Pulmonary segments parcellation is essential to thoracoscopic segmentectomy. Surgeons manually outline pulmonary segments from preoperative images before surgery, which is a time-consuming, labor-intensive and mental-stress procedure. This work proposes a novel small learning model of deep support vein machine without using annotated pulmonary segments data for automatic lung parcellation. Specifically, this machine can learn anatomical structures of pulmonary lobe, bronchus, artery, and vein by two cascade multilayer perceptrons to automatically divides the lung into eighteen segments. The perceptron module typically smooths the boundary of the pulmonary segment to attain robust and precise parcellation. Additionally, three new metrics are defined to quantitatively evaluate the quality of lung parcellation. We validate our methods on 108 clinical pulmonary computed tomography scans, with the experimental results showing that our proposed machine certainly outperforms current methods and provides a promising way to fully automated lung parcellation. Particularly, the dice similarity coefficient of lung parcellation was significantly improved from 0.886 to 0.918.

Automatic segmentation of pulmonary arteries and veins in CT has great clinical significance. Because the growth range of a single vessel is vast, and the arteries and veins have barely identical intensity values on CT and grow very close to or even interleaved, accurate segmentation of them requires intricate vascular texture information and long-distance vascular trunk information as the basis for artery and vein classification. In order to meet these two requirements simultaneously, we design a residual W-Unit, which concatenated two U-shaped structures. It allows the network to become deeper and improve the receptive field for global information while preserving the detailed features of the vessels. And we design a semantic embedding module using cross-attention, which enhances the expression of bronchial features and assists in further utilizing features. It explicitly leverages the anatomical knowledge of parallel growth between arteries and bronchi. Then we combine RWUs and SEMs to construct a concise network to extract and fuse the features with detailed information from different network depths and receptive fields. Finally, we use a post-processing scheme to reduce spatial inconsistency. We validated our networks on 40 training sets and 17 test sets, and the experimental results show that our networks outperform current segmentation methods.

Monocular endoscopic depth estimation is essential for surgical navigation. Current deeply learned estimation methods still suffer from lack of real data labels and porous, artifacts (e.g., bubbles), illumination variations (e.g., specular highlight), and weak texture in endoscopic video images. This paper proposes a new deep learning framework of cascade hole-aware transformers with geometric spatial consistency for accurate endoscopic depth estimation without using any image annotation. Specifically, this framework employs cascade hole-aware encoders to powerfully extract structural features of deep and shallow holes, while it further introduces multiscale filtering decoders to suppress non-hole region features, addressing the problems of specular highlights, weak textures or bubbles. Additionally, a geometric spatial consistency loss can strongly perceive geometric information and suppress the color difference between virtual and real images. We generated virtual endoscopic image data to train our network architecture and test it on both virtual and real endoscopic video images, with the experimental results showing that our method is robust to zero-shot evaluation of real data. Particularly, our method can attain lower root mean square error 1.551±1.147 mm and mean absolute error 1.004±0.632 mm than state-of-the-art deep learning approaches.

Pulmonary vessel CT segmentation is important to clinical diagnosis of lung diseases. But it is still a challenge due to limited CT quality and complicated vascular structures. This paper proposes new enhanced U-transformer networks that combine transformers, a contrast enhancement block with a reverse attention block to perform end-to-end vessel segmentation. Specifically, the contrast enhancement block directly augments edge or structural information while the reverse attention block conducts the network paying more attention to blurred boundaries and uncertain regions of vessels, leading to improving the accuracy and smoothness of pulmonary vessel segmentation. We validated our proposed method on 50 CT volumes selected from LIDC-IDRI, with the experimental results demonstrating that it works more effectively and stably than currently available approaches. Particularly, the average dice similarity coefficient and recall were improved from (85.23%, 85.37%) to (86.07%, 86.67%), respectively.