title: Tumor detection by virtual cystoscopy with color mapping of bladder wall thickness.
abstract: OBJECTIVE
  We determine the value of color mapping of bladder wall thickness for detection of tumor as a component of virtual cystoscopy.
  
  
  METHODS
  A total of 31 subjects with hematuria and/or a history of bladder tumor underwent helical computerized tomography of the pelvis after distention of the bladder with air. Three-dimensional (D) models were constructed, and thickness of the wall was color mapped according to a fixed and validated mm. scale. Axial source images and 3-D models were reviewed and graded for the presence of wall thickening. A comparison was made with findings on conventional cystoscopy in 31 patients and pathological specimen in 13.
  
  
  RESULTS
  Compared with conventional cystoscopy, the analysis of axial image yielded a sensitivity of 0.80, specificity 0.90, positive predictive value 0.80 and negative predictive value 0.90 for the presence of tumor. Examination of color mapped 3-D renderings resulted in 0.83, 0.36, 0.42 and 0.71, respectively.
  
  
  CONCLUSIONS
  Thin axial computerized tomography of the air distended bladder shows promise as a potential screening tool for bladder cancer. The low specificity of color mapped 3-D renderings makes the technique inappropriate for screening. It may valuable for guiding urologists to additional suspicious sites in a patient with a known tumor.
authors.affiliation: Department of Radiology and Division of Urologic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Fielding
authors.forename: Lennox  X
authors.initials: L
authors.lastname: Hoyte
authors.forename: Steven A
authors.initials: SA
authors.lastname: Okon
authors.forename: Andreas
authors.initials: A
authors.lastname: Schreyer
authors.forename: Jhelmon
authors.initials: J
authors.lastname: Lee
authors.forename: Kelly H
authors.initials: KH
authors.lastname: Zou
authors.forename: Simon
authors.initials: S
authors.lastname: Warfield
authors.forename: Jerome P
authors.initials: JP
authors.lastname: Richie
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Loughlin
authors.forename: Michael P
authors.initials: MP
authors.lastname: O'Leary
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Doyle
authors.forename: Ron
authors.initials: R
authors.lastname: Kikinis
mesh_terms: D000368:Aged; D003558:Cystoscopy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000473:pathology