How do I find out whether my device is MR Conditional?

Start with your device identification card, which names the manufacturer and model of the generator and the leads. The scanning center will still interrogate the device and, if needed, contact the manufacturer to confirm its labeled status. MR Conditional status applies to the whole system, so a conditional generator paired with a non-conditional lead does not count.

Is a 3 tesla scanner allowed with a cardiac device?

It depends entirely on the device label. FDA warns that a device that is MR Conditional at 1.5 tesla may be unsafe at a different field strength. The published guidance for non-MR-conditional devices is limited to 1.5 tesla, because very few studies have been done at other field strengths.

Will the MRI turn off my defibrillator for good?

No. Shock therapy is deliberately switched off before the scan so the scanner cannot trigger an inappropriate shock, and it is switched back on immediately afterward during the post-scan interrogation. In the Nazarian NEJM series, 0.4% of examinations caused a reset to a backup mode, and that reset was temporary in eight of nine cases.

Does Medicare pay for the scan if my device is not MR Conditional?

Yes, under conditions. The Medicare national coverage determination for MRI, effective April 10, 2018, covers these scans at 1.5 tesla in Normal Operating Mode when the facility follows a checklist. The device must have no fractured, epicardial or abandoned leads for that coverage to apply.

Do I have to wait a set time after my device was implanted?

Many protocols historically used a six-week wait so that lead measurement changes could not be confused with a settling implant. The Heart Rhythm Society consensus advises that the wait is not necessary when the exam is clinically indicated, and the Medicare decision memo did not require one. Your electrophysiology team makes that call.

Can You Get An MRI If You Have A Pacemaker Or Defibrillator?

The short answer: Yes, in most cases you can. A pacemaker or defibrillator was once an absolute reason to cancel an MRI. Many devices now carry FDA "MR Conditional" labeling, and two large 2017 studies found no lasting harm when older devices were scanned at 1.5 tesla under a strict protocol. The decision still belongs to your cardiology and radiology teams, who check your exact device, your leads and your pacing needs.

Is a pacemaker an automatic no for an MRI?

It used to be. The 2020 ISMRM safety recommendation in the Journal of Magnetic Resonance Imaging states that a cardiac implantable electronic device (CIED) was historically an absolute contraindication to MRI. The reported deaths and serious events happened mostly before 2000.

The physical risks are real. The FDA lists three: the static magnet can pull on magnetic material, radiofrequency energy can heat the device and nearby tissue, and the fields can make an electrically active device malfunction. FDA also states the rule behind every screening form: no MRI unless the device has been positively identified as MR Safe or MR Conditional.

Two things changed the picture. Manufacturers built devices tested for the scanner, and researchers scanned thousands of patients with older devices and published the results. For the wider list of implants that get screened, see our MRI safety guide.

What do "MR Conditional" and "MR Unsafe" actually mean?

These are regulated labeling terms, not opinions. FDA's guidance Testing and Labeling Medical Devices for Safety in the Magnetic Resonance (MR) Environment, issued October 10, 2023, defines MR Conditional as "a medical device with demonstrated safety in the MR environment within defined conditions including conditions for the static magnetic field, the time-varying gradient magnetic fields, and the radiofrequency fields." MR Unsafe means "a medical device which poses unacceptable risks to the patient, medical staff or other persons within the MR environment."

A pacemaker can never be MR Safe. That guidance says electrically active devices should be labeled MR Conditional or MR Unsafe, because they contain conductive parts. It also warns that a device MR Conditional at 1.5 tesla may be unsafe at another field strength.

The conditions are specific, and they have loosened over time. The first FDA-approved MR Conditional pacemaker, the Revo MRI SureScan system (approved February 8, 2011), required a 1.5 tesla scanner, Normal Operating Mode, whole body SAR under 2.0 W/kg and head SAR under 3.2 W/kg. It also required the scanner isocenter to sit above the C1 vertebra or below the T12 vertebra. That exclusion zone ruled out chest imaging.

Six years later, the St. Jude Medical MR Conditional Pacemaker System (Assurity MRI and Endurity MRI, approved January 31, 2017) listed scan regions as "Full Body" at 1.5 tesla. Two points carry over to every label: the generator and the leads must both be part of the approved combination, and the system has to sit in the left or right pectoral region.

Can you be scanned with an older, non-MR-conditional device?

Often yes, under a protocol. The MagnaSafe Registry, published in the New England Journal of Medicine in 2017, enrolled patients with non-MRI-conditional devices referred for clinically indicated nonthoracic MRI at 1.5 tesla. MRI was performed in 1,000 pacemaker cases and 500 ICD cases. No deaths, lead failures, losses of capture or ventricular arrhythmias occurred during scanning. One ICD generator could not be interrogated afterward and needed replacement, and it had not been programmed per protocol beforehand.

The Nazarian study, also in NEJM in 2017, went further and included thoracic scans. It covered 1,509 patients with a "legacy" pacemaker (58%) or ICD (42%) across 2,103 examinations at 1.5 tesla. No long-term clinically significant adverse events were reported. Nine examinations (0.4%) reset the device to a backup mode, and the reset was transient in eight of the nine. In the remaining case, a pacemaker with less than one month of battery life could not be reprogrammed and was replaced.

Payers followed the evidence. The Medicare national coverage determination for MRI (NCD 220.2), effective April 10, 2018, covers MRI for a non-MRI-conditional pacemaker, ICD, CRT-P or CRT-D when the scan uses 1.5 tesla in Normal Operating Mode and the facility follows a checklist. Coverage rules are part of why these scans get scheduled slowly, a theme we cover in why an MRI needs prior authorization.

What about abandoned, fractured or epicardial leads?

This is the sticking point. Medicare's coverage for non-MRI-conditional systems requires no fractured, epicardial or abandoned leads. Even the MR Conditional St. Jude label lists abandoned cardiac hardware, including lead extenders and adaptors, as a condition that rules out the scan.

The caution comes from bench work. The ISMRM recommendation notes that phantom studies show significantly higher heating in abandoned leads than in leads still connected to a generator. It places these patients in a higher-risk category.

Newer clinical data are more reassuring. A 2024 systematic review and meta-analysis in EP Europace pooled 21 publications covering 656 patients with 854 abandoned or epicardial leads and 929 MRI scans. It found no major adverse cardiac events and reported sensations of heating or pain in 1.65%. The authors concluded that for abandoned transvenous leads, a clinically indicated and carefully performed MRI at 1.5 tesla seems safe and feasible. Epicardial leads still need a full risk and benefit assessment.

What happens on the day of the scan?

Centers run a two-team process. The 2017 Heart Rhythm Society expert consensus statement, written with the American College of Radiology and ten other societies, is the reference document.

The device is identified as MR Conditional or not, with the manufacturer consulted if needed.
Electrophysiology interrogates the device and checks battery status, pacing thresholds, lead impedance and pacing dependence.
The device is reprogrammed before you enter the scanner room. Pacing-dependent patients usually get an asynchronous mode (DOO, VOO or AOO). Others may get a non-pacing or inhibited mode.
Shock therapy on an ICD, CRT-D or S-ICD is turned off, and the device's magnet mode is disabled.
A person with Advanced Cardiac Life Support training stays in the MRI suite, watching ECG and pulse oximetry on MR Conditional monitoring equipment.
An external defibrillator and a device programmer wait just outside the scanner zone.
Right after the scan, the device is interrogated again for lead impedance, pacing thresholds and P-wave and R-wave amplitudes, then reprogrammed to your normal settings.

Timing after implantation comes up often. Many early protocols used a six-week wait so that lead measurement changes could not be blamed on a fresh implant. The ISMRM report notes that the HRS statement advises the wait is not necessary when the exam is clinically indicated. Because the electrophysiology team has to be free, these appointments often run in set daytime hours. The rest of the visit looks like any other scan, which we walk through in what to expect at your first MRI. Loop in the team that manages your other cardiac risk factors, including blood pressure.

Does the device ruin the pictures?

It can degrade them near the chest. The ISMRM recommendation states that exams of anatomy close to the device, such as thoracic, cardiac and shoulder MRI, are often affected by artifact from device components, driven by strong static field variations around the generator.

Radiologists have workarounds. That same report suggests replacing balanced steady-state free precession sequences with spoiled gradient echo, and using a wide-bandwidth inversion pulse for late gadolinium enhanced imaging. A brain, spine or knee study sits far from the generator and is usually unaffected.

Artifact is an image quality problem. It is separate from the heating and programming questions above.

The bottom line

A pacemaker or defibrillator is a reason to plan an MRI carefully, not a reason to give up on one. If your system is MR Conditional, the scan follows the manufacturer's stated conditions. If it is a legacy system, most centers can still scan you at 1.5 tesla with electrophysiology involved, and Medicare has covered that since April 10, 2018. Abandoned, fractured and epicardial leads remain the hardest category. Bring your device identification card and let the imaging center talk to your cardiology team well before the scan date.

Last updated: September 2026. This article is for informational purposes only and does not constitute medical advice. Only your cardiologist, electrophysiologist and the radiologist at the scanning facility can decide whether an MRI is appropriate for your specific device and leads.