Limits of sensitivity of radiopertechnetate flow studies in the detection of asymmetrical renal perfusion

A canine model has been devised using electromagnetic flowmeter probes to study the sensitivity of radiopertechnetate renal angiography. Highly significant correlations were obtained when the measured flow rates were compared with normalized values of the peak activity and uptake slopes for each kidney. Analysis of the data suggests the unilateral renal disease associated with less then 20% difference in flow between the kidneys may not be diagnosed reliably from the pertechnetate perfusion test.