Patient information on Contrast Enhanced Mammography (CEM)

This leaflet explains contrast-enhanced mammography (CEM), why it may be recommended for you, and what to expect before, during and after your appointment. Please read it carefully and keep it for reference.

If you have any questions, the breast imaging team will be happy to discuss these with you.

What is CEM?

Contrast-enhanced mammography (CEM) is a type of breast X-ray that combines a standard mammogram with an injection of a contrast medium (sometimes called a “dye”) into a vein in your arm.

The contrast helps highlight areas of the breast that may need closer assessment, providing additional information compared with a standard mammogram alone.

When is CEM used?

CEM may be recommended to provide more detailed information about your breasts, including:

• To further assess findings seen on a mammogram or ultrasound
• To assess the extent of a known breast cancer before treatment planning
• To monitor how a breast cancer responds to chemotherapy

What happens during a CEM?

The appointment usually takes less than 30 minutes.

1. When you arrive, the radiographer will ask about your health and explain the procedure. This is a good opportunity to ask any questions.
2. A small plastic tube (called a cannula) is placed into a vein, usually in your hand or arm. You may feel a brief scratch.
3. The contrast medium is injected through the cannula. Some people notice a warm sensation or a metallic taste in the mouth. These feelings are normal and pass quickly.
4. You will be asked to undress from the waist up. The radiographer will then take X-ray images of each breast, with gentle compression, similar to a standard mammogram. Compression helps obtain clear images and keeps the radiation dose as low as possible. The compression may feel uncomfortable and lasts slightly longer than a routine mammogram, but only for a few seconds each time.
5. After the images are taken, you can get dressed. The cannula will be removed after a short observation period (about 15 minutes), and you can then leave the breast unit.

What happens after a CEM?

Your images will be carefully reviewed. In some cases, further tests such as a targeted ultrasound scan, breast MRI, or biopsy may be recommended. These may be performed on the same day, or more likely, be arranged for a later appointment.

All CEM examinations are reported by two consultant breast radiologists. Your results will be communicated to you through the appropriate clinical pathway. This may be by your referring clinician, a member of the breast care team, or by letter if no further action is required.

What are the risks?

CEM uses X-rays. The radiation dose is slightly higher than a standard mammogram and is equivalent to about four months of natural background radiation. This is well within accepted safety limits. The benefits of the examination are always carefully weighed against any potential risks.

Contrast medium (injection)

The contrast injection is generally very safe and is used routinely in X-ray departments.

• Minor reactions are uncommon (around 3 in 1,000 people) and may include itching, skin rash, nausea, dizziness or a runny nose. These are monitored and usually settle quickly.
• Moderate reactions are rare (about 1 in 2,500 people) and may include wheezing, persistent vomiting, facial swelling or palpitations. Staff are trained to recognise and treat these promptly.
• Serious reactions are very rare.

Emergency equipment and medication are always available, and staff are trained to manage any reactions.

Very rarely, contrast medium may leak into the tissues around the injection site. Care is taken to prevent this and to recognise early signs to minimise discomfort.

Checking Kidney Function:

In a small number of people, contrast medium can affect kidney function. If you have known kidney problems, the test may not be suitable for you, and alternative imaging will be considered.

When shouldn’t I have a CEM?

You should not have a CEM if:

• You have a known allergy to iodine-based contrast medium
• You have significant kidney failure
• You are unable to give informed consent
• You are unable to tolerate mammography due to physical limitations

CEM is not usually harmful in pregnancy or during breastfeeding; however, each case is assessed individually. Please inform the department if you are pregnant or breastfeeding.

Before the examination, the radiographer will complete a CEM safety checklist to ensure the test is appropriate for you.

How can I prepare for a CEM?

No special preparation is needed. You may eat and drink as normal.

Please note:

• Do not wear deodorant, powder, lotion or perfume on your breasts or underarms on the day of your appointment
• Wear clothing that is easy to remove from the waist up
• Keep well hydrated before your appointment
• Continue taking your usual medications unless advised otherwise
• Inform staff if you have breast implants
• If you need an interpreter, please contact the breast unit in advance
• Childcare facilities are not available; please arrange supervision if needed

What do I need to do after I go home?

You can return to your normal activities straight away. Drink fluids as usual.

If you have any questions or concerns after your appointment, please contact the breast imaging department.

Privacy and dignity

We will try to make your visit to our department as comfortable as we can. If you have any conditions that need accommodating please contact the Breast Unit before your appointment so that we can put measures in place for you.

We hope that the information in this leaflet will answer any questions you may have, but please feel free to contact us if you have any particular worries, questions or concerns.

If you have any further questions or concerns, please do not hesitate to speak to a member of the breast imaging team via Cambridge Breast Unit Reception: 01223 217627.