What Is the Difference Between an MRI With and Without Contrast?

A MRI scan of the brain, without contrast.
An MRI is done with contrast in order to make the images clearer and easier to interpret.
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  • Written By: Mary McMahon
  • Edited By: Shereen Skola
  • Last Modified Date: 24 November 2014
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Magnetic resonance imaging (MRI) with contrast involves the use of a tracer agent to enhance MRI results, while tests without contrast do not use such agents. For some tests, contrast may be necessary or recommended because of the nature of the patient's condition. A doctor can evaluate the patient to determine whether an MRI with or without contrast is more suitable, based on why the patient needs imaging and the patient's history. Patients should be aware that a test without contrast is not necessarily inferior; in some cases tracers are not necessary or may expose the patient to needless risk.

Imaging studies provide important information about what is going on inside a patient's body. MRI technology can offer extremely high resolution to help care providers differentiate between normal and diseased tissue. Such scans can also be used to look at internal organs for signs of structural or functional abnormalities, or other health issues, such as damage caused during a car accident.

One of the key differences between MRI with and without contrast is the level of resolution provided. Some kinds of tissue are difficult to differentiate on a routine MRI. It can be especially difficult to see some types of lesions, areas of abnormal tissue, in which case a doctor could miss a diagnosis or might underestimate the size of a lesion. In these cases, an MRI with contrast may offer superior imaging ability, and reduces the risk that the test might need to be repeated.

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Doctors can request both an MRI with and without contrast in some cases. They may want to see the results of both tests to collect as much information as possible about a patient before making a diagnostic decision. When a patient gets an MRI with and without contrast, it can take several hours to complete the testing. In some cases, patients may be allowed to leave and come back for repeat scans rather than having to wait in the imaging center.

Contrast agents used in magnetic resonance imaging are different from those used in other types of medical imaging studies. They tend to be less likely to cause allergic reactions, because they do not include iodine. The risks of an MRI with contrast can depend on the contrast agent used. Some are potentially dangerous, particularly for patients with poor kidney health who may have trouble processing them. Others are quite safe, and can be used in patients of all ages and at all levels of health.

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anon359869
Post 5

I had an MRI this year on my back from head to hips first without dye then with. I was in there four hours. It was not bad. They had headphones with music so I slept the whole time.

DylanB
Post 4

I knew that people having CT scans sometimes have to have contrast dye. I didn't realize that people having MRIs might need it, too.

It always seemed to me that an MRI was more advanced and thorough than a CT scan. Maybe I just thought this because in an MRI, the person is totally enclosed, while in a CT machine, the person is mostly sticking out of either end.

Oceana
Post 3

@kylee07drg – I think it's fairly common for people to feel a burning sensation with an MRI contrast dye. It's also common to experience nausea and even break out in hives.

However, some people are actually allergic to the dye and start to swell and itch. They get rashes and have trouble breathing.

These people need emergency help. Just a little burning or nausea isn't something doctors are usually concerned about, though.

Perdido
Post 2

I've never had an MRI with contrast, but I've had a regular MRI before. The hardest part was having to hold my breath for up to forty seconds at a time so that they could get a good image of my kidneys.

When the put me down on the table, they strapped a board across my abdomen. They had me put my arms over my head and told me that I would have to hold my breath now and then and to be as still as possible.

I closed my eyes as they started to roll me into the machine, because I knew the walls would be so close around me that I would become claustrophobic. I made it through, but it was tough. That MRI lasted 45 minutes!

kylee07drg
Post 1

My friend had an MRI with contrast a few years ago, and she had a bad experience. She said she could feel it burning inside her veins!

That would be a terrifying feeling. Just knowing that whatever is burning you is already in your bloodstream would be enough to make a person go nuts and start screaming in terror!

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