Optimal Cerebral Blood Flow Thresholds for Ischemic Core Estimation Using Computed Tomography Perfusion and...

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Computed tomography perfusion (CTP) is vital for assessing cerebral blood flow (CBF) in large vessel occlusion (LVO) stroke, guiding endovascular treatment (EVT).
• CTP imaging can overestimate the ischemic core volume, potentially impacting treatment decisions.
• Establishing precise regional cerebral blood flow (rCBF) thresholds is crucial for accurate CTP interpretation.

Purpose of the Study:

• To determine the optimal pre-EVT CTP rCBF thresholds for accurately estimating ischemic core volume in LVO stroke.
• To validate CTP-derived core volumes against immediate and delayed post-EVT diffusion-weighted imaging (DWI) lesion volumes.

Main Methods:

• Retrospective analysis of 175 acute LVO stroke patients who underwent successful EVT.
• Collected baseline CTP, immediate (<3 hours), and delayed (24-196 hours) post-EVT DWI scans.
• Compared CTP-estimated core volumes at various rCBF thresholds with DWI lesion volumes.

Main Results:

• The strongest correlations between CTP-estimated core and DWI lesions were observed at rCBF <22% for immediate DWI and rCBF <30% for delayed DWI.
• The time interval between CTP and recanalization was inversely correlated with ischemic core overestimation.
• Optimal rCBF thresholds demonstrated moderate to good correlation with DWI lesion volumes.

Conclusions:

• Optimal rCBF thresholds for ischemic core estimation using CTP are dependent on the timing of post-EVT DWI and the delay to recanalization.
• These thresholds may need to be adjusted based on specific clinical scenarios and imaging protocols.
• Accurate ischemic core assessment is critical for optimizing EVT in LVO stroke.