title: Voxel-based analysis of diffusion tensor indices in the brain in patients with Parkinson's disease.
abstract: OBJECTIVE
  To investigate the abnormal diffusion in cerebral white matter and its relationship with the olfactory dysfunction in patients with Parkinson's disease (PD) through diffusion tensor imaging (DTI).
  
  
  METHODS
  Diffusion tensor imaging of the cerebrum was performed in 25 patients with Parkinson's disease and 25 control subjects matched for age and sex. Differences in fractional anisotropy (FA) and mean diffusivity (MD) between these two groups were studied by voxel-based analysis of the DTI data. Correlations between diffusion indices and the olfactory function in PD patients were evaluated using the multiple regression model after controlling for the duration of the disease, Unified Parkinson's Disease Rating Sale (UPDRS), and age.
  
  
  RESULTS
  The damaged white and gray matter showed decreased FA or increased MD, localized bilaterally in the cerebellar and orbitofrontal cortex. In addition, in PD patients there was a positive correlation between FA values in the white matter of the left cerebellum and the thresholds of olfactory identification (TOI) and a negative correlation between MD values in the white matter of right cerebellum and the TOI.
  
  
  CONCLUSIONS
  In patients with PD, there was disruption in the cerebellar white matter which may play an important role in the olfactory dysfunction in patients with Parkinson's disease.
authors.affiliation: Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China. kaiyuanzhang@yahoo.cn
authors.forename: Kaiyuan
authors.initials: K
authors.lastname: Zhang
authors.forename: Chunshui
authors.initials: C
authors.lastname: Yu
authors.forename: Yujin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wu
authors.forename: Chaozhe
authors.initials: C
authors.lastname: Zhu
authors.forename: Piu
authors.initials: P
authors.lastname: Chan
authors.forename: Kuncheng
authors.initials: K
authors.lastname: Li
mesh_terms: D000465:Algorithms; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D000857:Olfaction Disorders / Q000209:etiology / Q000473:pathology*; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity