Yasargil aneurysm clips: evaluation of interactions with a 1.5-T MR system.

Abstract

It is safe to perform MR procedures at 1.5 T or less in patients with Yasargil aneurysm clips made with nonferromagnetic material.

Biomedical implants and devices: Assessment of magnetic field interactions with a 3.0‐Tesla MR system

“…For this condition, it is assumed that any risk imposed by the application of the magnetically-induced force is no greater than any risk imposed by normal daily activity in the Earth's gravitational field. Accordingly, findings from the deflection angle test permit implants and devices made from nonferromagnetic or weakly ferromagnetic materials that display deflection angles between 0 and 44°to be present in patients or individuals in the MR environment (10,11,15,22,23). A test procedure and acceptable measurement value for torque imposed on implants and devices has not yet been defined by the ASTM.…”

“…Certain types of aneurysm clips (e.g., aneurysm clips made from martensitic stainless steels) are an absolute contraindication to the use of MR procedures because magnetically-induced forces can displace these clips and cause serious injury or death (1)(2)(3)7,11,12,18,19,22,33,34). By comparison, aneurysm clips classified as "nonferromagnetic" or "weakly ferromagnetic," including those made from phynox, elgiloy, austentitic stainless steels, titanium alloy, or commercially pure titanium, are safe for patients undergoing MR procedures at 1.5-T or less (1)(2)(3)7,11,12,18,19,33,34). Specific guidelines for the management of patients and individuals with aneurysm clips with regard to exposure to the MR environment have been previously published (11,18,19).…”

“…By comparison, aneurysm clips classified as "nonferromagnetic" or "weakly ferromagnetic," including those made from phynox, elgiloy, austentitic stainless steels, titanium alloy, or commercially pure titanium, are safe for patients undergoing MR procedures at 1.5-T or less (1)(2)(3)7,11,12,18,19,33,34). Specific guidelines for the management of patients and individuals with aneurysm clips with regard to exposure to the MR environment have been previously published (11,18,19). Accordingly, it is not uncommon to use MR procedures in patients with nonferromagnetic or weakly ferromagnetic aneurysm clips.…”

Magnetic resonance safety update 2002: Implants and devices

“…A variety of techniques have been used to qualitatively or quantitatively determine magnetic field-related torque for implants and devices (1,20,22,25,31,39). To date, a test procedure and acceptable measurement value for torque imposed on implants or devices has not been defined.…”

“…These factors can greatly influence the MR safety aspects of these implants. While certain aneurysm clips are a contraindication for the MR environment, others classified as nonferromagnetic or weakly ferromagnetic are deemed safe for patients or individuals exposed to MR systems operating at 1.5 Tesla or less (1)(2)(3)(4)(5)8,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24).…”