1. Myelin Water Fraction Imaging of the Brain in Children with Prenatal Alcohol Exposure
- Author
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Tim F. Oberlander, Christine Loock, Alex L. MacKay, Kaitlyn McLachlan, James N. Reynolds, Irene M. Vavasour, Christian Beaulieu, and Ursula Brain
- Subjects
Male ,Internal capsule ,Adolescent ,Caudate nucleus ,030508 substance abuse ,Medicine (miscellaneous) ,Splenium ,Toxicology ,Corpus callosum ,White matter ,03 medical and health sciences ,0302 clinical medicine ,Pregnancy ,medicine ,Humans ,Child ,Myelin Sheath ,British Columbia ,medicine.diagnostic_test ,business.industry ,Putamen ,Brain ,Magnetic resonance imaging ,Anatomy ,Magnetic Resonance Imaging ,White Matter ,Psychiatry and Mental health ,medicine.anatomical_structure ,Fetal Alcohol Spectrum Disorders ,Female ,0305 other medical science ,business ,030217 neurology & neurosurgery ,Diffusion MRI - Abstract
Background Prenatal alcohol exposure (PAE) is linked to alterations of cerebral white matter, including volume and nonspecific diffusion magnetic resonance imaging (MRI) indices of microstructure in humans. Some animal models of PAE have demonstrated myelination deficiencies, but myelin levels have not yet been evaluated in individuals with PAE. Multiecho T2 MRI offers a quantitative method to estimate myelin water fraction (MWF; related to myelin content) noninvasively, which was used here to evaluate brain myelination in children with PAE. Methods Participants with PAE (n = 10, 6 females, mean age 13.9 years, range 7 to 18 years) and controls (n = 14, 11 females, mean age 13.2 years, range 9 to 16 years) underwent 3T MRI of the brain. T2 images (15 minutes acquisition for 32 echoes) were used to create MWF maps from which mean MWF was measured in 12 regions of interest (ROIs) including 8 in white matter and 4 in deep gray matter. Results As expected, across the combined sample, MWF was highest for major white matter tracts such as the internal capsule and genu/splenium of the corpus callosum (10 to 18%) while the caudate and putamen had MWF less than 5%. Mean MWF was similar across 11/12 brain white and gray matter regions for the PAE and control groups (L/R internal capsule, major forceps, putamen, caudate nucleus, L minor forceps, genu and splenium of corpus callosum). In the PAE group, MWF was positively correlated with age in the genu of corpus callosum and right minor forceps, notably 2 frontal tracts. Conclusions Given comparable MRI-derived myelination fraction measures in PAE relative to controls, white matter alterations shown in other imaging studies, such as diffusion tensor imaging, may reflect microstructural anomalies related to axon caliber and density.
- Published
- 2019
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