ADC mapping of normal human brain.
BACKGROUND
The quantification of diffusion conditions in normal human brain has been gaining more and more attention since diffusion weighted imaging (DWI) was proved to be an important tool in the evaluation of cerebral pathologies, especially regarding the diagnosis of hyperacute stroke. The purpose of this study was to investigate the apparent diffusion coefficient (ADC) and anisotropy index (AI) in normal human brain to evaluate physiological ADC values for an ADC mapping of different brain regions.


METHODS
22 regions of interest (ROIs) in the ADC maps of 53 volunteers showing no cerebral pathologies were measured in the gray and white matter of the frontal, parietal and occipital lobes, the corpus callosum, and the lateral ventricles.


RESULTS
Apparent diffusion is quite inhomogeneous for different brain regions. In both subcortical white matter (ADC: 525 x 10(-8) mm2/s, AI: 0.05) and in gray matter (ADC: 1486 x 10(-8) mm2/s, AI: 0.05) diffusion was isotropic, while in periventricular white matter (ADC: 408 x 10(-8) mm2/s, AI: 0.34) and the corpus callosum (ADC: 799 x 10(-8) mm2/s, AI: 0.77) anisotropic.


CONCLUSIONS
With the exception of children and young adults, ADC seems to be intra- and interindividually constant, with no sex or age dependency for the patient sample we investigated (mean age: 62+/-9.4 years). Hence the measurement of ADC may provide an index of lesion severity.
Ahlhelm
Frank
F
Department of Neuroradiology, University of Saarland, Homburg, Germany. frah1@gmx.de
Hagen
Thomas
T
Schneider
Guenther
G
Dorenbeck
Ulrich
U
Nabhan
Abdullah
A
Reith
Wolfgang
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016880:Anisotropy; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged