title: Cerebral atrophy measurement in clinically isolated syndromes and relapsing remitting multiple sclerosis: a comparison of registration-based methods.
abstract: OBJECTIVE
  Brain atrophy is a proposed marker of disease progression in multiple sclerosis (MS). Many magnetic resonance imaging-based methods of atrophy quantification exist, but their relative sensitivity and precision is unclear. Our aim was to compare atrophy rates from the brain boundary shift integral (BBSI), structural image evaluation, using normalization of atrophy (SIENA) (both registration-based methods) and segmented brain volume difference, in patients with clinically isolated syndromes (CIS), relapsing remitting MS (RRMS), and controls.
  
  
  METHODS
  Thirty-seven CIS patients, 30 with early RRMS and 16 controls had T1-weighted volumetric imaging at baseline and 1 year. Brain atrophy rates were determined using segmented brain volume difference, BBSI, and SIENA.
  
  
  RESULTS
  BBSI and SIENA were more precise than subtraction of segmented brain volumes and were more sensitive distinguishing RRMS subjects from controls. A strong correlation was observed between BBSI and SIENA. Atrophy rates were greater in CIS and RRMS subjects than controls (RRMS P < .001). With all methods, significantly greater atrophy rates were observed in CIS patients who developed clinically definite MS relative to subjects who did not.
  
  
  CONCLUSIONS
  Registration-based techniques are more precise and sensitive than segmentation-based methods in measuring brain atrophy, with BBSI and SIENA providing comparable results.
authors.affiliation: MS NMR Research Unit, University College London, Institute of Neurology, Queen Square, London, UK. vanderson@dementia.ion.ucl.ac.uk
authors.forename: Valerie M
authors.initials: VM
authors.lastname: Anderson
authors.forename: Kryshani T M
authors.initials: KT
authors.lastname: Fernando
authors.forename: Gerard R
authors.initials: GR
authors.lastname: Davies
authors.forename: Waqar
authors.initials: W
authors.lastname: Rashid
authors.forename: Chris
authors.initials: C
authors.lastname: Frost
authors.forename: Nick C
authors.initials: NC
authors.lastname: Fox
authors.forename: David H
authors.initials: DH
authors.lastname: Miller
mesh_terms: D000328:Adult; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*; D013577:Syndrome