Models of renal blood flow and their use in the detection of renal artery stenosis.

First-pass studies of renal blood flow using 99Tcm-DTPA have been analysed in normotensive patients and those with renal artery stenosis. One and two component models of renal blood flow were examined for their ability to discriminate between these two groups. Using a two component model, 5/7 kidneys with proven renal artery stenosis were identified, with 38/40 kidneys in normotensive patients lying within the defined normal range. The two kidneys not detected by this technique both had extremely poor function. This model was also applied to other hypertensive patients referred for routine screening and appears promising in increasing the specificity of the 99Tcm-DTPA study for detecting renal artery stenosis.