OBJECTIVETo investigate the role of contrast-enhanced ultrasound in the differential diagnosis of high- and low-grade urothelial carcinoma.

METHODSThe radiological data of 96 patients with urothelial carcinomas who had undergone gray-scale contrast-enhanced ultrasound from August 2010 to April 2011 were analyzed retrospectively. Pathological examination demonstrated that the tumors were high-grade in 55 cases (high-grade group) and low-grade in 41 cases (low-grade group). The dynamic images were analyzed by time-intensity curve, and the arrival time (AT), peak intensity (PI), time to peak (TTP), and washout time (WT) were measured. The enhancement patterns of different urothelial carcinomas were analyzed.

RESULTSBoth PI (P=0.005) and WT (P=0.002) were significantly higher in high-grade group than in low-grade group, whereas AT (P=0.374) and TTP (P=0.386) showed no significant difference between these two groups. In the high-grade group, 47 cases (85.5%) were identified as fast wash-in and slow wash-out; in the low-grade group, 35 (85.4%) were identified as fast wash-in and fast wash-out. When the enhancement pattern was used as a diagnostic indicator for differentiating urothelial carcinomas, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 85.5%, 90.2%, 87.5%, 92.2%, and 82.2% for high-grade tumor and 85.4%, 90.9%, 88.5%, 87.5%, and 89.3% for low-grade tumor.

CONCLUSIONSDifferent grade urothelial carcinomas show different enhancement finding on contrast-enhanced ultrasound. The enhancement pattern can serve as an important diagnostic indicator.