title: Comparison of Early Submucosal Enhancement and Tumor Stalk in Staging Bladder Urothelial Carcinoma.
abstract: 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.
  
  
  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.
  
  
  RESULTS
  Of the 42 tumors with stalks on DWI, 41 showed continuous and one had discontinuous submucosal enhancement on DCE-MRI. In 50 carcinomas without stalks on DWI, submucosal enhancement was absent in 34, continuous in 12, and discontinuous in four. The staging accuracy of DWI (91.3%, 84/92) and DCE-MRI (91.3%, 84/92) was improved to 94.6% (87/92) by combining the interpretations of both DWI and DCE-MRI.
  
  
  CONCLUSIONS
  Submucosal linear enhancement under the tumor base on DCE-MRI complements tumor stalk detection on DWI for differentiating stage T1 from stage T2 bladder urothelial carcinoma.
authors: 1 Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Rd 2, Guangzhou, Guangdong 510080, China.
authors: Huan-Jun
authors: HJ
authors: Wang
authors: 2 Department of Radiology, Conde de S. Januario Central Hospital, Macau, China.
authors: Margaret H
authors: MH
authors: Pui
authors: 1 Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Rd 2, Guangzhou, Guangdong 510080, China.
authors: Jian
authors: J
authors: Guan
authors: 1 Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Rd 2, Guangzhou, Guangdong 510080, China.
authors: Shu-Rong
authors: SR
authors: Li
authors: 1 Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Rd 2, Guangzhou, Guangdong 510080, China.
authors: Jin-Hua
authors: JH
authors: Lin
authors: 1 Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Rd 2, Guangzhou, Guangdong 510080, China.
authors: Bitao
authors: B
authors: Pan
authors: 1 Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan Rd 2, Guangzhou, Guangdong 510080, China.
authors: Yan
authors: Y
authors: Guo
keywords: DWI; bladder urothelial carcinoma; dynamic contrast-enhanced MRI; staging; stalk