Spontaneous Discharge of a Firearm in an MR Imaging Environment

American Journal of Roentgenology ^ | 6 November, 2001 | Anton Oscar Beitia1, Steven P. Meyers, Emanuel Kanal and William Bartell

[marktwain]

An incident recently occurred at an outpatient imaging center in western New York State, in which a firearm spontaneously discharged in a 1.5-T MR imaging environment with active shielding. To our knowledge, this is the first documented case of such an occurrence.

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An off-duty police officer went to an outpatient imaging center (not affiliated with our institution) in western New York State to have an MR imaging examination. The facility housed a 1.5-T MR unit (Signa; General Electric Medical Systems, Milwaukee, WI) with active shielding. The officer was carrying a model 1991 A-1 compact.45 caliber semiautomatic pistol (Colt's Manufacturing, Hartford, CT).

The officer notified the technologist that he was carrying the weapon before entering the MR dressing room. The technologist told the officer to take the gun with him. The technologist intended to meet the officer in the MR patient waiting area before the examination and secure the weapon in that room, where he felt it would be safe. However, the officer apparently misunderstood and took the gun into the MR suite. The technologist was entering the officer's personal data into the computer and did not see him entering the MR suite.

Once the officer was inside the MR suite, the gun was pulled from his hand as he attempted to place the gun on top of a cabinet 3 ft (0.9 m) away from the magnet bore. The gun was immediately pulled into the bore, where it struck the left side and spontaneously discharged a round into the wall of the room at the rear of the magnet. Fortunately, no one was injured.

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The weapon's thumb safety was reportedly engaged when the gun discharged.

[tarheelswamprat]

Actually “Technologist” is a term being used now in several technical areas. Sounds snappier than a simple “Technician”, and is designed to reflect the higher level of knowledge and education needed in some of these disciplines, say verses just being a screwdriver jockey.

I'm aware of the derivation of these sorts of titles - this "title inflation" has permeated every aspect of our culture. Custodial engineer "sounds snappier" than janitor, "waste management engineer" sounds snappier than garbageman, Human Resources Administrator sounds snappier than Personnel Manager, etc., etc., etc. ad nauseum....

None of that changes the fact that it's all pretentious puffery... /grin

[M1928A1 Thompson]

The gun fired because it slammed into the MRI machine with enough force that inertia overcame the firing pin spring and the pin hit the primer with enough force to make it fire. Having seen the rest of this report and pictures, when the gun was retrieved the safety was still on, LOCKING the slide forward and the EMPTY case was not ejected from the pistol. The hammer was still at full cock. My shooting buddy is a radiologist and this was big news last year when he showed the account of the incident.

The series 80 Colts have a firing pin lock that is supposed to prevent this freakish sort of slamfire.

[P8riot]

Ah yes, the Yugo (Glock) vs. Cadillac (1911) argument again. Shoot what you shoot best, arguments like this are childish.

Glocks don't work for me (the grip angle is way off for me), but I can nail 8" steel plates at 50 yds all day long with my 1911s, and none of them have ever given me any trouble.

[P8riot]

Yes I know

[Does so]

I had to read the article.

:-(

The MRI pulled up on the sear, internally. Short of an empty chamber, there was nothing that could be done to avoid this discharge. No safety "failed". All the the thumb safety did was to keep the weapon from chambering a new round. This article appeared at my forensic site last May, and apparently occurred eight years ago.

—Horatio

;-)

[Hacklehead]

“Missmatched parts? hard to tell, the slide, barrel and frame are all RR. did some armorer miss match the parts?”

Shortly after the start of WWII when production of 1911s was gearing up, colt shipped large batches of older parts (WWI vintage) to other manufacturers including RR. Consequently some have slides from Colt and Frames from RR, or vis versa. I think the ones with the mixed parts are favored by collectors.

[M1928A1 Thompson]

Most stainless steel alloys are not magnetic, a discovery that greatly annoyed my refrigerator magnet addicted sister upon completion of her kitchen remodeling frenzy.

I enjoyed much mirth and merriment at her wrath upon my cluttered ‘fridge door hating, aircraft mechanic brother-in-law, who understanding why compasses are mounted with brass or stainless screws, slyly endorsed her selection of stainless steel appliances.

[Dr.Zoidberg]

I’ve never had an MRI or CAT and haven’t had any but dental X-Rays in 20 years. So MRI tech is relatively unknown to me.

I knew an MRI was dangerous in the presence of ferrous materials, but that’s about it...

If they have metal detecting equipment, then they should use it and just eat the false alerts, what’s the use of having security equipment if you ignore it?

[Manly Warrior]

I believe that a 1991A1 is a series 80 action, with a firing pin safety that only releases the FP when the trigger is pressed fully rearwards.

I doubt even if the hammer notch failed when it struck the MRI machine that a round would discharge-again, the trigger would have to be pressed and the grip safety would have to have been released as well.....

I am betting on some spontaneous ignition of the primer via static or other EM energy source....

Any CE/ME/EEs out there with some insight on this circumstance?

Does lead styphnate (priming compound) combine under strong EM fields and detonate?

God Bless

[ejonesie22]

Yeah, it makes one feel better.

In away I am sympathetic. I have a lot of folks call me the “Computer guy” or “IT Guy”, belaying that fact that I am actually the IT manager/director and have hard earned degrees and certifications out the a$$. I kind of laugh it off, but my newest green tech is also a “Computer guy”

[Manly Warrior]

Hmm. I guess I fall into the “shoulda read more” crowd.

Okay, I’ll buy it -the magnetism retracted the firing pin plunger and pulled the FP hard enough to fire the round....

[tarheelswamprat]

Understood!... /grin

I’m on several boards of directors, President of one organization and Vice-President of another. Whenever I’m asked what my position is, however, I usually just say “chief gopher” or “designated lackey”. I’ve found it puts people at ease and usually makes it a lot easier to work with them.

I understand that there are legitimate professional distinctions and classifications, and that it’s sometimes helpful to be specific and precise when referring to them. I do believe, however, that our society as a whole has gone overboard with title inflation and organizational jargon to the point of fetishisation... /grin

[ejonesie22]

Hey, it is good for the economy, keeps business card makers busy ;-)

[VOA]

Once the officer was inside the MR suite, the gun was pulled from
his hand as he attempted to place the gun on top of a cabinet
3 ft (0.9 m) away from the magnet bore.

Reminds me of the History Channel's "Lost Worlds" series on
Oak Ridge TN.
(Hope I don't bungle the details of the following)
It was mentioned that in the early method of separating uranium
isotopes the devices used were a series of hugmongous electromagnets...
and that there was a painted line down the gallery of the machines
to remind people to not go any closer (3-4 ft?) to the magnets
unless they had ALL metal off their persons.

I think they said there were stories of forgetful technicians
getting pulled and stuck to the machines (until the clothing could
be cut away from the metal, such as a metal pen in the pocket).

[RetiredNavy]

The issue is one of complacency. When it goes off for every patient, soon people, even those that know better, tend to ignore the warning. We have also noticed that, over time, people tend to depend on the detectors for screening and the investigation and questioning process becomes a sometimes thing.

We have found that a much better process is to require a standardized questionnaire, consistent questioning, and if in doubt, investigation of specific types of implants to determine MRI compatibility. If there is ANY doubt whatsoever, that patient gets another type of study.

[RetiredNavy]

As you noted, current surgical staples and clips are almost invariably stainless steel, with a very low or non-existant magnet pull. Irregardless of the the type of metal, overexposure to a MRI magnetic field can still cause magnetic eddy currents which result in heating of the metal in question. In a normal study this typically is not a problem, but it can be a POTENTIAL issue with extended exams in high strength fields.

Those with tattoos should volunteer that information as many tattoo inks incorporate metallic compounds. The potential discomfort from heating can be alleviated with the use of cold compresses if the the technologist knows of them.