title: Detection of changes in the periaqueductal gray matter of patients with episodic migraine using quantitative diffusion kurtosis imaging: preliminary findings.
abstract: BACKGROUND
  The periaqueductal gray matter (PAG) is considered to play an important role in generating migraine, but findings from imaging studies remain unclear. Therefore, we investigated whether diffusion kurtosis imaging (DKI) can detect changes in the PAG of migraine patients.
  
  
  METHODS
  We obtained source images for DKI from 20 patients with episodic migraine and 20 healthy controls using a 3 T magnetic resonance imaging scanner. Mean kurtosis (MK), fractional anisotropy (FA), and mean diffusivity (MD) maps were generated, and the values of the PAG and other deep gray and white matter structures were automatically measured using an atlas-based region-of-interest analysis. The metrics of these structures were compared between the patients and controls.
  
  
  RESULTS
  The MK and MD values of the PAG were significantly increased in the migraine patients compared with the controls (p < 0.05). The FA values were not significantly different. There were no significant differences in the metrics of the other structures between the patients and controls. The MK values of the PAG were significantly positively correlated with both age and the untreated period in the patient group under univariate analysis (r = 0.53 and 0.56, respectively; p < 0.05) but not multivariate analysis.
  
  
  CONCLUSIONS
  DKI detected significant increases in the MK and MD values of the PAG in patients with migraine, which suggests that structural changes in the PAG are associated with the pathophysiological mechanisms of migraine.
authors.affiliation: Division of Ultra-High Field MRI, Institute for Biomedical Sciences, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate, 028-3694, Japan. keito@iwate-med.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Iwate, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Kudo
authors.affiliation: Division of Ultra-High Field MRI, Institute for Biomedical Sciences, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate, 028-3694, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Iwate, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Saito
authors.affiliation: Division of Ultra-High Field MRI, Institute for Biomedical Sciences, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate, 028-3694, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Yamashita
authors.affiliation: Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Hokkaido, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Harada
authors.affiliation: Research & Development Group, Hitachi, Ltd., Tokyo, Japan.
authors.forename: Suguru
authors.initials: S
authors.lastname: Yokosawa
authors.affiliation: Division of Ultra-High Field MRI, Institute for Biomedical Sciences, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate, 028-3694, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Uwano
authors.affiliation: Division of Ultra-High Field MRI, Institute for Biomedical Sciences, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate, 028-3694, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kameda
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Iwate, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terayama
mesh_terms: D000328:Adult; D002535:Cerebral Aqueduct / Q000000981:diagnostic imaging* / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000000981:diagnostic imaging / Q000473:pathology*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Diffusion kurtosis imaging; Headache; Migraine; Periaqueductal gray matter