Finding a lump in your breast or being told that you have a high risk of developing breast cancer is understandably worrying. As with most cancers, getting diagnosed as early as possible is key to maximising your chances of recovering well.

A breast cancer MRI (magnetic resonance imaging) scan is a reliable diagnostic tool available to doctors and medical specialists to diagnose or rule out breast cancer, and they’re available on the NHS and in private clinics around the country.

Commonly, mammograms are used as a first port of call for breast cancer diagnosis. However, MRI scans can be particularly useful for people with breast implants or dense breast tissue, both of which are less easily imaged with mammograms.

Getting a breast cancer diagnosis means that your medical team can create a treatment plan based on your individual type of breast cancer and your overall health and wellbeing.

In this article, we’re going to discuss everything you need to know about breast cancer MRI scans including the different types, why you might need one and what it feels like.

What is a Breast MRI?

A breast MRI is a type of scan that uses a strong magnetic field and radio waves to provide a detailed image of the breast and surrounding tissue. It’s carried out in a tubular MRI scanner machine by a trained medical professional called a radiologist. You will be required to lie down on a flat bed that moves into the scanner, and it takes around 30 minutes.

Types of Breast MRI

There are numerous different types of breast cancer MRI, and the MRI used in your case will depend on your own personal circumstances. Here’s the main types of MRI scanning used in confirming or ruling out a breast cancer diagnosis.

Contrast-Enhanced

Most breast cancer MRI scans require a contrast dye injected into the vein. This allows for clearer imaging results and a more conclusive diagnosis.

Non-Contrast

A non-contrast MRI scan doesn’t involve the use of a contrast dye and may be used if you’re having a breast MRI to detect leaking or ruptured breast implants.

Functional MRI (fMRI) of the Breast

A functional breast MRI is the same as a standard, contrast-enhanced MRI, but extra dyes or chemicals are used to obtain a more detailed image of the breast tissue, blood vessels, and any tumours. Examples include the dynamic contrast-enhanced and diffusion-weighted imaging scans mentioned below.

Dynamic Contrast-Enhanced MRI (DCE-MRI)

A dynamic contrast-enhanced MRI is a relatively new type of MRI scan for breast cancer that also provides detailed images of the surrounding blood vessels and the extent of blood flow to a tumour using a contrast dye.

Diffusion-Weighted Imaging (DWI)

A diffusion-weighted imaging MRI scan is another newer type of MRI that provides more information on the microstructure of the breast tissue and breast tumours, and can therefore provide more accuracy.

MR Spectroscopy (MRS)

Magnetic resonance spectroscopy is sometimes performed alongside a breast MRI scan to give more information about the chemical content of breast tumours. This information is then useful in developing the right treatment plan.

Pre-Surgical Breast MRI

Having an MRI prior to breast surgery following a breast cancer diagnosis will help your surgeon map out exactly where the cancerous cells are to ensure their complete removal.

Screening Breast MRI

You may have regular screening breast MRI scans if you have a strong family history of breast cancer or you’re known to be at a high risk of developing it, to help monitor and start treatment as early as possible if you do develop it.

Fast Breast MRI

A fast, or abbreviated, breast MRI takes fewer images in a shorter space of time, and can be useful for those who have dense breast tissue.

How Does a Breast MRI Work?

MRI scanning machines use a strong magnet field and radio waves to alter tiny particles in the body called protons. Different tissues in the body, including any tumours, contain protons that interact with the strong magnets during an MRI. Using the results from the magnetic field, radio waves and a computer programme, radiologists can generate images to determine if a breast tumour is present.

What Breast Cancer Looks Like on an MRI

A breast tumour will appear like a white spot or mass on MRI results. It differs from healthy tissue that appears darker on an MRI scan.

Reasons You Would Need a Breast MRI

There are various reasons why you may need to have a breast MRI including:

Discovering a lump in your breast
Experiencing other potential symptoms of breast cancer including an inverted nipple or discharge from the nipple
Abnormalities detected during a mammogram
Having dense breast tissue, meaning that mammograms may not pick up early breast cancers
Having scar tissue or breast implants situated such that mammograms may not pick up early breast cancers
Having a strong family history or a known increased risk of breast cancer
Carrying the BRCA1 or BRCA2 gene mutations (these mutations can mean an increased risk of developing ovarian or breast cancer)
Having had radiotherapy to the chest area between the ages of 10 and 30 years old

A breast MRI is also useful for monitoring changes in abnormal cells and any spread of breast cancer to the chest wall, lymph nodes or surrounding blood vessels and in detecting any changes to the other breast not affected by breast cancer (there’s around a 10% chance of someone with breast cancer in one breast, developing cancer in the other).

Although a breast MRI scan can be used to detect breast cancer, another reason why you may need a breast MRI is to detect suspected leaking or rupturing of a breast implant.

Potential Risks

There are some known risks to having an MRI scan, especially concerning metal objects, implants and medical devices. We cover these in more detail below. In addition to this, you must let your radiologist know if you’re pregnant, think you may be pregnant, you’re breastfeeding or you’ve had an allergic reaction to iodine or the contrast dye used during breast cancer imaging tests called gadolinium-DTPA.

On the whole however, MRI screening is considered safe as it doesn’t use radiation or x-rays.

Preparing For a Breast MRI

There are various things you’ll need to do to prepare for a breast cancer MRI scan and your medical team will give you all the information you’ll need. If you take any regular medications, speak to your doctor who can advise whether or not you should temporarily stop taking them.

Generally however, these are the things you’ll need to consider before having an MRI of the breast or breasts.

Eating & Drinking

You can eat and drink as normal on the day of your scan. However, if you’re very nervous or anxious, try to stick to plain, easy to digest foods to help minimise your chances of developing nausea, vomiting or a stomach upset.

What to Wear

At your appointment, you will be given a medical gown to wear for the duration of your scan. This gown will have no zips or other metal fastenings. Having any kind of cancer imaging test can feel overwhelming, so to minimise the things that you have to think about, it may be a good idea to arrive at your appointment wearing loose-fitting, comfortable clothing that’s easy to remove and put back on again.

Metal Objects

In the section below, we’ll talk in more depth about medical implants (such as a cochlear implant in the ear) and prostheses (medical devices that replace a body part, such as an artificial limb) when having MRI scanning. But metal objects that are easily removable, should be removed prior to your scan, including jewellery, body piercings and hair clips.

Anti-Anxiety Medication

For some, having an MRI scan can feel overwhelming due to the claustrophobic, loud nature of the MRI scanner machine, causing feelings of panic and distress. If you think you’ll struggle with being in an enclosed space, speak to your medical team who may be able to provide anti-anxiety medication that you take beforehand in order to make the experience less daunting and worrying.

Menstrual Cycle

Breast tissue can change throughout the menstrual cycle. If you’re pre-menopausal and have periods, it’s generally considered best to have a breast MRI between days six and 13 of your cycle.

Pregnancy

If you’re pregnant, you think you may be pregnant or you’re breastfeeding at the time of your appointment, speak to your doctor. You shouldn’t have an MRI scan during your first trimester (three months) of pregnancy. If your pregnancy is further along than this, your medical team will discuss the risks and benefits. If you’re breastfeeding, breast tissue may look different on an MRI scan which can affect the results.

Allergies

Most breast cancer MRI scans involve the use of a contrast dye that’s injected into a vein to create more detailed pictures in the final MRI results. This dye is called gadolinium-DTPA and contains iodine - if you have an allergy to either, let your radiologist know.

Implants to Report Before a Breast MRI

If you have any of the following medical implants or devices, you should let your radiologist know before having a breast MRI scan due to the strong magnetic field in the MRI scanner. Having any metal objects or implants that mean you’re unsuitable for a breast MRI, will mean that your surgical team will use other imaging tests to scan your breasts.

Defibrillator or Pacemaker

Some defibrillators and pacemakers are safe in an MRI scanner, so if you have one, have the make and model number available so that your radiologist can check.

Brain Aneurysm Clips

You may not be suitable for a breast cancer MRI scan if you’ve had a brain aneurysm and have had a neurosurgical clip put in place to prevent it from rupturing.

Cochlear Implant

Knowing the make and model number if you have a cochlear implant will again be useful, as some are safe in an MRI scanner.

Metal Coils in Blood Vessels

Metal coils used to support blood vessels affected by heart disease or strokes are not safe inside an MRI scanner. If you have any of these, you’re likely to be referred for a different type of breast imaging.

Artificial Heart Valves

Some artificial heart valves are MRI-safe, so if you have any, speak to your radiologist.

Metal Stents or Mesh

You may not be suitable for a breast cancer MRI if you have any metal stents or mesh implants.

Prosthetic Joints or Metal Rods

If you have a removable prosthetic, you will be asked to remove it before entering the MRI room. Speak to your radiologist before your scan about any internal prostheses, rods or implants that cannot be removed to find out if you’re suitable for an MRI of the breast.

Shrapnel or Bullet Fragments

Any metal fragments left in the body as a result of a shrapnel or gunshot wound should be investigated prior to your MRI scan appointment. Some may be safe, but others, such as those in the head or near the eyes, may not.

Insulin Pumps or Medication Ports

Some internal drug infusion pumps are MRI-safe, while others aren’t. Try to provide as much information as possible about yours to your radiologist so that they can determine if you’re suitable for a breast MRI.

Dental Implants with Metal Components

Fillings and some metal dental implants are usually safe in an MRI scanner, but let your radiologist know if you have any dental work that contains metal.

What Happens During a Breast MRI?

An MRI scanning machine is a large tube-shaped machine. If you’re having a contrast dye, it will be injected into a vein via an IV line (intravenous line) in your arm. You’ll then be asked to lie face down on a bed, with your breasts positioned in a special opening in the bed. The bed will move slowly into the machine so that your whole body is inside the MRI scanner, feet first.

Your radiologist will control the machine from a separate room, and you’ll be able to speak to them throughout for reassurance and support. You will need to lie still, and you will hear loud noises as the magnets and radio waves come together to produce detailed images. At some points, you may be asked to hold your breath for a few seconds. Your radiologist will use the images produced by the radio waves and a computer will collate the images to allow your specialist to read and interpret them.

What Does it Feel Like?

You won’t feel anything during a breast MRI. However, since an MRI scanning machine is a very small, enclosed space and makes a loud noise, you may understandably feel panicked or overwhelmed. Your medical team will do all they can to put you at ease, and you will be given earplugs to help reduce the noise, but if you feel like you need medication to help calm anxiety, ask them before your appointment.

How Long Does it Take?

A breast cancer MRI scan usually takes around 30 minutes and you will be required to lie still for the whole time. If you struggle to lie down or remain still for this length of time, speak to your medical team.

What Happens After a Breast MRI?

Once the MRI machine has produced enough images, and your radiologist is satisfied that they have all the information they need, the bed will slowly move you out of the MRI tunnel and you’ll be helped up and off the bed. You shouldn’t feel any side effects from the scan itself, but if you’ve had a contrast dye, you may feel some mild discomfort from the IV line once it’s removed. You’ll be free to return home soon after your breast MRI.

Getting the Results

The results and outcome of your breast cancer MRI will be passed from your radiologist to your specialist breast doctor. How long it takes to receive your results will depend on where you have your scan, but generally, it takes a few days. Your breast doctor will arrange for you to visit them in the clinic in order to give you your results.

Often, your MRI results will be combined with results from other tests and scans, including mammograms and ultrasound tests. You will be given a BI-RADS, or Breast Imaging Reporting and Database System, score. This score categorises abnormal findings and will ultimately help determine your treatment plan if breast cancer is detected.

MRI Scan Vs Mammogram

A breast cancer MRI scan is often performed in conjunction with a mammogram and an ultrasound, in order to help your doctor determine the size and grade of any breast tumours present.

Why an MRI Scan is a Good Option

Having a breast cancer MRI scan is extremely useful in diagnosing breast cancer so that you can begin your treatment without delay. Since it doesn’t use radiation or x-rays, there’s no risk of radiation exposure or any other side effects.

Find an MRI Scan for Breast Cancer

If you’re concerned about a breast lump or changes to your breasts, or you’ve been told you need to have further tests for breast cancer, having a breast MRI scan can help you either start treatment as soon as possible or put your mind at rest. Book a private MRI scan with us today, or if you're unsure if a breast MRI is right for you, book an appointment to speak to one of our specialist private consultants who can help you decide.

References

Breast Magnetic Resonance Imaging (MRI). (2024, July 3). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/breast-mri

Professional, C. C. M. (2024, October 28). Breast MRI. Cleveland Clinic. https://my.clevelandclinic.org/health/diagnostics/8332-breast-mri

Radiological Society of North America (RSNA) and American College of Radiology (ACR). (n.d.). Breast MRI. Radiologyinfo.org. https://www.radiologyinfo.org/en/info/breastmr

Breast magnetic resonance imaging (MRI). (n.d.). Cambridge University Hospitals. https://www.cuh.nhs.uk/patient-information/breast-magnetic-resonance-imaging-mri/

O’Flynn, E. A., & deSouza, N. M. (2011). Functional magnetic resonance: biomarkers of response in breast cancer. Breast Cancer Research, 13(1). https://doi.org/10.1186/bcr2815

Bolan, P. J., Nelson, M. T., Yee, D., & Garwood, M. (2005). Imaging in breast cancer: Magnetic resonance spectroscopy. Breast Cancer Research, 7(4). https://doi.org/10.1186/bcr1202

How an MRI Scan Can Detect Breast Cancer