Virtual cystoscopy from computed tomography: a pilot study

To assess the feasibility of virtual cystoscopy reconstructed from helical computed tomography (CT) obtained using an intravenous contrast agent, and to correlate the findings with flexible (FC) and rigid cystoscopy (RC) in patients with bladder tumours.

Eighteen patients (16 men and two women, mean age 72 years, range 59-80) with haematuria and found to have a bladder tumour on FC were included in a pilot study. Contrast-enhanced helical CT scans were taken and based on these datasets, virtual cystoscopy (VC) images were reconstructed by a radiologist unaware of the findings at cystoscopy. All patients had RC and a biopsy taken. The VC images were compared with the findings from FC and RC.

At FC, VC and RC, 32, 34 and 36 lesions were identified, respectively; 33 (92%) of the abnormal lesions at RC were correctly identified at VC. At VC, all lesions of >4 mm were identified but only one of three <4 mm was seen. There were two false-positive finding at VC; VC correctly identified 17 (94%) of 18 abnormal bladders. Only 25% of the ureteric orifices were seen. Carcinoma in situ and urethral tumours were not visualized.

CT-based VC has a high sensitivity for detecting bladder lesions and is comparable with FC; it may have a potential role as a single imaging tool for haematuria. Further larger studies are required to assess its clinical role.