title: A revised model for estimating g-ratio from MRI.
abstract: A key measure of white matter health is the g-ratio, which is defined as the ratio between the inner axon radius and the outer, myelinated, axon radius. Recent methods have been proposed to measure the g-ratio non-invasively using the relationship between two magnetic resonance imaging (MRI) measures. While this relationship is intuitive, it predicates on the simplifying assumption that g-ratio is constant across axons. Here, we extend the model to account for a distribution of g-ratio values within an imaging voxel, and evaluate this model with quantitative histology from normal and hypomyelinated mouse brains.
authors: Department of Biomedical Engineering, Vanderbilt University, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University, USA.
authors: Kathryn L
authors: KL
authors: West
authors: Department of Biomedical Engineering, Vanderbilt University, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University, USA.
authors: Nathaniel D
authors: ND
authors: Kelm
authors: Department of Pediatric Neurology, Vanderbilt University, USA.
authors: Robert P
authors: RP
authors: Carson
authors: Department of Biomedical Engineering, Vanderbilt University, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University, USA; Department of Radiology and Radiological Sciences, Vanderbilt University School of Medicine, USA; Department of Electrical Engineering, Vanderbilt University, USA. Electronic address: mark.does@vanderbilt.edu.
authors: Mark D
authors: MD
authors: Does
mesh_terms: D000818:Animals; D003337:Corpus Callosum / Q000473:pathology*; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D018345:Mice, Knockout; D009186:Myelin Sheath / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D066127:White Matter / Q000473:pathology*
keywords: Histology; Magnetic resonance imaging; Myelin; g-ratio