title: Quantitative blood flow measurements in gliomas using arterial spin-labeling at 3T: intermodality agreement and inter- and intraobserver reproducibility study.
abstract: OBJECTIVE
  QUASAR is a particular application of the ASL method and facilitates the user-independent quantification of brain perfusion. The purpose of this study was to assess the intermodality agreement of TBF measurements obtained with ASL and DSC MR imaging and the inter- and intraobserver reproducibility of glioma TBF measurements acquired by ASL at 3T.
  
  
  METHODS
  Two observers independently measured TBF in 24 patients with histologically proved glioma. ASL MR imaging with QUASAR and DSC MR imaging were performed on 3T scanners. The observers placed 5 regions of interest in the solid tumor on rCBF maps derived from ASL and DSC MR images and 1 region of interest in the contralateral brain and recorded the measured values. Maximum and average sTBF values were calculated. Intermodality and intra- and interobsever agreement were determined by using 95% Bland-Altman limits of agreement and ICCs.
  
  
  RESULTS
  The intermodality agreement for maximum sTBF was good to excellent on DSC and ASL images; ICCs ranged from 0.718 to 0.884. The 95% limits of agreement ranged from 59.2% to 65.4% of the mean. ICCs for intra- and interobserver agreement for maximum sTBF ranged from 0.843 to 0.850 and from 0.626 to 0.665, respectively. The reproducibility of maximum sTBF measurements obtained by methods was similar.
  
  
  CONCLUSIONS
  In the evaluation of sTBF in gliomas, ASL with QUASAR at 3T yielded measurements and reproducibility similar to those of DSC perfusion MR imaging.
authors.affiliation: Department of Diagnostic Radiology, Kumamoto University, KumamotoJapan. t-hirai@kumamoto-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Hirai
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Okuda
authors.forename: A
authors.initials: A
authors.lastname: Sasao
authors.forename: Y
authors.initials: Y
authors.lastname: Shigematsu
authors.forename: D
authors.initials: D
authors.lastname: Utsunomiya
authors.forename: S
authors.initials: S
authors.lastname: Oda
authors.forename: H
authors.initials: H
authors.lastname: Uetani
authors.forename: M
authors.initials: M
authors.lastname: Morioka
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D001932:Brain Neoplasms / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D005260:Female; D005910:Glioma / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology / Q000503:physiopathology*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels