Measurement of the apparent diffusion coefficient in diffuse renal diseaseby diffusion-weighted echo-planar MR imaging

The purpose of this study was to determine the relationship between the app arent diffusion coefficient (ADC) and diffuse renal disease by diffusion-we ighted echolanar magnetic resonance (MR) imaging [EPI], Thirty-four patient s were examined with diffusion-weighted EPI, The average ADC values were 2. 55 x 10(-3) mm(2)/sec for the cortex and 2.84 x 10(-3) mm(2)/sec for the me dulla in the normal kidneys. The ADC values in both the cortex and medulla in chronic renal failure [CRF] kidneys and in acute renal failure [ARF] kid neys were significantly lower than those of the normal kidneys. In renal ar tery stenosis kidneys, the ADC values in the cortex were significantly lowe r than those of the normal and the contralateral kidneys, In the cortex, AD C values were above 1.8 x 10-3 mm(2)/sec in all 32 normal kidneys, ranging from 1.6 to 2.0 x 10(-3) mm(2)/sec in all 8 ARF kidneys, and below 1.5 x 10 -3 mm(2)/sec in 14 of 15 CRF kidneys. In the medulla, there was considerabl e overlap in the ADC values of the normal and diseased kidneys. There was a linear correlation between ADC value and sCr level in the cortex (r = 0.75 ) and a weak linear correlation in the medulla (r = 0,60), Our results show that diffusion-weighted MR imaging may be useful to identify renal dysfunc tion, (C) 1999 Wiley-Liss, Inc.