CONTRAST-ENHANCED ULTRASOUND IN DIFFERENTIAL DIAGNOSIS BETWEEN ANGIOMYOLIPOMA AND RENAL CELL CARCINOMA

Literature data on differential diagnosis between benign and malignant kidney tumours with CEUS is controversial. The purpose of this study was to evaluate the usefulness of Contrast-Enhanced Ultrasound (CEUS) in differentiating between renal cell carcinoma (RCC) and renal angiomyolipoma (AML). We examined 48 patients 16 with AML and 32 with RCC. We estimated the size, shape, blood flow of the formation using Conventional and Doppler Ultrasound and by CEUS we evaluated the contrasting of the formation and we did analyses of time-intensity curves (TIC). Triplex ultrasound described formations of different sizes from 10 to 70 mm, with a heterogeneous structure in RCC. By Doppler ultrasound we found a lack of blood supply at 11/16 or peripheral blood supply at 2/16 AML and neovascularisation at 30/32 RCC. By CEUS - angiomyolipoma was contrasted from the periphery to the centre with hyper-enhancement in the late phase and homogenous distribution of contrast agent in the formation, while in RCC the entering of the contrast agent was chaotic, with heterogeneous enhancement. We found two types of TIC, which were the same for AML and RCC - slow wash-in and -out, and the second one - rapid wash-in and slow wash -out. In the first type of TIC our results showed that MTT (Mean transit time) and TTP (Time to peak) were shorter at AML with presence of hyper-enhanced formation (p < 0.05). In the second type of curve - MTT was longer in RCC (p < 0.05).