Shortcut Learning in Medical Image Segmentation
This work addresses a pervasive challenge in medical image segmentation by uncovering shortcuts that can mislead models, which is incremental as it extends shortcut learning from classification to segmentation.
The study investigated shortcut learning in medical image segmentation, identifying clinical annotations and dataset preprocessing as shortcuts that reduce segmentation accuracy, and proposed mitigation strategies to improve model generalizability.
Shortcut learning is a phenomenon where machine learning models prioritize learning simple, potentially misleading cues from data that do not generalize well beyond the training set. While existing research primarily investigates this in the realm of image classification, this study extends the exploration of shortcut learning into medical image segmentation. We demonstrate that clinical annotations such as calipers, and the combination of zero-padded convolutions and center-cropped training sets in the dataset can inadvertently serve as shortcuts, impacting segmentation accuracy. We identify and evaluate the shortcut learning on two different but common medical image segmentation tasks. In addition, we suggest strategies to mitigate the influence of shortcut learning and improve the generalizability of the segmentation models. By uncovering the presence and implications of shortcuts in medical image segmentation, we provide insights and methodologies for evaluating and overcoming this pervasive challenge and call for attention in the community for shortcuts in segmentation. Our code is public at https://github.com/nina-weng/shortcut_skinseg .