Gun goes off in MRI

[Bill Glasheen]

To give you an idea of the forces involved...

Chair gets stuck in an MRI machine

Here's the incident Ian talked about.

Child killed in MRI machine by oxygen canister

The family settled out of court for $2.9 million.

Here's a demonstration designed to show how this could happen, and the forces involved. This is a small oxygen tank.

mri oxygen bottle

This one's a little bigger.

Dangers of MRI's

Another demonstration.

Gurney Let Loose in MR Scan Room

Yet another, less dramatic one.

How strong is an MRI magnet?

- Bill

[IJ]

The watermelon stuff is fine, the mental images are terrible. If anyone has a morbid curiosity with regard to engineering snafus, especially medical ones, there is an entertaining book called "Set Phasers to Stun" which records, without commentary, a variety of terrible results of well meaning individuals and engineering plans and occasionally engineering "triumphs."

There isn't an MRI crush in the book but there are some other electrical powered mishaps and the title refers to an incident with a powerful radiation oncology device. It's a downer.

http://www.amazon.com/Set-Phasers-Stun- ... 884&sr=8-1

Maybe Toyota will make the next edition.

Oh, and not all metal is bad. Most metal implants are made to be MRI safe, and the consequences of a metal fragment heating up in your eyeball is obviously worse than one heating up in a scar on your shoulder or something. Just... fill out that screening form carefully.

[Van Canna]

Simply shocking.

[Jason Rees]

So what happens if you have some metal in your body? No MRI?

Well, you'd hope. Otherwise, getting that metal ripped out of your body really, really won't feel good. Any arteries in the way... messy... Bone in the way? Getting dragged across the room by your skull would really suk.

[Van Canna]

Well, you'd hope. Otherwise, getting that metal ripped out of your body really, really won't feel good. Any arteries in the way... messy... Bone in the way? Getting dragged across the room by your skull would really suk.

Wonder if any of this has previously happened.

[Bill Glasheen]

Wonder if any of this has previously happened.

From The Joint Commission

Five MRI-related cases in the Joint Commission’s Sentinel Event database resulted in four deaths and affected four adults and one child. One case was caused by a projectile; three were cardiac events, and one was a misread MRI scan that resulted in delayed treatment.

In 2005, Jason Launders, MSc, a medical physicist with the ECRI Institute, conducted an independent analysis of the FDA’s MAUDE (Manufacturer and User Facility Device Experience Database) reporting database over a 10-year time span, which revealed 389 reports of MRI-related events, including nine deaths: three related to pacemaker failure; two to insulin pump failure; and the remaining four events related to implant disturbance, a projectile, and asphyxiation from a cryogenic mishap during installation of an MR imaging system. More than 70 percent of the 389 reports were burns; 10 percent were projectile-related; another 10 percent were “other events, including implant disturbance; 4 percent were acoustic injuries; 4 percent were fire-related; and 2 percent were internal heating-related.

The most common patient injuries in the MRI suite are burns and the most common objects to undergo significant heating are wires and leads. Other objects associated with burns are pulse oximeter sensors and cables, cardiorespiratory monitor cables, safety pins, metal clamps, drug delivery patches (which may contain metallic foil), and tattoos (which may contain iron oxide pigment). Less common injuries involve pacemakers. The American College of Radiology (2) recommends that implanted cardiac pacemakers and implantable cardioverter/defibrillators should be considered a relative contraindication for MRI. Any exception should be considered on a case-by-case basis and only if the site is staffed with individuals with the appropriate radiology and cardiology knowledge and expertise. (2)

While only one missile-effect case has been reported to the Joint Commission, they are more common than is generally recognized. Many people—including health care workers—are unaware that the magnets in the MRI scanner are always “on” and that turning them “off” (quenching) is an expensive and potentially dangerous undertaking, involving the controlled release of cryogenic gases that can be deadly if released into a contained area. As a result of the magnets, many of the objects pulled into the MRI scanner are cleaning equipment or tools taken into the MRI suite by housekeeping staff or maintenance workers.

[Van Canna]

Many people—including health care workers—are unaware that the magnets in the MRI scanner are always “on” and that turning them “off” (quenching) is an expensive and potentially dangerous undertaking, involving the controlled release of cryogenic gases that can be deadly if released into a contained area.

OK...so it is now a bit more clear...

And so it did happen before...like people getting messed up in that infernal machine.

[Bill Glasheen]

Ian had to remind us all of this earlier. After he said it, it made sense to me FWIW... I spent more time in my biomedical engineering training understanding the theory behind the machine, and processing the 3-D images that come out. Cool stuff.

In any case... this is likely the reason for leaving the things on. These massive electromagnets are as strong as they are (without costing oodles of money to operate and/or getting super hot) because they turn the materials into near superconductors by chilling them to near absolute zero. Therein lies the problem with switching them on and off. I suppose the things are filled with liquid nitrogen that you don't really want to have to bleed out if you don't have to.

Many hospital MRI machines are kept busy 24/7 to keep the unit cost of an MRI down.

- Bill

[Van Canna]

What is the difference between the 'open MRI machine' vs. the conventional 'Tube' one?

[Bill Glasheen]

What is the difference between the 'open MRI machine' vs. the conventional 'Tube' one?

Smarter engineering.

Some patients (my dad included) get claustrophobic in the tubes. They're tight, and the machine makes lots of noises. Some patients tend to panic.

The open designs were a response to patient concerns. They otherwise work the same.

- Bill

[Van Canna]

Well...in an open machine..maybe you can 'sidestep' an incoming fire extinguisher

[IJ]

Open MRI's don't produce as good images, I'm told.

[mhosea]

They're tight, and the machine makes lots of noises. Some patients tend to panic.

My shoulders were a little too wide when I literally had my head examined , so I had to scrunch. As I recall, that threw me off my game for a short time. I adapted mentally and actually emerged from it feeling very relaxed and refreshed, but I can imagine how some people react. I remember when my daughter had her first MRI (she's a trooper!) there was a middle-aged guy waiting on his MRI who was getting attended to by an anesthesiologist. He told me that last time he had freaked out, so he was going to get some drugs to help him through it.

[Topos]

Van,

Now that is what I call a DISARM!

Eons ago I saw a Ranger instructor teaching a firearm disarm and he was a blur. Guess in the age of Remotely Piloted Vehicle Pilots a miniaturization of that MRI issued to all LEOs might not be far behind.

[Van Canna]