Sometimes a contrast material is used for magnetic resonance imaging, or MRI imaging. You may swallow the contrast, or you may have an IV so the contrast can be given into your bloodstream. The contrast material used for an MRI exam is called gadolinium. (This is not the same as the contrast dye used in CT scans.)
If contrast dye is used, you may experience a flushing sensation or a feeling of coldness, a salty or metallic taste in your mouth, a brief headache, itching, or nausea and/or vomiting. These effects usually last for a few moments. Some people have other reactions to the contrast material, such as:
- A headache that develops a few hours after the test is over
- Low blood pressure leading to a feeling of lightheadedness or faintness (rare)
- A reaction to contrast more than 1 day after they receive contrast, such as rashes, itchy skin, headaches, or nausea, requiring treatment with skin lotions, steroids, and antihistamines (rare).
Small amounts of gadolinium can stay in the brain, bones, skin and other parts of your body for a long time (several months to years) after the test. It’s not known if this might have any health effects, but so far, studies haven’t found any harmful effects in patients with normal kidneys.
Sources
- American Cancer Society
(https://www.cancer.org/treatment/understanding-your-diagnosis/tests/mri-for-cancer.html) - John Hopkins Medicine
(https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/magnetic-resonance-imaging-mri)