Movable intraoperative magnetic resonance imaging incorporating a seismic system

Introduction: A high-field ceiling-mounted and movable intraoperative MR imaging (iMRI) can minimize additional risks for MRI and enhance safety by not moving the patient. In this system, hanging the heavy magnet from the ceiling requires structural stability; this stability was confirmed in earlier studies, but not proved during a seismic event. Objective: We have installed a 1.5 T movable iMRI system with an incorporated seismic system in our hospital in Japan, a seismic event-prone region. This arrangement is the first in the world, to our knowledge. The objective of this study was to describe the mechanism of this seismic system and the first clinical experience using this system. Methods: The seismic system consists of a stabilizer pad that is mounted directly under the magnet, in addition to the structural stability. The seismic system was tested with using a shaker table testing at a test laboratory. Results: Ninety-one patients underwent neurosurgical intervention using this iMRI and seismic system at our hospital. In all patients, intra-, pre, and/or postoperative MR images were successfully obtained, and image quality was excellent. The workflow of moving the magnet and scanning were smooth and unproblematic. We had 169 seismic events in our city during this time period, but had no incidental or accidental events related to the seismic events. Conclusion: With the use of the seismic system, a ceiling-mounted, movable iMRI system can be more safely used. This seismic system may contribute to the spread of movable iMRI systems in countries where seismic events occur. (C) 2015 Elsevier B.V. All rights reserved.