- Reference Number: HEY1587/2025
- Departments: Nuclear Medicine
- Last Updated: 30 April 2025
Introduction
This leaflet has been produced to give you general information about your scan. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and your doctor, but may act as a starting point for discussion. If after reading this you have any concerns or require further explanation, please discuss this with a member of the healthcare team caring for you.
What is a MAG3 renogram?
You have probably been troubled by some symptoms. Following discussion with your doctor they have advised for you to have a renogram.
A renogram is a nuclear medicine procedure that uses a radioactive tracer to assess how well the kidneys drain into the bladder. This scan can be used to identify if there are any blockages/obstructions or if there is delayed drainage.
MAG3 is the chemical name of the radioactive substance that we use.
Why do I need this scan?
The results of this scan will give your doctor(s) more information about your condition and help them to plan your treatment.
Alternative imaging such as CT, ultrasound and x-rays can show the size and shape of your kidneys but not how they function.
Pregnancy and chest/breastfeeding
Because this scan involves an injection of a radioactive tracer, you must tell us if you are, or think that you might be, pregnant or are chest/breastfeeding. If possible, please tell us as soon as you receive your appointment.
Can there be any complications or risks?
The scan uses a very small amount of radioactivity, which is not known to cause harm. Most patients experience no side effects. The tracer is injected into a vein and will naturally leave your body through your urine over the next day.
The radioactive tracer administered will expose you to a small amount of ionising radiation but the potential benefits of the scan outweigh the very small risks.
If you would like to read more, the government has published information about radiation exposure from medical imaging (tinyurl.com/5b4326s5).
How do I prepare for the scan?
You can eat, drink and take any medicines as normal.
Please inform the department if you are on any form of dialysis as it may be necessary to coordinate your nuclear medicine appointment with your dialysis treatment.
Before attending your appointment, you will need to drink plenty of fluids to ensure you are well hydrated. However, it is not necessary to have a full bladder for the scan so empty your bladder as required.
You should be prepared to be at the hospital for approximately 1 hour.
What will happen?
On the day of your scan, you will book in at the reception in the nuclear medicine department and will be asked to drink some water. You will then meet our team of technologists. They will explain the procedure to you and you can ask any questions you may have about the scan.
Before your scan we will place a small plastic tube (cannula) into your arm or hand. Sometimes you may need to have a diuretic before the scan. A diuretic is a drug that makes your kidneys work harder. It will be given as an injection through your cannula. It may cause you to feel that you need to empty your bladder more frequently. This is normal.
Just before the scan, we will ask you to empty your bladder then we will take you into the camera room. You will be asked to remove any metal items such as your mobile phone, wallet and/or belt.
For your scan, you will be lying on your back on the imaging bed with the camera above and below you. The camera will come close but it will not touch you. We will then give you the injection of the radioactive tracer through your cannula.
The scan takes 20 to 35 minutes and it is important that you remain still for this time. We will then take a 1 minute image before and after you empty your bladder.
What happens afterwards?
Eat as normal and keep well hydrated.
You may need to use the toilet more frequently after the scan due to the diuretic – this is perfectly normal and the effects should wear off within a few hours.
After the scan you will still have some radioactivity left in your body. The technologists looking after you will give you advice on the day on what precautions to take to prevent radioactive contamination.
If you already have an appointment booked in clinic to discuss the results of the test, please let our team know.
Your images will be reviewed by our doctors and a report will be sent to the doctor that referred you for this scan. You will get your results from them.
Contact Details
Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Nuclear Medicine Department on tel: 01482 622125 or hyp-tr.nucmed-hri@nhs.net. You can find more information about our department on our website at www.heynm.org.uk.
General Advice and Consent
Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.
Consent to treatment
Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.
The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:
- you must be able to give your consent
- you must be given enough information to enable you to make a decision
- you must be acting under your own free will and not under the strong influence of another person
Information about you
We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.
We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.
Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.
If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.
