Infarct density defined by ADC threshold is associated with long-term functional outcome after endovascular...

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Endovascular thrombectomy (EVT) is a key treatment for acute ischemic stroke.
• While EVT improves outcomes, predicting long-term results solely by final infarct volume is limited.
• Novel imaging metrics are needed to better quantify tissue injury and predict functional recovery.

Purpose of the Study:

• To develop and validate a novel MRI-ADC-based metric, infarct density, to predict long-term outcomes after EVT.
• To compare the predictive performance of infarct density against traditional infarct volume.
• To test the hypothesis that infarct density outperforms infarct volume in predicting good functional outcome.

Main Methods:

• Retrospective analysis of 120 acute stroke patients undergoing successful EVT with anterior circulation large vessel occlusion.
• MRI-ADC imaging processed using RAPID software to determine final infarct volume and infarct density.
• Logistic regression models used to assess the association between imaging metrics (infarct volume and density) and 90-day modified Rankin Scale (mRS) scores.

Main Results:

• Lesion volume at an ADC threshold of <470 showed the strongest association with good outcome.
• Infarct density, calculated as the percentage of final infarct volume below a specific ADC threshold, was independently associated with good outcome (aOR 0.68 per 10%).
• Final infarct volume was not independently associated with good outcome in multivariate analysis (aOR 0.98 per 10 mL).

Conclusions:

• Infarct density is a more robust predictor of long-term clinical outcome after EVT compared to final infarct volume.
• This novel MRI metric offers improved prognostic value for stroke patients treated with EVT.
• Further validation of infarct density may refine patient selection and treatment monitoring in stroke care.