title: Huntington disease: volumetric, diffusion-weighted, and magnetization transfer MR imaging of brain.
abstract: OBJECTIVE
  To investigate whether diffusion-weighted and magnetization transfer (MT) magnetic resonance (MR) imaging depict regional and/or global brain abnormalities in patients with Huntington disease (HD).
  
  
  METHODS
  Twenty-one carriers of the HD mutation (mean age, 58 years +/- 11 [SD]) and 21 healthy control subjects (mean age, 54 years +/- 13) underwent conventional, diffusion-weighted, and MT MR imaging. Volumes, mean apparent diffusion coefficients (ADCs), and MT ratios (MTRs) for left and right caudate nucleus, putamen, and cerebral periventricular white matter-as well as an index of normalized brain volume and whole-brain ADC and MT histograms-were computed. Asymmetry in volume, ADC, and MTR measurements in caudate nucleus, putamen, and periventricular white matter in control subjects and HD carriers were evaluated with Wilcoxon testing for paired samples. Differences in MR imaging variables between HD carriers and control subjects were evaluated with Mann-Whitney U testing; correlations between stages of clinical severity and MR imaging data were investigated with Spearman rank correlation testing.
  
  
  RESULTS
  No significant asymmetry was observed for any of the MR imaging variables. Caudate nucleus, putamen, and whole-brain volumes were smaller (P <.001 for all) in HD carriers than in control subjects. HD carriers also had increased ADC in the caudate nucleus (P =.002), putamen (P <. 001), cerebral periventricular white matter (P <.001), and whole brain (P <.001). MTR was not significantly different between HD carriers and control subjects. Correlation was observed between stages of increasing clinical disease severity and both decrease in volume of caudate nucleus (Spearman rho = -0.63), putamen (rho = -0.64), and whole brain (rho = -0.46) and increase in ADC in caudate nucleus (rho = 0.52), periventricular white matter (rho = 0.45), and whole brain (rho = 0.44).
  
  
  CONCLUSIONS
  Regional and global volume loss in HD is accompanied by an increase in ADC; this correlates with disease severity.
authors.affiliation: Radiodiagnostic Section, Department of Clinical Physiopathology and Department of Neurological Sciences, University of Florence, Viale Morgagni 85, Florence, Italy. m.mascalchi@dfc.unifi.it
authors.forename: Mario
authors.initials: M
authors.lastname: Mascalchi
authors.forename: Francesco
authors.initials: F
authors.lastname: Lolli
authors.forename: Riccardo
authors.initials: R
authors.lastname: Della Nave
authors.forename: Carlo
authors.initials: C
authors.lastname: Tessa
authors.forename: Raffaele
authors.initials: R
authors.lastname: Petralli
authors.forename: Cinzia
authors.initials: C
authors.lastname: Gavazzi
authors.forename: Letterio S
authors.initials: LS
authors.lastname: Politi
authors.forename: Marco
authors.initials: M
authors.lastname: Macucci
authors.forename: Massimo
authors.initials: M
authors.lastname: Filippi
authors.forename: Silvia
authors.initials: S
authors.lastname: Piacentini
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged