Abstract P3-04-07: Safety and artifact testing of a nitinol breast biopsy clip in an ultra-high resolution magnetic resonance imaging (MRI) environment

Abstract

Background: The lack of safety clearance of several metallic breast implants in 7T(Tesla) poses a significant hurdle to standard clinical breast cancer care and research from reaping the benefits of ultra-high resolution MR imaging. A breast biopsy clip (Ultracor Twirl, Becton, Dickinson and Company, Vernon Hills, IL) composed of nitinol, was tested for safety and artifact susceptibility clearance in a 7T MRI scanner, using standardized procedures. This clearance is significant in henceforth allowing patients with this implant to be scanned in now FDA approved ultra-high-field MRI scanners of 7T or less for clinical and research purposes. Methods: Tests for magnetic susceptibility (torque and translational attraction), MRI-related heating, and artifacts were conducted as per standardized protocols. The torque and translational attraction tests evaluated the effects of magnetic force by the MRI to cause the clip to move and twist respectively. The heating test was conducted with customized MR parameters of short TR (repetition time) and maximum echo-train length, designed to induce temperature change. The artifact test using T1 weighted spin and gradient echo imaging sequences, evaluated potential localized signal loss that may result in misrepresentation of the imaged area. This may occur due to the presence of the metallic clip in the MR environment. Results: The torque and translational attraction tests respectively indicated that the MR environment did not induce any movement in the clip in eight orientations, with a deflection angle of 0 degrees. Results of the heating test indicated no significant temperature change of the clip. A temperature change of less than 0.45C° was observed in the phantom gel in both the absence and presence of the clip, which is well within the safety threshold (< 1°C). Results of the artifact test indicated a very small artifact, with the largest artifact cross-sectional area appearing on gradient echo images. Conclusion: These cumulative results indicate that the Ultracor Twirl breast biopsy clip is safe for imaging patients at 7T. Citation Format: William Dong, Kanchna Ramchandran, Adam Galloy, Marco A. Nino, Marla Kleingartner, Madhavan L. Raghavan, Sneha Phadke, Vincent A. Magnotta. Safety and artifact testing of a nitinol breast biopsy clip in an ultra-high resolution magnetic resonance imaging (MRI) environment [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-04-07.