Ultrasound of renal tumors

Despite the limitations of US in providing a complete evaluation of renal t umors before treatment planning, initial screening, characterization of ren al masses and staging of RCCs can benefit from some recent advances of the technique. One of the most relevant clinical benefits of US is the increase d early detection of RCCs. Recent technical improvement of gray-scale imagi ng has increased US performance in the detection of small renal tumors. Com bined gray-scale and color Doppler US findings may strongly suggest the his topathologic nature of a renal tumor with respect to the size, the US atten uation characteristics, and the vascular distribution of the lesion. Ultras ound contributes additional diagnostic information for differential diagnos is of some renal masses that remain equivocal at CT, including: atypical cy stic lesions; solid renal tumors with poor vascularity; and angiomyolipomas with minimal fat component. Ultrasound also may provide additional diagnos tic information over CT in selected cases of RCCs with venous invasion. In addition to some diagnostic and therapeutic procedures that can benefit fro m US guidance, intraoperative US remains the only available tool that enabl es to ensure renal-parenchymal-sparing surgery.