evident at the tumor base on DWI or when continuous linear submucosal enhancement was detected in the early phase of DCE-MRI. Tumors without stalks or with discontinuous linear submucosal enhancement were categorized as stage T2. RESULT...