Comparative Diagnostic Performance of Contrast-Enhanced ultrasound versus Baseline Ultrasound for Renal Pelvis Lesions

The aim of this study was to assess the relative efficacy of contrast-enhanced ultrasound (CEUS) and baseline ultrasound (B-US) in diagnosing renal pelvic lesions. B-US findings on 58 suspected renal pelvis lesions were examined. The B-US and CEUS results were classified into five grades. Receiver operating characteristic curve analysis was used to compare the diagnostic efficacy of the two imaging modalities. CEUS characteristics of renal pelvis malignancies at different tumor stages and pathologic grades were examined. In the final diagnosis, 29 patients had malignant lesions (27 transitional cell carcinomas, 1 squamous cell carcinoma and 1 renal cell carcinoma) and 29 had benign lesions. On B-US, echogenicity and renal pelvis separation pattern in patients with malignant renal lesions overlapped those of patients with benign lesions. CEUS significantly increased the diagnostic grade of malignant lesions and decreased the grade of benign lesions (p = 0.000). The area under the receiver operating characteristic curve of CEUS was larger than that of B-US (p = 0.030). Enhancement shape and intensity in the wash-in phase markedly differed in lesions of higher tumor stage and higher pathologic grade, compared with lesions of lower stage and grade. In this study, compared with B-US, CEUS had significantly higher diagnostic efficacy in patients with renal pelvis lesions.