Reconsideration of split kidney function tests in hypertension: a new technique.

The role of the split kidney function tests in the diagnosis of renal hypertension is reviewed, and a new technique is described which is designed to diminish the number of false negative results sometimes encountered in unilateral pyelonephritis and segmental renal arterial stenosis. Split kidney function tests still have an important role in diagnosis of renal hypertension, particularly when the results of other investigations are equivocal and when facilities for differential renal renin assay are not available.