title: Myelin water imaging of multiple sclerosis at 7 T: correlations with histopathology.
abstract: Myelin water imaging (MWI) promises to be invaluable in understanding neurological diseases like MS. However, a limitation of MWI is signal to noise ratio. Recently, a number of investigators have performed MWI at field strengths higher than 1.5 T. Our goal was to determine if myelin water imaging at increased SNR, arising from the use of a small bore 7 T MR system with optimized coil geometry, enables the production of superior myelin water maps with increased spatial detail and enables better correlations with histology. Ten formalin-fixed MS brain samples underwent a 32-echo T(2) relaxation experiment which measured myelin water fraction (MWF) on a 7-T animal MRI scanner. MWF correlated strongly qualitatively and quantitatively with luxol fast blue staining for myelin [mean (range): R(2)=0.78 (0.56-0.95), p<0.0001]. The quality and detail of 7 T myelin water maps were far superior to that previously seen at 1.5 T, allowing for visualization of fine structures such as the normal prominent myelination of the deeper cortical layers, the alveus of the hippocampus and rings of preserved myelin in a concentric Balo's lesion. 7 T imaging will allow detailed assessment of myelin pathology to a degree not possible with lower field strengths.
authors.affiliation: Department of Radiology, University of British Columbia, Vancouver, BC, Canada. claule@physics.ubc.ca
authors.forename: Cornelia
authors.initials: C
authors.lastname: Laule
authors.forename: Piotr
authors.initials: P
authors.lastname: Kozlowski
authors.forename: Esther
authors.initials: E
authors.lastname: Leung
authors.forename: David K B
authors.initials: DK
authors.lastname: Li
authors.forename: Alex L
authors.initials: AL
authors.lastname: Mackay
authors.forename: G R Wayne
authors.initials: GR
authors.lastname: Moore
mesh_terms: D000328:Adult; D000465:Algorithms; D002549:Diffuse Cerebral Sclerosis of Schilder / Q000473:pathology; D005260:Female; D005557:Formaldehyde; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007211:Indoles; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D009186:Myelin Sheath / Q000737:chemistry / Q000473:pathology*; D016610:Tissue Embedding; D016707:Tissue Fixation; D014867:Water / Q000737:chemistry*
chemical_list: D007211:Indoles; D014867:Water; C018588:Luxol Fast Blue MBS; D005557:Formaldehyde