title: A pathology-MRI study of the short-T2 component in formalin-fixed multiple sclerosis brain.
abstract: OBJECTIVE
  To determine the pathologic basis of areas not exhibiting signal of the short-T2 component of the T2 relaxation distribution in MS, as studied in formalin-fixed brain.
  
  
  BACKGROUND
  A myelin-specific MRI signal would be of great importance in assessing demyelination in patients with MS. Evidence indicates that the short-T2 (10 to 50 millisecond) component of the T2 relaxation distribution originates from water in myelin sheaths. The authors present two cases of MS in which the anatomic distribution of the short-T2 component was correlated with the pathologic findings in postmortem formalin-fixed brain.
  
  
  METHODS
  One half of the formalin-fixed brain was suspended in a gelatin-albumin mixture cross-linked with glutaraldehyde, and scanned with a 32-echo MRI sequence. The brain was then cut along the center of the 5-mm slices scanned, photographed, dehydrated, and embedded in paraffin. Paraffin sections, stained with Luxol fast blue and immunocytochemically for 2',3'-cyclic nucleotide 3'-phosphohydrolase for myelin and by the Bielschowsky technique for axons, were compared with the distribution of the amplitude of the short-T2 component of the comparable image slices.
  
  
  RESULTS
  The anatomic distribution of the short-T2 component signal corresponded to the myelin distribution. Chronic, silent MS plaques with myelin loss correlated with areas of absence of short-T2 signal. The numbers of axons within lesions were reduced, but many surviving axons were also seen in these areas of complete loss of myelin.
  
  
  CONCLUSIONS
  In formalin-fixed MS brains the short-T2 component of the T2 relaxation distribution corresponds to the anatomic distribution of myelin. Chronic, silent demyelinated MS plaques show absence of the short-T2 component signal. These results support the hypothesis that the short-T2 component originates from water related to myelin.-1510
authors.affiliation: Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, BC, Canada. wmoore@vanhosp.bc.ca
authors.forename: G R
authors.initials: GR
authors.lastname: Moore
authors.forename: E
authors.initials: E
authors.lastname: Leung
authors.forename: A L
authors.initials: AL
authors.lastname: MacKay
authors.forename: I M
authors.initials: IM
authors.lastname: Vavasour
authors.forename: K P
authors.initials: KP
authors.lastname: Whittall
authors.forename: K S
authors.initials: KS
authors.lastname: Cover
authors.forename: D K
authors.initials: DK
authors.lastname: Li
authors.forename: S A
authors.initials: SA
authors.lastname: Hashimoto
authors.forename: J
authors.initials: J
authors.lastname: Oger
authors.forename: T J
authors.initials: TJ
authors.lastname: Sprinkle
authors.forename: D W
authors.initials: DW
authors.lastname: Paty
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*