Felix V. Guettler, Presenter: Nothing to Disclose

Andreas Heinrich, Abstract Co-Author: Nothing to Disclose

Ulf Karl Martin Teichgraeber MD, Abstract Co-Author: Nothing to Disclose

The numbers of ferromagnetic objects that are unconsciously brought into the MRI-scanning area, are decreased with a Ferrodetector. Thus, MRI scan accidents can be reduced. The highest risk of an MRI examination is the impact of ferromagnetic objects, that are unconciously brought into the magnetic room. Effective mechanisms are mandatory to avoid MR-accidents.

In the static magnetic field of an MRI-System, a significant attraction and rotational force act on ferromagnetic objects. Those ferromagnetic objects on and in the body of a patient, can cause severe injuries. A metallic object that entered the eye of a patient, for example, led to his blindness, an intracerebral aneurysm clip severed the middle cerebral artery of a patient who died, a flat metal hook on the pants provoked facial injuries to another patient. This study aims to evaluate if a detector system for ferromagnetic metal (Ferrodetector) is able to reduce the number of ferromagnetic objects that are unconsciously brought into MRI-scanning area.

360 patients were scanned with the Ferrodetector before their examination. 16% (59/360) of the patients had implants. In 4% (16/360) of the patients, the detector did alert on ferromagnetic metals. Thereby, 10 patients had implants with ferromagnetic parts and 5 patients had ferromagnetic objects on their clothes. In one case, an unknown, ferromagnetic metal was found in the thoracic spine. In 344 patients (96%), no ferromagnetic metal could be detected. The scanning time with the Ferrodetektor took in 58% under one minute, in 33% under two minutes and in 9% under three minutes.

The Ferrodetector Ferroguard Screener (Metrasens, Malvern, GB) was used for this study. The outpatients and the stationary patients were asked to put off all metal objects. Subsequently, the patients were scanned with the Ferrodetector. Once the scanner detected a ferromagnetic object on or in the body of the patient, the reason for the alarm triggering was analysed. The implants in the patient’s body, the scanning time and the result of the scanning as well as the cause of the alarm were documented in an evaluation protocol.

Guettler, F, Heinrich, A, Teichgraeber, U, Patient Screening of Ferromagnetic Objects before MRI.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12038146.html