A Comparative Study Between Contrast Enhanced Ultrasound And Acoustic Radiation Force Impulse Imaging In Differential Diagnosis Of Benign And Malignant Renal Solid Tumors

Objectives:1. To study the characteristics of contrast-enhanced ultrasound(CEUS) and acoustic radiation force impulse-imaging(ARFI) in renal masses.2. To compare the value of CEUS and ARFI in differential diagnosis of renal solid massesMethods:A total of 67 patients with suspected renal solid tumors by conventional ultrasound, CT or MRI examination were underwent CEUS and ARFI,, the CEUS was performed in the lesions and the patterns of CEUS were analyzed. Then the ARFI technique was applied, the values of shear wave velocity(SWV) of the lesions and the surrounding normal renal solid tissue were obtained. Achieveing the area under the curve(AUC) and the optimum cut-off point by using a receiver operating characteristic(ROC) curve. The sensitivity, specificity, positive predictive, negative predictive value, diagnostic accuracy rate were evaluated by the two diagnostic methods. All the test results were pathologically confirmed after operation or following-up. The analysis of benign and malignant renal tumors were performed by using CEUS and ARFI in a double blind method.Results:1. In the 67 renal solid tumors patients,there were 49 malignant lesions(44 clear cell renal cell carcinomas, 4 papillary renal cell carcinomas, 1 chromophobe renal cell carcinomas) and 18 benign lesions(8 angiomyolipomas, 2 oncocytoma, 1 renal capillary hemangioblastoma), the remaining 7 cases(6 angiomyolipomas, 1 renal pseudotumor) were examined by MRI and enhanced CT, and ultrasound followed-up for more than 8 months without change.2.In the 49 renal cell carcinoma lesions, enhancement features and patterns of CEUS were shown by fast in in 40 cases(40/49,81.63%), hyperenhancement in 42cases(42/49,85.71%), heterogeneous enhancement in 43 cases(43/49,87.76%) andperilesional rim-like enhancement(pseudocapsule) in 39 cases(39/49,79.59%); In the18 renal benign lesions, enhancement features and patterns of CEUS were shown by slowly in in 11 cases(11/18,61.11%), hypo-enhancement in 14 cases(14/18,77.78%),homogeneous enhancement in 13 cases(13/18,72.22%) and pseudocapsule in 2cases(2/18,11.11%). There were statistically difference among the patterns of CEUS of benign and malignant renal lesions(P< 0.05). With fast in, hyperenhancement,heterogeneous enhancement or pseudocapsule, the diagnostic sensitivity was 89.80%,specificity was 95.65%, positive predictive was 88.89%, negative predictive value was 76.19%, accuracy rate was 89.55% of CEUS in differential diagnosis of renal solid masses..3. The SWV values between benign or malignant tumors and the peripheral renal cortex were statistically difference(P<0. 05), and the peripheral renal cortical hardness were greater than benign and malignant tumors.4. The SWV values between benign and malignant tumors were statistically difference(P<0. 05).5. A ROC curve was made with the pathological and follow-up results, the AUC of ROC curve was 0.801. With SWV=2.30m/s as the optimum cut-off point of the diagnosis criteria of malignant tumor, the diagnostic sensitivity was 81.63%,specificity was 83.33%, positive predictive was 93.02%, negative predictive value was 62.50%, accuracy rate was 82.09% of VTQ in diagnosis of renal cell carcinoma.6. There were no statistically significance(P>0.05) between CEUS and ARFI in the differential diagnosis of benign and malignant tumors, this shows the two ultrasound technology are consistent in differential diagnosis of benign and malignant renal solid masses.Conclusion:Both CEUS and ARFI have high application value in differential diagnosis of benign and malignant renal solid masses, there were the similar sensitivity and diagnosis rate in the diagnosis of benign and malignant renal tumor with CEUS and ARFI, each method has complementary effect in differential diagnosis of benign and malignant renal tumors and provide important information for clinical diagnosis andtreatment of diseases.