Epicardium Prompt-guided Real-time Cardiac Ultrasound Frame-to-volume Registration

TL;DR

This paper presents CU-Reg, a lightweight neural network that improves real-time 2D-3D cardiac ultrasound registration accuracy by leveraging epicardium prompts and inter-frame regularization, aiding cardiac surgery guidance.

Contribution

Introduction of CU-Reg, a novel end-to-end network utilizing epicardium prompts and regularization for enhanced ultrasound frame-to-volume registration.

Findings

Outperforms existing methods in accuracy and efficiency

Effective in low-quality ultrasound modalities

Meets clinical guidance requirements

Abstract

A comprehensive guidance view for cardiac interventional surgery can be provided by the real-time fusion of the intraoperative 2D images and preoperative 3D volume based on the ultrasound frame-to-volume registration. However, cardiac ultrasound images are characterized by a low signal-to-noise ratio and small differences between adjacent frames, coupled with significant dimension variations between 2D frames and 3D volumes to be registered, resulting in real-time and accurate cardiac ultrasound frame-to-volume registration being a very challenging task. This paper introduces a lightweight end-to-end Cardiac Ultrasound frame-to-volume Registration network, termed CU-Reg. Specifically, the proposed model leverages epicardium prompt-guided anatomical clues to reinforce the interaction of 2D sparse and 3D dense features, followed by a voxel-wise local-global aggregation of enhanced features, thereby boosting the cross-dimensional matching effectiveness of low-quality ultrasound modalities. We further embed an inter-frame discriminative regularization term within the hybrid supervised learning to increase the distinction between adjacent slices in the same ultrasound volume to ensure registration stability. Experimental results on the reprocessed CAMUS dataset demonstrate that our CU-Reg surpasses existing methods in terms of registration accuracy and efficiency, meeting the guidance requirements of clinical cardiac interventional surgery.