Is infarct core growth linear? Infarct volume estimation by computed tomography perfusion imaging

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Current stroke treatment guidelines rely on time since symptom onset and computed tomography perfusion (CTP) imaging to assess the penumbra.
• Treatment windows are often based on linear infarct growth assumptions, but individual growth rates can vary significantly.

Purpose of the Study:

• To evaluate the accuracy of a linear growth model in estimating follow-up infarct volume (FIV) using baseline CTP imaging.
• To determine if infarct growth is linear in patients undergoing endovascular treatment (EVT) for large vessel occlusion (LVO).

Main Methods:

• Retrospective analysis of 48 patients with LVO who underwent EVT, CTP, and had known symptom onset times.
• Calculated infarct growth rate based on CTP core volume and time from onset to baseline imaging.
• Estimated follow-up infarct volume (eFIV) using a linear model and compared it to the actual FIV at 24 hours.

Main Results:

• Infarct growth was nonlinear in 87% of patients (40/48).
• Hypoperfusion intensity ratio (HIR) did not significantly differ between linear and nonlinear growth groups.
• Estimated FIV exceeded actual FIV in over half of patients with successful recanalization.

Conclusions:

• Infarct growth is predominantly nonlinear in EVT candidates.
• Relying solely on time from symptom onset and CTP core volume is inadequate for clinical decisions in EVT.
• Further research is needed to refine predictive models for infarct growth and optimize EVT timing.