The PoleStar iMRI. The open-bore configuration PoleStar N-20, despite its low-field 0.15T magnet, has allowed many institutions to take advantage of iMRI without completely remodeling their operative suite to accommodate a larger, high-field stationary iMRI. The Polestar is compact enough to be stored in a shielded room (pictured on the right side of the figure) when not in use. If a smaller room cannot be dedicated to storage, an in-suite “hangar” can be set up to shield the magnet when not in use. (Courtesy of Medtronic Navigation, Louisville, CO; with permission.)