| خلاصه مقاله | White matter hyperintensities (WMHs) on
FLAIR MRI are critical indicators of cerebrovascular
dysfunction associated with elevated risks of stroke, dementia,
and death. Current automated segmentation methods suffer
from false positive detection in periventricular regions, failing
to distinguish normal aging-related hyperintensities from
pathologically significant lesions, which reduces clinical
applicability and diagnostic accuracy. This study investigates
whether training deep learning models to explicitly differentiate
between normal and abnormal WMH improves pathological
WMH segmentation performance compared to traditional
binary approaches. Four state-of-the-art architectures (U-Net,
Attention U-Net, DeepLabV3Plus, Trans-U-Net) were evaluated
across two training scenarios using 1,974 FLAIR images from
100 MS patients with expert-annotated ground truths. Scenario
1 employed binary training (background vs abnormal WMH),
while Scenario 2 utilized three-class training (background,
normal WMH, abnormal WMH). Statistical analysis included
paired t-tests and Cohen's d effect size calculations. U-Net
achieved the most substantial improvement in Scenario 2 with
55.6% increase in Dice coefficient (0.693 vs 0.443) and 131%
precision enhancement (p < 0.0001, Cohen's d = 0.971).
Traditional CNN-based architectures demonstrated larger
effect sizes than transformer-based models. The three-class
training approach significantly enhances pathological WMH
segmentation while maintaining clinical feasibility, providing a
validated framework for improving automated neuroimaging
tools' diagnostic utility.
Keywords— White matter hyperintensities (WMH); deep
learning; medical image segmentation; FLAIR MRI; multi-class
classification; U-Net; pathological segmentation; neuroimaging |