Diagnosis of renovascular disease by intra- and extrarenal Doppler scanning

The purpose of this prospective, angiographically controlled study was to determine the diagnostic value of color Doppler sonography with two differing approaches of scanning in patients with clinical clues for renal artery stenosis (RAS). In 135 hypertensive patients peak systolic velocity in the main renal arteries and the resistive index (RI) of the intrarenal arteries were measured. The RI side-to-side-difference (delta RI) greater than 0.05 or peak systolic velocity greater than 2 m/s were used to discriminate normal from stenotic renal arteries, defined as angiographically confirmed RAS > 50%. In 88 of 135 patients 107 RAS were demonstrated by selective arteriography. Five renal artery occlusions occurred, which were all diagnosed by color Doppler sonography. Seventy-six RAS were detected by increased peak systolic velocity, and an additional 19 stenoses were identified by delta RI. The combined analysis of peak systolic velocity and delta RI resulted in a sensitivity of 89% and specificity of 92%. The positive predictive value was 92% and the negative predictive value was 88%. Our data suggest that only the combination of intra- and extrarenal scanning with color Doppler sonography represents an effective screening method for significant renal artery stenosis in hypertensive patients.