Safety of magnetic resonance imaging of stapes prostheses.
OBJECTIVE
Assess the safety of performing magnetic resonance imaging (MRI) on patients with stapes prostheses.


METHODS
Survey and animal model.


METHODS
A survey regarding implant usage, MRI procedures, and adverse outcomes after MRI in patients previously undergoing stapes procedures. Guinea pigs implanted with ferromagnetic 17 to 4 stainless steel, 316L nonferromagnetic stainless steel, titanium, and fluoroplastic stapes prostheses underwent a MRI in a 4.7 Tesla MR system.


RESULTS
: Three adverse outcomes were reported on the clinical survey. One adverse event occurred during an MRI performed on a recalled ferromagnetic prosthesis. The other two adverse events were probably not secondary to MRI exposure. No damage or inflammation was observed in the region of the oval window or vestibule of implanted guinea pigs exposed to a 4.7 Tesla MR system.


CONCLUSIONS
The combination of prior studies, the clinical survey, and the absence of histopathologic evidence of damage in the guinea pigs is compelling evidence that MRI for patients with stapes prostheses is safe. Implanting physicians should feel comfortable clearing a patient for a MRI in a 1.5 Tesla or 3.0 Tesla MRI. It is imperative for the physician to qualify the field strength when clearing a patient to undergo a MRI.
Syms
Mark James
MJ
Barrow Neurologic Institute, Phoenix, Arizona, USA. m.syms@arizonaear.com
D000497:Alloys; D000818:Animals; D003625:Data Collection; D005465:Fluorocarbon Polymers; D006168:Guinea Pigs; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects; D008280:Magnetics; D009998:Ossicular Prosthesis; D010969:Plastics; D011474:Prosthesis Design; D012449:Safety; D013193:Stainless Steel; D013201:Stapes Surgery; D014025:Titanium
D000497:Alloys; D005465:Fluorocarbon Polymers; D010969:Plastics; D013193:Stainless Steel; C013616:nitinol; D014025:Titanium