title: Combined perfusion- and diffusion-weighted MR imaging in acute ischemic stroke during the 1st week: a longitudinal study.
abstract: OBJECTIVE
  To compare findings with different magnetic resonance (MR) perfusion maps in acute ischemic stroke.
  
  
  METHODS
  Combined diffusion-weighted (DW) and perfusion-weighted (PW) MR imaging was performed in 49 patients with acute (<24 hours) stroke, on the 1st and 2nd days and 1 week after stroke. Volumes of hypoperfused tissue on maps of relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT) were compared with the volume of infarcted tissue at DW imaging.
  
  
  RESULTS
  The mean infarct volume increased from 41 to 65 cm(3) between the 1st and 2nd days (P: <.001; n = 49). On the 1st day, all perfusion maps on average showed hypoperfusion lesions larger than the infarct at DW imaging (P: <.001; n = 49). MTT maps showed significantly (P: <.001) larger hypoperfusion lesions than did rCBF maps, which showed significantly (P: <.001) larger hypoperfusion lesions than did rCBV maps. The sizes of the initial perfusion-diffusion mismatches correlated significantly with the extent of infarct growth (0.479 < r < 0.657; P: </=.001). The hypoperfusion volume on the initial rCBV maps correlated best with the final infarct size at 1 week (r = 0.891; P: <.001).
  
  
  CONCLUSIONS
  Combined DW and PW imaging is a powerful tool in evaluating the hemodynamics of acute ischemic stroke.
authors: Depts of Clinical Radiology, Kuopio University Hospital, Puijonlaaksontie 2, FIN-70210 Kuopio, Finland. jari.karonen@kuh.fi
authors: J O
authors: JO
authors: Karonen
authors: Y
authors: Y
authors: Liu
authors: R L
authors: RL
authors: Vanninen
authors: L
authors: L
authors: Ostergaard
authors: P L
authors: PL
authors: Kaarina Partanen
authors: P A
authors: PA
authors: Vainio
authors: E J
authors: EJ
authors: Vanninen
authors: J
authors: J
authors: Nuutinen
authors: R
authors: R
authors: Roivainen
authors: S
authors: S
authors: Soimakallio
authors: J T
authors: JT
authors: Kuikka
authors: H J
authors: HJ
authors: Aronen
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D020520:Brain Infarction / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D020521:Stroke / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology