Can DWI-ASPECTS substitute for lesion volume in acute stroke?

Area of Science:

• Neurology
• Radiology
• Stroke Medicine

Background:

• Diffusion lesion extent on pretreatment imaging is a key predictor of poor outcomes and hemorrhagic transformation post-thrombolysis.
• Established volume cut-offs (70-100 mL) for diffusion-weighted imaging lesion volume (VolDWI) are crucial but challenging to estimate acutely.

Purpose of the Study:

• To evaluate if the DWI-Alberta Stroke Program Early CT Score (DWI-ASPECTS) can serve as a substitute for VolDWI in acute stroke assessment.
• To determine the reliability of DWI-ASPECTS in predicting specific lesion volume thresholds.

Main Methods:

• Retrospective analysis of pretreatment MRI in 330 consecutively treated middle cerebral artery stroke patients.
• Measurement of both DWI-ASPECTS and VolDWI, with a median onset-to-MRI delay of 122 minutes.

Main Results:

• A strong negative correlation (ρ=-0.82) was observed between DWI-ASPECTS and VolDWI.
• Patients with DWI-ASPECTS ≥ 7 (n=207) consistently had VolDWI < 70 mL.
• Patients with DWI-ASPECTS < 4 (n=34) predominantly had VolDWI > 100 mL, while intermediate scores (4-6) showed high volume variability.

Conclusions:

• DWI-ASPECTS < 4 is a reliable surrogate for VolDWI > 100 mL.
• DWI-ASPECTS ≥ 7 is a reliable surrogate for VolDWI < 70 mL.
• While intermediate DWI-ASPECTS scores show volume variability, extreme scores offer reliable volumetric estimation in acute stroke.