Pose-GuideNet: Automatic Scanning Guidance for Fetal Head Ultrasound from Pose Estimation

TL;DR

Pose-GuideNet is a novel method that estimates fetal head pose from 2D ultrasound to guide sonographers in locating standard planes, enabling automatic navigation without 3D ultrasound acquisition.

Contribution

It introduces a 2D/3D registration approach using pose estimation and semantic-aware contrastive learning for fetal head localization in ultrasound.

Findings

Accurately predicts fetal head pose and direction.

Aligns freehand 2D ultrasound with 3D anatomical atlas.

Demonstrates feasibility for sensor-free ultrasound navigation.

Abstract

3D pose estimation from a 2D cross-sectional view enables healthcare professionals to navigate through the 3D space, and such techniques initiate automatic guidance in many image-guided radiology applications. In this work, we investigate how estimating 3D fetal pose from freehand 2D ultrasound scanning can guide a sonographer to locate a head standard plane. Fetal head pose is estimated by the proposed Pose-GuideNet, a novel 2D/3D registration approach to align freehand 2D ultrasound to a 3D anatomical atlas without the acquisition of 3D ultrasound. To facilitate the 2D to 3D cross-dimensional projection, we exploit the prior knowledge in the atlas to align the standard plane frame in a freehand scan. A semantic-aware contrastive-based approach is further proposed to align the frames that are off standard planes based on their anatomical similarity. In the experiment, we enhance the existing assessment of freehand image localization by comparing the transformation of its estimated pose towards standard plane with the corresponding probe motion, which reflects the actual view change in 3D anatomy. Extensive results on two clinical head biometry tasks show that Pose-GuideNet not only accurately predicts pose but also successfully predicts the direction of the fetal head. Evaluations with probe motions further demonstrate the feasibility of adopting Pose-GuideNet for freehand ultrasound-assisted navigation in a sensor-free environment.