title: Relationship between sodium intensity and perfusion deficits in acute ischemic stroke.
abstract: OBJECTIVE
  To assess the relationship between sodium signal intensity changes and oligemia, measured with perfusion-weighted imaging (PWI), in ischemic stroke patients.
  
  
  METHODS
  Nine ischemic stroke patients (55 ± 13 years), four with follow-up scans, underwent sodium and proton imaging 4-32 hours after symptom onset. Relative sodium intensity was calculated as the ratio of signal intensities in core (identified as hypertintense lesions on diffusion-weighted imaging [DWI]) or putative penumbra (PWI-DWI mismatch) to contralateral homologous regions.
  
  
  RESULTS
  Sodium intensity increases in the core were not correlated with the severity of hypoperfusion, measured with either cerebral blood flow (rho = 0.157; P = 0.61) or cerebral blood volume (rho = -0.234; P = 0.44). In contrast, relative sodium intensity was not elevated (4-7 hours 0.96 ± 0.07; 17-32 hours 1.00 ± 0.07) in PWI-DWI mismatch regions.
  
  
  CONCLUSIONS
  Sodium signal intensity cannot be predicted by the degree of hypoperfusion acutely. Sodium intensity also remains unchanged in PWI-DWI mismatch tissue, indicating preservation of ionic homeostasis. Sodium magnetic resonance imaging (MRI), in conjunction with PWI and DWI, may permit identification of patients with viable tissue, despite an unknown symptom onset time.
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Tsang
authors.forename: Robert W
authors.initials: RW
authors.lastname: Stobbe
authors.forename: Negar
authors.initials: N
authors.lastname: Asdaghi
authors.forename: Muhammad S
authors.initials: MS
authors.lastname: Hussain
authors.forename: Yusuf A
authors.initials: YA
authors.lastname: Bhagat
authors.forename: Christian
authors.initials: C
authors.lastname: Beaulieu
authors.forename: Derek
authors.initials: D
authors.lastname: Emery
authors.forename: Ken S
authors.initials: KS
authors.lastname: Butcher
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001783:Blood Flow Velocity; D002545:Brain Ischemia / Q000150:complications* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012964:Sodium / Q000378:metabolism*; D020521:Stroke / Q000209:etiology* / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D011522:Protons; D012964:Sodium