Post-anoxic quantitative MRI changes may predict emergence from coma and functional outcomes at discharge.

Area of Science:

• Neurology
• Radiology
• Critical Care Medicine

Background:

• Traditional neurological prognosis predictors are unreliable post-targeted temperature management.
• Absence of pupillary reflexes is a reliable predictor of poor outcome.
• Diffusion-weighted imaging (DWI) shows potential for predicting neurological recovery.

Purpose of the Study:

• Compare quantitative MRI characteristics with pupillary exam for predicting outcomes.
• Evaluate the predictive value of apparent diffusion coefficient (ADC) sequences.
• Assess prediction of coma persistence and functional outcomes at discharge.

Main Methods:

• Identified 69 patients with MRIs within seven days of cardiac arrest.
• Used a semi-automated algorithm for quantitative volumetric analysis of ADC sequences.
• Estimated ROC-AUC to compare predictive values of MRI and pupillary exam.

Main Results:

• ≥2.8% diffusion restriction at ADC ≤650×10^-6m²/s predicted failure to wake up with 100% specificity.
• ADC changes at ≤450 and ≤650×10^-6m²/s significantly outperformed pupillary reflexes in predicting coma persistence.
• >0.01% diffusion restriction at ADC ≤450×10^-6m²/s predicted poor functional outcome in survivors with 100% specificity.

Conclusions:

• Quantitative brain MRI, specifically post-anoxic diffusion changes, aids in predicting neurological prognosis.
• DWI metrics offer a more objective and potentially superior method for outcome prediction compared to pupillary exams.
• This imaging technique may improve clinical decision-making for patients after cardiac arrest.