Objective: The objective of this study was to investigate the value of contrast material-filled virtual cystoscopy in the detection of bladder tumors. Materials and methods: Thirty-nine patients who had recent diagnosis or were followed up due to priory history of bladder tumor underwent virtual cystoscopy. After the intravenous injection of contrast medium, the bladder was examined with helical computed tomography (CT) scan. The data were transferred to a workstation for interactive navigation using surface rendering. Two radiologists independently interpreted the axial and virtual images, and discrepancies were resolved by consensus. The results of virtual cystoscopy were compared with the findings of conventional cystoscopy. Results: Forty-nine of 54 bladder lesions detected with conventional cystoscopy in 33 patients were also shown on virtual images. On virtual cystoscopy, three of the seven lesions 5 mm or smaller in diameter could be identified. There were no false-positive findings. The sensitivity of the technique was 96.2% for polypoid tumors and 88.9% for sessile lesions. When axial and virtual images were evaluated together, the sensitivity rate increased to 94.4%. Conclusion: Bladder tumors can be diagnosed noninvasively using contrast medium-filled virtual cystoscopy. Evaluation of both the axial and virtual images increases the sensitivity of the technique. (C) 2004 Elsevier Inc. All rights reserved.