Navigated liver biopsies in a closed-bore MR scanner: first clinical experience

Introduction/Purpose Most image-guided interventions such as biopsies or tumor ablations can be readily performed under CT or ultrasound guidance. MRI may be indicated whenever a suspect lesion can not reliably be visualized with these imaging modalities [1]. In a standard 1.5T MRI scanner, however, the remaining space is practically too small to handle an instrument inside the bore. Freehand biopsies outside the bore with intermediate control imaging are usually inaccurate and time consuming. Our concept combines an optical instrument tracking with an automatic patient registration [2] where the needle is manipulated outside the bore and control imaging can be performed at any time. For interventions in a moving organ (liver), a special respiratory training was evaluated. The goal of this work was to present a more reliable solution that may be flexibly added to a closed-bore scanner environment and to report on our first clinical experience in 15 patients with liver lesions.