Prognostic value of diffusion-weighted MRI for post-cardiac arrest coma.

Area of Science:

• Neuroimaging
• Neurology
• Cardiology

Background:

• Comatose cardiac arrest survivors require accurate prognostication for clinical decision-making.
• Quantitative diffusion-weighted imaging (DWI) MRI offers potential for objective outcome prediction.

Purpose of the Study:

• To validate specific quantitative DWI MRI thresholds for predicting poor outcomes in comatose cardiac arrest survivors.
• To assess the accuracy of apparent diffusion coefficient (ADC) values in prognostication.

Main Methods:

• Prospective, clinician-blinded study enrolling comatose adult cardiac arrest survivors.
• MRIs were obtained within 7 days post-arrest and analyzed for ADC values.
• Poor outcome defined as Glasgow Outcome Scale ≤2 at 6 months; prognostication algorithm used.

Main Results:

• In 51 patients with MRI by postarrest day 7, >10% brain tissue with ADC <650 ×10^-6 mm²/s predicted poor outcome with 96% specificity and 94% PPV.
• Mean whole-brain ADC was higher in patients with good outcomes.
• Quantitative DWI MRI improved prognostication accuracy for both good and poor outcomes.

Conclusions:

• The study validates that DWI MRI with ADC <650 ×10^-6 mm²/s in >10% brain tissue by postarrest day 7 is highly specific for poor outcome.
• Quantitative DWI MRI is a valuable tool for prognostication in comatose cardiac arrest survivors.