What IUDs Are Not MRI Safe?

IUDs made primarily of stainless steel are the ones classified as MRI unsafe. These devices experience strong magnetic pull and twisting forces inside the scanner bore, posing a real risk of movement or tissue injury. The vast majority of IUDs used today, including copper models and hormone-releasing plastic systems, fall into the “MR conditional” or fully MR safe categories and can go through a scan without being removed. The distinction comes down to the specific metal in the device, and the details matter more than most patients or even some clinicians realize.

The Stainless Steel Problem

Stainless steel is strongly attracted to the powerful magnets used in MRI scanners. A laboratory study that tested several types of metallic IUDs found that a stainless steel device experienced a deflection angle of 90 degrees when placed in a worst-case magnetic field gradient, meaning the magnet pulled the device so hard it stood essentially straight up toward the field. By comparison, copper and gold IUDs barely budged, showing deflection of only about 7 degrees under the same conditions. The stainless steel IUD also showed high torque, the twisting force the magnet exerts on the device, while copper and gold IUDs showed none.¹

An IUD sitting inside the uterus that suddenly tries to flip or slide toward a magnet is not a theoretical concern. The forces measured on the stainless steel device exceeded 7.5 newtons, which is several times the force of gravity on a small object. That is enough to tug on uterine tissue, potentially causing pain, perforation, or displacement. For this reason, stainless steel IUDs carry an “MR unsafe” classification, meaning they should not enter the MRI room at all.¹

Stainless steel IUDs are uncommon in the United States and Western Europe today, but they are not extinct. Some older-generation devices sold in parts of Asia, the Middle East, and Eastern Europe used stainless steel frames. The Chinese stainless steel ring IUD is probably the most widely recognized example, and millions were placed over decades. If you are unsure whether your IUD contains stainless steel, the safest step is to check the device’s brand name and material composition before scheduling an MRI.

Why Copper and Gold IUDs Are Considered Safe

Copper is not ferromagnetic. It does not get pulled by a magnet the way iron or certain steel alloys do. That is the fundamental reason copper IUDs like the Paragard (Copper T 380A) can go into an MRI scanner. Testing of the Copper T 380A found it compatible with current safety standards adopted by the American Society for Testing and Materials and the FDA, earning the device an “MR conditional” rating.²

“MR conditional” does not mean “perfectly inert inside the scanner.” It means the device has been tested under specific conditions and found to pose no significant risk when those conditions are met. For copper and gold IUDs, the conditions typically include field strengths of 1.5 and 3.0 tesla and energy absorption rates up to 4 watts per kilogram, which covers nearly all clinical MRI exams performed today.¹

Gold-core IUDs, which use a small gold element within a copper or plastic frame, behave similarly. Gold is also non-ferromagnetic, so it produces minimal interaction with the magnetic field. The same laboratory study that flagged stainless steel as dangerous confirmed that gold and copper IUDs showed only negligible magnetic force, roughly half a millinewton, which is far too small to move the device or cause discomfort.¹

Hormonal IUDs and Fully Plastic Devices

Hormonal IUDs like Mirena, Kyleena, Liletta, and Skyla use a plastic (polyethylene) frame to deliver levonorgestrel locally. These devices contain no metal at all. Because there is nothing for the magnet to interact with, they are considered MR safe at any field strength in terms of the material used.³

The same applies to the few fully plastic non-hormonal IUDs that have been marketed over the years. If there is no metal component, the device is invisible to the magnetic field. You do not need to remove it, delay your scan, or take any special precautions. The MRI technologist will still ask about implants as part of the standard screening questionnaire, and you should still disclose it, but the answer will be straightforward.

What Happens to Imaging Quality

Even when an IUD is physically safe in the scanner, it can still interfere with the images. Metal creates what radiologists call susceptibility artifacts, areas of signal distortion that show up as dark voids or bright halos on the scan. The practical question is whether the artifact is small enough that the radiologist can still see the anatomy around it.

For copper and gold IUDs at 3 tesla, the artifact diameter measured only about 4 millimeters.¹ That is tiny, barely larger than the IUD’s arm width itself. In a clinical study of women with copper IUDs who underwent pelvic MRI at 3 tesla, the radiologists found no IUD-related susceptibility artifacts at all, and the devices were clearly visible on standard imaging sequences.⁴ In other words, a copper IUD does not ruin a pelvic MRI. The IUD itself is visible on the images, which can actually be useful for confirming placement, and the surrounding uterine and pelvic structures remain interpretable.

Stainless steel tells a very different story. The artifact diameter for a stainless steel IUD reached about 200 millimeters using gradient echo sequences.¹ That is roughly eight inches of signal distortion radiating outward from the device. An artifact that large would obliterate the entire pelvis on the image, making the scan diagnostically useless even if the physical safety risk could somehow be managed. So stainless steel IUDs fail on both counts: they are dangerous in the magnetic field and they destroy the images.

Field Strength Matters

Most clinical MRI scanners operate at either 1.5 tesla or 3.0 tesla. Copper and gold IUDs have been formally tested and cleared as MR conditional at both of these field strengths. However, one older review noted that at the time of publication, metal-containing IUDs had not been fully evaluated at 3 tesla and recommended treating them as a contraindication at that strength.³ That concern has since been addressed by more recent testing. The 2018 study that tested copper, gold, and stainless steel IUDs specifically examined both 1.5 and 3.0 tesla environments and found copper and gold devices safe at both.¹

Research-grade scanners operating at 7 tesla or above are a different situation. Very few of these are used on patients clinically, but if you are participating in a research study using an ultra-high-field scanner, the safety data for metallic IUDs at those strengths is limited. The MR conditional label applies to the tested conditions, not to all magnets everywhere.

Does an MRI Affect Contraceptive Function

A reasonable worry is whether the magnetic field could shift the IUD enough to compromise its effectiveness as a contraceptive, even if the movement is too small to cause injury. In one clinical follow-up of 18 women with copper IUDs who underwent 3-tesla MRI, one patient reported a dislocation of her IUD after the scan. All other patients had no signs of any field interaction.⁴

One dislocation in a small group is hard to interpret. IUD dislocations happen spontaneously at a low rate even without MRI exposure, so it is unclear whether the magnetic field played any role. Still, if you have a copper IUD and undergo an MRI, it is reasonable to confirm that your device is still properly positioned at your next gynecological visit. Your provider can check placement with a simple ultrasound. This is not an emergency concern; it is a sensible follow-up step.

Why Confusion Persists

Despite clear evidence that copper and hormonal IUDs are safe in standard clinical MRI settings, some patients are still told they cannot have a scan until the IUD is removed. This happens for a few reasons. The most common is that screening questionnaires at imaging centers ask a blanket question about metal implants, and when a patient says “yes, I have a copper IUD,” the technologist may not know offhand whether copper is ferromagnetic. Rather than risk a mistake, some facilities default to canceling or rescheduling the scan.

Another source of confusion is the language itself. “MR conditional” sounds cautious, and people understandably read “conditional” as something close to “risky.” In practice, MR conditional simply means the device has been tested and approved for use under specific, well-defined scanner settings that cover the vast majority of clinical exams. Nearly all modern orthopedic implants, cardiac stents, and surgical clips also carry the MR conditional label. It is the standard safety tier for metallic medical devices, not a warning flag.

The gap between the evidence and what happens at the front desk can be frustrating, especially if you need a time-sensitive scan. If you are told your IUD is a problem, asking the MRI facility to check the specific device model in the MRI safety database maintained by the Institute for Magnetic Resonance Safety, Education, and Research (mrisafety.com) can resolve the issue quickly. That database lists the MR compatibility of virtually every implanted device by brand and model.

Essure and Other Non-IUD Implants

Essure was a permanent sterilization device, not technically an IUD, but it lived in the reproductive tract and comes up in these conversations. It consisted of small coils made of stainless steel and a nickel-titanium alloy that were placed into the fallopian tubes. An older evaluation found that at 1.5 tesla, Essure did not interact with the magnetic field in a clinically significant way, but at 3 tesla the device had not been fully assessed and was considered a potential contraindication.³ Essure was pulled from the U.S. market in 2018 after years of safety complaints unrelated to MRI, but many people still have the inserts in place. If you have Essure coils and need an MRI, you should alert the imaging facility so they can verify the scanner conditions fall within the device’s tested range.

Subdermal contraceptive implants like Nexplanon sit in the upper arm and are made entirely of a plastic polymer with no metal. They pose no MRI safety concern at all. Similarly, contraceptive vaginal rings and patches contain no metal and are irrelevant to MRI screening.

How to Prepare for an MRI With an IUD

Before your appointment, find out the exact brand and model of your IUD. This information is usually in your medical record from the insertion visit, or your gynecologist’s office can look it up. When you arrive at the imaging center, tell the technologist the specific device name rather than just saying “I have an IUD.” Specificity lets them verify its MR safety classification without guesswork.

If you have any of the widely used devices on the market in North America and Europe today, here is a quick orientation:

Paragard (Copper T 380A): MR conditional at 1.5 and 3.0 tesla. Safe for routine clinical MRI.
Mirena, Kyleena, Liletta, Skyla: No metal. MR safe.
Gold-core copper IUDs: MR conditional at 1.5 and 3.0 tesla. Same safety profile as standard copper devices.
Stainless steel ring or frame IUDs: MR unsafe. Must be removed before scanning or the scan cannot proceed.

If your device is not on this list, the MRI facility can check the manufacturer’s labeling or the MRI safety database. The key piece of information is what metal the frame contains. Copper, gold, titanium, and plastic are fine. Stainless steel is the problem.

When the Scan Is Not of the Pelvis

Patients sometimes assume MRI safety only matters when the scan targets the area near the IUD. In reality, the magnetic field fills the entire bore of the scanner regardless of which body part is being imaged. If you are having a brain MRI, your pelvis is still inside a strong magnetic field. The safety classification of your IUD applies to every MRI, not just pelvic scans.

That said, the imaging artifact question is localized. A copper IUD will only affect image quality in scans that include the pelvis in the field of view. If you are getting a knee or shoulder MRI, the tiny artifact produced by a copper IUD is irrelevant because the scanner is not looking at that region. The physical safety issue and the image-quality issue are separate considerations, and the physical one is the one that applies universally.