Diffusion-Weighted MRI Stroke Volume Following Recanalization Treatment is Threshold-Dependent

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Infarct lesion segmentation using diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) is challenging due to variable thresholding methods.
• Accurate assessment of stroke lesion volume and evolution is critical for evaluating treatment efficacy.

Purpose of the Study:

• To examine differences in stroke lesion volume and evolution using magnetic resonance imaging (MRI) at $<5$ hours and 24 hours post-treatment.
• To compare lesion volumes segmented with various absolute ADC and relative DWI thresholds.

Main Methods:

• 33 acute ischemic stroke patients underwent MRI $<5$ hours and 24 hours post-reperfusion.
• Lesion volumes were segmented on ADC maps and average DWI using literature-cited thresholds.
• Bland-Altman analysis was used to compare lesion volumes and calculate infarct growth.

Main Results:

• Significant differences in lesion volumes were observed with varying relative DWI and absolute ADC thresholds (p < 0.05).
• Median infarct growth varied from 3.5 ml to 6.5 ml for different ADC thresholds and 4.2 ml to 10.1 ml for DWI thresholds.
• Threshold choice significantly impacts the measurement of lesion volume and infarct growth.

Conclusions:

• Absolute lesion volumes and infarct growth after recanalization treatment are dependent on the chosen ADC and DWI thresholds.
• Standardization of DWI lesion volume measurement techniques is urgently needed for clinical significance.