Longitudinal analysis of quantitative brain MRI in astronauts following microgravity exposure Journal Article

  

Authors:	Riascos, R. F.; Kamali, A.; Hakimelahi, R.; Mwangi, B.; Rabiei, P.; Seidler, R. D.; Behzad, B. B.; Keser, Z.; Kramer, L. A.; Hasan, K. M.
Article Title:	Longitudinal analysis of quantitative brain MRI in astronauts following microgravity exposure
Abstract:	BACKGROUND AND PURPOSE: Assessment of the effects of microgravity on astronauts’ brains using microstructural measures by utilizing quantitative MRI, before and after spaceflight would help understand the structural changes. METHODS: Quantitative MRI data sets in 19 astronauts were acquired before and after space missions. Both diffusion tensor metrics and volumetric measures were analyzed in the brain regions involved in the visual function. RESULTS: The fractional anisotropy was reduced in the right posterior thalamic radiations (P =.0009) and remained significant after a false discovery rate (FDR) correction (P =.03). A trend of increase in the mean diffusivities of different subregions of the occipital cortex on the right side, including calcarine, middle occipital, inferior occipital, and fusiform gyri, was noted and became insignificant after FDR correction. Similarly, there was a trend of cortical thinning involving the right occipital lobe and bilateral fusiform gyri, volume reduction of the left thalamus, and increase in lateral ventricular volume in the postflight scans. CONCLUSION: Gray and white matter alterations are detected by quantitative MRI before and after space flight. Our findings may be used to understand the neuroanatomical mechanisms of possible brain dysfunction or neuroplasticity in microgravity condition in the future studies. © 2019 by the American Society of Neuroimaging
Keywords:	adult; nuclear magnetic resonance imaging; retrospective study; brain; quantitative analysis; nerve cell plasticity; vision; diffusion weighted imaging; brain region; white matter; normal human; longitudinal study; human experiment; primary somatosensory cortex; brain size; diffusion tensor imaging; exposure; gray matter; neuroanatomy; thalamus; occipital lobe; fractional anisotropy; mean diffusivity; lateral brain ventricle; cosmonaut; space flight; human; male; female; article; dti; occipital cortex; quantitative mri; microgravity; astronaut; cortical thickness (brain); entorhinal cortex; fusiform gyrus; middle occipital gyrus
Journal Title:	Journal of Neuroimaging
Volume:	29
Issue:	3
ISSN:	1051-2284
Publisher:	Wiley Blackwell
Date Published:	2019-05-01
Start Page:	323
End Page:	330
Language:	English
DOI:	10.1111/jon.12609
PUBMED:	30784130
PROVIDER:	scopus
DOI/URL:	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061912542&doi=10.1111%2fjon.12609&partnerID=40&md5=26f1f2720d7e954f7ce0437d2695ab0c
Notes:	Article -- Export Date: 3 June 2019 -- Source: Scopus

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