Cardiac Magnetic Resonance in Patients With Cardiac Implantable Electronic Devices: Challenges and Solutions.

Until recently, cardiac implantable electronic devices (CIEDs) were an absolute contraindication to magnetic resonance imaging (MRI), due to concerns about their adverse interaction in the MRI environment. The increasing clinical need to perform MRI examinations in these patients was an impetus to the development of MR-Conditional CIEDs. Secure performance of MRI in these patients requires scanning under specified MR conditions as well as operating the device in MR-scanning mode. This requires robust institutional protocols and a well-trained multidisciplinary team of radiologists, cardiologists, device applications specialists, physicists, nurses, and MRI technologists. MRI can also be performed in patients with non-MRI Conditional or "legacy" CIEDs by following safety precautions and continuous monitoring. Cardiac magnetic resonance (CMR) is additionally challenging due to expected susceptibility artifacts generated by the CIEDs, which are either near or in the heart. As the most common indication for CMR in these patients is the evaluation of myocardial scar/fibrosis, acquiring a high-quality late gadolinium enhancement image is of the utmost importance. This sequence is hampered by artifactual high signal due to inadequate myocardial nulling. Several solutions are available to reduce these artifacts, including reducing inhomogeneity, technical adjustments, and use of sequences that are more resilient to artifacts. In this article, we review the precautions for CMR in patients with CIEDs, provide guidelines for secure performance of CMR in these patients, and discuss techniques for obtaining high quality CMR images with minimized artifacts.