Sensorless and real-time registration between 2D ultrasound and preoperative images of the liver

Abstract

Synchronization between real-time ultrasound (US) and preoperative images can provide much information for US-guided intervention. For the synchronization, we present a real-time registration system between the two images of the liver without any help of sensors. In this system, we first generate a 4D preoperative image, which is composed of multiple 3D images along the respiration, by considering their local deformation. In the intraoperative stage, we achieve the pose information of a pose-fixed 3D US transducer by using several 3D US images. We then acquire 2D US images and find their corresponding images in real-time from the 4D preoperative image. The related registration is done by comparing a gradient-based similarity measure between a 2D US image and generated 2D preoperative image candidates. By the visual assessment of registration results, we confirm the feasibility of the proposed system for image-guidance.