Safety and MRI artifact evaluation at 1.5 T of metallic mounting sheath of a marking clip inadvertently deployed at stereotactic biopsy.

ABSTRACT

OBJECTIVE: The purpose of our study was to assess the MRI risk factors for the patient after an unusual case of inadvertent deployment of the mounting sheath of a metallic clip used at stereotactic breast biopsy. MATERIALS AND METHODS: We evaluated the materials for ferromagnetic properties, heating, and artifacts. RESULTS: Our analysis showed significant deflection and prominent susceptibility artifacts of the sheath at 1.5 T, although the clip itself showed no deflection and only minimal artifact. Our study shows that a device and its delivery apparatus may have significantly different ferromagnetic properties. CONCLUSION: In case of inadvertent deployment of the sheath, a delay of 6-8 weeks before MRI is recommended as a conservative approach to ensure tissue ingrowth and to minimize the chance of harm to the patient. In the case of metallic clips used for breast biopsy, caution is warranted when a portion of the device unintended for placement is introduced into the breast.