title: Diffusion tensor quantification of the human midsagittal corpus callosum subdivisions across the lifespan.
abstract: The midsagittal corpus callosum (CC) cross-sectional area subdivisions have been used as early and sensitive markers of human brain white matter connectivity, development, natural aging and disease. Despite the simplicity and conspicuity of the appearance of the CC on anatomical magnetic resonance imaging (MRI), the published quantitative MRI literature on its regional sex and age trajectories are contradictory. The availability of noninvasive quantitative methods to assess the CC regions across the human lifespan would help clarify its contribution to behavior and cognition. In this report, we extended the utility of a recently described semi-automated diffusion tensor imaging (DTI) tissue segmentation method to utilize the high orientation contrast of the CC on DTI. Using optimized DTI methods on a cohort of 121 right-handed children and adults aged 6-68 years, we examined the CC areas and corresponding DTI metrics of the different functionally specialized sectors of the CC. Both the area and fractional anisotropy metrics followed inverted U-shaped curves, while the mean and radial diffusivities followed U-curves reflecting white matter progressive and regressive myelination dynamics that continue into young adulthood.
authors.affiliation: Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, MSB 2.100, Houston, Texas 77030, USA. Khader.M.Hasan@uth.tmc.edu
authors.forename: Khader M
authors.initials: KM
authors.lastname: Hasan
authors.forename: Arash
authors.initials: A
authors.lastname: Kamali
authors.forename: Larry A
authors.initials: LA
authors.lastname: Kramer
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Papnicolaou
authors.forename: Jack M
authors.initials: JM
authors.lastname: Fletcher
authors.forename: Linda
authors.initials: L
authors.lastname: Ewing-Cobbs
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001921:Brain / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology; D002648:Child; D003337:Corpus Callosum / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012737:Sex Factors