Predictors exploration of abnormal brain magnetic resonance versus normal brain computed tomography imaging in acute carbon monoxide poisoning

Acute brain lesions observed on magnetic resonance imaging (MRI) performed during acute-phase carbon monoxide (CO) poisoning were associated with patient prognosis. However, it may be difficult in critically ill patients because of the long examination time and for patients who have economical limitations due to the high price. The purpose of this study was to identify predictive factors for abnormal brain lesions on MRI in cases of normal brain findings on brain computed tomography (CT) in acute CO poisoning patients. This study was retrospectively analyzed at the tertiary emergency medical center located in Gyeonggi-do, Korea by prospectively collecting CO poisoning registry. From August 2016 to August 2019, 287 patients visited the hospital due to CO poisoning. Exclusion criteria included age under 18 years, being discharged against medical advice, no initial MRI data, no initial CT data, and having abnormal lesions on brain CT. Of the 103 patients included in the final study, the median age was 39 years old; 35 (34.0%) were male and 74 (71.8%) were intentionally exposed to CO. 27 (26.2%) patients had abnormal MRI findings. Based on multivariable analysis, elevated blood urea nitrogen (BUN) concentration (odds ratio, 1.165; 95% confidence interval, 1.037???1.308; p = 0.01) showed a significant association with abnormal MRI findings. The area under the curve was 0.753 (95% confidence interval, 0.636???0.869) in the receiver operating characteristic curve of BUN concentration for abnormal brain MRI presentations. Brain injury may be detected on brain MRI in acute CO poisoning patients even there was a normal brain CT scan. Our study revealed that elevated BUN concentration may be significantly correlated with abnormal MRI findings.