Comparison of CT Virtual Cystoscopy and Conventional Cystoscopy in Diagnosis of Bladder Tumors

Aim: The purpose of this study was to investigate the value of contrast material-filled virtual cystoscopy in the detection of bladder tumors. Material and method: Thirty-six consecutive patients (28 male and 8 female; range age, 51-82 years; mean age ± SD, 65 ± 7 years) who had painless hematuria and suspected to have bladder neoplasm prospectively evaluated with virtual cystoscopy. After the intravenous injection of contrast medium, the contrast material-filled bladder was examined with single detector helical computed tomography (CT) scan with 2-mm slice thickness. Source CT data were transferred to a workstation for interactive navigation using surface rendering. All patients also underwent conventional cystoscopy. The results of virtual cystoscopy were compared with the findings of conventional cystoscopy. Results: Seventy-one of 78 bladder tumors detected with conventional cystoscopy in 28 patients were also shown on virtual images. Five patients had a normal appearance on both conventional cystoscopy and virtual cystoscopy. On virtual cystoscopy, seven of the 12 lesions 5 mm or smaller in diameter could be identified. We found the following statistical values for the identification of bladder lesions on virtual cystoscopy: sensitivity, 94%; specificity, 90%; positive predictive value, 87%; negative predictive value, 93%; and accuracy 93%. Conclusion: CT virtual cystoscopy is a noninvasive technique which is used successfully for detection of bladder tumors larger than 5 mm.