Comparison of virtual cystoscopy and transabdominal ultrasonography with conventional cystoscopy for bladder tumor detection.

PURPOSE We compare virtual cystoscopy (VC) and transabdominal ultrasonography (US) with conventional cystoscopy (CC),the gold standard, for detection of bladder tumors. PATIENTS AND METHODS Forty-five patients suspected to have bladder neoplasms were evaluated prospectively.They underwent transabdominal US, followed by VC and CC. We compared sensitivity and specificity of US and VC and their positive and negative likelihood ratios. US and VC detection rates for tumors <or= 1 cm and tumors larger than 1 cm were compared. Histologic grade and multiplicity were correlated to detection rate. RESULTS In the study population of 33 men and 12 women, mean age was 67.1 +/-10.9 years. Thirty-nine lesions were observed on VC and 26 lesions were observed on US of the 41 neoplasms detected at CC. Transitional bladder cancer was present in 75.6% of cases, chronic cystitis in 9.75%, endometriosis in 4.9%, and other conditions accounted for 9.75%. Thirty-one tumors were polypoid and nine were sessile; 61% were larger than 1 cm and 39% were <or=1 cm. Both US and VC 91.2% specificity, but sensitivity was better for VC (95.1%) than for US (63.4%). Multiple tumors had a better detection rate by both methods (p < 0.001). Histologic grade was positively correlated to detection rate for US (p < 0.01) but not for VC. VC was more accurate in detection of polypoid tumors compared with US (p < 0.05). CONCLUSIONS VC showed better accuracy for detection of bladder neoplasms, especially in tumors smaller than 1 cm and for polypoid lesions.