[Virtual cystoscopy with reduced tube current: an alternative to cystoscopy?].
OBJECTIVE
Virtual cystoscopy at different mAs settings in patients with tumors of the bladder in comparison with cystoscopy and axial CT.


METHODS
The study included 28 patients with bladder tumors and 28 patients without tumors as control group. The bladder was distended with air and scanned at two different mAs settings (protocol 1 and 2). The radiation exposure was reduced by 82 % for protocol 2 in comparison with protocol 1. Three readers compared virtual cystoscopy with cystoscopy and axial CT as to tumor location and size. Sensitivity, specificity and accuracy were calculated.


RESULTS
Of the 47 tumors seen at cystoscopy, all readers detected 45 tumors by virtual cystoscopy using protocol 1 and 44 tumors using protocol 2, with p > 0.05 in comparison with cystoscopy. Virtual cystoscopy showed higher sensitivity than axial CT (97.2 % vs. 86.5 % for protocol 1) and (96.5 % vs. 86.5 % for protocol 2) with the same specificity (100 %). The accuracy was 0.982 for protocol 1 and 0.978 for protocol 2. In comparison with virtual cystoscopy, axial CT shoved more often over- and underestimation of the tumor size.


CONCLUSIONS
Virtual cystoscopy at reduced mAs setting is a modality suitable for the detection of polypoid tumors, but does not provide data of the mucosa and thus cannot replace cystoscopy yet.
Bernhardt
T M
TM
Institut für Klinische Radiologie, Universität Münster, Münster. bernhart@uni-muenster.de
Krause
U W
UW
Philipp
C
C
Allhoff
E P
EP
Rapp-Bernhardt
U
U
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003558:Cystoscopy / Q000379:methods*; D005260:Female; D006417:Hematuria / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D001743:Urinary Bladder / Q000000981:diagnostic imaging*; D001749:Urinary Bladder Neoplasms / Q000000981:diagnostic imaging*; D014584:User-Computer Interface