MRI With Contrast: Uses, Procedure, and Side Effects

What to expect when undergoing this test

Jonathan Cluett, MD, is a board-certified orthopedic surgeon with subspecialty training in sports medicine and arthroscopic surgery.

Yaw Boachie-Adjei, MD, is a board-certified, double-fellowship Orthopedic Surgeon.

An MRI with contrast is an imaging test that combines magnetic and radio wave imaging with an injection of a contrast agent (dye). The dye highlights blood vessels, organs, and specific soft tissues so they show up more clearly and help your radiologist determine a diagnosis.

MRIs, or magnetic resonance imaging, can be done with or without contrast.

An MRI with contrast is performed in a hospital or outpatient facility. During the procedure, a healthcare provider will most often inject the contrast material into a vein in your arm, then place you in an MRI machine for the scan.

This article explains how MRI with contrast works as well as the different dyes a radiologist may use. It also describes the potential risks and what to expect if you need to undergo this common procedure.

When contrast is added to the bloodstream, the targeted tissues won't just appear in shades of gray, like what happens during a regular MRI. They will appear to glow, helping a healthcare provider get a better understanding of what's going on inside your body.

Most of the contrast agents used contain a rare metal called gadolinium that interacts with the magnetic field created by the MRI machine. Gadolinium-based contrast agents (GBCAs) come in several types that are differentiated by:

Some GBCAs are organ-specific, while others have a heavier molecular weight so they remain within the circulatory system and don't diffuse into adjacent tissues. Others still can target specific cells like tumors.

MRI contrast agents approved for use by the U.S. Food and Drug Administration (FDA) include:

An MRI with contrast isn't a good choice for every situation. For example, gadolinium can't readily cross the blood-brain barrier (BBB) that protects the brain from harmful substances. While helpful in diagnosing diseases with a compromised BBB, like multiple sclerosis, GBCAs aren't as useful if the barrier is intact.

The decision to use contrast is based on whether the aim of the procedure is:

Their use is directed in part by the American College of Radiology (ACR) Appropriateness Criteria.

The list of conditions in which contrast may or may not be useful is extensive. They are broadly outlined by the ACR in the following chart.

As the guidelines illustrate, the choice to use or not use contrast is largely subjective and relies on a healthcare provider's judgment and experience.

Be sure to dress appropriately before heading to your procedure. Because MRI utilizes strong magnetic fields, you will not be allowed to wear anything that contains metal during the procedure, including:

It's best to leave jewelry at home and to remove metal accessories from the body, such as piercings and hairpieces.

You'll be given a gown to change into if your clothing interferes with the MRI readings. Dentures and hearing aids should be removed prior to the procedure. Medical staff will provide you with a secure place to store your belongings.

You may also have to make changes to your diet prior to the procedure. For GBCAs delivered by injection or IV, you can usually eat, drink, and take medications as you normally would. The same does not apply to oral GBCAs, which may require you to stop eating and drinking four or more hours in advance.

Be sure to arrive 15 to 30 minutes before your appointment to fill out the necessary paperwork and settle in. Bring your photo ID and insurance card with you as well as an approved form of payment for any copay/coinsurance costs.

it's important to tell radiology staff in advance if you:

For an MRI with contrast, you'll be working with a technician certified in the administration of intravenous, oral, and intra-articular GBCAs. Qualified technicians are also allowed to administer sedation, although a nurse may also be on hand to do so.

After filling out the necessary paperwork and signing a consent form, you will be led to a changing room to change into a hospital gown (if needed).

Prior to the MRI, the technician or nurse will check your weight, height, heart rate, temperature, and blood pressure. The technician will then prepare you for the scan by injecting the dye in your arm or giving you several doses of a solution to drink.

A sedative can also be administered through a portal in the catheter if needed.

After the GBCA is delivered, you'll be led to the flatbed of the MRI machine and strapped in to prevent movement.

For MRIs of the head, a cage-like head brace may be used. Depending on the level of sedation used, breathing, heart rate, blood oxygen, and blood pressure may be tracked during the procedure, especially in children.

You may also be given a pair of noise-reducing headphones through which you can communicate with the technician.

The MRI itself can take anywhere from 15 minutes to an hour. To ensure the best quality images, follow the technician's instructions and keep absolutely still until you're told to relax. You may also need to hold your breath during some parts of the scan.

It is not uncommon to feel a little warmth during the scan. You will also need to be prepared to experience a loud noise, which some describe as locomotive-like, as each image is taken. Newer machines are far quieter, however.

If you are unable to hold a position, are cramping, or suddenly feel nauseated, let the technician know. It is not a problem to stop and rest until you are ready to proceed.

Once the technician has completed the requested scans, the images will be reviewed to ensure that all are clear and correctly positioned. In some cases, a part of the scan may need to be repeated.

If a sedative was not used, you can usually dress and leave immediately. The technician or nurse may want to check that you have no ill effects before you are allowed to go.

If a sedative was used, you will be taken to a recovery room and monitored until you are able to sit up steadily. Once you are able to stand, someone will need to drive you home. Ideally, that person will stay with you for 24 hours in the event of an unexpected side effect.

In most cases, there will be no immediate or lasting effects from an MRI with contrast. Still, it is important to call your healthcare provider immediately if you have any unusual or severe symptoms, including:

If you have normal kidney function, the dye should leave your body within 24 hours after the test. Contrast dye is processed by the kidneys and removed from the body when you urinate.

If you're breastfeeding, some healthcare providers will tell you to wait 24 to 48 hours before nursing your baby. However, the American College of Obstetricians and Gynecologists (ACOG) says that's unnecessary and that you can continue breastfeeding uninterrupted after an MRI with contrast.

MRI with contrast scans are interpreted by a radiologist who will review the findings in context with previous scans and your available medical history. They'll then issue a radiology report within a few days, which your healthcare provider will review with you.

A typical radiology report includes a copy of each individual scan along with notations of any abnormalities seen. Typically, each image will be broadly classified as either:

Specific details will be listed in the impressions section of the report, which your healthcare provider can explain to you.

Based on an evaluation of the scans and a review of your medical history, the radiologist may offer a specific diagnosis or a list of possible causes in a differential diagnosis.

If findings are abnormal or potentially abnormal, you may be sent for additional imaging tests or procedures to either confirm the diagnosis or determine the severity of the condition.

For example, a growth suspected of being cancerous may require a positron emission tomography (PET) scan, which can identify malignancies based on changes in metabolism, or a biopsy, in which a tissue sample is obtained for examination by a pathologist.

If a finding is inconclusive, the MRI may be repeated or an alternative method of imaging may be used. For example, CT scans are often better at imaging bone disorders than MRIs, which are better able to image soft tissues.

GBCAs are generally considered safe. Side effects are rare and usually minor but they can occur. The side effects, which usually occur immediately, depend on the way the dye is delivered. The most common side effects of GBCA infusions include:

Side effects of oral GBCAs include nausea and vomiting, and GBCA delivered intra-articularly can cause localized pressure and pain at the injection site.

On rare occasions, certain GBCAs have been known to cause a serious condition called nephrogenic systemic fibrosis (NSF) in people with severe kidney disease. NSF can cause tightening and hardening of the skin similar to scleroderma, as well as the contraction of tendons and muscles, impairing movement and joint mobility.

The long-term, cumulative effects of GBCAs are unknown. There's some evidence that prolonged use of gadolinium can result in deposits of the material in brain tissues, but it's unclear whether that poses any health risks.

People who are pregnant should not get an MRI with contrast because the dye poses risks to the fetus. People with an implanted pacemaker, cochlear implant, or any metal inside the body may not be able to get an MRI.

A study published in the British Journal of Radiology reported that between 0.18% and 0.76% of people who undergo MRI with contrast experience side effects, mostly nausea and vomiting.

A 2017 review of studies in Lancet Neurology concluded that no harm or behavioral changes were seen in animals exposed to high doses of gadolinium over a long period of time. The few studies involving humans also demonstrated no ill effects.

An MRI with contrast is an imaging test involving the injection of a contrast agent (or dye) that's used to help blood vessels, organs, and soft tissues show up more easily. It help with the diagnosis of certain conditions, such as cancer.

The dye contains a rare metal called gadolinium, and can be delivered with an IV, orally, or with an injection. A healthcare provider will use their judgment to determine if you should have an MRI with contrast or a regular MRI.

Getting an MRI with contrast is generally safe but rarely may cause side effects such as nausea and vomiting. People who are pregnant or have severe kidney disease should not get an MRI with contrast.

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By Jonathan Cluett, MDJonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams.