A breast Magnetic resonance imaging (MRI) scan is a non-invasive medical imaging test that uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the structures within the breast. As no X-rays are used during the test there is no radiation.
An MRI breast scan is often used to look for lobular breast cancer as it doesn’t show up well on a mammogram or breast ultrasound. It also used when a patient has a high risk of developing breast cancer (they may have family members with cancer or gene abnormalities).
How are the procedures performed?
When you arrive for the breast MRI, the radiographer may ask you to change into a hospital gown. You will then be instructed to lie on your back on a couch that can slide into the MRI machine (see image). An MRI checklist form is filled out prior to the procedure.
You may then have a special dye called ‘contrast medium’ (specifically gadolinium-DTPA) injected into a vein in your arm through a small plastic tube (cannula). This helps the scanner to see the inside of your breasts more clearly so it can take detailed pictures.
You will then be asked to lie on your front on the MRI couch. The radiographer will place your breasts through two holes in the couch. The couch then slowly slides through the MRI scanner and the images are taken.
During the test the MRI scanner will make a knocking or drumming noise. The character of the noise will change several times during your scan. This is perfectly normal.
During the procedure the radiographer will operate the MRI scanner from behind a partition. They will be able to see you throughout the procedure and you will be able to talk to each other through an intercom in the MRI scanner.
The procedure will usually take around 30 minutes to an hour. You usually stay in the department for about 15 minutes after you scan if you’ve had the dye. This is in case it makes you feel unwell.
A breast MRI is extremely safe and doesn’t use radiation. Some people can’t have an MRI but the checklist picks this up beforehand.
There is a chance you may suffer some bruising in the area where the cannula is inserted. There is also a small chance that the contrast medium will leak outside the vein. This can cause swelling and pain in your arm but its occurrence rare. Tell your radiographer if you feel any swelling or pain.
In rare cases the dye injection can make you feel nauseous , give you a headache, make you come over all warm or give you a metallic taste in your mouth. Such symptoms are generally mild and will only last for a short period of time. If you feel unwell tell your radiographer straight away.
Prior to your breast MRI you will be asked to fill out a safety checklist. In this sheet you will need to detail any operations you’ve had or if you have any metal implants or other metals in your body. As an MRI scanner uses strong magnetism it could affect any metal you have in your body.
Before your test you can eat, drink and take medications as normal. We do advise you drink plenty of water before and after the scan as the contrast medium injection can sometimes leave you feeling dehydrated.
Once a report has been validated by the radiologist they are sent to the consultant. A follow up appointment will be made with the breast unit. The consultant will discuss these results. (Possibly a week post MRI procedure).