Magnet Safety in MRI - Essay Example

Magnet Safety in MRIMRI is mainly used to diagnose tumors in softer tissues in human body parts. Mainly it is used to look into the brain and figure out the inconsistencies using the functional magnetic resonance imaging. Since, it is a special process involving the administration of magnetic resonance, so there are bound to issues related to safety. One such study was carried out by Kanal et al (1996) to study the ferromagnetic properties on aneurysm clips while undergoing MRI. There have been many such studies regarding this issue and different types of conclusions were drawn from such studies.

Taking note of such variations, the US Food and Drug Administration (FDA) came out with the statement in March 1993 that suggestion such concerns need to be probed further before asking the industry for package labeling of the implant device, in regard to its MR compatibility and ferromagnetic properties. During this study, experiments were conducted on Yasargil FE intracranial aneurysm clips, Yasargil FD clips (Aesculap), Sugita aneurysm and Perneczky aneurysm clips from different manufacturers for a better understanding of the magnetic properties of these clips.

These clips were observed for translational motion (sliding across the glass surface) and rotational motion. The tests were also performed by two individuals simultaneously, independent of each other, to lend further credence to the study. Quite a few clips tested positive to the ferromagnetic effect and were found to have some kind of motion and realignment when exposed to magnetic resonance. All such clips that tested positive were retested by a third observer and the results were confirmed.

On analyzing the results Kanal et al (1996) found that;None of the Yasargil FE clips demonstrated gross translational motion on the plate glass and majority of them also did not demonstrate any rotational motion as well. But quite intriguingly some of the clips that demonstrated rotational motion were of identical model, shape and size as others having not such motion. All the Yasargil FD clips demonstrated alignment to the field, but the degree of attraction varied to a great extent. None of the Sugita clips displayed any response to the magnetic fieldWhile signs of definite alignment was observed in majority of the Perneczky clipsThese results surely generated debate amongst the radiologists and it was felt that the variations observed could be as a result of changes in the manufacturing process, composition of the clip, contamination by other metals, differences in post distribution handling, storage, re-sterilization etc.

Aesculap also tested two of the ‘positive’ clips, and found out that these clips are indeed having ‘feeble ferromagnetic’ properties, but the company clarified that all their clips are made non-ferromagnetic and the effect could have been introduced after distribution. But the researchers avoided issuing any categorical statement in favor or against any model of these clips on account of the variability observed in the experiments, but they felt that with the increasing use of MRI there’s a need for further investigation into the field in order to minimize the threat emanating out of the ferromagnetism in aneurysm clips and any other surgical implant or device.

Researchers suggested that if patients with aneurysm clips should avoid undergoing the MR examination, without an extreme need for it. It is further suggested that a product labeling can be worked out to clearly inform the users about their devices’ compatibility with MR imaging.References:1. Kanal, Emanuel; Shellock, Frank G. and Lewn, Jonathan S. (1996). Aneurysm Clip Testing for Ferromagnetic Properties: Clip Variability Issues.