title: Texture analysis of ultrahigh field T2*-weighted MR images of the brain: application to Huntington's disease.
abstract: OBJECTIVE
  To develop a framework for quantitative detection of between-group textural differences in ultrahigh field T2*-weighted MR images of the brain.
  
  
  METHODS
  MR images were acquired using a three-dimensional (3D) T2*-weighted gradient echo sequence on a 7 Tesla MRI system. The phase images were high-pass filtered to remove phase wraps. Thirteen textural features were computed for both the magnitude and phase images of a region of interest based on 3D Gray-Level Co-occurrence Matrix, and subsequently evaluated to detect between-group differences using a Mann-Whitney U-test. We applied the framework to study textural differences in subcortical structures between premanifest Huntington's disease (HD), manifest HD patients, and controls.
  
  
  RESULTS
  In premanifest HD, four phase-based features showed a difference in the caudate nucleus. In manifest HD, 7 magnitude-based features showed a difference in the pallidum, 6 phase-based features in the caudate nucleus, and 10 phase-based features in the putamen. After multiple comparison correction, significant differences were shown in the putamen in manifest HD by two phase-based features (both adjusted P values=0.04).
  
  
  CONCLUSIONS
  This study provides the first evidence of textural heterogeneity of subcortical structures in HD. Texture analysis of ultrahigh field T2*-weighted MR images can be useful for noninvasive monitoring of neurodegenerative diseases.
authors.affiliation: Division of Image Processing (LKEB), Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Nhat Trung
authors.initials: NT
authors.lastname: Doan
authors.forename: Simon J A
authors.initials: SJ
authors.lastname: van den Bogaard
authors.forename: Eve M
authors.initials: EM
authors.lastname: Dumas
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Webb
authors.forename: Mark A
authors.initials: MA
authors.lastname: van Buchem
authors.forename: Raymund A C
authors.initials: RA
authors.lastname: Roos
authors.forename: Jeroen
authors.initials: J
authors.lastname: van der Grond
authors.forename: Johan H C
authors.initials: JH
authors.lastname: Reiber
authors.forename: Julien
authors.initials: J
authors.lastname: Milles
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis / Q000473:pathology*; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated; D012016:Reference Values; D018709:Statistics, Nonparametric
keywords: Huntington's disease; MR images; neurodegenerative diseases; subcortical structures; texture analysis; ultrahigh field