Visualization of tumor vessels in renal tumors: Comparison between power Doppler ultrasonography and angiography

Purpose: To compare the ability of power Doppler ultrasonography (PDUS) with that of renal angiography for assessment of renal tumor vessels. Material and Methods: We performed PDUS and angiography in 52 histologically proven renal parenchymal tumors (50 renal cell carcinomas (RCCs) and 2 oncocytomas), and compared vascularity on PDUS and angiography. The vascularity of PDUS was graded as follows: grade 0 - no recognizable tumor vessel; grade 1 - hypovascular to surrounding renal interlobar arteries; grade 2 - hyper-or isovascular to surrounding renal interlobar arteries. Results: With PDUS, 41 tumors were grade 2 and 11 were grade 1. With angiography, 44 lesions had iso/hypervascular pattern, 6 hypovascular pattern, and 2 were judged to be avascular. Among 44 iso/hypervascular tumors, 41 were grade 2, and 3 were grade 1. These latter 3 were located deeper than 7 cm. Six hypovascular tumors and 2 avascular tumors were grade 1. The 2 avascular tumors were small and hypovascular. The κ-level of agreement was 0.81. Conclusion: There was very good agreement betweeen PDUS and angiography in visualizing renal tumor vessels. PDUS appears appropriate for assessing renal tumor vascularity as compared to angiography in small and hypovascular lesions, but deep location reduced the detectability of tumor vessels with PDUS.