Perfusion computer tomography: imaging and clinical validation in acute ischaemic stroke

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Computed tomography perfusion (CTP) imaging is crucial for acute stroke assessment.
• Further validation is needed to optimize CTP parameters for defining infarct core and hypoperfused tissue.

Purpose of the Study:

• To establish optimal CTP parameters for defining infarct core and critically hypoperfused tissue in acute ischemic stroke.
• To validate these parameters against magnetic resonance imaging (MRI) and clinical outcomes.

Main Methods:

• Analysis of sub-6-hour CTP and 24-hour DWI-MRI from 314 ischemic stroke patients.
• Pixel-based analysis to define optimal CTP thresholds for infarct core and hypoperfused tissue.
• Comparison of CTP-derived volumes with 24-hour DWI lesions and 24-hour/90-day clinical outcomes.

Main Results:

• Relative delay time >2s accurately predicted hypoperfused tissue (AUC=0.86).
• Cerebral blood flow <40% within relative delay time >2s lesions accurately defined infarct core (AUC=0.85).
• CTP mismatch salvage correlated with clinical improvement at 24h and 90 days; larger infarct core predicted poorer recovery.

Conclusions:

• Optimized CTP thresholds accurately identify tissue at risk of infarction and the final infarct core.
• CTP parameters are valuable for predicting final infarct volume and clinical outcomes in acute ischemic stroke.
• CTP imaging provides reliable data for guiding acute stroke management and predicting patient recovery.