Radiology, Vol 193, 711-715, Copyright © 1994 by Radiological Society of North America
Functional imaging of the kidney by means of measurement of the apparent diffusion coefficient
MF Muller, PV Prasad, D Bimmler, A Kaiser and RR Edelman
Department of Radiology, Harvard Medical School, Boston, MA 02215.
PURPOSE: To determine the relationship between the apparent diffusion
coefficient (ADC) and renal function. MATERIALS AND METHODS: Twenty- three
volunteers and seven pigs underwent diffusion-sensitive magnetic resonance
(MR) imaging of the kidneys with a stimulated-echo acquisition mode
excitation and echo-planar imaging readout under various physiologic
conditions. The effect of hydration and anisotropic diffusion was studied
in human subjects, and the effect of renal artery stenosis, ureteral
obstruction, and diuresis was studied in the animal model. RESULTS: The
renal ADC values of dehydrated subjects were substantially increased with
rehydration. Diffusion was highest in the medulla, with a pronounced radial
component in the renal collecting system. In the pig model, induced renal
artery stenosis resulted in immediate decrease in renal ADC; the degree of
change was related to the flow deficit. The ADC also decreased with
ureteral obstruction, but diuresis had no meaningful effect. CONCLUSION: In
vivo measurement of ADC has the potential for use as a noninvasive means to
explore the functional status of the kidney.
