Time-dependent association of grey-white ratio on early brain CT predicting outcomes after cardiac arrest at hospital discharge

Cerebral edema after cardiac arrest can be quantified by the ratio of grey matter to white matter radiodensity (GWR) on computed tomography (CT). Severe edema predicts worse outcomes. We hypothesized the sensitivity and false positive rate of GWR predicting outcomes change over the first 24 hours post-arrest. We performed a single-center retrospective cohort study including patients resuscitated from cardiac arrest between January 2010 and December 2023 who were unresponsive to verbal commands. We excluded patients who arrested from a primary traumatic or neurological etiology and those without brain imaging within 24 hours of arrest. We divided patients into groups based on time from arrest to CT, then quantified the performance of GWR dichotomized at