Clinically-aligned ischemic stroke segmentation and ASPECTS scoring on NCCT imaging using a slice-gated loss on foundation representations
This study addresses a critical limitation in current deep learning approaches for segmenting ischemic stroke lesions on non-contrast CT (NCCT) scans: the neglect of the anatomical coupling between the basal ganglia (BG) and supraganglionic (SG) levels as defined by the ASPECTS scoring system, which undermines alignment with clinical evaluation logic. To bridge this gap, the authors propose the first integration of this structured clinical prior into foundation model training through an anatomy-aware gated loss (TAGL). By combining a frozen DINOv2 backbone with a lightweight decoder, their method enforces BG-SG consistency without increasing inference overhead. Evaluated on the AISD dataset, the approach achieves a Dice score of 0.6385, outperforming existing CNNs and foundation models. On an in-house ASPECTS dataset, it further improves the average Dice from 0.698 to 0.767, significantly enhancing segmentation consistency with clinical standards.