title: Time course of lesion development in patients with acute stroke: serial diffusion- and hemodynamic-weighted magnetic resonance imaging.
abstract: OBJECTIVE
  We sought to characterize the evolution of acute ischemic stroke by MRI and its relationship to patients' neurological outcome.
  
  
  METHODS
  Fourteen patients with acute ischemic stroke underwent MRI within 13 hours of symptom onset (mean, 7.4+/-3 hours) and underwent repeated imaging and concurrent neurological examination at 8, 24, 36, and 48 hours and 7 days and >42 days after first imaging.
  
  
  RESULTS
  Diffusion-weighted imaging (DWI) lesion volumes increased between the first and second scans in 10 of 14 patients; scans with maximum DWI lesion volume occurred at a mean of 70.4 hours. Initial DWI lesion volume correlated with the largest T2 lesion volume (r=0.97; P<0.001). Final lesion volume was smaller than maximum lesion volume in 12 of 14 patients. There was positive correlation between the follow-up National Institutes of Health Stroke Scale score and the initial DWI lesion volume (r=0.67; P=0. 01) and maximum T2 lesion volume (r=0.77; P<0.01) and negative correlation with initial mean apparent diffusion coefficient ratio (ADCr) (r=-0.64; P<0.05). The ADCr was 0.73 at initial imaging and fell between the initial and second scans in 10 of 14 patients. Mean ADCr did not rise above normal until 42 days after stroke onset (P<0. 001).
  
  
  CONCLUSIONS
  Serial MRI demonstrates the dynamic nature of progressive ischemic injury in acute stroke patients developing over hours to days, and it suggests that both primary and secondary pathophysiological processes can be valuable targets for neuroprotective interventions.
authors.affiliation: Departmentof Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Mass. 02114, USA.
authors.forename: L H
authors.initials: LH
authors.lastname: Schwamm
authors.forename: W J
authors.initials: WJ
authors.lastname: Koroshetz
authors.forename: A G
authors.initials: AG
authors.lastname: Sorensen
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: W A
authors.initials: WA
authors.lastname: Copen
authors.forename: R
authors.initials: R
authors.lastname: Budzik
authors.forename: G
authors.initials: G
authors.lastname: Rordorf
authors.forename: F S
authors.initials: FS
authors.lastname: Buonanno
authors.forename: P W
authors.initials: PW
authors.lastname: Schaefer
authors.forename: R G
authors.initials: RG
authors.lastname: Gonzalez
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome