A cryogen-free open superconducting magnet for interventional MRI applications

摘要

A 0.5 T cryogen-free superconducting magnet with an open geometry has been designed for use in MRI-guided minimally invasive surgery and other interventional procedures. The magnet consists of a split pair of coils to allow surgeons direct access to the patient within the field-of-view of the imaging system. The magnet is wound using Nb/sub 3/Sn tape conductor and is maintained at approximately 10 K using a pair of Gifford-McMahon refrigerators. High-Tc superconducting current leads have been used in order to minimize the heat leak to the magnet. A passive quench protection system was developed for this unique magnet geometry. High quality MR images have been produced and used for interventional procedures. Descriptions of the design, fabrication, and test results of the magnet are presented.