The perfomance of small renal cell carcinoma with contrast-enhanced ultrasonography

Objective To compare features between color Doppler flow imaging(CDFI) and contrast-enhanced ultrasonography(CEUS) in the diagnosis of small renal cell carcinoma(SRCC) and investigate the diagnostic value of CEUS. Methods The images of CDFI and CEUS examination were retrospectively analyzed in forty-five SRCC (≤3 cm in diameter) which were confirmed sequentially by operation and pathology. Inner echoes,boundary,dark-ring and color flow of tumors were observed by CDFI. The degree of tumor vascularity was subjectively graded from 0 to Ⅳ. Enhancement patterns and phases on uhrasonography were reviewed, including enhancement start time, peak time, wash-out time and enhancement appearances of SRCC. Results The images were observed as homogeneous or relatively homogeneous (19) and heterogeneous or relatively heterogeneous(26), clear boundaries(37, including 10 with dark-ring) and ill-defined margins(8). The tumor vascularity was showed as grade 0(5) ,grade Ⅰ (6),grade Ⅱ (14),grade Ⅲ (14),grade Ⅳ(6) on CDFI. All lesions were showed mean enhancement start time (13.84±3.80) seconds,peak time (19.49±4.73) seconds,wash-out time (26.91±5.86) seconds respectively on CEUS. All cases were observed as simultaneous wash-in(39) and gradually wash-in(6),hyperechoic(14) and isoechoic(22) and hypoechoic(9) in peak time, simultaneous wash-out (19) and rapidly wahs-out (19) and gradually wahs-out(7). After contrast medium injection, tumors were detected partly non-enhaneement or cellular enhancement (25) and pseudocapsule (20). Conclusions CEUS is effective in improving the sonographic visualization of tumoral vascularity ,internal structure and pseudocapsule. It plays an important role in the diagnosis of SRCC. Key words: Ultrasonography, Doppler, color;  Microbubbles;  Kidney neoplasms