Correlation between renal blood flow and intrarenal Doppler measurements in canine autotransplanted kidney.

For proper interpretation of the changes in intrarenal Doppler ultrasound measurements, we evaluated the direct correlation between total renal blood flow and intrarenal Doppler parameters. Under progressive constriction of the renal artery in canine autotransplanted kidneys. we simultaneously measured blood flow at the main renal artery and Doppler parameters at the segmental artery. The changes in total renal blood flow were well correlated to changes in peak systolic velocity, end diastolic velocity and resistive index (RI) of the segmental artery (r = 0.964, 0.960 and 0.486, respectively). The acute reduction of total renal blood flow produces a linear decrease in Doppler parameters at intrarenal arteries. These results should be helpful for better understanding the changes in renal hemodynamics in various pathologic conditions as well as those induced by various vasoactive agents including angiotensin converting enzyme inhibitor.