title: Effects of image orientation on the comparability of pediatric brain volumes using three-dimensional MR data.
abstract: OBJECTIVE
  The purpose of this study was to examine the comparability of morphometric measurements made on pediatric data sets collected at five scanner locations, each using variations on a 3D spoiled gradient-recalled echo (SPGR) pulse sequence.
  
  
  METHODS
  Archived MR data from 60 typically developing children were collected and separated into seven groups based on the pulse sequence used. A highly automated image-processing procedure was used to segment the brain data into white tissue, gray tissue, and CSF compartments and into various neuroanatomic regions of interest.
  
  
  RESULTS
  Volumetric comparisons between groups revealed differences in areas of the temporal and occipital lobes. These differences were observed when comparing data sets with different image orientations and appeared to be due to partial volume averaging (PVA) and susceptibility-induced geometric distortions.
  
  
  CONCLUSIONS
  Our results indicate that slice selection and image resolution should be controlled in volumetric studies using aggregated data from multiple centers to minimize the effects of PVA and susceptibility-induced geometric distortions.
authors.affiliation: Stanford Psychiatry Neuroimaging Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, CA 94305-5719, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Patwardhan
authors.forename: S
authors.initials: S
authors.lastname: Eliez
authors.forename: I S
authors.initials: IS
authors.lastname: Warsofsky
authors.forename: G H
authors.initials: GH
authors.lastname: Glover
authors.forename: C D
authors.initials: CD
authors.lastname: White
authors.forename: J N
authors.initials: JN
authors.lastname: Giedd
authors.forename: B S
authors.initials: BS
authors.lastname: Peterson
authors.forename: D C
authors.initials: DC
authors.lastname: Rojas
authors.forename: A L
authors.initials: AL
authors.lastname: Reiss
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001921:Brain / Q000033:anatomy & histology*; D002648:Child; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016018:Least-Squares Analysis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015588:Observer Variation