title: Effects of image distortion correction on voxel-based morphometry.
abstract: OBJECTIVE
  We aimed to show that correcting image distortion significantly affects brain volumetry using voxel-based morphometry (VBM) and to assess whether the processing of distortion correction reduces system dependency.
  
  
  METHODS
  We obtained contiguous sagittal T(1)-weighted images of the brain from 22 healthy participants using 1.5- and 3-tesla magnetic resonance (MR) scanners, preprocessed images using Statistical Parametric Mapping 5, and tested the relation between distortion correction and brain volume using VBM.
  
  
  RESULTS
  Local brain volume significantly increased or decreased on corrected images compared with uncorrected images. In addition, the method used to correct image distortion for gradient nonlinearity produced fewer volumetric errors from MR system variation.
  
  
  CONCLUSIONS
  This is the first VBM study to show more precise volumetry using VBM with corrected images. These results indicate that multi-scanner or multi-site imaging trials require correction for distortion induced by gradient nonlinearity.
authors.affiliation: Department of Radiological Technology, University of Tokyo Hospital.
authors.forename: Masami
authors.initials: M
authors.lastname: Goto
authors.forename: Osamu
authors.initials: O
authors.lastname: Abe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kabasawa
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Takao
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.forename: Naoto
authors.initials: N
authors.lastname: Hayashi
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kurosu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iwatsubo
authors.forename: Fumio
authors.initials: F
authors.lastname: Yamashita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Sachiko
authors.initials: S
authors.lastname: Inano
authors.forename: Harushi
authors.initials: H
authors.lastname: Mori
authors.forename: Akira
authors.initials: A
authors.lastname: Kunimatsu
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.forename: Kenji
authors.initials: K
authors.lastname: Ino
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yano
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult