I’ve been toying with the idea of writing a comedy murder mystery story in vein of ‘Kind Hearts and Coronets’, and I’m trying to come up with a few outlandish ways for my main character to bump off his adversaries. Anyway, I thought of one today which I think might suffice, but, as my knowledge of science and medicine is virtually non-existant, I wanted to check to see if it would actually work.
Anyway, the idea is that the murderer poisons his victim with a birthday cake with some teeny-tiny iron filings mixed in with the whipped cream. The next day the victim goes for an MRI scan and the machine rips the little filings out and he dies.
Would that actually work? If not, is there any way to modify the principle so as to make it work?
I am going to theorize that your (character’s) evil plan would not work.
There are storage molecules in the body (ferritin and hemosiderin) that accumulate iron (hemosiderin aggregates are plenty big enough to be seen under relatively low microscopic magnification, and both hemosiderin and ferritin commonly build up in enough quantity to be visualized on MRI imaging). This site describes them as “superparamagnetic”. If having these multiple tiny internal bits of iron was so hazardous, lots of people would be killed by MRIs.
Another problem with the idea is that there are supposed to be ferromagnetic screens used in MRI facilities, to detect problematic internal iron in people who (for instance) might forget that they have an implant or pacemaker.
From what I understand of it, MRIs will not cause any bits of metal to be accelerated such that they puncture internal organs. The resonance that is used is the spin of the electrons in atomic orbits reacting to a changing magnetic field and thus it will not cause macroscopic movements of any molecules.
I think the force on each iron filing piece would be too small to do any damage. Even a spoonful ingested probably wouldn’t do any damage, since it would be pretty well dispersed through your digestive tract.
However you do have to distinguish between iron and iron compounds. I don’t know anything about this question actually, but nothing stated above convinces it cannot work.
Incidentally my pacemaker contains no iron, but it does contain some microelectronics and the strong magnetic field of an MRI would strongly disrupt them and maybe even destroy the pacemaker. Although I have been assured that the airport scanners can do nothing to it, but it does register on them and the TSA forbids me to go through them. Fine.
What about swallowing small magnets? Maybe disguised as the silver bead sparkles on a cupcake. And yes there are people who a. eat that fast and b. are that stupid.
An MRI scanner is built with a seriously strong magnet. At least 1 Tesla, and sometimes more. Ferromagnetic objects are lethal in the room that houses the scanner - as the field is strong enough to accelerate objects to speeds where they could kill someone in the scanner tunnel. Oxygen bottles for instance. My father relates how many years ago he went into the scanner room and the magnet picked the pen out of his pocket by nothing more than its metal clip and it sailed across the room into the magnet.
What they worry about with metal objects in a person is whether it moving slightly could cause damage. For instance being a welder is a deal breaker - as many welders have tiny metal particles in their eyes - and the dear is that a particle could move enough to endanger sight. Shrapnel would be bad.
But this also tells you that a tummy full of dispersed iron filings is not going to be a real danger. They will likely move, and could conceivably cause some discomfort as they did, but they are not going to rip through flesh.
Button sized rare earth magnet - well there you may well have damaging potential. But you would probably need a lucky positioning. Lethal is still a bit hard to believe.
Assume that it is a child, who might be fooled into swallowing a penny. And that child is in the line of succession above your villain, so must die for him to inherit the fortune.
(But I think that the MRI pre-scan would catch this. When I had one last year, besides asking me about pacemakers, etc. repeatedly by several people, they ran me through a pre-scan procedure which was supposed to check for such things.
Possibly a confederate on the MRI team could deliberately mis-read the scan so it isn’t noticed?)
You can also get burns. The movement of the iron can heat it up. There have been a few reports of people with tattoos containing odd metallic dyes experiencing painful heating of their tattoos during MRIs.
To answer the OP: Very unlikely, and I think the filings would be partially or fully digested/dissolved. And any filings too small to be detected while eating, would also probably be too small to cause meaningful harm.
That could kill the victim all on its own, without the MRI - two magnets ingested sufficiently far apart in time that they are still separate on entering the intestine - they attract each other from different loops of the gut and pinch hard enough to cause an intestinal fistula. Bad things ensue.
ETA: I see that’s what your link was actually describing. So for a single magnet, not so much risk under normal circumstances, but yes, in an MRI, I think it would be pretty bad.
Very tiny specks of iron are going to have a pretty large surface area for their mass; large enough that the surrounding tissue should hold them in place against a magnetic field (at least up to some threshold).
Regardless of the feasibility of the idea, you’ve got another problem with this scenario : even if the victim gets shredded within an MRI, they’re in a hospital. So they’ll get treated right away, and I doubt teeny tiny stomachal and/or intestinal tears are going to be harder to repair then - much less as dangerous as - a bullet wound, an abscess or suchlike.
You’re just trying to kill the guy and you know he’s scheduled for an MRI at a certain place and time?
It was awhile ago, so I’m sure I’m mis-remembering the details, but a cop wandered to close to an MRI machine and had his gun launched by the machine and it went off, narrowly avoiding killing the patient.
You could probably hire a concealed-carry nurse to strategically position himself during the MRI exam and voila, an obviously totally accidental death.
Former MRI Tech here - pacemakers’ main issues w/ MRI’s are not ferrous-related (and some pacers are OK if not inside the dewar itself, IME - had many reference notebooks of pacer or implant manufacturer’s tests and certifications for what was OK via risk -v- benefit) due to the torque(s) from the fluctuating/rapidly-changing pulses of energy (the buzzing/thumping heard during active scan) that varies the effect of the normally static field of magnetism from the dewar.
The non-ferrous metals want to line up with the flux fields, in essence (simply put). The pacer’s battery-pack/controller and the lead(s) into the heart would likely be turned/bent, etc immensely and possibly tear the inner parts of heart/blood vessel(s) to shreds and/or heat up considerably due to induced currents in the metals. Hope that makes sense…