Ferromagnetic sand: A possible MRI hazard.

While the ferromagnetic properties of metallic objects, implantable medical devices, and cosmetics are well known, sand is not generally considered a consequential substance. Beaches in specific geographic regions, including the San Francisco Bay Area, have a propensity for ferromagnetic sand because of their geologic history. We describe a case in which ferromagnetic sand in a patient's hair coated the magnetic resonance imaging (MRI) scanner bore and caused significant imaging artifact, fortunately with no harm to the patient. We recommend that MRI facilities in areas where ferromagnetic sand is found consider educating technologists and screening patients for recent black sand exposure prior to scanning.