Clinical Outcomes and Imaging Metrics in Extensive Ischemic Stroke

Overview

This study compared cerebral edema volume (EV) and midline shift (MLS) as imaging biomarkers in patients with large anterior circulation ischemic strokes. EV demonstrated similar accuracy to MLS in predicting malignant infarction and very poor functional outcomes, and remained reliable even in infarcts without apparent MLS.

Background

Ischemic edema is a critical pathophysiological feature of ischemic stroke, especially in large hemispheric infarcts where it can cause increased intracranial pressure and worsen outcomes. Midline shift (MLS) is the traditional imaging biomarker for edema but only detects large infarcts with mass effect. CT densitometry-based net water uptake (NWU) allows quantification of edema volume (EV) by measuring tissue hypodensity and water content. Accurate early imaging biomarkers are essential for prognosis and treatment evaluation, particularly in patients undergoing thrombectomy for large vessel occlusions.

Data Highlights

Key Findings

• EV and MLS showed comparable accuracy in predicting malignant infarction and very poor functional outcomes (mRS 5–6 at discharge).
• MLS detects edema only in large infarcts causing mass effect, limiting its sensitivity in smaller infarcts.
• EV quantification via CT densitometry provides a direct and early measure of ischemic edema volume.
• EV remains a reliable biomarker even in infarcts without apparent MLS, expanding its clinical utility.
• Patients with large vessel occlusions and ASPECTS ≤ 5 were studied, reflecting a population relevant for thrombectomy treatment.

Clinical Implications

CT densitometry-based edema volume measurement offers a sensitive and quantitative imaging biomarker for ischemic edema that can complement or substitute MLS, especially in patients without significant midline shift. Early and accurate edema quantification may improve risk stratification and guide therapeutic decisions in large vessel occlusion strokes. Incorporating EV assessment into routine imaging protocols could enhance prognostication and evaluation of treatment effects such as thrombectomy.

Conclusion

Edema volume measured by CT densitometry is a valuable imaging biomarker comparable to midline shift for predicting malignant infarction and poor outcomes in extensive ischemic stroke. Its ability to detect edema in infarcts without MLS supports its broader clinical application.

References

1. University Medical Center Hamburg-Eppendorf Stroke Registry -- Clinical Outcomes and Imaging Metrics in Extensive Ischemic Stroke