MR Safe—an item that poses no known hazards resulting from exposure to any MR environment. MR Safe items are composed of materials that are electrically nonconductive, nonmetallic, and nonmagnetic.
An item composed entirely of electrically nonconductive, nonmetallic and nonmagnetic materials may be determined to be MR Safe by providing a scientifically based rationale rather than test data. Examples of MR Safe items are a cotton blanket or a silicone catheter.
MR Conditional - An item with demonstrated safety in the MR environment within defined conditions. At a minimum, address the conditions of the static magnetic field, the switched gradient magnetic field and the radiofrequency fields. Additional conditions, including specific configurations of the item, may be required.
Supplementary Marking - Additional information that, in association with a marking as “MR Conditional,” states via additional language the conditions in which an item can be used safely within the MR environment.
MR Unsafe—an item which poses unacceptable risks to the patient, medical staff or other persons within the MR environment.