What an MRI scan is
An MRI (magnetic resonance imaging) scan is a safe and painless test that can provide detailed pictures of the inside of your body. It uses a strong magnetic field and radio waves to create pictures, on a computer, of tissues, organs and other structures.
A contrast (dye) injection is sometimes used to get more information from MRI scans.
When and why MRI contrast is used
For some MRI scans you may need to have an injection of a special dye called contrast. This makes certain tissues or blood vessels show up more clearly and in greater detail.
The doctor has chosen to use MRI contrast for your examination after considering the risks and benefit to you. Contrast is a colourless solution which is injected into your arm.
If you need a blood test
You may need to have a blood test a few days before your MRI scan. If you do, you'll find a form and instructions for where and when to go for your blood test with your appointment letter.
What you need to tell us before your scan
You must tell us before your scan if you answer 'yes' to any of the following if you:
- have ever had an allergic reaction to MRI contrast
- are or think you are pregnant
- suffer from any renal or kidney problems
- had or are you waiting for a liver transplant
Preparing for your MRI with contrast examination
It's very important to be well hydrated before your MRI scan if you're having a contrast injection. Drink lots of water the day before your appointment. Also make sure you check your appointment letter for any specific examination instructions.
After your MRI with contrast examination
MRI contrast is very safe. You may have a feeling of warmth or cold during your examination but this should quickly wear off.
Symptoms you need to tell us about immediately
Very rarely, contrast can cause unwanted effects. Tell a doctor or radiographer straight away if you experience:
- wheeziness, difficulty in breathing, or tightness or pain in the chest
- skin rash, lumps or itchy spots
- a decrease in the amount of urine you pass, or a change in its colour
- stinging pain at or near the injection site immediately following the injection
Other symptoms and when you should report them
Occasionally, people experience the symptoms listed below. These are unusual, but may happen during or after the examination and they are usually mild and don't last long.
If any of the following symptoms become severe or last for more than a few days, you should contact your doctor and the Radiology Department:
- a change in your sense of smell or taste
- nausea and / or vomiting
- cramps in arms, legs or other muscles
- loose stools
- rapid pulse
- pain in the joints
- skin rash, itchy spots or other allergic symptoms
MRI contrast does not have any known effect on your ability to drive vehicle or use machines.
If you are breastfeeding
If you are breastfeeding, throw away your milk for 24 hours after your MRI examination.
More about MRI contrast
If you are due to have blood, urine or other tests on the same day as your MRI contrast injection, you should tell your doctor or hospital staff about your injection.
If you have questions about your appointment or MRI contrast, call us on +44 (0) 1534 442844.