Multi-Center Study of Diffusion-Weighted Imaging in Coma After Cardiac Arrest

Area of Science:

• Neurology
• Radiology
• Critical Care Medicine

Background:

• Predicting outcomes for cardiac arrest survivors with acute coma is challenging.
• Brain diffusion-weighted magnetic resonance imaging (DWI MRI) shows promise as a prognostic tool.
• This multi-center study evaluated established DWI MRI thresholds for outcome prediction.

Purpose of the Study:

• To assess the predictive value of previously defined DWI MRI apparent diffusion coefficient (ADC) thresholds.
• To determine the correlation between ADC values and brain volumes with patient outcomes.
• To validate DWI MRI as a prognostic tool in a multi-center cohort of comatose cardiac arrest survivors.

Main Methods:

• Retrospective observational study of comatose post-cardiac arrest patients.
• Analysis of brain DWI MRIs to determine apparent diffusion coefficient (ADC) values.
• Correlation of ADC thresholds and affected brain volumes with defined poor outcomes (lack of consciousness or death).

Main Results:

• 125 patients were analyzed; 33 (26%) had a good outcome.
• An ADC value < 650 × 10(-6) mm(2)/s in ≥10% of brain volume predicted poor outcome with 91% specificity and 72% sensitivity.
• This DWI MRI threshold was an independent predictor of poor outcome (p = 0.002).

Conclusions:

• Quantitative DWI MRI findings correlate with early consciousness recovery in comatose cardiac arrest survivors.
• A DWI MRI threshold of 650 × 10(-6) mm(2)/s in ≥10% brain volume differentiates good from poor outcomes.
• While useful, this threshold was not 100% specific for poor outcomes in this cohort.