MRI Safety Demonstration: Big Magnet + Metal

Описание: http://www.botsford.org/imaging

by Nancy Thomas-Bracken, registered technologist at Botsford Imaging Center

What happens when metal goes near an MRI? Find out when a Botsford MRI technologist demonstrates our new, open-bore MRI scanner and the strong magnetic field it produces.

What is MRI and how does it work?
Magnetic Resonance Imaging (MRI) is a way of getting pictures of various parts of your body without the use of x-rays or radiation. A MRI scanner consists of a very strong magnet in which a patient lies. A radio wave antenna is used to send signals to the body and receive signals back. The returning signals are converted into pictures by a computer attached to the scanner.

Why is MRI safety so important?
Because of the MRI's strong magnetic pull, it is extremely important that patients and staff are screened before entering restricted areas of the MRI scanning environment. Any ferrous (compounds containing iron) metal object will be attracted to the center of the scanner. If the metal object is heavy or sharp, it can be dangerous as it becomes a projectile toward the center of the magnet. In addition to external metal items, internal devices such as pacemakers, aneurysm clips, or certain implants may also be affected by the magnetic field and not be safe to go in the magnet.

MRI safety demonstration
To demonstrate why MRI safety is so important, we created a video to help visualize the magnetic field and to show what happens when metal approaches that field. In the video, a steel paper clip is attached to a paper sign. At a distance of approximately 3 feet there is no noticeable pull towards the center of the bore. As I move closer you can see the paper clip is pulled in. The closer I get the stronger the pull.

What MRI safety precautions are taken?
At Botsford Hospital, safety is our number one priority. Between our patient questionnaire during the scheduling process, the additional questions at time of appointment and the visual inspection by staff doing the scan, we assure absolute patient safety before any MRI scan.