title: Reliability of MR imaging-based virtual cystoscopy in the diagnosis of cancer of the urinary bladder.
abstract: OBJECTIVE
  Our purpose was to evaluate MR imaging-based virtual endoscopy in patients with urinary bladder cancer compared with conventional cystoscopy as the gold standard.
  
  
  METHODS
  Twenty-five patients with urinary bladder cancer diagnosed on conventional cystoscopy underwent MR imaging of the pelvis. Patients were examined without external bladder filling or administration of IV contrast medium. No medications were administered. The data obtained by MR imaging were reconstructed for virtual endoscopy on a workstation. The locations and sizes of tumors were individually determined and compared with results of conventional cystoscopy.
  
  
  RESULTS
  Twenty-four patients were evaluated; one patient's examination was excluded from analysis because of metallic artifacts. Seventeen patients were diagnosed with a single bladder tumor. Five patients had two tumors each, and two patients had three tumors. Tumor diameter ranged from 0.4 to 6.4 cm. Thirty (90.9%) of 33 tumors detected on cystoscopy were visualized with virtual endoscopy. The detection rate for 23 tumors of 1 cm or greater was 100%. Difficult conditions for conventional cystoscopy, including hematuria, anterior wall involvement, and urethral strictures, had no deleterious impact on virtual cystoscopy. Difficulties in detection on virtual endoscopy were associated with flat bladder tumors with minimal surface elevation.
  
  
  CONCLUSIONS
  The results of this study suggest a high reliability in the diagnosis of urinary bladder cancer by MR imaging-based virtual cystoscopy-a noninvasive method, independent of medication or contrast enhancement, that may be of value for screening, primary diagnosis, and surveillance. Virtual MR cystoscopy may be indicated when conventional cystoscopy cannot be performed or is ineffective.
authors.affiliation: Department of Radiology, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Str. 22, D-81675 Munich, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Lämmle
authors.forename: Ambros
authors.initials: A
authors.lastname: Beer
authors.forename: Marcus
authors.initials: M
authors.lastname: Settles
authors.forename: Christian
authors.initials: C
authors.lastname: Hannig
authors.forename: Hartwig
authors.initials: H
authors.lastname: Schwaibold
authors.forename: Carsten
authors.initials: C
authors.lastname: Drews
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003558:Cystoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D001749:Urinary Bladder Neoplasms / Q000473:pathology*