Domain Adaptive Lung Nodule Detection in X-ray Image
Haifeng Zhao, Lixiang Jiang, Leilei Ma, Dengdi Sun, Yanping Fu
TL;DR
This work tackles the domain shift problem in cross-center chest X-ray lung nodule detection by integrating mean teacher self-training with hierarchical region- and pixel-level contrastive learning and a nodule-level domain-invariant feature learning (NDL) module. The method leverages a gradient reversal layer and an adversarial domain classifier to align nodule representations across domains, while refining pseudo-label quality through multi-scale contrastive signals. A new annotated B-Nodule dataset is introduced to support cross-domain evaluation. Experimental results across three datasets show improved cross-domain performance, outperforming strong baselines and demonstrating enhanced robustness in detecting nodules amidst domain variations, which is crucial for real-world, multi-center radiology workflows.
Abstract
Medical images from different healthcare centers exhibit varied data distributions, posing significant challenges for adapting lung nodule detection due to the domain shift between training and application phases. Traditional unsupervised domain adaptive detection methods often struggle with this shift, leading to suboptimal outcomes. To overcome these challenges, we introduce a novel domain adaptive approach for lung nodule detection that leverages mean teacher self-training and contrastive learning. First, we propose a hierarchical contrastive learning strategy to refine nodule representations and enhance the distinction between nodules and background. Second, we introduce a nodule-level domain-invariant feature learning (NDL) module to capture domain-invariant features through adversarial learning across different domains. Additionally, we propose a new annotated dataset of X-ray images to aid in advancing lung nodule detection research. Extensive experiments conducted on multiple X-ray datasets demonstrate the efficacy of our approach in mitigating domain shift impacts.
