Kids Health Info

Nuclear medicine

  • Nuclear medicine is a type of medical imaging that involves the use of radio-pharmaceuticals (also known as radioactive medicines or tracer medicines).

    Nuclear medicine imaging combines the use of tracer medicines and gamma cameras (cameras that can detect the gamma radiation that the tracer medicine emits), to provide images that can see inside the body.

    While nuclear medicine scans involve radiation exposure (like with X-rays and CT-scans), the exposure is limited as much as possible.

    Why does my child need a nuclear medicine scan?

    Nuclear medicine scans are performed for many different reasons, including:

    • to see how different organs in the body are functioning
    • to look at the shape or structure of parts of the body
    • for early detection, treatment, and management of diseases.

    Nuclear medicine scans can be performed on most organs of the body, and are commonly done to examine the kidney, heart, gastrointestinal tract (digestive system) and brain. They can also be used to examine bones. 

    Common nuclear medicine scans include:

    • bone scans
    • Mag3 renal scans
    • DMSA renal scans
    • gastric emptying and gastro-intestinal transit studies
    • thyroid scans and therapy
    • brain perfusion (epilepsy)
    • GFR renal studies
    • MIBG whole-body imaging.

    What to expect with a nuclear medicine scan

    Before the scan

    It can be very helpful to your child if the procedure is explained to them before they come in for their appointment. Explain that:

    • the scans do not take long
    • the scans are painless
    • a parent or carer can stay with them during the scan.

    Preparation for a nuclear medicine scan depends on the type of scan your child is having, and your child’s individual needs. Some scans require fasting for the actual imaging sequences, and others require fasting for sedation (see below).

    If your child requires an injection of tracer medicine, a topical anaesthetic cream can be applied to the injection site to make it numb. The cream usually takes at least 30 minutes to work, so you will be required to attend the department earlier than your appointment time. You will be advised if you need to do this when you are given your appointment.

    Most children can watch a DVD while having their scans, and you are welcome to bring in a smartphone, tablet, MP3 player, books or your child's favourite DVD to keep your child occupied and distracted during the scan.

    During the scan

    Your child will be invited into the camera room by a technologist and the procedure will be explained to you and your child. Your child will then be positioned on the scanning bed. Seat belts may be placed around your child to help them remain still, as well as for safety purposes as the scanning bed is quite narrow and can move.

    Your child will be given tracer medicine, which is given by one of the following ways:

    • intravenous (IV) needle (the most common method)
    • oral drink
    • oral tablet.

    The imaging can take place after the tracer has been administered. It may involve the camera moving slowly over or around your child's whole body, or a specific area of their body. Your child is required to keep very still while the camera is taking images.

    The average time for a nuclear medicine examination is 30–45 minutes, but there may be multiple scans or sequences required over a longer period of time.

    After the scan

    Your child will be observed for 10 minutes after the scan to ensure they don’t have a reaction to any medicines they’ve been given. It is very rare for a child to have an allergic reaction to the tracer medicine, but if a reaction does occur staff are well trained to manage any adverse events associated with contrast.

    A report will be prepared by the nuclear medicine physician and sent to the referring doctor. This will usually take a few days, but in urgent cases this can be done earlier if requested by the doctor.

    Clerical staff cannot give out scan results over the telephone. If you have any questions about the results of your scan, speak to your doctor.

    Nuclear medicine scan with sedation

    If your child is unable to remain still or they are very anxious or distressed and can't be calmed down, they may need sedation before their nuclear medicine scan. See our fact sheet Sedation for procedures.

    Whether or not your child needs sedation depends on their age, the scan they are having and their individual circumstances. Your child will be assessed to ensure that the sedation is suitable for them. Studies that may require sedation include bone scans, MIBG whole-body scans and brain scans.

    You will be given fasting instructions to follow before the scan. After the scan, your child will be required to remain under the care of the department nurse until they have recovered properly.

    Nuclear medicine scan with general anaesthetic

    Some nuclear medicine scans need to be performed under a general anaesthetic. This is rare, but may be required if your child cannot use sedation.

    Your child will need to fast before the general anaesthetic; you will be given instructions about this.

    After the scan, you will need to wait until your child is fully awake and staff say it is OK to go home. Do not worry if your child feels sick or vomits once or twice after leaving hospital. If your child continues to vomit, please call your child's anaesthetist or your nearest hospital emergency department.

    Key points to remember

    • Nuclear medicine scans use tracer medicines and gamma cameras to provide images of organs and bones inside the body.
    • Some scans require fasting for the actual imaging sequences, and others require fasting for sedation. 
    • Your child will be on a scanning bed and has to keep very still during the procedure. 
    • Sedation may be required for children who are unable to stay still or who are very scared.
    • The scans are painless, and if an injection is required your child can have numbing cream applied to the injection site.

    For more information

    Common questions our doctors are asked

    My child is very anxious about medical procedures and I am worried she won't stay still for the procedure. How can I help her?

    Show your child our Be Positive video of a child having a nuclear medicine scan at The Royal Children's Hospital (RCH). It will help her to know what to expect. You can also download our Okee in Medical Imaging app, which includes games and information especially designed to help children feel more comfortable about having medical imaging done at the RCH, and includes fun training on how to keep still. To get some ideas of how to talk to your child about the scan before you come to hospital, see our fact sheet Reducing your child's discomfort during procedures

    How safe is the tracer medicine my child will be given?

    It is very rare to have a reaction to the tracer used in nuclear medicine. Specialised staff or on hand to provide help should any symptoms arise, however unlikely. Once the scan is complete, your child will pass the tracer (through wee, poo and sweat) without any long-term consequences.

    Developed by The Royal Children's Hospital Nuclear Medicine department. We acknowledge the input of RCH consumers and carers.

    Reviewed October 2018.

    Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit

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This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital, Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.