What is a CT scan – and how is it done?
In this article, we will describe what is a CT scan, and how it is done.
A CT (Computed Tomography) scan is a painless medical imaging test that uses x-rays and computer technology to produce detailed cross-sectional images of the body. Here’s a step-by-step guide on how a CT scan is done:
Preparation
-
Arrival and registration: You will arrive at the hospital or imaging centre and register for the procedure
-
Changing into a gown: You will be asked to change into a hospital gown and remove any metal objects, such as jewellery, glasses, or clothing with metal fasteners
-
Removing electronic devices: You will need to remove any electronic devices, such as phones, watches, or hearing aids.
CT scan procedure
-
Positioning on the table: The technician (called a radiographer) will help position you on a narrow, motorised table that slides into the CT scanner
- Contrast dye/agent (if necessary): Depending on the type of CT scan, you may receive a contrast dye/agent through an IV to help highlight specific areas of the body
-
Scanner rotation: The CT scanner, which is shaped like a large doughnut, will rotate around you, taking 100s x-ray measurements from different angles
-
X-ray beams: The scanner will send x-ray beams through your body, which will be absorbed or transmitted to varying degrees, depending on the density of the tissues
- Computer reconstruction: The x-ray pictures will be sent to a computer, which will reconstruct detailed cross-sectional images of your body
- Time: Most CT scans take 3-7 minutes.
After the scan
-
Removal of IV line (if used): If you received a contrast agent, the IV line will be removed
-
Waiting for images: The technician will review the images to ensure they are complete and of high quality
-
Results: The images will be interpreted by a radiologist (x-ray doctor), and the results will be sent to your doctor.
Normal CT of abdomen and pelvis.
Summary
We have described what is a CT scan, and how it is done. We hope it has been helpful.
