A comparative study of contrast-enhanced ultrasound and contrast-enhanced computed tomography in the diagnosis of benign and malignant space occupying renal lesions

Objective To compare the enhanced characteristics of renal masses with contrast-enhanced ultrasound(CEUS)and contrast-enhanced CT and to evaluate the diagnostic value of CEUS and contrast-enhanced CT in renal masses.Methods The CEUS and contrast-enhanced CT examination data of 52 patients with renal masses(52 lesions) treated in the First Hospital of Shanxi Medical University from January 2008 to December 2010 were analyzed retrospectively and compared.All patients were proved by operation and pathology.Results Among 52 lesions with renal masses,42 lesions were malignant,including 32 clear cell carcinomas(of which 4 lesions were cystic renal cell carcinomas),2 chromophobe cell carcinomas,4 papillary cell carcinomas and4 transitional cell carcinomas;10 lesions were benign,including 6 renal angiomyolipomas,3 renal cysts and 1 renal juxtaglomerular cell tumor.Enhancement patterns of CEUS and contrast-enhanced CT in the majority of 42 renal malignant lesions showed 'fast-in and fast-out' and 'hyper-enhanced'.The enhancement patterns of the majority of 10 renal benign lesions showed 'slow-in and slow-out' and 'hypo-enhanced' in CEUS and 'fast-in and slow-out' and 'hypo-enhanced' in contrast-enhanced CT.The diagnostic sensitivity,specificity,accuracy of benign and malignant space occupying renal lesions was 88.1%,80.0% and 86.5% for CEUS and 90.5%,60.0% and 82.7% for contrast-enhanced CT respectively,and there was no statistical significance(Fisher's exact test,P=1.000,0.628 and 0.780,respectively).Conclusions CEUS and contrast-enhanced CT may also be of value in evaluating and differentiating renal tumors.The combination of CEUS with contrast-enhanced CT is helpful to obtain the definite diagnosis of renal masses.