title: Gray Matter-White Matter De-Differentiation on Brain Computed Tomography Predicts Brain Death Occurrence.
abstract: BACKGROUND
  Previous studies have shown that a loss of distinction between gray matter (GM) and white matter (WM) on unenhanced CT scans was predictive of poor outcome after cardiac arrest. The aim of this study was to identify a marker/predictor of imminent brain death.
  
  
  METHODS
  In this retrospective study, 15 brain-dead patients after anoxia and cardiac arrest were included. Patients were paired (1:1) with normal control subjects. Only patients' unenhanced CT scans performed before brain death and during the 24 hours after initial signs were analyzed. WM and GM densities were measured in predefined regions of interest (basal ganglia level, centrum semi-ovale level, high convexity level, brainstem level). At each level, GM and WM density and GM/WM ratio for brain-dead patients and normal control subjects were compared using the Wilcoxon signed-rank test.
  
  
  RESULTS
  At each level, a lower GM/WM ratio and decreased GM and WM densities were observed in brain-dead patients' CT scans when compared with normal control subject CT scans. A cut-off value of 1.21 at the basal ganglia level was identified, below which brain death systematically occurred.
  
  
  CONCLUSIONS
  GM/WM dedifferentiation on unenhanced CT scan is measurable before the occurrence of brain death, highlighting its importance in brain death prediction. The mechanism of GM/WM differentiation loss could be explained by the lack of oxygen caused by ischemia initially affecting the mitochondrial system.
authors: Faculté de Médecine Lyon-Est, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.
authors: C
authors: C
authors: Vigneron
authors: Service de Coordination des prélèvements d'organes et de tissus, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, Lyon, France.
authors: V
authors: V
authors: Labeye
authors: Faculté de Médecine Lyon-Est, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France; Service de Réanimation Médicale, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, Lyon, France.
authors: M
authors: M
authors: Cour
authors: CREATIS, CNRS UMR5220 & INSERM U1206, Université de Lyon, France.
authors: S
authors: S
authors: Hannoun
authors: Faculté de Médecine Lyon-Est, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.
authors: A
authors: A
authors: Grember
authors: Faculté de Médecine Lyon-Est, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.
authors: F
authors: F
authors: Rampon
authors: Faculté de Médecine Lyon-Est, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France; CREATIS, CNRS UMR5220 & INSERM U1206, Université de Lyon, France; Service de Radiologie, Groupement Hospitalier Sud, Hospices civils de Lyon, Lyon, France. Electronic address: francois.cotton@chu-lyon.fr.
authors: F
authors: F
authors: Cotton
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology; D001926:Brain Death / Q000000981:diagnostic imaging* / Q000473:pathology*; D054337:Cell Dedifferentiation; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006323:Heart Arrest / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D066127:White Matter / Q000473:pathology*