Just out of curiosity, why aren’t there metal detectors set up near the entrances to these machines? Just as a precaution should someone forget.
Seems like a common sense measure to prevent such items from getting close enough to the magnetic field to be a threat.
Seems like a common sense measure to prevent such items from getting close enough to the magnetic field to be a threat.
I believe that metal detectors work by using magnetic fields: These things put out such overwhelming fields, my guess is that it would be useless anywhere nearby. I've seen cases where the monitor screens of the office computers used by the staff were skewed, and this is a good distance from the imaging hardware and behind well shielded walls.
Mark
To make the situation even more interesting, the newer 3 Tesla (3T) magnets have an acceleration factor up to 14 times greater than than the 1.5 T magnet in this story and are thus much more dangerous when ferrous materials are present in the vicinity.
Besides the danger and fear factors contained in this story, mention was made in passing of having to turn off the magnet to remove the pistol. While this is a relatively easy process, it is also an expensive one. The last bill I received after a magnet quench (turning off the magnet) was over $140,000. Sometimes you can prevent this expense by pulling the item out of the magnet (the only such incident at a facility I worked in concerned a metal mop bucket brought into the space by a new employers who ignored the signs), took a nylon rope and 12, yes I said 12, full grown men to remove it. Superconductor magnets are not to be trifled with.
Irregardless of any other precautions put in place, the ultimate responsibility for MRI safety is the technologist working with a MRI machine. NOBODY, and I mean NOBODY should lay a hand on the door of that MRI room without the MRI technologist giving permission for that person to do so, and then only after through questioning and inspection of that persons corpus.
It is not only external materials that are potential problems. Internal parts (replacement hips, other joints, ear devices in kids, cardiac stents, brain stents, etc.) are also a potential danger to the patient during an MRI study. Orthopedic implants should be in place a minimum of 90 days before a patient has an MRI, while incomputable metallic implants in soft tissues can and will move and heat up during an MRI exam.
Folks, If you are ever unsure of what to do when getting one of these exams done, make sure you ask the technologist and share your concerns with him/her.
Be safe, be well.