Common implants, which may present a hazard when undergoing CMR, include pacemakers, ICD’s, cochlear implants, neurostimulators, hydrocephalus shunts, metal-containing ocular implants, pacing wires, and metallic cerebral clips [5]. A full list is available in www.​mrisafety.​com. The clinician must be aware if the patient has an implantable device and whether or not it is magnetic resonance (MR) safe, conditional or not safe. If decision is made to perform CMR to a patient with a device, knowledge of device programming is necessary. Some of the risks of performing CMR in patients with pacemaker or cardioverter-defibrillators include burns from generation of an electrical current from the metallic hardware and the “antenna effect”, device movement, inappropriate discharging and sensing. Appropriate emergency equipment and medications to treat possible adverse reactions must be readily available.

Although more frequent with the use of iodinated contrast, some patients may require pretreatment prior to injection of contrast media even if gadolinium is used for prevention of anaphylactic reaction and/or acute kidney injury. Special caution must be performed in patients with decreased renal function, especially with a GFR <30 mL/min due to the risk for nephrogenic systemic fibrosis, a potentially catastrophic complication of gadolinium exposure.