title: Automated assessment of early hypoxic brain edema in non-enhanced CT predicts outcome in patients after cardiac arrest.
abstract: Early prediction of potential neurological recovery in patients after cardiac arrest is challenging. Recent studies suggest that the densitrometic gray-white matter ratio (GWR) determined from cranial computed tomography (CT) scans may be a reliable predictor of poor outcome. We evaluated an automated, rater independent method to determine GWR in CT as an early objective imaging predictor of clinical outcome.
  
  
  
  We analyzed imaging data of 84 patients after cardiac arrest that underwent noncontrast CT within 24h after arrest. To determine GWR in CT we applied two methods using a recently published automated probabilistic gray-white matter segmentation algorithm (GWR_aut) and conventional manual measurements within gray-white regions of interest (GWR_man). Neurological outcome was graded by the cerebral performance category (CPC). As part of standard routine CPC was assessed by the treating physician in the intensive care unit at admission and at discharge to normal ward. The performance of GWR measures (automated and manual) to predict the binary clinical endpoints of poor (CPC3-5) and good outcome (CPC1-2) was assessed by ROC analysis with increasing discrimination thresholds. Results of GWR_aut were compared to GWR_man of two raters.
  
  
  
  Of 84 patients, 55 (65%) showed a poor outcome. ROC curve analysis revealed reliable outcome prediction of GWR_aut (AUC 0.860) and GWR_man (AUC 0.707 and 0.699, respectively). Predictive power of GWR_aut was higher than GWR_man by each rater (p=0.019 and p=0.021, respectively) at an optimal cut-off of 1.084 to predict poor outcome (optimal criterion with 92.7% sensitivity, 72.4% specificity). Interrater reliability of GWR_man by intra-class correlation coefficient (ICC) was moderate (0.551).
  
  
  
  Automated quantification of GWR in CT may be used as an objective observer-independent imaging marker for outcome in patients after cardiac arrest.
authors.affiliation: Department of Clinical Radiology, University Hospital of Muenster, Germany; Insitute of Epidemiology and Social Medicine, University of Muenster, Germany.
authors.forename: Uta
authors.initials: U
authors.lastname: Hanning
authors.affiliation: Department of Clinical Radiology, University Hospital of Muenster, Germany.
authors.forename: Peter Bernhard
authors.initials: PB
authors.lastname: Sporns
authors.affiliation: Department of Cardiovascular Medicine, University of Muenster, Germany.
authors.forename: Pia
authors.initials: P
authors.lastname: Lebiedz
authors.affiliation: Department of Clinical Radiology, University Hospital of Muenster, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Niederstadt
authors.affiliation: Department of Clinical Radiology, University Hospital of Muenster, Germany.
authors.forename: Tarek
authors.initials: T
authors.lastname: Zoubi
authors.affiliation: Institute of Biostatistics and Clinical Research, University of Muenster, Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Schmidt
authors.affiliation: Department of Neurology, Mauritius Hospital Meerbusch and Clinical Neuroscience, University Duesseldorf, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Knecht
authors.affiliation: Department of Clinical Radiology, University Hospital of Muenster, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
authors.affiliation: Institute of Neuroradiology, University Hospital of Luebeck, Germany; Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Germany. Electronic address: andre.kemmling@uksh.de.
authors.forename: André
authors.initials: A
authors.lastname: Kemmling
mesh_terms: D000368:Aged; D001929:Brain Edema / Q000000981:diagnostic imaging* / Q000401:mortality; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging*; D006323:Heart Arrest / Q000150:complications* / Q000209:etiology / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: CT; Cardiac arrest; Coma; Outcome