What Is Pet CT?

PET (Positron Emission Tomography) is a diagnostic tool which combines the functional information of a PET scan with the structural information of a CT scan. It shows the chemical function of an organ or tissue. A radioactive glucose is injected via a vein and is then absorbed by tissue into your body. The PET scanner then detects the activity within your organs and how they function which will help your Doctor plan the appropriate treatment for you.

CT imaging is a highly advanced form of x-ray which shows the anatomical detail inside the body and detects alterations of structure caused by diseases.

A PET/CT scanner is a very specialized device. The scans from the PET camera show abnormal functioning disease within the body which is overlaid on the anatomical map provided by the CT scanner.

The combination of the two scans has been proven to be extremely sensitive for detecting the early stages of disease and can detect abnormalities even in the absence of structural change. Small amounts of a tumour may be found even if they are undetectable by other imaging procedures or CT imaging alone. This can have a major impact in choosing the best treatment methods. PET/CT information can be used to determine what combination surgery, radiation therapy and / or chemotherapy is most likely to be successful in managing a patient's condition. PET/CT can also help to monitor the effectiveness of therapy and assist planning for surgery and radiotherapy.

Global Diagnostics provides nuclear medicine at the following locations:

Patient Preparation

If you are diabetic?

If you are a diabetic please advise our staff at the time of making your appointment.Please follow the preparation instructions for Diabetics below.

It is very important you follow the preparation given to ensure your scan is successful.

  • You will be required to fast for 6 hours prior to your examination.
  • It is important you are well hydrated so we encourage you to drink plenty of water.
  • You will need to abstain from any strenuous exercise 12 hours prior to your examination as this may affect the glucose distribution within the body.
  • Please cease smoking 24 hours prior to your examination.
  • Wear warm, comfortable loose fitting clothing without metal fasteners such as clips, buttons or zips. Avoid wearing an underwire bra and jewellry.

Note: if you have a colostomy bag, please bring a spare bag with you to your appointment.

Diet controlled Diabetes:

No Special  preparation. Follow instructions for "All Patients as above."

Non-insulin dependent - Appointment before 12pm:

  • Fast from midnight.
  • Do not have breakfast and do not take your oral diabetic medication on the morning of your examination.

Non-insulin dependent - Appointment after 12pm:

  • Have your normal breakfast with your normal medication then fast for 6 hours before your appointment time.

Insulin dependent:

  • An appointment before 12pm is preferred.
  • After a light breakfast and your normal insulin injections, fast for 4 hours before your appointment time.
  • Bring your insulin with you to your appointment.
Are there any risks or side effects

The PET/CT is a very safe and routine procedure. The radioactive glucose you will receive is very safe with no known side-effects. However, because our staff are processing many patients please do not be offended when they keep a safe distance from you. The amount of radioactivity administered is small and will be out of your system by the end of the day. Because it does take a few hours to leave your system it is suggested you minimise contact with others, especially children and pregnant women for 6 hours following your scan.

The CT is also safe. It may be necessary to have an injection of contrast for the CT part of your scan. You may experience some side-effects from the contrast media. All this will be explained to you by the medical team when you are in the department.

During your PET/CT Scan

If you are pregnant or breastfeeding?

This procedure is not advisable for pregnant women, unless in exceptional circumstances. In such cases the dose of radioactivity administered will probably be reduced. Please advise us if you think you may be or are pregnant or if you will be accompanied by someone who may be pregnant.
If you are breast feeding we advise that you express enough milk for your baby to feed for 24 hours. During the 24 hours following the administration of the radioactive dye, ensure that you express and discard your breastmilk for your own comfort.


Please take all of your medications as normal except if you are diabetic. (Please see preparation instructions for Diabetics).

May you bring a friend or relative?

You can bring a family member with you; however they will not be able to accompany you through the examination process. Due to limited seating in our department we do ask family members and friends to leave the department while your examination is taking place.

What should I bring along to my appointment?

Please bring along with you all previous imaging you may have had. These can provide valuable information for the Radiologist when they are reporting your exam. Bring your Medicare/Concession cards.

Note: If you have a colostomy bag, please bring a spare bag with you to your appointment.

Billing Policy

Medicare only provides a rebate for some PET/CT examinations if they are referred by a medical specialist. Please ask our staff if there will be a fee for your scan and if it is Medicare rebateable.

When you  arrive?

Please arrive 15 minutes prior to your appointment and report to the reception desk. Once you have been arrived you will be called from the waiting room by one of our nursing staff and taken down to our PET/CT department.
Within the department the toilets are clearly sign posted should you need them.

Upon collection

Our nursing staff will confirm with you that you have followed the preparation instructions and you will be given the opportunity to ask any questions you may have. There will be a questionnaire and consent form that will need to be completed. The technologist will also explain to you what will happen during the examination.

Whom will you see?

The examination is performed by a qualified Nuclear Medicine Technologist.

What happens during the PET CT examination?

  • You will be weighed, a finger prick blood sugar test done and a cannula inserted.
  • You will then be shown to the injection room where you will be given a radioisotope via your IV cannula.
  • Post injection, you will rest in a recliner chair for approximately one hour.
  • Before your scan you will be asked to go to the toilet to empty your bladder.
  • Your PET scan will take approximately 20 -30 minutes.
  • If a diagnostic CT has been requested this will follow on from the PET scan.

Will it be uncomfortable?

You should not experience any discomfort during the examination. PET/CT scans are generally painless, although the injection may sting a little.

How long will it take?

You will be in the department for 2-3 hours. The actual scan itself will take about 20 -30 minutes.

After your PET/CT

  • You can resume your normal diet after the examination
  • The radioactive tracer will decay over time and your body will eliminate any residue through your kidneys and your bowel. You should drink plenty of water after your scan to assist eliminate the tracer. Please ensure that you dual flush (flush twice) the toilet for 24 hours after your exam.
  • You will able to drive and return to normal activity after your examination.
  • Some of the radioactivity from your examination may deposit in your breast milk and be transferred to a breast feeding baby resulting in unnecessary exposure to radiation. We advise that you do not breastfeed for 24 hours after the administration of the radioactive Isotope.
  • It is advisable that you limit contact with small children and pregnant women for 6 hours after your scan.

Cancellation of your appointment:

All PET/CT patients have an individual Radio-Isotope ordered and specifically prepared for each appointment. This is a high cost item. If you need to cancel your appointment please advise us at least 24 hours prior to your exam if this possible.

If you have a query?

If you feel you would like more information before your PET/CT examination, or have any concerns whatsoever, you are very welcome to contact our clinical team. Global Diagnostics employs nursing staff to answer any patient queries and to accompany you to the test should this be required. Please ring our Radiology Department between 9am and 5pm, Monday to Friday.