title: Multiple sclerosis: Benefits of q-space imaging in evaluation of normal-appearing and periplaque white matter.
abstract: BACKGROUND
  Diffusion tensor imaging (DTI) reveals white matter pathology in patients with multiple sclerosis (MS). A recent non-Gaussian diffusion imaging technique, q-space imaging (QSI), may provide several advantages over conventional MRI techniques in regard to in vivo evaluation of the disease process in patients with MS. The purpose of this study is to investigate the use of root mean square displacement (RMSD) derived from QSI data to characterize plaques, periplaque white matter (PWM), and normal-appearing white matter (NAWM) in patients with MS.
  
  
  METHODS
  We generated apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps by using conventional DTI data from 21 MS patients; we generated RMSD maps by using QSI data from these patients. We used the Steel-Dwass test to compare the diffusion metrics of regions of interest in plaques, PWM, and NAWM.
  
  
  RESULTS
  ADC differed (P<0.05) between plaques and PWM and between plaques and NAWM. FA differed (P<0.05) between plaques and NAWM. RMSD differed (P<0.05) between plaques and PWM, plaques and NAWM, and PWM and NAWM.
  
  
  CONCLUSIONS
  RMSD values from QSI may reflect microstructural changes and white-matter damage in patients with MS with higher sensitivity than do conventional ADC and FA values.
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan. Electronic address: mahori@juntendo.ac.jp.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hori
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Yokoyama
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kamagata
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan; Department of Health Science, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Kumagai
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan; Department of Health Science, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan.
authors.forename: Issei
authors.initials: I
authors.lastname: Fukunaga
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kouhei
authors.initials: K
authors.lastname: Kamiya
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Michimasa
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Masutani
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Hamasaki
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan; Philips Electronics Japan, Tokyo, Japan.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, Juntendo University Urayasu Hospital, Chiba, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Kyogoku
authors.affiliation: Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hattori
authors.affiliation: Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
mesh_terms: D000328:Adult; D016880:Anisotropy; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D015203:Reproducibility of Results; D066127:White Matter / Q000473:pathology
keywords: Diffusion tensor imaging; Multiple sclerosis; Normal-appearing white matter; Periplaque white matter; Root mean square displacement; q-space imaging