MRI Scan

Magnetic resonance imaging (MRI) is a medical imaging technique that uses a magnetic field and computer-generated radio waves to create detailed images of the organs and tissues in your body. Most MRI machines are large, tube-shaped magnets.

Is an MRI safe?

An MRI scan is generally safe and poses almost no risk to the average person when appropriate safety guidelines are followed.

The strong magnetic field the MRI machines emit is not harmful to you, but it may cause implanted medical devices to malfunction or distort the images.

There’s a very slight risk of an allergic reaction if your MRI requires the use of contrast material. These reactions are usually mild and controllable by medication. If you have an allergic reaction, a healthcare provider will be available for immediate assistance.

Healthcare providers generally don’t perform gadolinium contrast-enhanced MRIs on pregnant people due to unknown risks to the developing baby unless it’s absolutely necessary.

How long does an MRI scan take?

Depending on the type of exam and the equipment used, the entire exam usually takes 30 to 50 minutes to complete. Your healthcare provider will be able to give you a more exact time range based on the specific reason for your scan.

What’s the difference between an MRI scan and a CT scan?

Magnetic resonance imaging (MRI) uses magnets, radio waves and a computer to create images of the inside of your body, whereas computed tomography (CT) uses X-rays and computers.

Healthcare providers often prefer to use MRI scans instead of CT scans to look at the non-bony parts or soft tissues inside your body. MRI scans are also safer since they don’t use the damaging ionizing radiation of X-rays.

MRI scans also take much clearer pictures of your brain, spinal cord, nerves, muscles, ligaments and tendons than regular X-rays and CT scans.

However, not everyone can undergo an MRI. The magnetic field of MRI can displace metal implants or affect the function of devices such as pacemakers and insulin pumps. If this is the case, a CT scan is the next best option.

MRI scanning is usually more expensive than X-ray imaging or CT scanning

What does an MRI show?

Magnetic resonance imaging (MRI) produces detailed images of the inside of your body. Healthcare providers can “look at” and evaluate several different structures inside your body using MRI, including:

Your brain and surrounding nerve tissue.

Organs in your chest and abdomen, including your heart, liver, biliary tract, kidneys, spleen, bowel, pancreas and adrenal glands.

Breast tissue.

Your spine and spinal cord.

Pelvic organs, including your bladder and reproductive organs (uterus and ovaries in people assigned female at birth and the prostate gland in people assigned male at birth).

Blood vessels.

Lymph nodes.

What is an MRI with contrast?

Some MRI exams use an injection of contrast material. The contrast agent contains gadolinium, which is a rare earth metal. When this substance is present in your body, it alters the magnetic properties of nearby water molecules, which enhances the quality of the images. This improves the sensitivity and specificity of the diagnostic images.

• Contrast material enhances the visibility of the following:
• Tumors.
• Inflammation.
• Infection.
• Blood supply to certain organs.
• Blood vessels.

If your MRI requires a contrast material, a healthcare provider will insert an intravenous catheter (IV line) into a vein in your hand or arm. They’ll use this IV to inject the contrast material.

Contrast materials are safe drugs. Side effects ranging from mild to severe do occur, but severe reactions are very rare.

What are the side effects of MRI contrast?

On very rare occasions, some people who have contrast material for their MRI experience side effects, including:

Nausea.

Headache.

Pain at the site of the injection.

It’s very rare to experience hives, itchy eyes or other signs of an allergic reaction to the contrast material. If you have allergic symptoms, tell the technologist. A healthcare provider will be available to provide immediate medical care.

Nephrogenic systemic fibrosis (NSF), which causes thickening of your skin, organs and other tissues, is a rare complication in people with kidney disease that undergo an MRI with contrast material. Because of this, people with severe kidney disease may not be able to have gadolinium-based contrast material for their MRI.

There’s evidence that tiny traces of gadolinium may stay in different organs of your body after contrast-enhanced MRI. While there are no known negative effects from this, your provider may take gadolinium retention into account when selecting a contrast agent.