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Topic: A Funny Thing Happened On The Way To The MRI.....
Username: Queso
Posted 2006-12-20 20:15:05 and read 2236 times.

You might want to leave your 1991 (1911) -frame handgun in the car if you go for an MRI.

Full report: http://www.ajronline.org/cgi/content/full/178/5/1092

Sorry for the long quote, but it's all pertinent information and it's not the full report.  hypnotized 

Excerpts:
Spontaneous Discharge of a Firearm in an MR Imaging Environment

"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. The event confirms previously reported theoretic risks of a firearm discharging in an MR imaging environment."

"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. Although the gun struck the magnet bore, only minimal cosmetic damage occurred to the magnet itself. The MR unit had full functional capability immediately after the gun discharged. The weapon's thumb safety was reportedly engaged when the gun discharged.

An unsuccessful attempt to remove the gun from the magnet resulted in the gun being pulled to the right side of the magnet. The decision was then made to power down the magnet to remove the gun."

"Examination of the weapon by a ballistics laboratory concluded that the force of the magnetic field was responsible for the firearm's discharge."

"At the time the weapon discharged, it was reportedly in a cocked and locked position; that is, the hammer was cocked and the thumb safety was engaged to prevent the hammer from striking the firing pin. A live round was in the chamber. (Many people who choose this weapon for personal protection will carry it in this manner because it allows them to quickly fire the weapon if needed.)

When the firearm was removed from the magnet, the gun was still in a cocked and locked position. An empty cartridge was found in the chamber. The presence of an empty cartridge in the chamber is highly unusual. If the thumb safety were not engaged and the weapon fired normally by depressing the trigger, the normal backward recoil of the slide should have automatically ejected the empty cartridge, and a new live round should have automatically been chambered. As discussed earlier, the thumb safety performs two functions: it prevents the sear from releasing the hammer, thereby preventing the hammer from striking the firing pin; it also locks the slide in place, preventing retrograde motion of the slide and automatic ejection of the empty cartridge. Thus, the presence of an empty cartridge in the chamber confirms that the thumb safety was engaged at the time the gun was fired. Given that the thumb safety was engaged when the gun discharged, it is also likely that the normal trigger and hammer mechanism of firing the gun was bypassed because the thumb safety would have also prevented release of the hammer."

"The gun likely discharged as a result of the effect of the magnetic field on the firing pin block. The firing pin block was probably drawn into its uppermost position by force of the magnetic field. The firing pin block has to overcome only light pressure from a relatively small spring to release the firing pin. The pistol was likely drawn into the magnetic field so that the muzzle struck the magnet's bore first. With the firing pin allowed to move freely in its channel, the force of the impact on the muzzle end was sufficient to cause the firing pin to overcome its spring pressure and move forward to strike the primer of the chambered round."

"In this incident, the gun discharged despite the thumb safety being engaged. This has important implications in that it shows that the weapon poses a risk for discharging in an MR imaging environment even with the thumb safety engaged."

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: Aloges
Posted 2006-12-20 20:25:22 and read 2219 times.

That MRI needs a gun so it can defend itself!

Signed,
Charlton Heston

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: ANCFlyer
Posted 2006-12-20 20:35:46 and read 2206 times.

Quoting Aloges (Reply 1):
That MRI needs a gun so it can defend itself!

Signed,
Charlton Heston

 rotfl 

Quoting Queso (Thread starter):
"In this incident, the gun discharged despite the thumb safety being engaged.

See, get a Glock, eliminate the non-functioning safety altogether!  bigthumbsup 

Seriously, this is quite the story. Wonder what instantly went through that officers mind as he heard "Bang"? Better still, what went through the mind of the MRI technologist when it went "Bang"?

Pretty scarey in fact. Could have had a casualty there . . .

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: Queso
Posted 2006-12-20 20:43:16 and read 2192 times.

Quoting ANCFlyer (Reply 2):
Wonder what instantly went through that officers mind as he heard "Bang"?

It was an "Oh Shit" moment. How must it have felt for the gun to have been acted upon by some "invisible" outside force suddenly pulling it from his hand? I can't imagine why they even tried to remove it with the magnet energized!

Well, it still goes in the category of "negligent discharge" as far as I see it. Both the technologist and the patient should have been more responsible and aware with their own and each other's "tools".

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: MDorBust
Posted 2006-12-20 20:44:06 and read 2187 times.

Quoting Queso (Thread starter):
You might want to leave your 1991 (1911) -frame handgun in the car if you go for an MRI.

 banghead 

One must wonder what he was thinking in regards to the NO METAL warnings that pervade MRI locations.

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: Ilikeyyc
Posted 2006-12-20 20:52:54 and read 2175 times.

That is quite a story! I'm glad no one got hurt. Don't 1911s have a grip safety too?

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: Sprout5199
Posted 2006-12-20 20:55:12 and read 2172 times.

Quoting Queso (Reply 3):
Well, it still goes in the category of "negligent discharge" as far as I see it. Both the technologist and the patient should have been more responsible and aware with their own and each other's "tools".

More of an"accidental" discharge than anything else. The officer did tell the tech. that he had a weapon. The tech said "take it with you". The officer was smart enough to know not to take it into the MRI itself, but did not know how strong the magnetic field was, and thought 3 feet was far enough away. This should be sent to all law enforcement departments as an officer/public safety issue. A "lessons learned" thing.

Dan in Jupiter

Topic: RE: A Funny Thing Happened On The Way To The MRI.....
Username: Queso
Posted 2006-12-20 21:10:13 and read 2149 times.

Quoting Ilikeyyc (Reply 5):
Don't 1911s have a grip safety too?

Yes, but the failure occurred in the slide itself, with the firing pin disconnect being depressed (as it would be upon the trigger being depressed) because of the strong magnetic field. The grip safety only prevents the trigger from being pulled. The full article has more information on the mechanism of failure and how the 3 safeties were defeated.

The same mechanism of failure could have occurred with almost any modern handgun because most of them are designed in the same manner with regard to the firing pin disconnect.

That's how I read the article, somebody please tell me if I am incorrect in my comprehension of it.


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