title: Distributions of Magnetic Resonance Diffusion and Spectroscopy Measures with Traumatic Brain Injury.
abstract: Magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) studies have demonstrated that measures of altered metabolism and axonal injury can be detected following traumatic brain injury. The aim of this study was to characterize and compare the distributions of altered image parameters obtained by these methods in subjects with a range of injury severity and to examine their relative sensitivity for diagnostic imaging in this group of subjects. DTI and volumetric magnetic resonance spectroscopic imaging data were acquired in 40 subjects that had experienced a closed-head traumatic brain injury, with a median of 36 d post-injury. Voxel-based analyses were performed to examine differences of group mean values relative to normal controls, and to map significant alterations of image parameters in individual subjects. The between-group analysis revealed widespread alteration of tissue metabolites that was most strongly characterized by increased choline throughout the cerebrum and cerebellum, reaching as much as 40% increase from control values for the group with the worse cognitive assessment score. In contrast, the between-group comparison of DTI measures revealed only minor differences; however, the Z-score image analysis of individual subject DTI parameters revealed regions of altered values relative to controls throughout the major white matter tracts, but with considerable heterogeneity between subjects and with a smaller extent than the findings for altered metabolite measures. The findings of this study illustrate the complimentary nature of these neuroimaging methods.
authors.affiliation: 1 Department of Radiology, University of Miami School of Medicine , Miami, Florida.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Maudsley
authors.affiliation: 1 Department of Radiology, University of Miami School of Medicine , Miami, Florida.
authors.forename: Varan
authors.initials: V
authors.lastname: Govind
authors.affiliation: 2 Department of Neurology, University of Miami School of Medicine , Miami, Florida.
authors.forename: Bonnie
authors.initials: B
authors.lastname: Levin
authors.affiliation: 1 Department of Radiology, University of Miami School of Medicine , Miami, Florida.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Saigal
authors.affiliation: 1 Department of Radiology, University of Miami School of Medicine , Miami, Florida.
authors.forename: Leo
authors.initials: L
authors.lastname: Harris
authors.affiliation: 1 Department of Radiology, University of Miami School of Medicine , Miami, Florida.
authors.forename: Sulaiman
authors.initials: S
authors.lastname: Sheriff
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: MR spectroscopy; Z-score image analysis; diffusion tensor imaging; traumatic brain injury