title: The impact of lesion in-painting and registration methods on voxel-based morphometry in detecting regional cerebral gray matter atrophy in multiple sclerosis.
abstract: OBJECTIVE
  VBM has been widely used to study GM atrophy in MS. MS lesions lead to segmentation and registration errors that may affect the reliability of VBM results. Improved segmentation and registration have been demonstrated by WM LI before segmentation. DARTEL appears to improve registration versus the USM. Our aim was to compare the performance of VBM-DARTEL versus VBM-USM and the effect of LI in the regional analysis of GM atrophy in MS.
  
  
  METHODS
  3T T1 MR imaging scans were acquired from 26 patients with RRMS and 28 age-matched NC. LI replaced WM lesions with normal-appearing WM intensities before image segmentation. VBM analysis was performed in SPM8 by using DARTEL and USM with and without LI, allowing the comparison of 4 VBM methods (DARTEL + LI, DARTEL - LI, USM + LI, and USM - LI). Accuracy of VBM was assessed by using NMI, CC, and a simulation analysis.
  
  
  RESULTS
  Overall, DARTEL + LI yielded the most accurate GM maps among the 4 methods (highest NMI and CC, P < .001). DARTEL + LI showed significant GM loss in the bilateral thalami and caudate nuclei in patients with RRMS versus NC. The other 3 methods overestimated the number of regions of GM loss in RRMS versus NC. LI improved the accuracy of both VBM methods. Simulated data suggested the accuracy of the results provided from patient MR imaging analysis.
  
  
  CONCLUSIONS
  We introduce a pipeline that shows promise in limiting segmentation and registration errors in VBM analysis in MS.
authors.affiliation: Department of Neurology, Brigham and Women's Hospital, Laboratory for Neuroimaging Research, Partners MS Center, Harvard Medical School, Boston, MA 02445, USA.
authors.forename: A
authors.initials: A
authors.lastname: Ceccarelli
authors.forename: J S
authors.initials: JS
authors.lastname: Jackson
authors.forename: S
authors.initials: S
authors.lastname: Tauhid
authors.forename: A
authors.initials: A
authors.lastname: Arora
authors.forename: J
authors.initials: J
authors.lastname: Gorky
authors.forename: E
authors.initials: E
authors.lastname: Dell'Oglio
authors.forename: A
authors.initials: A
authors.lastname: Bakshi
authors.forename: T
authors.initials: T
authors.lastname: Chitnis
authors.forename: S J
authors.initials: SJ
authors.lastname: Khoury
authors.forename: H L
authors.initials: HL
authors.lastname: Weiner
authors.forename: C R G
authors.initials: CR
authors.lastname: Guttmann
authors.forename: R
authors.initials: R
authors.lastname: Bakshi
authors.forename: M
authors.initials: M
authors.lastname: Neema
mesh_terms: D000328:Adult; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*