ADJUSTED RESISTIVE INDEX - A METHOD TO ESTIMATE RAPIDLY RENAL BLOOD-FLOW - PRELIMINARY VALIDATION IN HYPERTENSIVES

The Doppler RI, measured in a blinded fashion, was correlated with RBF , RVR, and GFR calculated by simultaneous clearance measurements. Nine hypertensive patients were studied weekly while receiving increasing doses of the vasodilator minoxidil. In 36 studies, RI was significantl y correlated with RBF (r = -0.42) but not with RVR or GFR. When RI val ues were adjusted for ERV, correlations strikingly improved and were f urther improved by adjustment for pulse pressure. The ARI allowed semi quantitative predictions of RBF and RVR more accurately than blood ure a nitrogen or serum creatinine levels. Correlation with GFR was weak.