NHBS-Net: A Feature Fusion Attention Network for Ultrasound Neonatal Hip Bone Segmentation

Ultrasound is a widely used technology for diagnosing developmental dysplasia of the hip (DDH) because it does not use radiation. Due to its low cost and convenience, 2-D ultrasound is still the most common examination in DDH diagnosis. In clinical usage, the complexity of both ultrasound image standardization and measurement leads to a high error rate for sonographers. The automatic segmentation results of key structures in the hip joint can be used to develop a standard plane detection method that helps sonographers decrease the error rate. However, current automatic segmentation methods still face challenges in robustness and accuracy. Thus, we propose a neonatal hip bone segmentation network (NHBS-Net) for the first time for the segmentation of seven key structures. We design three improvements, an enhanced dual attention module, a two-class feature fusion module, and a coordinate convolution output head, to help segment different structures. Compared with current state-of-the-art networks, NHBS-Net gains outstanding performance accuracy and generalizability, as shown in the experiments. Additionally, image standardization is a common need in ultrasonography. The ability of segmentation-based standard plane detection is tested on a 50-image standard dataset. The experiments show that our method can help healthcare workers decrease their error rate from 6%-10% to 2%. In addition, the segmentation performance in another ultrasound dataset (fetal heart) demonstrates the ability of our network.

I. Introduction

Developmental dysplasia of the hip (DDH) is a common disease that is often found in infants. The prevalence rate of DDH is as high as 3% [1]. Identifying DDH in the early stage is essential because treatments such as the Pavlik harness are available. DDH that is not diagnosed in time can influence the quality of the patient’s whole life. Moreover, serious consequences can occur, including secondary anatomical changes and leg length discrepancies, sometimes even necessitating replacement of the entire hip joint. Some researchers claim that DDH accounts for 30% of hip replacements in patients under 60 years old [2]. Thus, early and timely diagnosis of DDH is essential to maintain the quality of life of these patients.