E2873. A Case Based Review of Active Implant Safety in MRI
Authors
Christina Sammet;
Rush University Medical Center
Steffen Sammet;
University of Chicago
Background
Active implants such as pacemakers, stimulators, and cochlear implants present unique challenges in MRI imaging. Often there are challenging decisions to be made about risk versus benefit when imaging active implants that involves input of the radiologist, ordering provider, medical physicist, and MRI staff. The MR conditional labeling for these devices can sometimes be complex and intimidating to those unfamiliar with the process of safely scanning active implants. This exhibit takes a case-based approach to explore the process of identifying active implant models, researching their associated MRI conditional labels, and discussing the risks versus benefits of scanning the implant. When MRI is deemed appropriate, a description of the process to comply with device labeling that requires stricter than normal scan operation mode will be discussed.
Educational Goals / Teaching Points
The educational goals and teaching points of this exhibit are to learn to identify the manufacturer and model of several common active implants; learn to find and interpret the MRI conditional labeling associated with these implants; in a case-based manor, learn the process of balancing the risk to the patient from MRI scanning with the benefit that the MRI imaging will have to care management; and in cases where MRI scanning is deemed appropriate, learn to understand the process to conduct the MRI consistent with the manufacturer safety labeling, especially in circumstances where the label is stricter than normal operation mode.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This exhibit will discuss MRI safety with respect to several specific active implant devices. The first case will discuss active pacemakers and remnant/orphaned pacer wires from a pacer placed during surgery. The second case will discuss both active vagal nerve stimulators and remnant/orphaned vagal nerve stimulator wires. The third case will discuss cochlear implants and workflow for assessing make, model, compatibility, and MRI appropriateness for the increasing number of patients presenting with cochlear implants.
Conclusion
Implant safety in MRI is increasingly complex as implanted medical devices become more common and often use sophisticated electronic sensor and stimulator technology. Fortunately, device manufacturers have started to label these devices for compatibility with MRI. This case-based review of the process to safety triage and scan patients with active implants in the MRI may help build confidence in interpreting the labels and incorporating these workflows in the clinical practice.
