title: Quantification of cervical cord pathology in primary progressive MS using diffusion tensor MRI.
abstract: OBJECTIVE
  To investigate the extent and severity of cervical cord damage using diffusion tensor MRI (DT-MRI) and histogram analysis in patients with primary progressive MS (PPMS).
  
  
  METHODS
  Diffusion-weighted sensitivity-encoded (SENSE) echoplanar images of the cervical cord and brain dual-echo and diffusion-weighted scans were acquired from 24 patients with PPMS and 13 healthy controls. Cord and brain mean diffusivity and fractional anisotropy histograms were produced. An analysis of variance model, adjusting for cord volume, was used to compare cord DT-MRI parameters from controls and patients.
  
  
  RESULTS
  Compared to healthy controls, PPMS patients had reduced cervical cord cross-sectional area and average cord fractional anisotropy (p = 0.007), and increased cord mean diffusivity (p = 0.024). No correlations were found between DT-MRI metrics of the cord and quantities obtained from conventional and DT-MRI of the brain.
  
  
  CONCLUSIONS
  DT-MRI of the cervical cord can quantify the extent of diffuse cord pathology in patients with PPMS. Such cord diffusivity changes in patients with PPMS are likely to reflect irreversible axonal injury and reactive gliosis and seem to be independent of brain damage.
authors.affiliation: Neuroimaging Research Unit, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Agosta
authors.forename: B
authors.initials: B
authors.lastname: Benedetti
authors.forename: M A
authors.initials: MA
authors.lastname: Rocca
authors.forename: P
authors.initials: P
authors.lastname: Valsasina
authors.forename: M
authors.initials: M
authors.lastname: Rovaris
authors.forename: G
authors.initials: G
authors.lastname: Comi
authors.forename: M
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D001369:Axons / Q000473:pathology; D002574:Cervical Vertebrae; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005911:Gliosis / Q000209:etiology / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000150:complications / Q000473:pathology*; D016037:Single-Blind Method; D013116:Spinal Cord / Q000473:pathology*