Learning to learn skill assessment for fetal ultrasound scanning
Yipei Wang, Qianye Yang, Lior Drukker, Aris T. Papageorghiou, Yipeng Hu, J. Alison Noble
TL;DR
The paper tackles the challenge of subjective fetal ultrasound skill assessment by introducing a bi-level optimisation framework that jointly learns a task predictor for a segmentation-based clinical task and a skill predictor that gauges frame sequences by how well the task predictor performs. Skill scores weight the task loss and vice versa, enabling task-centric, frame-level skill evaluation without manually defined ratings. Validated on the PULSE fetal ultrasound dataset with three landmarks, the approach demonstrates that frames deemed high-skill by the predictor tend to enhance downstream task performance, supporting real-time, task-specific guidance for sonographers. The method offers a scalable, label-efficient alternative to conventional supervision, with potential for adaptation to other clinical tasks and prospective clinical validation.
Abstract
Traditionally, ultrasound skill assessment has relied on expert supervision and feedback, a process known for its subjectivity and time-intensive nature. Previous works on quantitative and automated skill assessment have predominantly employed supervised learning methods, often limiting the analysis to predetermined or assumed factors considered influential in determining skill levels. In this work, we propose a novel bi-level optimisation framework that assesses fetal ultrasound skills by how well a task is performed on the acquired fetal ultrasound images, without using manually predefined skill ratings. The framework consists of a clinical task predictor and a skill predictor, which are optimised jointly by refining the two networks simultaneously. We validate the proposed method on real-world clinical ultrasound videos of scanning the fetal head. The results demonstrate the feasibility of predicting ultrasound skills by the proposed framework, which quantifies optimised task performance as a skill indicator.
