Imaging-to-recanalization delay influences perfusion CT threshold calibration for follow-up infarct volume estimation

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Computed tomography perfusion (CTP) is crucial for estimating ischemic core volume (ICV) in acute ischemic stroke (AIS).
• Accurate ICV estimation is vital for guiding treatment decisions and predicting outcomes.

Purpose of the Study:

• To evaluate the relationship between relative cerebral blood flow (rCBF) thresholds used in CTP and follow-up infarct volume (FIV).
• To assess the impact of imaging-to-recanalization delay on the accuracy of CTP-derived ICV in AIS patients undergoing endovascular treatment (EVT).

Main Methods:

• Retrospective analysis of 236 AIS patients with middle cerebral artery or internal carotid artery occlusion undergoing EVT.
• ICV was calculated using various rCBF thresholds (10%-30%) within syngo.via Neuro Perfusion software.
• Correlation between admission CTP-derived ICV and postprocedural FIV was analyzed, with subgroup analysis based on reperfusion times.

Main Results:

• The highest correlation between CTP-derived ICV and FIV in patients reperfused within 100 minutes was observed at rCBF thresholds of <22% and <20% (R=0.86).
• The rCBF <20% threshold demonstrated less ICV overestimation.
• In patients reperfused within 120 minutes, the highest correlation was found at an rCBF threshold of <24% (R=0.84).

Conclusions:

• The optimal rCBF threshold for CTP-derived ICV estimation in AIS is dependent on the imaging-to-recanalization delay.
• These findings suggest that dynamic adjustment of CTP thresholds may be necessary in clinical practice to account for treatment delays.
• Further exploratory research is warranted to validate these vendor-specific findings in diverse patient populations and workflows.