title: Multi-Center Study of Diffusion-Weighted Imaging in Coma After Cardiac Arrest.
abstract: BACKGROUND
  The ability to predict outcomes in acutely comatose cardiac arrest survivors is limited. Brain diffusion-weighted magnetic resonance imaging (DWI MRI) has been shown in initial studies to be a simple and effective prognostic tool. This study aimed to determine the predictive value of previously defined DWI MRI thresholds in a multi-center cohort.
  
  
  METHODS
  DWI MRIs of comatose post-cardiac arrest patients were analyzed in this multi-center retrospective observational study. Poor outcome was defined as failure to regain consciousness within 14 days and/or death during the hospitalization. The apparent diffusion coefficient (ADC) value of each brain voxel was determined. ADC thresholds and brain volumes below each threshold were analyzed for their correlation with outcome.
  
  
  RESULTS
  125 patients were included in the analysis. 33 patients (26%) had a good outcome. An ADC value of less than 650 × 10(-6) mm(2)/s in ≥10% of brain volume was highly specific [91% (95% CI 75-98)] and had a good sensitivity [72% (95% CI 61-80)] for predicting poor outcome. This threshold remained an independent predictor of poor outcome in multivariable analysis (p = 0.002). An ADC value of less than 650 × 10(-6) mm(2)/s in >22% of brain volume was needed to achieve 100% specificity for poor outcome.
  
  
  CONCLUSIONS
  In patients who remain comatose after cardiac arrest, quantitative DWI MRI findings correlate with early recovery of consciousness. A DWI MRI threshold of 650 × 10(-6) mm(2)/s in ≥10% of brain volume can differentiate patients with good versus poor outcome, though in this patient population the threshold was not 100% specific for poor outcome.
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA. kghirsch@yahoo.com.
authors.forename: K G
authors.initials: KG
authors.lastname: Hirsch
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Mlynash
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: I
authors.initials: I
authors.lastname: Eyngorn
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Pirsaheli
authors.affiliation: Stanford University Oncology Division, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Okada
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Komshian
authors.affiliation: Department of Neurology, Sutter Pacific Medical Foundation, San Francisco, CA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.affiliation: Mount Sinai Healthcare System, Departments of Neurology and Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Mayer
authors.affiliation: Department of Neurology, Mayo Clinic Florida, Jacksonville, FL, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Meschia
authors.affiliation: Davee Department of Neurology, Feinberg School of Medicine of Northwestern University, Northwestern University, Chicago, IL, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Bernstein
authors.affiliation: Department of Radiology, Athinoula A Martinos Center, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: O
authors.initials: O
authors.lastname: Wu
authors.affiliation: Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Greer
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Wijman
authors.affiliation: Stanford Stroke and Neurocritical Care Program, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Albers
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D001926:Brain Death; D003128:Coma / Q000175:diagnosis* / Q000209:etiology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies
keywords: Cardiac arrest; Coma; DWI; MRI; Prognosis