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This page has been written by the Lysholm Department of Neuroradiology at The National Hospital for Neurology and Neurosurgery (NHNN). The aim of the page is to provide information about contrast extravasations (contrast leakage) that occur during imaging examination.
It is intended for use by patients (or their families or carers) who have experience a contrast extravasation in CT or MRI. If you have any questions about this a member of the Neuroradiology team will be happy to answer them for you.
What is an extravasation?
Contrast agents are usually given to patients having a CT or MRI scan by injection into a vein in your arm or hand. Occasionally the injection may leak out from the vein to the tissues under the skin – this is known as extravasation.
How can contrast help?
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.
What will happen if I choose not to have contrast?
If you do not wish to have contrast, this is your choice, and you will not be treated any differently.
Contrast is given to help distinguish between normal and abnormal tissues and organs; this will give your doctors the best opportunity to make a diagnosis and to plan your future management and care.
What happens during an extravasation?
Staff will take steps to reduce the possibility of an extravasation such as testing the cannula first with 10mls of saline (sterile salty water), assessing the skin and asking you if feel any discomfort. During certain imaging a pump injector will be used, the radiographer will still perform a test injection of saline prior to the main scan.
If an extravasation occurs, you will experience a stinging sensation near where the cannula is sited. This is where the contrast has gone into the surrounding tissue, and it can be painful. This will usually wear off after about 30 minutes. You may also have some swelling of the arm or hand.
What will happen if there has been an extravasation?
The radiographer will massage your affected arm and attempt to aspirate the contrast from the cannula site as soon as possible. Your arm will be elevated to aid the lymphatic drainage of the contrast and a cold compress will be applied to the area if required.
A doctor will examine you before you leave the department and advise you if any further treatment is necessary.
Sometimes you may need another injection of contrast and if necessary, this will be discussed with you.
What are the risks following an extravasation?
The risk of extravasation is rare and in 97% of cases this is a minor injury and does not require any treatment. These effects include localised swelling (79%), and pain/stinging (24%).
In very rare cases severe complications can include skin ulceration, soft tissue necrosis (breakdown of tissue) and compartment syndrome (where the pressure within a muscle increase, restricting the blood flow to the area and potentially damaging the muscles and nearby nerves).
What should be expected after an extravasation?
It is recommended you continue to massage the area where the contrast has gone into the tissue for a short time after the extravasation has occurred.
If there is swelling:
- Elevate the affected arm above the level of your heart for the next four hours. At night, keep it elevated on two pillows (you should continue to do this until the swelling has gone down).
- Apply an intermittent cold pack (15 mins on, followed by 15 mins off) to the site for the next hour. Continue to apply a cold pack to the site for 15mins one to three times a day for the next three days or until the symptoms have resolved.
- Take paracetamol or your usual over the counter painkiller if necessary for any discomfort at the injection site.
Watch for:
- The pain becoming more severe and not easily controlled by simple painkillers.
- Increased swelling of the arm or hand.
- Changes in colour of the affected arm/hand.
- Pins and needles or altered sensation in the arm or hand.
- Blistering or ulceration of the skin around the injection site.
If any of these symptoms occur, please notify the department where you had your scan performed if between 9am and 5pm Monday to Friday or go to the closest A&E outside these hours. Please take this leaflet with you to provide health care staff with information regarding your injection, see table below.
To be completed by the Radiographer
| Contrast agent used | Date and Time | Amount of contrast extravasated | Site of extravasation |
|
|
Where can I get more information?
You can find more information about current guidelines as recommended by the Royal Colleague of Radiologists (https://
NHS Direct is a useful source of health information (https://
UCLH cannot accept responsibility for information provided by other organisations.
References
Wang, Cohan, Ellis, Adusumilli, Dunnick. (2015). Frequency, management, and outcome of extravasation of nonionic iodinated contrast medium in 69,657 intravenous injections.
How to contact us
Lysholm Department of Neuroradiology
National Hospital of Neurology and Neurosurgery
Queen Square
London
WC1N 3BG
Direct line to CT: 020 344 83443
Direct line to MRI: 020 344 83581
Switchboard: 020 3456 7890
Extension: 83440/83103
Fax: 020 344 84723
Website: www.
Where to find us
Services
Page last updated: 20 June 2024
Review due: 01 June 2026