- Contraindication to MRI including but not limited to intracranial aneurism clips (except Sugita), history of intra-orbital metal fragments that have not been removed by an MD (as confirmed by orbital X-Ray), pacemaker and non-MR compatible heart valves, inner ear implants, history of claustrophobia or subject feels unable to lie still on their back for a period of 1.5 hours in the MRI scanner.