Registration of ultrasound echography for intraoperative use: a newly developed multiproperty method

Nowadays, several studies on 3D medical image registration are being investigated. The main purpose of these studies is to integrate complimentary information provided by different modalities. This paper describes a newly developed registration method of ultrasound echography to 3D medical image. The registration process consists of two stages. In the first stage, a registration process of the ultrasound echography to the pre- operative 3D images is performed using a position sensor. This is a rigid transformation, which can't provide a perfect match because the intra-operative organ is deformed or moved. The second step is a local matching process, where the current position of the ultrasound echography is approximated with a search-based surface matching algorithm. We used the 3D chamfer matching for this approximation. In this method, a goodness-of- match function, i.e., generalized distance, that rates the geometrical transformation is computed and minimized. In a preliminary experiment, the search-based matching process was examined. The algorithm and its accuracy were evaluated with an artificial transformed set of coordinates given as the initial guess. We also performed a clinical application and results confirmed the suitability of this method to clinical use.