Airway segmentation is essential for chest CT image analysis. However, it
remains a challenging task because of the intrinsic complex tree-like structure
and imbalanced sizes of airway branches. Current deep learning-based methods
focus on model structure design while the potential of training strategy and
loss function have not been fully explored. Therefore, we present a simple yet
effective airway segmentation pipeline, denoted NaviAirway, which finds finer
bronchioles with a bronchiole-sensitive loss function and a
human-vision-inspired iterative training strategy. Experimental results show
that NaviAirway outperforms existing methods, particularly in identification of
higher generation bronchioles and robustness to new CT scans. Besides,
NaviAirway is general. It can be combined with different backbone models and
significantly improve their performance. Moreover, we propose two new metrics
(Branch Detected and Tree-length Detected) for a more comprehensive and fairer
evaluation of deep learning-based airway segmentation approaches. NaviAirway
can generate airway roadmap for Navigation Bronchoscopy and can also be applied
to other scenarios when segmenting fine and long tubular structures in
biomedical images. The code is publicly available on
https://github.com/AntonotnaWang/NaviAirway