MRI Scans with Contrast Versus MRI Scans Without Contrast: What Patients Should Know

Your doctor has recommended an MRI examination with a contrast dye, and you’re concerned about what that means. Are contrast dyes safe—and are they really necessary for diagnosing your condition?

In case you’re looking for a simple answer, here it is: In the vast majority of cases, MRI contrast dyes are completely safe, and they’re often necessary to provide your physician with diagnostically useful information. If your physician and radiologist agree that you need an MRI with a contrast dye, you’ve got nothing to worry about.

Still, most patients have reasonable concerns about contrast agents. In this piece, we’ll look at the risks, benefits, and potential side effects of different types of contrasts (while providing some info about reducing your expenses).

When are MRI contrast dyes necessary?

A magnetic resonance imaging (MRI) machine uses powerful magnets to create detailed three-dimensional images of various body structures (read more about MRI scans here). It essentially forces the protons in your body to align with its magnetic field, then detects the energy emitted by those protons as they re-align. That might sound scary, but MRI machines are considered one of the safest imaging technologies available, since they don’t use any type of ionizing radiation.

Contrast agents increase the speed of the proton realignment, resulting in a clearer, brighter image. If your diagnostician needs a very detailed view of a body structure—and, given that you’re getting an MRI, that’s likely the case—they’ll usually administer some type of contrast agent. These agents contain gadolinium, a rare-earth metal.

How are MRI contrast dyes used?

Most gadolinium-based contrast agents are administered intravenously through a single injection. The location of this injection will vary depending on the nature of your MRI.

After your examination is complete, you can go about your day normally. Gadolinium may cause some mild nausea or headaches in rare cases, but it won’t affect your ability to drink or eat. The metal will be processed through your kidneys, and most of it will leave your body in a day or so. You can increase your fluid intake to get the contrast material out of your body more quickly.

What are the risks of MRI contrast dyes?

Gadolinium contrast dyes are considered safe, and side effects are rare. More than 300 million doses of gadolinium-based contrast dyes have been administered over the last three decades, and given that large sample size, if the agents were extremely dangerous, we’d certainly know about it by now.

Even so, in rare cases, a contrast agent may have adverse effects. If you’re allergic to gadolinium, you’ll obviously experience an immediate reaction—but, again, this is exceptionally uncommon. One study found that gadolinium hypersensitivity occurred in 0.121 percent of MRI patients.

If you’re one of those unfortunate few, you can expect unpleasant symptoms to subside quickly. The most common reactions included hives, headaches, and itchy skin at the point of injection. Allergic reactions are typically easy to treat, and most aren’t severe. If you experience any discomfort after the dye is administered, tell your technologist.

So, if you’ve got a gadolinium allergy, are you out of luck? Not necessarily. Certain contrast agents were less likely to cause a reaction than others, so if you’re susceptible to allergic reactions, your radiology team may still be able to find a contrast agent that works for you.

What patients should avoid MRI contrast agents?

If you don’t have a gadolinium allergy, you’re probably in the clear. However, there are a few other potential adverse health effects that technologists will consider when determining whether or not to use contrast media:

  • Kidney issues. Patients with severe renal problems may be at risk for nephrogenic systemic fibrosis, a rare condition that may be linked to gadolinium contrast dyes. If you are on dialysis, or if you have a history of kidney disease, be sure to tell your MRI team.
  • Pregnancy. MRI technologists usually avoid administering gadolinium to pregnant women. There is currently no evidence to show that gadolinium is dangerous for unborn children, but because a small amount of the metal stays in the body after the examination, it may pose some risk that researchers haven’t encountered yet.
  • We’ve got a detailed piece here that looks into the current research regarding MRIs and pregnancy. In one study of 1.4 million pregnancies, congenital abnormalities weren’t any higher for women who’d received MRIs than women who hadn’t received them. Furthermore, a 2006 study concluded that gadolinium-based contrast agents are likely safe for pregnant women and breastfeeding mothers.

    To summarize, if you’re pregnant, your MRI team may avoid contrast dyes, but if they recommend using one, you should follow their suggestion. Contrast media can make an enormous difference in the quality of your diagnostic images, and they’re not always an optional part of the examination.

  • Family history. If you’re genetically susceptible to severe kidney issues, or if you have a family history of gadolinium sensitivity, your technologist might decide to avoid contrast dyes.

Ultimately, contrast agents are considered very safe, and there’s no reason to refuse a contrast agent if your technologist concludes that it’s medically necessary. Make sure that you’re working with an experienced MRI team, and make sure that you’re paying a fair rate. carefully analyzes the capabilities of every MRI clinic in our database, and our cost comparison tool can greatly limit the cost of an MRI with or without contrast dyes—even if you don’t have insurance. To get started, call at 888-322-7785.