Bronchovascular Tree-Guided Weakly Supervised Learning Method for Pulmonary Segment Segmentation
Journal:
arXiv
Published Date:
May 20, 2025
Abstract
Pulmonary segment segmentation is crucial for cancer localization and
surgical planning. However, the pixel-wise annotation of pulmonary segments is
laborious, as the boundaries between segments are indistinguishable in medical
images. To this end, we propose a weakly supervised learning (WSL) method,
termed Anatomy-Hierarchy Supervised Learning (AHSL), which consults the precise
clinical anatomical definition of pulmonary segments to perform pulmonary
segment segmentation. Since pulmonary segments reside within the lobes and are
determined by the bronchovascular tree, i.e., artery, airway and vein, the
design of the loss function is founded on two principles. First, segment-level
labels are utilized to directly supervise the output of the pulmonary segments,
ensuring that they accurately encompass the appropriate bronchovascular tree.
Second, lobe-level supervision indirectly oversees the pulmonary segment,
ensuring their inclusion within the corresponding lobe. Besides, we introduce a
two-stage segmentation strategy that incorporates bronchovascular priori
information. Furthermore, a consistency loss is proposed to enhance the
smoothness of segment boundaries, along with an evaluation metric designed to
measure the smoothness of pulmonary segment boundaries. Visual inspection and
evaluation metrics from experiments conducted on a private dataset demonstrate
the effectiveness of our method.
