Tumor detection by virtual cystoscopy with color mapping of bladder wall thickness.
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.
Fielding
Julia R
JR
Department of Radiology and Division of Urologic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Hoyte
Lennox  X
L
Okon
Steven A
SA
Schreyer
Andreas
A
Lee
Jhelmon
J
Zou
Kelly H
KH
Warfield
Simon
S
Richie
Jerome P
JP
Loughlin
Kevin R
KR
O'Leary
Michael P
MP
Doyle
Christopher J
CJ
Kikinis
Ron
R
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