“…All of them rely on the acquisition of data during the procedure, providing information about the current tissue deformations. While Magnetic Resonance Imaging (MRI) is the reference preoperative exam, various intraoperative imaging systems are used in the literature such as MRI (Clatz et al, 2005;Vigneron et al, 2012), laser range scanners (LRS) (Sun et al, 2014;Miga et al, 2015), stereo cameras (Sun et al, 2005a) or ultrasound (US) imaging (Reinertsen et al, 2014;Rivaz & Collins, 2015). However, the data obtained cannot be directly used for surgical navigation: US images are of poor quality compared to preoperative MRI, and surface data alone are not clinically relevant.…”