Changes of Brain Water Apparent Diffusion Coefficient with Age

Objective To determine the effect of aging on ADC values of human brain.Materials and Meth-ods One hundred and twenty health adults(60 men and 60 women)were divided into six age groups:20-29,30-39,40-49,50-59,60-69 years old and 70 years or older(n=20 each,10 man and 10 women).All subjects were underwent conventional MRI and diffusion weighted imaging with fluid attenuated inversion recovery(FLAIR)in three orthogonal directions with two b values(0 and 1000 s/mm2)at 3.0 T MR.Bilateral ADC values were determined in 19 regions of interest encompassing the entire brain.Results ADC values of the whole brain was(7.41±0.56)×10-4 mm2/s.The ADC values significantly differed in various age groups in parietal gray and white matter,frontal gray and white matter,occipital gray matter,temporal white matter,cerebellar white matter,putamen,thalamus,internal capsule,centrum semiovale,cingulate gyrus,genu of corpous callosum.And these phenomenons became obvious after 60 years old.The ADC values significantly increased with advancing age in parietal white matter(R=0.188,P0.05),frontal white matter(R=0.451,P0.01),centrum semiovale(R=0.365,P0.01)and the genu of corpous callosum(R=0.248,P0.01),gray matter of frontal lobe(R=0.193,P0.05),thalamus(R=0.556,P0.01).Conclusion The ADC values significantly increase with age mainly in the white matter,this tendency can also be seen in gray matter of frontal lobe and the thalamus.