title: Alteration of fractional anisotropy and apparent diffusion coefficient in obsessive-compulsive disorder: a diffusion tensor imaging study.
abstract: BACKGROUND
  Abnormalities of fractional anisotropy (FA) have been reported in previous diffusion tensor imaging (DTI) studies in patients with obsessive-compulsive disorder (OCD). However, there are some inconsistencies in the results and the apparent diffusion coefficient (ADC) has not been investigated. The goal of this study was to investigate white matter abnormalities and water diffusivity, as reflected by FA and ADC, using DTI in patients with OCD.
  
  
  METHODS
  Fifteen patients with OCD and 15 healthy volunteers underwent DTI. Voxelwise analysis was used to compare FA in white matter and ADC in gray matter/white matter of the two groups.
  
  
  RESULTS
  Compared with healthy volunteers, the patients had higher FA in the bilateral semioval center extending to the subinsular white matter; and a higher ADC in the left medial frontal cortex. There were no areas with a significantly lower FA or ADC in patients compared with healthy volunteers.
  
  
  CONCLUSIONS
  A significantly higher FA was found in regions associated with the emotion of disgust and a trend for a higher ADC was found in a region associated with the regulation of emotions. These findings suggest that neurocircuits involved in disgust processing may play an important role in the pathophysiology of OCD.
authors.affiliation: Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan. nakamae@koto.kpu-m.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamae
authors.forename: Jin
authors.initials: J
authors.lastname: Narumoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Shibata
authors.forename: Ryohei
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Yurinosuke
authors.initials: Y
authors.lastname: Kitabayashi
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Kei
authors.initials: K
authors.lastname: Yamada
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Nishimura
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukui
mesh_terms: D000328:Adult; D016880:Anisotropy; D001931:Brain Mapping; D016022:Case-Control Studies; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis* / Q000503:physiopathology