[Study on age and white matter neuronal integrity in healthy volunteers based on automating fiber-tract quantification].

Objective: To analyze age-related change in cerebral matter tract, especially fractional anisotropy, based on automating fiber-tract quantification(AFQ). Methods: A total of 64 years old normal persons and 43 young volunteers were enrolled respectively from the Affiliated Drum Tower Hospital of Nanjing University Medical School and community from January 2015 to June 2016.All of them underwent MRI scan, which included DTI and 3D T(1)WI sequence .All cases were divided into 3 groups according to their ages, the young group 20-35 years old, the middle old group 60-75 years old, the old group 76-90 years old.AFQ was used to identify 20 major white matter tracts in brains of all subjects and make measurements at anatomically equivalent locations along their trajectories. Results: The FA change trend of each fiber was similar among three groups. The old and the middle old group had different FA value in both sides of inferior fronto-occipital fasciculus(left t =-2.73, right t =-6.12, P <0.05), thalamic radiation(left t =-4.79, right t =-19.61, P <0.05), arcuate(left t =10.53, right t =-2.72, P <0.05), callosum forceps(genu t =-2.66, splenium t =28.64, P <0.05), cingulum(left t =-4.53, right t =-2.22, P <0.05)and right corticospinal tract( t =3.10, P <0.05), among which each location of callosum forceps minor was different between the old group and the young group, and this area decreased in the middle group. The old group had different FA value in both sides of uncinate fasciculus(left t =-4.52, right t =-4.53, P <0.05), left corticospinal tract( t =-2.19, P <0.05)and right inferior longitudinal fasciculus( t =11.12, P <0.05). Compared to the young group, there was no statistical difference in the FA of both superior longitudinal fasciculus and left inferior longitudinal fasciculus in the old and the middle old group. Conclusion: AFQ has an impact on the further specific study of the age-related white matter tract.