Renal apparent diffusion coefficients (ADCs) were anisotropic within and significantly different between cortex and medulla using a relatively motion-insensitive one-dimensional technique in 20 volunteers. ADC values ranged from 1.79 +/- .39 to 2.95 +/- .58 (x 10(-3)mm2/sec), relatively high but similar to other reports. Further investigation may help clarify this data, and determine whether the findings result from diffusion properties (and/or radially oriented parenchymal architecture), or artifacts due to factors such as bulk motion.