Is CT-Based Perfusion and Collateral Imaging Sensitive to Time Since Stroke Onset?

Area of Science:

• Neuroradiology
• Neuroimaging
• Stroke Imaging

Background:

• CT-based perfusion and collateral imaging are vital for acute stroke assessment.
• Time since stroke onset is crucial for thrombolysis eligibility and efficacy.
• Animal studies suggest ischemic penumbra volume diminishes over time.

Purpose of the Study:

• To evaluate if CT imaging can detect a relationship between perfusion or collateral status and time since stroke onset.
• To assess the impact of time on ischemic penumbra volume and collateral function in acute stroke patients.

Main Methods:

• 53 patients with proximal vessel occlusions underwent whole-brain CT perfusion (CTp) imaging.
• Penumbra and core volumes were defined using CT perfusion parameters (CBF, MTT, CBV).
• Collateral status was assessed using CT angiography (CTA); CTp ASPECTS scores were also calculated.

Main Results:

• Both penumbra fractions (PenCBF and PenMTT) showed a trend of decreasing with increasing time since stroke onset.
• The CBF/CBV ASPECTS ratio demonstrated a significant decrease over time.
• Collateral response did not show a significant relationship with time since stroke onset.

Conclusions:

• Perfusion CT imaging may reveal a time-dependent decrease in ischemic penumbra volume within 4.5 hours of stroke onset.
• No significant time-dependent relationship was observed for collateral status.
• Further studies with larger datasets are warranted to confirm these findings and explore applications for unknown stroke onset times.