Are the eddy currents induced by MRIs too insufficient to see rapid temperature increase? I understand MRIs are incredibly attracted to ferrous material, but what happens to non-ferrous metals in the body?
In: Physics
Probably something to do with the continuous and low total surface area of implants, but that’s a guess. Eddy currents are sufficient to heat things up to the point of burning the patient in the scanner. One example of that is wearing Lululemon’s clothing with Silverescent technology into an MRI, which has metallic fibers woven into the fabric c.f. https://www.marketwatch.com/story/people-wearing-yoga-pants-are-getting-burned-during-mris-2018-05-09 metallic fibers would have a much higher total surface area.
Also, the risk of heating from eddy currents likely has something to do with the specific scan sequence, and I would assume higher risks with those which use higher gradient angles, e.g. MPRAGE. This implies a case of greater oscillating changes in the angle of the magnetic field and are known to produce greater eddy currents and SAR (specific absorption rate). I believe these types of scan sequences are probably more common in research related MR scanning, but I don’t know much about typical medical scanning procedures in hospital environments.
Edit: added some words for better detail
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