title: Biomechanical Analysis of Normal Brain Development during the First Year of Life Using Finite Strain Theory.
abstract: The first year of life is the most critical time period for structural and functional development of the human brain. Combining longitudinal MR imaging and finite strain theory, this study aimed to provide new insights into normal brain development through a biomechanical framework. Thirty-three normal infants were longitudinally imaged using MRI from 2 weeks to 1 year of age. Voxel-wise Jacobian determinant was estimated to elucidate volumetric changes while Lagrange strains (both normal and shear strains) were measured to reveal directional growth information every 3 months during the first year of life. Directional normal strain maps revealed that, during the first 6 months, the growth pattern of gray matter is anisotropic and spatially inhomogeneous with higher left-right stretch around the temporal lobe and interhemispheric fissure, anterior-posterior stretch in the frontal and occipital lobes, and superior-inferior stretch in right inferior occipital and right inferior temporal gyri. In contrast, anterior lateral ventricles and insula showed an isotropic stretch pattern. Volumetric and directional growth rates were linearly decreased with age for most of the cortical regions. Our results revealed anisotropic and inhomogeneous brain growth patterns of the human brain during the first year of life using longitudinal MRI and a biomechanical framework.
authors.affiliation: Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.|Department of Diagnostic Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
authors.forename: Jeong Chul
authors.initials: JC
authors.lastname: Kim
authors.affiliation: Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.|Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.|Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
authors.affiliation: Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.|Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
authors.forename: Weili
authors.initials: W
authors.lastname: Lin
mesh_terms: D001696:Biomechanical Phenomena; D001921:Brain / Q000000981:diagnostic imaging / Q000254:growth & development*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000254:growth & development*; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000254:growth & development; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000254:growth & development; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D009778:Occipital Lobe / Q000000981:diagnostic imaging / Q000254:growth & development; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000254:growth & development*