title: Comparison of arterial spin labeling and dynamic susceptibility contrast perfusion MRI in patients with acute stroke.
abstract: BACKGROUND
  The aim of this study was to evaluate whether arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) can reliably quantify perfusion deficit as compared to dynamic susceptibility contrast (DSC) perfusion MRI.
  
  
  METHODS
  Thirty-nine patients with acute ischemic stroke in the anterior circulation territory were recruited. All underwent ASL and DSC MRI perfusion scans within 30 hours after stroke onset and 31 patients underwent follow-up MRI scans. ASL cerebral blood flow (CBF) and DSC time to maximum (T(max)) maps were used to calculate the perfusion defects. The ASL CBF lesion volume was compared to the DSC Tmax lesion volume by Pearson's correlation coefficient and likewise the ASL CBF and DSC T(max) lesion volumes were compared to the final infarct sizes respectively. A repeated measures analysis of variance and least significant difference post hoc test was used to compare the mean lesion volumes among ASL CBF, DSC T(max) >4-6 s and final infarct.
  
  
  RESULTS
  Mean patient age was 72.6 years. The average time from stroke onset to MRI was 13.9 hours. The ASL lesion volume showed significant correlation with the DSC lesion volume for T(max) >4, 5 and 6 s (r = 0.81, 0.82 and 0.80; p<0.001). However, the mean lesion volume of ASL (50.1 ml) was significantly larger than those for T(max) >5 s (29.2 ml, p<0.01) and T(max) >6 s (21.8 ml, p<0.001), while the mean lesion volumes for T(max) >5 or 6 s were close to mean final infarct size.
  
  
  CONCLUSIONS
  Quantitative measurement of ASL perfusion is well correlated with DSC perfusion. However, ASL perfusion may overestimate the perfusion defects and therefore further refinement of the true penumbra threshold and improved ASL technique are necessary before applying ASL in therapeutic trials.
authors.affiliation: Department of Neurology, Chang Gung Memorial Hospital at Chiayi, Chang-Gung University College of Medicine, Tao-Yuan, Taiwan.
authors.forename: Yen-Chu
authors.initials: YC
authors.lastname: Huang
authors.forename: Ho-Ling
authors.initials: HL
authors.lastname: Liu
authors.forename: Jiann-Der
authors.initials: JD
authors.lastname: Lee
authors.forename: Jen-Tsung
authors.initials: JT
authors.lastname: Yang
authors.forename: Hsu-Huei
authors.initials: HH
authors.lastname: Weng
authors.forename: Meng
authors.initials: M
authors.lastname: Lee
authors.forename: Mei-Yu
authors.initials: MY
authors.lastname: Yeh
authors.forename: Yuan-Hsiung
authors.initials: YH
authors.lastname: Tsai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000473:pathology*