title: Quantification of Serial Cerebral Blood Flow in Acute Stroke Using Arterial Spin Labeling.
abstract: Perfusion-weighted imaging is used to select patients with acute ischemic stroke for intervention, but knowledge of cerebral perfusion can also inform the understanding of ischemic injury. Arterial spin labeling allows repeated measurement of absolute cerebral blood flow (CBF) without the need for exogenous contrast. The aim of this study was to explore the relationship between dynamic CBF and tissue outcome in the month after stroke onset.
  
  
  
  Patients with nonlacunar ischemic stroke underwent ≤5 repeated magnetic resonance imaging scans at presentation, 2 hours, 1 day, 1 week, and 1 month. Imaging included vessel-encoded pseudocontinuous arterial spin labeling using multiple postlabeling delays to quantify CBF in gray matter regions of interest. Receiver-operator characteristic curves were used to predict tissue outcome using CBF. Repeatability was assessed in 6 healthy volunteers and compared with contralateral regions of patients. Diffusion-weighted and T2-weighted fluid attenuated inversion recovery imaging were used to define tissue outcome.
  
  
  
  Forty patients were included. In contralateral regions of patients, there was significant variation of CBF between individuals, but not between scan times (mean±SD: 53±42 mL/100 g/min). Within ischemic regions, mean CBF was lowest in ischemic core (17±23 mL/100 g/min), followed by regions of early (21±26 mL/100 g/min) and late infarct growth (25±35 mL/100 g/min; ANOVA P<0.0001). Between patients, there was marked overlap in presenting and serial CBF values.
  
  
  
  Knowledge of perfusion dynamics partially explained tissue fate. Factors such as metabolism and tissue susceptibility are also likely to influence tissue outcome.
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.). george.harston@rdm.ox.ac.uk.
authors.forename: George W J
authors.initials: GW
authors.lastname: Harston
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Okell
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Fintan
authors.initials: F
authors.lastname: Sheerin
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Ursula
authors.initials: U
authors.lastname: Schulz
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Phil
authors.initials: P
authors.lastname: Mathieson
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Ian
authors.initials: I
authors.lastname: Reckless
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Kunal
authors.initials: K
authors.lastname: Shah
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Gary A
authors.initials: GA
authors.lastname: Ford
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Michael A
authors.initials: MA
authors.lastname: Chappell
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: Peter
authors.initials: P
authors.lastname: Jezzard
authors.affiliation: From the Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, United Kingdom (G.W.J.H., J.K.); Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (T.W.O., M.A.C., P.J.); Department of Neuroradiology (F.S.) and Acute Stroke Service (U.S., P.M., I.R., K.S., G.A.F., J.K.), Oxford University Hospitals NHS Foundation Trust, United Kingdom; Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, United Kingdom (M.A.C.).
authors.forename: James
authors.initials: J
authors.lastname: Kennedy
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods; D011446:Prospective Studies; D013113:Spin Labels; D020521:Stroke / Q000000981:diagnostic imaging* / Q000503:physiopathology*
chemical_list: D013113:Spin Labels
keywords: biomarkers; cerebral infarction; magnetic resonance imaging; perfusion imaging; stroke