at 30 minutes after intravenous administration of the glomerular renal agent tc-99m-dtpa, both right and left lateral views were obtained. we analyzed the ratio of optical densities (behind the ureter/in front of the ureter). in patients without gross renal failure or retroperitoneal disease, the ratio was always less than 1 (range 0.38 to 0.95, mean 0.68). this represents greater perfusion of ...
