Hypoperfusion ratio predicts infarct growth during transfer for thrombectomy

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Stroke management requires timely reperfusion therapy.
• Transferring patients between stroke centers can delay treatment.
• Predicting infarct growth during transfer is crucial for optimizing care.

Purpose of the Study:

• To evaluate if automated collateral assessment on computed tomography (CT) perfusion can predict infarct growth rate.
• To determine the utility of the hypoperfusion intensity ratio (HIR) in guiding clinical decisions during inter-facility stroke transfer.

Main Methods:

• Retrospective analysis of 28 patients undergoing endovascular stroke treatment transfer.
• Assessment of collateral status using the hypoperfusion intensity ratio (HIR) on pre-transfer CT perfusion scans.
• Correlation of HIR with infarct growth rate and analysis using receiver operating characteristic (ROC) curves.

Main Results:

• Infarct growth rate strongly correlated with HIR (r=0.78, p<0.001).
• HIR ≥ 0.5 predicted significant infarct growth (median growth 10.1 ml/h vs 0.9 ml/h, p<0.001).
• Patients with HIR ≥ 0.5 had an 83% probability of significant core growth, while those with HIR < 0.5 had an 88% probability of core stability.

Conclusions:

• Automated CT perfusion collateral assessment, specifically HIR, effectively predicts infarct growth during inter-facility transfer.
• HIR ≥ 0.5 is a reliable indicator for significant infarct expansion in transfer patients.
• These findings may inform decisions on repeat brain imaging after transfer to a comprehensive stroke center.