PLEASE NOTE: Gold Coast Spine does not perform these investigations, we are supplying information for your reference only.
What is a CT scan?
Computed Tomography Scans (CT scans) provide a way of using x-rays to take a series of images that are very fine slices through the part of the body that your surgeon is investigating. These fine slices may range from 4 to 64 slices or even up to 320 slices and can be used by the radiographer to reconstruct the images to help the radiologist have a detailed picture of the structures making up the body. This can assist with diagnosis so that the right treatment can be planned. CT scans can be used to provide detail of internal organs, bones, soft tissue and blood vessels in greater detail than regular x-rays.
How do I prepare for my CT scan?
In most cases, there is no special preparation for a CT scan of your spine. Generally you will be able to eat and drink normally on the day of the scan and you can continue to take any prescribed medication.
It is also important that you bring your referral letter or request form and all x-rays, previous CT scans, MRIs or ultrasounds taken in the last 2 years that may be relevant to why you are having the scan. The radiologist may like to compare the information or see if your condition has changed since your last scan.
Some types of CT require an injection of an iodine-containing contrast material to be injected to show blood vessels and some organs. This will generally be discussed at the time of booking or when your surgeon refers you for the scan. For these tests, patients will be required to fast (not eat or drink) prior to the scan. If you do require a contrast injection, you will have a cannula inserted into your vein so that the contrast material can be given during the test. Most patients report a strange metallic taste in the mouth and feel a warm sensation in the body when the contrast is injected. This is a common sensation and usually goes away within a few minutes.
It is important that you tell your surgeon if you have any medical conditions such as asthma, diabetes, heart disease, kidney disease or thyroid problems and also any medications you are taking. You should also notify your doctor if you are pregnant or if you have any allergies to contrast dye or iodine prior to the scan.
How is a CT scan done?
CT scans are tailored to the specific part of the body being investigated and the specific condition. The CT machine consists of a large square machine with a circular hole or tunnel through it. Patients are generally required to lie down on a flat bed attached to the scanner and then the bed slides in and out of the tunnel several times. The x-ray tube or ring will rotate around you several times. It is particularly important that you remain still during the scan to ensure that the highest quality image is produced. A computer workstation will process the imaging information, which is generally in a separate control room.
Like many types of radiology, a CT scan involves exposure to radiation. An increased lifetime cancer risk is a rare risk due to this exposure to x-rays. Due to this exposure this test should also be avoided in female patients who are, or may be, pregnant.
Delivery of Results
During your scan, the images will be reviewed for clarity and accuracy by the radiographer. Following your scan, a specialist radiologist will interpret the images; however, this takes some time. A copy of the images obtained from your scan and the radiologist report will be delivered to your surgeon. This delivery generally takes several days.
How is a CT scan different to an MRI?
Both a CT and MRI scan provide images of high detail; however, each scan allows the surgeon to have different resolutions and images of internal body structures. MRI scans provide better contrast resolution by allowing a differentiation of tissue structures within the body. In contrast, CT scans provide better spatial resolution which allows finer detail to be seen. The images of both scans can be manipulated via a computer to show the tissue in different planes. While neither scan is superior to the other, each scan has its benefits to help assess the disease process and diagnosis depending on the pathology being investigated. In terms of radiation exposure risk, MRI scans do not carry this risk while CT scans do.