What is a breast MRI?
A breast MRI (magnetic resonance imaging) is a non-invasive scan that creates detailed images of the inside of your breasts. It uses a strong magnetic field, radio waves, and computer technology to show your breast tissue in high resolution.
Unlike a mammogram or ultrasound, a breast MRI can offer a more precise view, especially of soft tissue structures, which helps your doctor identify breast abnormalities that may not be visible on other imaging tests.
When is breast MRI used?
Your doctor may recommend a breast MRI scan for several reasons, including having a dense breast. Here are the most common situations:
For women at high risk
If you have a high genetic risk of breast cancer (carry certain genes like BRCA1 or BRCA2) that increases your cancer risk, your doctor may suggest yearly breast MRI scans along with your regular mammograms. These extra screening tests help catch any problems as early as possible.
After a breast cancer diagnosis
If you've been diagnosed with breast cancer, an MRI can help your medical team:
See exactly how large the cancer is
Check if the cancer has spread to other areas of your breast
Look for cancer in your other breast
Plan the best treatment for you
To check breast implants
If you have breast implants, MRI is the best way to check if they're still in good condition. It can find:
Small tears or leaks in the implant
Problems that might not cause symptoms yet
Whether the implant needs to be replaced
When other tests aren't clear
Sometimes mammograms or breast ultrasounds don't give doctors a clear picture of what's happening. In these cases, an MRI can provide more detailed information to help your doctor make the right diagnosis.
During cancer treatment
If you're receiving chemotherapy or other cancer treatments, your doctor may use MRI scans to:
See how well the treatment is working
Check if the tumor is getting smaller
Decide if any changes to your treatment plan are needed
For more information about breast MRI scans and to determine if it’s appropriate for your condition, consider speaking with a healthcare professional. You may contact Thomson Medical to arrange a consultation for personalised guidance tailored to your individual healthcare needs.
What do you need to know about getting a breast MRI?
A breast MRI is a painless procedure, but you’ll need to lie still for about 30 to 60 minutes while the scan takes place. To get the clearest images, your doctor may give you a contrast dye through a vein in your arm—this helps highlight any abnormalities in breast tissue.
The scan is usually done at a speciality imaging centre using an MRI machine specifically designed for breast imaging.
Unlike mammograms and CT scans, breast MRI doesn't use any radiation or X-rays. Instead, it uses magnetic fields and radio waves to create detailed pictures of your breast tissue. This makes it a safe option that can be repeated if needed without concerns about radiation exposure.
How do I prepare for a breast MRI?
To get the most accurate results from your breast MRI, there are a few important steps to follow:
Let your doctor know if you are pregnant, breastfeeding, or have any metal implants, such as pacemakers or surgical clips.
Avoid caffeine for at least 24 hours before your scan, as it may affect the clarity of the images.
Remove all metallic items before the test, including jewellery, piercings, and underwire bras.
If you are premenopausal, try to schedule the MRI during the second week of your menstrual cycle, as this is when breast tissue is least dense and images are clearest.
If you have previously experienced a reaction to contrast dye, please inform your doctor ahead of time.
You should also let your healthcare team and MRI technologist know if you have any metal object in your body or use certain medical devices. These include:
A pacemaker or defibrillator
Cochlear implants or other ear devices
Stents, aneurysm clips, or metal coils
Nerve stimulators or other implanted electronic devices
Metal fragments in your body or eyes (e.g., from injury or past surgery)
How does the test work?
For your breast MRI, you will lie face down on a padded table with your breasts positioned through specially designed openings. The table then moves into the MRI scanner, which uses magnetic fields and radio waves to create high-resolution images of your breast tissue.
If your doctor recommends using a contrast dye, it will be injected into a vein in your arm through a small cannula to help highlight any areas of concern.
The entire procedure usually takes 30 to 60 minutes. You may hear loud tapping or thumping sounds during the scan, but earplugs or headphones will be provided to reduce the noise and help you stay comfortable.
Once the scan is complete, you can return to your usual activities straight away, unless you’ve been given a sedative.
What are the potential risks and side effects of this test?
Breast MRI is generally very safe when proper safety procedures are followed. However, there are a few possible risks to be aware of:
Physical discomfort:
You will need to lie still on your front for 30 to 60 minutes, which can be uncomfortable for some, especially if you have joint or back pain.
Allergic reaction to contrast dye:
In some cases, people may have a mild allergic reaction to the dye used during the scan. Symptoms may include itching or a rash.
Serious reactions are rare and can be treated quickly by your healthcare provider if they occur.
False-positive results:
Because breast MRI is very sensitive, it may sometimes detect changes that are not harmful. This can lead to additional tests or breast biopsies to confirm whether anything serious is present.
Your doctor will help guide you through these next steps if needed.
FAQ
What will an MRI of the breast show?
A breast MRI is a type of imaging test that provides high-resolution images of breast tissue. It helps detect abnormal tissue such as tumours, fluid-filled cysts, and areas of increased blood supply that may suggest breast cancer.
Does breast cancer light up on MRI?
Yes, cancerous tissues often absorb contrast dye more than normal tissues, making them appear brighter on MRI scans.
Why would a breast MRI be ordered?
A breast MRI may be advised for high-risk cancer screening to better understand the size and spread of a tumour, monitor treatment responses, assess implant integrity, or investigate uncertain results from other imaging tests.
Can a breast MRI detect cysts?
Yes, breast MRI can distinguish between solid masses (which may be cancerous) and fluid-filled cysts (which are usually benign).
Can you wear a bra during an MRI?
No. You should not wear a bra for the scan, especially if it contains metal parts like underwires or hooks, as they can interfere with the MRI images. You will be provided with a hospital gown for the procedure.
Is breast MRI better than mammogram?
A breast MRI and a mammogram are not directly comparable, as they are designed for different purposes.
Mammograms remain the standard breast screening tool for most women, especially for routine checks. However, a breast MRI offers more detailed imaging and is often used alongside mammography for women at higher risk of breast cancer or those with dense breast tissue.
Each test has its own strengths, and your healthcare provider will recommend the most appropriate option based on your individual risk factors and medical history.
The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations based on your medical conditions, arrange a consultation with Thomson Medical.
For more information, contact us:
Thomson Specialists (Women's Health)
Thomson Women's Clinic (TWC)
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