Novel magnetic technology for intraoperative intracranial frameless navigation: In vivo and in vitro results

OBJECTIVE: To characterize the accuracy of the Magellan electromagnetic nav igation system (Biosense Webster, Tirat HaCarmel, Israel) and to demonstrat e the feasibility of its use in image-guided neurosurgical applications. DESCRIPTION OF INSTRUMENTATION: The Magellan system was developed to provid e real-time tracking of the distal tips of flexible catheters, steerable en doscopes, and other surgical instruments, using ultra-low electromagnetic f ields and a novel miniature position sensor for image-correlated intraopera tive navigation and mapping applications. METHODS: An image registration procedure was performed, and static and qual itative accuracies were assessed in a series of phantom, animal, and human neurosurgical studies. EXPERIENCE AND RESULTS: During the human study phase, an accuracy error of up to 5 mm was deemed acceptable. Results demonstrated that this degree of accuracy was maintained throughout all procedures. All anatomic landmarks w ere reached with precision and were accurately viewed on the display screen . Navigation that relied on the system was also successful. No interference with operating room equipment was noted. The accuracy of the system was ma intained during regular surgical procedures, using standard surgical tools. CONCLUSION: The system provides precise lesion localization without limitin g the line of vision, the mobility of the surgeon, or the flexibility of in struments. Electromagnetic navigation promises new advances in neuronavigat ion and frameless stereotactic surgery.