PULSATILITY AND RESISTANCE INDEXES IN INTRARENAL ARTERIES OF NORMAL ADULTS

In order to establish the normal range of values of Pulsatility (PI) a nd Resistance (RI) Indices in the intrarenal vasculature, a study of 5 0 healthy volunteers (23 males, 27 females), divided into five groups of 10 according to age, was performed with Duplex Doppler ultrasound. Both kidneys were examined in all individuals and, in 12, indices were also compared between upper and lower poles of both kidneys. In addit ion, repeat examinations were performed in nine subjects on three diff erent days, in order to assess the reproducibility of the method. No d ifferences were found in the mean values of both indices between males and females, upper and lower poles, right and left kidneys. A statist ically significant increase (p < 0.01, unpaired t-test) was demonstrat ed when the oldest age group (7th decade) was compared to the youngest age group (3rd decade). The method appeared remarkably reproducible f or RI (4.2-7%), with wider variation in the PI (9.5-22.7%).