How dangerous are magnetic items near an MRI magnet?

UPDATE: Questions about why we were doing what we were doing? Please see the FAQ under "MRI magnet quench: the movie." That video is also entertaining, btw.

Fun, games and safety implications with a 4 tesla (T) MRI magnet that was about to be decommissioned. Note how magnetic objects let loose tend to oscillate along the magnet bore. That's because the peak magnetic field gradients are at either end (near the magnet face), causing peak acceleration as the object enters, followed by progressively damped changes of direction. See practiCalfMRI.blogspot.com for more information.

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  Science & Technology

[redwinmedia]

This is not a modern scanner, let alone a clinical scanner. This is an OLD 4T research magnet with an enormous fringe field. In the interest of full disclosure on behalf of practiCalfMRI, no one getting a routine MR scan would be exposed to this field strength.

[practiCalfMRI]

The 4 T magnet was actively shielded so the fringe field was fairly well constrained. Modern 3 T magnets are also actively shielded, but there is of course a difference in overall stray field strength because 4 > 3! Thus, the overall fringe field was definitely larger for the 4 T than a new 3 T clinical scanner, but the effects wouldn't be drastically different on a new 3 T. As a general rule, the "point of no return" can be considered to be halfway down the patient bed for both.

[cattac61]

2,000 lbs on a steel cable that's attached to a crumbling chair. I would not have been in that room.

[stickdiggler]

this is why i always take off my cock ring before getting an MRI

[gianpa]

that's so cruel! I want that mri don't brake it give it to me I can use that :(

[dyoung1844]

no pennies are non magnetic

[jegsimmonsproduction]

sucks for the guy who forgot he had fillings.

[invertedlow]

Have someone eat a bunch of ball bearings and jump in.

[jkufool]

Nice to know what MRI's are fun to play with let go find one in fucking WAL MART!

[ex0wa77]

what about the iron in our blood?

[sarakat99]

Just be thankful you aren't Wolverine.

[Veotine]

o-o and to think I have to go in an MRI..

[AlwayzPr0]

Cthulhu.