Positron Emission Tomography (PET)

Positron Emission Tomography (PET) is an invaluable imaging technology used most commonly in cancer management. PET makes it possible to diagnose and monitor changes in the body’s metabolism.


    Positron Emission Tomography (PET) is an invaluable imaging technology used most commonly in cancer management. PET makes it possible to diagnose and monitor changes in the body’s metabolism.

    Positron Emission Tomography uses small amounts of a radioactive tracer (most commonly, a short-lived form of radioactive glucose called 18FDG), injected intravenously, to display normal and abnormal metabolic patterns in various organs throughout the body.

    By combining PET images with CT (computerised Tomography) scanned at the same time by the same machine, the accuracy and sensitivity of the images are maximized.


    A doctor’s referral and an appointment are required for a PET examination

    You will need to bring:

    • Your request form
    • Completed questionnaires
    • Any relevant previous imaging
    • Your Medicare card and any concession cards
    • Any medication you may need on the day

    You will receive detailed printed instructions from your referring doctor or specialist before the PET examination. We need to receive your referral form and know your weight before the appointment and you must fast for at least 6 hours before the examination. You may drink small amounts of water during this time.

    • If you are a diabetic and need to eat at regular intervals please notify Lake Imaging when making your appointment so that special instructions can be provided. You should also let us know of any other conditions which may affect the scan, including being pregnant, breastfeeding or caring for a small child.
    • It is important to arrive on time for your PET examination, and give plenty of notice if you need to cancel or reschedule, as our isotope supply is costly, and has a very short shelf life.
    • Most patients will have an additional, diagnostic CT scan scheduled immediately after the PET/CT scan. This is done immediately on the same scanner.
    • The duration of both procedures, including preparation time is approximately 1.5 to 2.5 hours.

    When you attend your appointment at Lake Imaging you will be asked to answer a few safety questions, remove any jewellery, watches etc, then change into an examination gown.

    The technologist will prepare and inject the tracer into an arm vein. You will then rest alone for 45-60 minutes while the tracer distributes through the body. We may ask you to drink a liquid contrast material during this time to outline the bowel later on the CT scan.

    After the “uptake” time, the technologist will position you for the scan. The PET scanner is similar in appearance to a normal CT scanner; it takes around 15-25 minutes to complete the images. You are able to breathe normally, but must not move during this time.

    If a diagnostic CT scan is scheduled, our radiographer will start this immediately after the PET scan. The CT procedure will be very similar to the PET scanning and may involve further injections of contrast material.

    At Lake Imaging all PET/CT scans are performed by registered Medical Imaging Technologists, and a PET-credentialed radiologist or physician will review your relevant medical history, and other imaging, before reporting your PET/CT scans.


    After the images are checked, we may ask you some further questions before leaving. There are generally no precautions to follow after your procedure.

    Radiation from the injected isotope diminishes to a safe level by the end of the procedure, and you are free to resume normal activities immediately.

    If you are caring for a small child, or breastfeeding, we may ask you to take some minor precautions. This will be explained to you by the staff at Lake Imaging.

    If your results are required urgently, or you have an appointment straight after your scan with your referring doctor or health care provider, Lake Imaging will arrange to have your results available immediately. Otherwise your referring doctor or health care provider will receive your report within 48 hours of your examination.


    PET/CT procedures are considered to be very safe and there have been no reported adverse reactions attributable to the use of 18FDG. Exposure to low doses of gamma radiation carries an extremely small theoretical risk of contributing to future cancer formation. These factors will be taken into consideration by your referring doctor in the light of your medical history and be balanced against the benefits of performing the test. All radiation doses are reduced to a level as low as reasonably achievable.

    The contrast media taken during the PET and CT scans (Methylcellulose) is an inert, indigestible liquid. Occasionally it may cause mild diarrhoea or digestive discomfort for a short time.

  • WHAT IS Gallium PSMA

    A new PET molecular imaging technique using prostate-specific membrane antigen (PSMA) has demonstrated excellent sensitivity in detection of low volume metastatic PCa.

    PSMA is a cell surface target that is highly expressed by nearly all prostate cancers with enhanced expression levels found in poorly differentiated, aggressive tumours, metastatic and hormone-refractory carcinomas. Due to the high PSMA uptake in PCa cells it is an ideal biological target for PET imaging of PCa, especially for visualising small lymph node, bone and liver metastases. The ability to identify and localise PCa recurrence in patients with elevated serum (PSA) but with no other symptoms after definitive therapy, is the goal of PSMA PET-CT.

    Please note that Gallium PSMAs are only offered at our Ballarat – St John of God Hospital and Geelong – St John of God Hospital locations.


    Preparation requirements for this procedure are specific for individuals and any conditions they may have, please contact Lake Imaging St John of God – Ballarat to make your booking and obtain the correct preparation.


    You will be asked to relax in one of our specially prepared rooms for 45-60 minutes. During this period you will be asked to avoid frequent muscular activity, speaking and reading. During this period we may or may not perform part of the images depending on the imaging protocol.  Also, we may have ask you to drink a special contrast material, again depending on the protocol of imaging.

    After this period is the scanning time which is approximately 30 minutes. You will lie on your back with your arms above your head in a scanner similar to the CT scanner.

    Total length of the procedure: Allow 2-3 hours for the whole procedure, this time may vary depending on the production of the radioactive material. Failure of production and passing the quality control may happen. In this case, you be asked to present later in the day or reschedule you appointment.

    Radiation Safety precaution: As you will be injected with a radioactive material. We require you to keep away from pregnant women and young children up till the afternoon. No other precautions required.


    After finishing the scan you may be asked to wait for some time until one of our specialist doctors reviews the images. There are no driving restrictions, unless you require some sedation. In this case, you need to arrange someone to drive you home.


    The type of radiation used in X-rays is called ionising radiation. Medical research has been unable to establish conclusively that there are significant effects for patients exposed to ionising radiation at the doses used in diagnostic X-ray imaging.

    Radiographers are trained to use the smallest possible amount of X-rays required to produce a satisfactory image. The benefits of an X-ray generally out outweigh the risks involved.

    Many imaging tests that use x-rays are not performed during pregnancy, in order to avoid exposing the fetus to unnecessary radiation. If an x-ray is necessary, precautions are taken to minimise exposure. The results of your scan will be sent directly to your referring Doctor, and it is very important you book a timely follow-up appointment to discuss your results.

Make an appointment online or call our dedicated bookings line