A novel algorithm for CT-ultrasound registration

The fusion of ultrasound (US) with CT plays a vital role in clinical diagnosis and image guided intervention. A registration framework between preoperative CT and tracked 2D intraoperative US is proposed here for hepatic intervention. After a landmark based registration method is carried out to get the initial registration, a simulation model of US from CT scan is developed to simulate the major US effects. The innovation is incorporating spatial and intensity scale information in a new similarity metric, which is to register the selected US image containing crucial anatomical features and the simulated US from CT. Experiments of 5 patients illustrate that our registration method achieved an average FRE and TRE of 3.81 ± 1.16 mm and 4.13 ± 1.27 mm.