Multimodal HIE Lesion Segmentation in Neonates: A Comparative Study of Loss Functions
Annayah Usman, Abdul Haseeb, Tahir Syed
TL;DR
This study addresses the challenge of segmenting hypoxic-ischemic encephalopathy (HIE) lesions in neonatal MRI under limited data by systematically evaluating loss functions for a 3D U-Net. It compares Dice, Dice-Focal, Tversky, Hausdorff Distance, and two proposed compound losses (Dice-Focal-HausdorffDT and Tversky-HausdorffDT) to balance overlap, class imbalance, and boundary accuracy. Compound losses generally outperform standalone losses, with Tversky-HausdorffDT achieving the best Dice and NSD and Dice-Focal-HausdorffDT minimizing MSD, demonstrating the benefit of integrating region-based and boundary-aware cues. The findings highlight the importance of task-specific loss design in small datasets and suggest that such compound losses can help approach benchmark performance with fewer training epochs. This work informs loss-function design for HIE lesion segmentation and points toward future gains via advanced architectures and zero-shot approaches in data-limited contexts.
Abstract
Segmentation of Hypoxic-Ischemic Encephalopathy (HIE) lesions in neonatal MRI is a crucial but challenging task due to diffuse multifocal lesions with varying volumes and the limited availability of annotated HIE lesion datasets. Using the BONBID-HIE dataset, we implemented a 3D U-Net with optimized preprocessing, augmentation, and training strategies to overcome data constraints. The goal of this study is to identify the optimal loss function specifically for the HIE lesion segmentation task. To this end, we evaluated various loss functions, including Dice, Dice-Focal, Tversky, Hausdorff Distance (HausdorffDT) Loss, and two proposed compound losses -- Dice-Focal-HausdorffDT and Tversky-HausdorffDT -- to enhance segmentation performance. The results show that different loss functions predict distinct segmentation masks, with compound losses outperforming standalone losses. Tversky-HausdorffDT Loss achieves the highest Dice and Normalized Surface Dice scores, while Dice-Focal-HausdorffDT Loss minimizes Mean Surface Distance. This work underscores the significance of task-specific loss function optimization, demonstrating that combining region-based and boundary-aware losses leads to more accurate HIE lesion segmentation, even with limited training data.
