Quantitative renal blood flow in urinary tract obstruction.

Technetium-labeled red blood cell scintigraphy using a bolus injection was used to obtain a noninvasive quantitative measurement of renal blood flow. The method used is an adaptation of the one used for calculating cerebral blood flow which involves deconvolution of the first pass of the isotope through the kidneys. The relative renal blood flow of 18 normal patients and 18 patients with unilateral urinary tract obstruction was performed. All patients with obstruction, but one, were reexamined after surgery. There was a significant difference between the normal and partially obstructed patients (p less than 0.001) and between those with partial and complete obstruction (p less than 0.01). After surgery a statistically observable improvement in the relative renal blood flow was obtained.