DOPPLER SONOGRAPHY IN THE DIAGNOSIS OF ANTEPARTUM PYELONEPHRITIS - VALUE OF INTRARENAL RESISTIVE INDEX MEASUREMENTS

This study aims to define the effects of pyelonephritis on intrarenal resistive indices and to determine the role of Doppler sonography in t he diagnosis of pyelonephritis in pregnant patients. Twenty pregnant w omen with pyelonephritis underwent renal Doppler sonography with calcu lation of intrarenal resistive indices. The resistive index was calcul ated for the upper, lower, and interpolar areas of each kidney in the patients with pyelonephritis (40 kidneys) and was compared to the resi stive indices for a control group of 153 normal asymptomatic pregnant women (306 kidneys). Doppler findings were correlated with the locatio n (sidedness) of flank pain in the pyelonephritis group. The mean resi stive index values of patients with pyelonephritis were 0.04 higher th an in the controls, and this difference was statistically significant (P < 0.001). Four patients with pyelonephritis had a mean resistive in dex greater than or equal to 0.70, whereas the remaining 16 patients h ad resistive indices within the normal range of less than or equal to 0.70. In patients with confirmed pyelonephritis and unilateral pain, t he average resistive index in the kidney on the side of pain was 0.03 greater than that on the asymptomatic side (P = < 0.01). The mean rena l resistive index is significantly greater in pregnant patients with p yelonephritis than in pregnant women without pyelonephritis. Even so, the magnitude of the differences in resistive index is too small and t he overlap between the groups too large for this parameter to be of di scriminating clinical value.