Magnetic resonance imaging of stapes prostheses

Objective: To assess the magnetic resonance imaging (MRI) compatibility of stapes prostheses. Data Sources: A comprehensive review of the English literature evaluating M RI compatibility of stapes prostheses. Multiple series of stapes prostheses from different manufactures placed in a 1.5-tesla MRI field to determine f erromagnetic properties. Results: When MRI was first introduced, reports demonstrated the MRI compat ibility of stapes prostheses. The testing was performed on single copies of various prostheses from several manufacturers. Although implant manufactur ers have indicated MRI compatibility, several reports of variable ferromagn etic properties of aneurysm clips have been reported. This variability has led to rotation of the clips and hemorrhage in patients with supposed MRI-c ompatible clips. These findings suggest that testing single stapes prosthes es from a manufacturer might not completely assess the safety of MRI on pat ients with stapes prostheses. We performed MRI compatibility testing on sev eral series of stapes prostheses from Xomed Surgical Products and Smith & N ephew Richards. Two series of Xomed stapes prostheses were found to have fe rromagnetic properties. Conclusion: Manufacturing variability could lead to stapes prostheses bring MRI incompatible. Each prosthesis should be tested before implantation for ferromagnetic properties.