Placement of a ferromagnetic intracerebral aneurysm clip in a magnetic field with a fatal outcome.

Magnetic resonance (MR) imaging may be contraindicated in patients with biomedical devices, among the most dangerous of which are intracranial aneurysm clips, owing to the possibility of torque and dislodgement. A case is presented in which a patient with a reportedly nonferromagnetic clip was placed in a magnetic field. The patient developed an acute intracerebral hemorrhage in the MR unit, with a fatal outcome. Imaging studies strongly suggested a torqued clip as the cause. Autopsy revealed a torn middle cerebral artery from clip movement, and the clip was identified as a ferromagnetic type. This is the first reported case, to the authors' knowledge, of a fatal outcome due to an intracranial aneurysm clip placed in a magnetic field.