For certain tests like CT brain, sinus, facial bones, temporal bones, spine, knee, wrist, and CTs of the bones, no preparation is required. However, specific instructions tailored to your CT scan will be provided by our clinic.  

If necessary, our clinic will give you instructions for your CT scan before your appointment.  

Some scans may require fasting from food up to 4 hours before the procedure, while others may involve drinking a liter of water an hour before your appointment or consuming three special drinks to enhance visibility of the bowel and other abdominal organs (see more information on preparing for an abdominal CT below). Details about preparations, including the administration of IV contrast, will be explained during appointment scheduling. 

In some cases, you may also be administered with an IV contrast. See section further down the page for more information on this. 

If you have concerns about fasting, the iodinated contrast injection or your medication, contact your doctor or our clinic before your appointment. 

Some other important points to note are:

• If you use reading glasses, please bring them 
• Non-English-speaking patients to bring a companion who speaks or reads English 
• Patient with Diabetes - please bring a list of your diabetes medications 
• Before the examination, you may be asked to fill out a questionnaire regarding your health status, medications and any known allergies.

Following the preparation instructions is important as they may affect the test's accuracy or require it to be rebooked if you are not properly prepared for the CT scan.

Tests investigating your abdomen may require you to drink a different kind of iodinated contrast solution to outline your intestine (part of your digestive system). 

Please do not have anything to eat or drink for 4 hours before your appointment. Please tell the receptionist when you book if you may be pregnant. 

Full Oral Preparation - At the time of booking your CT, you will be given 2 sachets. These sachets contain a liquid which will outline the bowel for your scan. The first sachet is mixed with 200mls of water and drunk one and a half hours prior to your scan. The second sachet is drunk one hour prior to your appointment and a final sachet will be given to you to drink just before your scan. 

Water Preparation - Drinking water prior to your CT Abdomen/Pelvis will distend and outline the upper gastrointestinal tract. Our receptionist will advise the amount when booking your appointment.  

Depending on the type of scan that you are having you may be asked to change into a gown to avoid parts of your clothing affecting the scan.

It is important to follow the instructions you are given to ensure that the test is done safely, accurately and efficiently and so that you do not need to have the scan rescheduled or repeated.

Many types of CT scans require an injection of an iodinated contrast material. This is a colourless dye that shows up on x-ray pictures and scans and is used to highlight structures in the body that can't be seen without it. This contrast agent causes no complication in most people who have it.  

For these tests we will ask you to fast (not eat) prior to your appointment. It is important that the need to fast does not affect you if you have special dietary requirements (e.g. diabetes). Please check with your doctor or our clinic if you have any concerns. 

All patients are asked if they have kidney disease, diabetes or if taking metformin. If ‘yes’ to any of the above, ask patient to bring copies of recent blood tests (within the last 3 months) to their appointment. 

If you do require an iodinated contrast injection for your test, the radiologist or radiographer will discuss this with you. They will then use a needle to insert a cannula (a small plastic tube) into a vein in your arm or the back of your hand so that the iodine contrast can be inserted into the cannula during the test. 

While the iodinated contrast used for injections is considered very safe, there are precautions that must be taken when using it, particularly if you have poor kidney function or diabetes. 

Many people describe a feeling of warmth around their body and an unusual taste in the mouth. This is normal and lasts for a minute or two. Brief nausea may occur. Some people develop minor allergic symptoms such as hives, itchiness or a stuffy nose or eyes. 

Allergies 

If you have any of the following, the Radiologist may suggest you have another radiology examination that doesn't require contrast media, or suggest you take something (e.g. antihistamine) prior to your appointment. 

• Previous allergic reaction to a contrast medium 
• Asthma 
• Strong history of allergies 

Patients taking Metformin 

An association has been found between the intravenous administration of contrast media and lactic acidosis, in patients with diabetes mellitus receiving Metformin. The association is rare and happens only in patients with impaired renal function. If you have an examination needing contrast medium, you may need to stop taking the Metformin before your study and not start it again for two days. This will depend on a blood test of your kidney function. Your Doctor and the Radiologist will discuss the best method of imaging to meet your needs. Inform the receptionist you are taking Metformin, when you phone to make your appointment. 

You will be asked to lie on a table which is moved into the centre of the scanner.  This contains the x-ray tube and sensitive detectors.  These rotate around the part of the body that is being examined but will not touch you. 

The CT staff will go into the control room to operate the scanner.  They can see you, hear you speak and can talk to you via an intercom.  You may need to hold your breath for short periods of time while the CT scanner is taking images. 

If you are given IV contrast 

When the iodinated contrast is injected, most people will get a strange metallic taste in the mouth and feel a warm sensation through the body. This warm sensation may concentrate around the groin or buttock region and can feel like you may have wet yourself, even though you have not. Do not be concerned if this happens, it is a common sensation and usually goes away within a couple of minutes. 

Once the scan is completed, you will have the cannula removed so you can go home. 

Most examinations will be completed within 30 minutes, although attendance may take up to 2 hours from some scans.

Once the scan is completed the Radiographer and Radiologist will look at the CT data to ensure all the necessary images have been taken.  The information from the scan is then processed by a computer to produce cross-sectional images which is then reviewed and reported by the Radiologist. 

Due to the large number of images produced and the complex post scan processing required; the review of these CTs can take several hours. The results will be sent to your referring Doctor. 

If you have any questions, please do not hesitate to call us!

Most people who have a CT scan have no aftereffects at all. After the test, you should be able to eat and drink as normal and resume regular activities. 

If you have an injection of iodinated contrast, the sensations of warmth and the strange taste usually experienced should go away within a few minutes. In very uncommon cases, some people may be allergic to the iodinated contrast given into the vein in your arm or the back of your hand. 

It is not possible to predict if a person will be allergic to the iodinated contrast, though our staff are well trained to deal with allergic reactions should they arise. It is important to make the radiographer aware of any other allergies that you may have, prior to having the injection. 

People who are allergic to the iodinated contrast used in CT may get some of the following symptoms: 

• Gagging or feeling of suffocation or swelling of the inside of the throat or mouth 
• Dizziness and/or headache 
• Sneezing and/or watering eyes 
• Itching 
• A skin rash or hives 
• Nausea and/or vomiting 
• Change in blood pressure 

If you do feel any of these symptoms after your scan, it is important to tell the radiographer immediately. If these feelings come on after leaving the clinic, you should return immediately (if close by), or attend the nearest doctor or emergency department. 

CT scans are a fast, effective and accurate way of assisting your doctor to make a diagnosis and treat your condition. 

Radiation exposure

As is the case with most tests and medications prescribed by your doctor, CT does have risks that cannot be avoided. 

Our staff are highly trained to minimise these risks by using the lowest possible radiation dose to achieve quality images that allow the radiologist to make an accurate diagnosis. The radiographer will only scan the part(s) of the body required, and do their best to avoid scanning areas that are particularly sensitive to radiation - this may involve the use of shields made of lead or bismuth (a type of metallic substance). 

A CT scanner uses x-rays to obtain the pictures required for the radiologist to make a diagnosis. As is commonly known, x-rays are a form of radiation and must be used carefully by trained professionals to decrease the risks involved. 

These risks are: 

• A very small increase in the risk of developing cancer later in life. This low risk is considered to be outweighed by the benefits provided by the scan. 
• Risk to an unborn child if you are pregnant. This risk could take the form of a very small increase in the risk of cancer or a malformation if you are exposed to radiation during the first months of your pregnancy. 

Minimising risks from radiation include making sure that every CT scanner in use is regularly maintained and calibrated (tested and set to ensure accuracy) by specialised technicians. This is required by State and Federal laws. 

Your doctor will receive a written report on your test as soon as it is practicable. 

It is very important that you discuss the results with the doctor who referred you so that they can explain what the results mean for you.