Voxel-based analysis of white matter during adolescents and young adults
QIU Ming-guo1, LI Qi-yu2, LIU Guang-jiu2, XIE Bing3, WANG Jian3
1. Department of Medical Informatics and Imaging, College of Biomedical Engineering and Medical Imaging,Third Military Medical University, Chongqing 400038, China;2. Department of Anatomy, Third Military Medical University, Chongqing 400038, China;3. Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
Abstract：Objective: To evaluate differences in white matter by voxel-based analysis in healthy adolescents and young adults. Materials and Methods: Echo-planar diffusion-tensor magnetic resonance(MR) imaging was performed in 3 groups of healthy subjects aged 11~13 years, 16~18 years and 23~25 years. Linear correlative analysis was performed for fractional anisotropy(FA) and mean diffusivity(MD) with age, as well as an intergroup t-test comparison for FA and MD maps. All tests on FA were performed using an absolute threshold of FA>0.15, and set all MD>0.001 to zero. Results: Significant positive correlation of FA with age was found in the internal capsule, the frontal and parietal white matter, the genu and body of the corpus callosum. Statistically significant negative correlation of the MD with age was found in the peripheral frontal and parietal white matter. The minimal overlap in decreases of the MD and increases of FA may indicate that they mainly reflect different physiologic processes. Conclusion: Diffusion-tensor MR imaging results indicate that white matter maturation assessed at different ages involves increases in both white matter density and organization during adolescents and young adults. The FA and MD may reflect different physiologic processes in healthy adolescents and young adults.
2009, Vol. 20 
