A CT scanner uses x-rays to obtain data which is then processed by a special computer. Detailed images of soft tissue, blood vessels and bone are produced.
How is the test performed?
The duration of an examination depends on which part of the body is being examined. If you are asthmatic or diabetic it is very important that you inform reception staff. You may need to change into a gown and you will be asked to lie on a narrow bed.
The bed is designed to slide through a large ‘O’ shaped x-ray tube. Depending on the specific examination you will be oriented to pass either head first or feet first through the tube.
A radiographer controls the scanner from behind a partition near the scanner. The table will move during the examination as images are obtained.
You might be given breathing instructions during the scan – these are recorded on the machine and played back to you when necessary.
What is the preparation for the test?
Preparation will vary depending on the area being examined.
Will I feel anything?
If you receive a contrast injection you may feel a slight warmth and metallic taste.
How long will it take?
Most scans take 20 minutes.
CT Scans for Children
During a CT scan, the objective is that your child is exposed to the smallest amount of radiation necessary to make a diagnosis. The Australian Government through the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and the health professionals who refer and deliver medical imaging promote the following strategies for minimising radiation exposure in children:
- Only use CT when there is a clear medical benefit.
- Use other diagnostic imaging methods such as ultrasound or magnetic resonance imaging (MRI), which do not use x-ray beams, when possible and appropriate.
- Use the lowest amount of radiation for adequate imaging based on the size and age of the child.
- Image only the indicated area.
- Avoid multiple scans where possible.
- CT for Children Parent Information Sheet
Information for Patients: www.insideradiology.com.au/computed-tomography/
Information for Health Professionals: www.insideradiology.com.au/computed-tomography-hp/