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Intraoperative MRI has been a helpful addition to the field of neurosurgery and has allowed neurosurgeons to more accurately resect tumors, make smaller incisions, and then evaluate the resection during the actual operative time period. There is a significant risk of injury due to the strong force of the magnet of the MRI and thus maintaining safety is of utmost importance. Gauss is used to describe the strength of the magnetic force and to help determine the “safe distance” away from the MRI scanner. The 5-Gauss line defines the perimeter around the MRI scanner within which static magnetic fields are higher than 5 Gauss. Thus, outside (or beyond) the 5-Gauss line is considered the safe area for anesthesia equipment.