Topological GCN Guided Improved Conformer for Detection of Hip Landmarks from Ultrasound Images.

The B-mode ultrasound based computeraided diagnosis (CAD) has shown its effectiveness for diagnosis of Developmental Dysplasia of the Hip (DDH) in infants within 6 months. Hip landmark detection is a feasible way for the CAD of DDH according to the Graf's method. However, existing landmark detection algorithms mainly focus on designing special models to capture the features from hip ultrasound images, but generally ignore the important spatial relations among different landmarks. To this end, a novel weakly supervised learning-based algorithm, the Topological Graph Convolutional Network (TGCN) guided Improved Conformer (TGCN-ICF), is proposed for detecting landmarks from hip ultrasound images. The TGCN-ICF includes two subnetworks: an Improved Conformer (ICF) subnetwork to generate heatmaps and constraint vectors from ultrasound images, and a TGCN subnetwork to additionally explore topological relations among hip landmarks with the guidance of class labels for further refining and improving the detection accuracy. Moreover, a new Mutual Modulation Fusion (MMF) module is developed to fully exchange and fuse the extracted feature information from the convolutional neural network (CNN) and Transformer branches in ICF. Meanwhile, a novel Mutual Supervision Constraint (MSC) strategy is designed to provide a constraint for detection of each hip landmark. The experimental results on two realworld DDH datasets demonstrate that the TGCN-ICF outperforms all the compared algorithms, suggesting its potential applications. The source code is publicly available on https://github.com/Tianxiang-Huang/TGCN-ICF.