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Breast MRI

Read our guide below about what to expect from your breast MRI.

You can also download a PDF version of this patient information by following the link on the right.

Your breast MRI appointment

The MRI department will send you an appointment letter telling you the date and time of your breast MRI scan. The scans are usually done within 2 weeks from the time the doctor requests your scan.

You’ll get an MRI safety questionnaire and an MRI information sheet with your appointment letter. Fill in the safety questionnaire and bring it with you on the day of the scan. It will help to ensure that an MRI scan is safe and suitable for you.

Before the scan you may eat and drink as normal and continue taking your usual medication.

What is a breast MRI?

MRI stands for magnetic resonance imaging. The technique uses magnetic fields and radio waves to produce detailed images of the breasts. An MRI scanner is a large cylinder (tube)
that contains powerful magnets.

During the scan you lie face down on a couch that moves automatically through the cylinder. This will take between 20 and 30 minutes.

When is breast MRI used?

Breast MRI is not a replacement for mammograms (breast X-rays) or ultrasound. We use it to provide additional information about your breast tissue, for example to:

  • accurately measure the size of a cancerous lump if there’s a difference between the mammogram and ultrasound sizes
  • check for other cancers in cases when more than one breast cancer has been identified on ultrasound and mammograms
  • investigate invasive lobular cancer – a small number of cases with this subtype of breast cancer may have another small cancerous lump in the same breast or in the other breast
  • determine the size of the cancerous mass and measure the effect of neo-adjuvant chemotherapy  on the lumo by monitoring the size on subsequent scans
  • provide additional screening for some cases who have an increased risk of breast cancer.

What are the possible side effects or complications?

A breast MRI scan is a safe, painless and relatively quick procedure that doesn’t use radiation.

You may:

  • have some discomfort or an allergic reaction in a small numb er of people from the dye that we inject into your arm
  • feel uncomfortable lying on your front during the MRI
  • find the MRI noisy but we can give you headphones or earplugs to wear.

How will I get my results?

How you get the results of your MRI scan will depend on the reason for your scan and who referred you.  You maight get the results by letter, phone or at an appointment in
person depending on your treatment.

To avoid delays in your investigations and treatment, we may call you for further tests before you get your formal MRI results. This is because MRI is a very sensitive test and often highlights areas that we want to look at more closely.

One of the drawbacks of breast MRI is that it detects non-cancerous (benign) lumps as well as cancers. Sometimes normal tissue might look a little abnormal on breast MRI.

Most new areas identified by MRI are benign although a small proportion are cancers. If the abnormality isn’t seen on ultrasound and there’s still concern that it could be a small
cancerous lump,we’ll arrange an MRI guided biopsy. Only a few people will need to have this done.

If you have any questions

Call our breast care nurses at Wycombe Hospital who will answer any further questions or concerns. Leave a message and they’ll return your call.

How can I help reduce healthcare associated infections?

Infection prevention and control is important to the wellbeing of our patients so we have procedures in place. Keeping your hands clean is an effective way of preventing the spread of infections.

You, and anyone visiting you, must use the hand sanitiser available at the entrance to every ward before coming in and after you leave. You may need to wash your hands at the sink using soap and water. Hand sanitisers are not suitable for dealing with patients who have symptoms of diarrhoea.

More help or advice

Contact our patient advice and liaison service (PALS) on 01296 316042 or

About our patient information

We aim to make the information as up to date and accurate as possible, but please note that it’s subject to change. You must always check specific advice on any concerns you may have with your doctor.

Breast Care Nurses
Breast Care Nurses

01494 426228