title: Brain injury after cardiopulmonary arrest and its assessment with diffusion-weighted magnetic resonance imaging.
abstract: OBJECTIVE
  To characterize the frequency and pattern of diffusion-weighted imaging (DWI) abnormalities detected as part of brain magnetic resonance imaging (MRI) and their association with short-term neurologic outcomes in patients successfully resuscitated after cardiopulmonary arrest (CPA).
  
  
  METHODS
  We retrospectively analyzed a case series of patients who experienced CPA between May 1, 2000, and April 29, 2004, at St Luke's Hospital in Jacksonville, Fla. Eligible patients required treatment by the Code Blue team and had 1 DWI study before discharge or death. Two neuroradiologists jointly classified DWI abnormalities by anatomic location. Outcome was measured by Cerebral Performance Category score.
  
  
  RESULTS
  Resuscitation was performed 628 times during the 48-month study period. Of 514 CPA survivors, 18 (3.5%) had MRI studies. The median age was 62 years (interquartile range [IQR], 49-73), and 10 were men. Median code duration was 16 minutes (IQR, 11-19 minutes), and median code-to-scan time was 72 hours (IQR, 28-229 hours). A DWI abnormality was noted in 9 (50%) of 18 patients. Cortical areas (global and regional) were the most common sites of restricted diffusion. Diffusion-weighted imaging abnormalities were present in 7 (70%) of 10 patients with a poor neurologic outcome at discharge.
  
  
  CONCLUSIONS
  Magnetic resonance imaging is performed rarely after survival of CPA. In this study with limited sample size, a greater proportion of patients with normal DWI findings had a good neurologic outcome at the time of hospital discharge vs those with abnormal findings. Prospective studies of early and serial MRI (with DWI) are needed to confirm this association and to clarify the prognostic usefulness of such studies.
authors.affiliation: Department of Neurology, College of Medicine, Mayo Clinic, Jacksonville, FL 32224, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Barrett
authors.forename: William D
authors.initials: WD
authors.lastname: Freeman
authors.forename: Steven M
authors.initials: SM
authors.lastname: Weindling
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Brott
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Broderick
authors.forename: Michael G
authors.initials: MG
authors.lastname: Heckman
authors.forename: Julia E
authors.initials: JE
authors.lastname: Crook
authors.forename: Gavin D
authors.initials: GD
authors.lastname: Divertie
authors.forename: James F
authors.initials: JF
authors.lastname: Meschia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001930:Brain Injuries / Q000145:classification / Q000175:diagnosis / Q000209:etiology*; D016887:Cardiopulmonary Resuscitation; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications* / Q000628:therapy