[Intrarenal arterial Doppler sonography in patients with various renal disease: correlation of resistive index with biopsy findings].

Duplex Doppler sonography (ultrasonic equipment: Toshiba SSA-270A) were performed in the patients with various renal disease (male 44, female 32) admitted to our hospital between June 1990 and August 1991. Interlobar arterial blood flow velocity was measured at the side of renal pyramid through a longitudinal scan. Both the maximum blood flow velocity (Vmax) and the minimum blood flow velocity (Vmin) were measured quantitatively and resistive index (RI: defined as (Vmax-Vmin)/Vmax) were calculated. Vmax and Vmin correlated well with the creatinine clearance (Ccr) (r = 0.56, r = 0.66 respectively), whereas RI, by which we can detect Doppler waveform changes, correlated weak with Ccr (r = 0.39). We found twenty-nine patients (40%) with an elevated RI (greater than or equal to 0.70). They had severe renal dysfunction and active pathologic findings in the tubulo-interstitial or vascular compartment of the kidney. Doppler examination of renal blood flow velocity was valuable not only to estimate renal function but also to assess pathophysiology of renal disease.