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If you thought MRI scanners that explode are scary, what follows may be even more terrifying (and educative)…

From the May 2002 issue of the American Journal of Roentgenology.

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 [1]. In this report, we examine the incident in detail from the official police and ballistic reports.

[read the free full text article here, download pdf here]

Photograph shows gun (arrow) stuck on right side of MR imaging magnet bore [Image Credit]

Photograph shows the actual gun involved in the incident; a 1991 A-1.45 caliber Colt semiautomatic pistol [Image Credit]

A short extract from the case report detailing how it happened (emphases are mine)…

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 (Fig. 1). The decision was then made to power down the magnet to remove the gun. [Read the rest of the article which include the findings of the ballistics lab here]

I got the link to this article from one of the images in the fascinating collection of photos of objects in MRI scanners at Dr. Moriel NessAiver’s Simply Physics site. Many thanks to Suresh who sent me the link via email. You can see the entire collection as a slide show at

DANGER! Flying Objects!

As Dr. NessAiver says:

Once you’ve been in the MRI field for any length of time, you start hearing all of the various horror stories about thing that have flown into a scanner. Often, newcomers don’t take the real danger of flying objects seriously until they witness an oxygen tank or gurney flying into a magnet themselves. This page will contain a collection of pictures and stories of metalic projectiles. Please show this page to all MRI newcomers, for their own safety and the safety of their patients!

Don’t miss the one with the horse! Or the one with the tiger!!

Start Slide Show with PicLens Lite