ABSTRACT
This chapter presents a feasibility study of a tracking tool for brain deformations based on intraoperative three-dimensional (3D) ultrasound (US) image sequences. It deals with the rigid registration of the preoperative magnetic resonance (MR) image with the first US image. The chapter aims to develop an automatic intensity based nonrigid tracking algorithm suited for real time US image sequences, based on encouraging preliminary results. The use of stereotactic systems is a standard procedure for neurosurgery. However, these systems assume that the brain is in fixed relation to the skull during surgery. In practice, relative motion of the brain with respect to the skull occurs, mainly due to tumor resection, cerebrospinal fluid drainage, hemorrhage, or even the use of diuretics. Even if there is a poor signal to noise ratio in US images, the speckle is usually persistent in time and may produce reliable landmarks within the time sequence.
