title: A comparison of mean displacement values using high b-value Q-space diffusion-weighted MRI with conventional apparent diffusion coefficients in patients with stroke.
abstract: OBJECTIVE
  Q-space analysis using high b-value diffusion-weighted magnetic resonance (MR) data provides information on tissue microstructure in contrast to conventional MR imaging (MRI) based on low b-value diffusion-weighted imaging (DWI). The purpose of this study was to evaluate the use of mean displacement (MDP) map in stroke patients using q-space diffusion-weighted MRI (QSI).
  
  
  METHODS
  Twenty-one patients presenting with a total of 22 acute or subacute cerebral infarctions were included. MR protocol consisted of conventional MR sequences, DWI (b-value; 1000 s/mm(2)) and QSI (b-value; maximum 12,000 s/mm(2)). Apparent diffusion coefficient (ADC) maps of conventional DWI and MDP maps of QSI data were obtained and compared in the ischemic lesions and corresponding normal tissues.
  
  
  RESULTS
  Decreased ADC values were present in all lesions. There was no correlation between ADC and MDP values in the lesions (r = 0.21). MDP values of the lesions were 8.60 ± 1.26 μm (mean ± SD). Most of the lesions (16/22) had higher MDP values than normal brain tissue. Three lesions showed lower MDP values and three showed mixed MDP values.
  
  
  CONCLUSIONS
  The MDP maps using QSI data provides additional information for stroke patients compared to conventional DWI.
authors.affiliation: Department of Radiology, University of Yamanashi, Yamanashi, Japan. mahori@juntendo.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hori
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Zareen
authors.initials: Z
authors.lastname: Fatima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kumagai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikenaga
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ishigame
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Onodera
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yagi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D020520:Brain Infarction / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology*