title: Staging urinary bladder cancer after transurethral biopsy: value of fast dynamic contrast-enhanced MR imaging.
abstract: OBJECTIVE
  To evaluate contrast enhancement patterns of urinary bladder cancer and surrounding structures and to evaluate a fast dynamic first-pass magnetic resonance (MR) imaging technique in tumor and node staging and in differentiation of urinary bladder cancer from postbiopsy effects.
  
  
  METHODS
  Sixty-one consecutive patients with histologically proved urinary bladder cancer were referred to undergo unenhanced and dynamic MR imaging 1-4 weeks after transurethral resection or biopsy. Subtraction and time (to beginning of enhancement) images were acquired.
  
  
  RESULTS
  Results with unenhanced T1- and T2-weighted images were compared with those obtained with the unenhanced images plus dynamic contrast material-enhanced single-section turbo fast low-angle shot (FLASH) images. Urinary bladder cancer started to enhance 6.5 seconds +/- 3.5 (standard deviation) after the beginning of arterial enhancement, which was 4 seconds earlier than most other structures (postbiopsy tissue, 13.6 seconds +/- 4.2). In differentiation of postbiopsy tissue from malignancy on the basis of the beginning of enhancement depicted on time and subtracted images, accuracy improved from 79% to 90% (P < .02) and specificity improved from 33% to 92% (not significant). Overall, tumor staging accuracy improved significantly from 67% to 84% (P < .01) by adding the turbo FLASH images.
  
  
  CONCLUSIONS
  Fast dynamic first-pass MR imaging, with at least one image acquired every 2 seconds, improved delineation of urinary bladder cancer, tumor staging, and detection of metastases.
authors.affiliation: Department of Radiology, University Hospital Nijmegen, The Netherlands.
authors.forename: J O
authors.initials: JO
authors.lastname: Barentsz
authors.forename: G J
authors.initials: GJ
authors.lastname: Jager
authors.forename: P B
authors.initials: PB
authors.lastname: van Vierzen
authors.forename: J A
authors.initials: JA
authors.lastname: Witjes
authors.forename: S P
authors.initials: SP
authors.lastname: Strijk
authors.forename: H
authors.initials: H
authors.lastname: Peters
authors.forename: N
authors.initials: N
authors.lastname: Karssemeijer
authors.forename: S H
authors.initials: SH
authors.lastname: Ruijs
mesh_terms: D001706:Biopsy; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D003287:Contrast Media; D004338:Drug Combinations; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009367:Neoplasm Staging; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D019786:Gadolinium DTPA