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Updated: Nov 11, 2025
Brain Infarct Segmentation and Registration on MRI or CT for Lesion-symptom Mapping
Published on: September 25, 2019
MRI Diffusion-Weighted Imaging to Measure Infarct Volume: Assessment of Manual Segmentation Variability
Petra Cimflova1,2,3,4, Jiri Kral5,6, Ondrej Volny1,3,5
1Departments of Clinical Neurosciences, Calgary Stroke Program, Cumming School of Medicine, University of Calgary, Calgary, Canada.
Background And Purpose:
Manual segmentation of infarct volume on follow-up MRI diffusion-weighted imaging (MRI-DWI) is considered the gold standard but is prone to rater variability. We assess the variability of manual segmentations of MRI-DWI infarct volume.
Methods:
Consecutive patients (May 2018 to May 2019) with the anterior circulation stroke and endovascularly treated were enrolled. All patients underwent 24- to 32-hour follow-up MRI. Three users manually segmented DWI infarct volumes slice by slice twice. The reference standard of DWI infarct volume was generated by the STAPLE algorithm. Intra- and interrater reliability was evaluated using the intraclass correlation coefficient (ICC) by comparing manual segmentations with the reference standard. Spatial measurements were evaluated using metrics of the Dice similarity coefficient (DSC). Volumetric measurements were compared using the lesion volume.
Results:
The dataset consisted of 44 patients, mean (SD) age was 70.1 years (±10.3), 43% were women, and median baseline NIHSS score was 16. Among three users, the mean DSC for MRI-DWI infarct volume segmentations ranged from 80.6% ± 11.7% to 88.6% ± 7.5%, and the mean absolute volume difference was 2.8 ± 6.8 to 13.0 ± 14.0 ml. Interrater ICC among the users for DSC and infarct volume was .86 (95% confidence interval [95% CI]: .78-.91) and .997 (95% CI: .995-.998). Intrarater ICC for the three users was .83 (95% CI: .69-.93), .84 (95% CI: .72-.91), and .80 (95% CI: .64-.89) for DSC, and .99 (95% CI: .987-.996), .991 (95% CI: .983-.995), and .996 (95% CI: .993-.998) for infarct volume.
Conclusions:
Manual segmentation of infarct volume on follow-up MRI-DWI shows excellent agreement and good spatial overlap with the reference standard, suggesting its usefulness for measuring infarct volume on 24- to 32-hour MRI-DWI.
Insights
Manual segmentation of diffusion-weighted imaging infarct volumes shows excellent agreement and good spatial overlap with the reference standard. This method is useful for measuring infarct volume on follow-up MRI scans.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Manual segmentation of infarct volume on MRI-DWI is the gold standard.
- This method is susceptible to rater variability.
Purpose of the Study:
- To assess the variability of manual segmentations of MRI-DWI infarct volume.
- To evaluate the reliability and spatial overlap of manual segmentations against a reference standard.
Main Methods:
- Consecutive anterior circulation stroke patients undergoing endovascular treatment were enrolled.
- Three users performed manual slice-by-slice segmentation of DWI infarct volumes twice.
- Intra- and interrater reliability were assessed using ICC, and spatial overlap using DSC.
Main Results:
- Mean DSC ranged from 80.6% to 88.6%, with mean absolute volume differences from 2.8 to 13.0 ml.
- Interrater ICC for DSC and infarct volume were .86 and .997, respectively.
- Intrarater ICC for DSC ranged from .80 to .84, and for infarct volume from .99 to .996.
Conclusions:
- Manual segmentation of infarct volume on follow-up MRI-DWI demonstrates excellent agreement with the reference standard.
- The method shows good spatial overlap, confirming its utility for measuring infarct volume in 24- to 32-hour follow-up MRI-DWI.
