Information alert

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This page provides information about examinations using contrast agents in MRI. It is intended for use by patients (or their families or carers) who have been referred to our service for imaging requiring contrast agent and are currently breast feeding.

If you have any questions about this a member of the neuroradiology team will be happy to answer them for you.

Contrast agents are used to enhance specific blood vessels, tissues or body cavities during your scan or procedure. Contrast agents can come in many different forms; in neuroradiology these can be injected, or on occasion swallowed.

Contrast agents are made of different compounds depending on what they are being used for. They are not dyes that permanently discolour internal organs. They are substances that temporarily change the way x-rays or other imaging tools interact with the body.

In MRI we use gadolinium based contrast agents (GBCAs). When GBCA’s are present in the body, they alter the magnetic properties of nearby water molecules, which enhance the quality of MR images.

Contrast agents are used to improve and enhance the images produced when you are having a scan or procedure; helping distinguish selected areas of the body from surrounding tissues. This helps the radiologist diagnose medical conditions or plan and carry out treatments.

The scans and procedures using contrast agents have helped in the diagnosis and treatment of many patients with various diseases and injuries. It is important however, that the benefits of having a contrast enhanced scan or procedure outweigh the risks associated with the use of contrast.

The radiographers performing your examination will ask you some questions and/or review your medical records in order to ensure it is appropriate for you to have contrast agent.

In neuroradiology we follow current published guidance and use contrast agents with the lowest possible associated risks. If you have known kidney problems, renal failure or ever been on dialysis please contact Neuroradiology prior to your appointment. New evidence has found that “only tiny amounts of GBCA given to the lactating mother reach the milk and only a minute proportion entering the baby’s gut.” [1] – approximately 0.8%.

There is no need to discontinue breastfeeding after a GBCA has been given or to pump to clear milk of the contrast agent [2]. Our policy has been recently updated to reflect new research and guidelines from the Royal College of Radiologists UK, which states ‘while no special precaution or cessation of breastfeeding is required the continuation or cessation of breast feeding for 24 hours should be at the discretion of the breastfeeding patient in consultation with the clinician’ [3].

For full information on all risks of having gadolinium based contrast please see the related information leaflet “Contrast agent for MRI Examinations: An Information Guide”.

The decision to have a GBCA is entirely yours. To decline to have this procedure will not affect our attitude towards you or influence any other aspect of your care. It may mean, however, that your consultant cannot be as certain or specific about any future treatment or diagnosis.

Your doctor or clinical nurse specialist will have taken into account the potential risks and benefits of having a scan or procedure involving contrast when referring you to neuroradiology. There are some alternative scan methods in MRI or ultrasound that do not use contrast agent, the possibility of these should be discussed with your referring doctor or clinical nurse specialist first.

Please contact neuroradiology prior to your scan should you have:

  • Kidney problems
  • Kidney failure
  • Ever been on dialysis

Eating and drinking guidance

  • Before your scan or procedure please see your specific appointment letter
  • Gently increase your intake of fluids starting the day before your scan and continuing for another 24 hours after the scan to ensure you are well hydrated.

Medication Guidance

  • Take other medications as normal, before and after contrast, unless advised otherwise
  • Contact neuroradiology if you are unsure about any of your medications.

If possible, aim to arrive shortly before your appointment to give the staff time to prepare you for your scan or procedure. The length of your scan or procedure will vary depending on which type of scan you are having, please see your appointment letter or associated information leaflets for further information. Although it is not necessarily recommended to express breastmilk in preparation for having contrast, you may do so if you wish.

We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with a contrast scan or procedure, by law we must ask for your consent. This confirms that you agree to have the procedure and understand what it involves.

Staff will explain all the risks, benefits and alternatives before they ask you to verbally consent to contrast. If you are unsure about any aspect of your proposed scan or procedure, please don’t hesitate to speak with a senior member of staff again.

You will be given a GBCA during your MRI scan through a cannula or small plastic tube placed in your vein in the hands, arms or feet. This cannula will remain in the vein for the duration of your scan.

The radiographer will observe you throughout the duration of your scan and inform you when they are about to inject the contrast through the cannula, this may be done by hand or by an automatic pump injector.

If you have had an injection of gadolinium based contrast, we will ask you to remain in the neuroradiology department for up to 30 mins after your injection unless you are an inpatient where you will return to the ward. We will keep the cannula in place during this time, in case we need to give you any further medication.

After this, our staff will check you feel well enough to leave the department. Although it is not necessarily recommended to express and discard breastmilk after having contrast, you may do so if you wish.

Please ensure you read the related information leaflets before having an MRI scan involving gadolinium based contrast “Contrast agent for MRI Examinations: An Information Guide” and “Having an MRI scan” available at the neuroradiology reception or on our trust website

You can find more information about current guidelines as recommended by the Royal Colleague of Radiologists

You can visit the breast feeding network for further information

UCLH cannot accept responsibility for information provided by other organisations.


[1] Webb JA, Thomsen HS, Morcos SK; Members of Contrast Media Safety Committee of European Society of Urogenital Radiology (ESUR).

[2] Goergen S, Molan M The Royal Australian and New Zealand College of Radiologists Gadolinium Contrast Medium (MRI Contrast agents) 2009. UqyvmsUt

[3] RCR Clinical Radiology The Royal College of Radiologists 2019. Guidance on gadolinium-based contrast agent administration to adult patients

Lysholm Department of Neuroradiology
National Hospital of Neurology and Neurosurgery
Queen Square London

Direct line: 020 3448 3440
Switchboard: 0845 155 5000 / 020 3456 7890
Extension: 83440 / 83103
Fax: 020 3448 4723 

The Lysholm Department of Neuroradiology reception is located in Chandler Wing, on the lower ground floor of the National Hospital for Neurology and Neurosurgery, Queen Square. Please turn left when you exit the Chandler Wing lifts on the lower ground floor to find our main neuroradiology reception.

Page last updated: 16 May 2024

Review due: 01 October 2024