A computed tomography scan (CT scan) uses computers and rotating X-ray machines to create cross-sectional images of the body, taking a series of X-rays from different angles. These images provide more detailed information than normal

X-ray images as they create slices or cross-sections of the body. They may also be combined to produce a 3D image of a particular area of the body. They can show the soft tissues, blood vessels and bones in various parts of the body.

How is it performed?

• Before the scan begins, the patient is asked to change into a hospital gown and all metal objects, like jewellery, dentures and so on, must be removed.
• While performing the scan, it is important that the patient lies still in order to obtain the clearest images. If they are unable to do so, a mild sedative might be given.
• The patient lies down on a table that slides into the CT machine.
• Once the scan begins, the table slides slowly into the scanner while the X-ray machine rotates around the table. Each rotation produces numerous images of thin slices of the patient’s body.
• A special dye called a contrast material might be administered intravenously or orally (depending on which part of the body needs to be highlighted) to help visualise internal structures.

• The contrast material blocks X-rays and appears white on the images, allowing it to highlight the intestines, blood vessels or other structures in the area being examined.
• When in use, the machine produces clicking, buzzing and whirring. The table moves a few millimetres at a time until the exam is finished. The entire procedure may take anywhere from 20 minutes to one hour.
• Once the scan is over, the images are sent to the radiologist for examination.
• There is very little risk associated with a CT scan. Though these scans expose the patient to more radiation than typical X-rays, the risk of radiation-induced cancer is negligible.
• Some people might have an allergic reaction to the contrast material.

An X-ray is a common imaging test that can help diagnose, monitor and treat many medical conditions. While the most common use of X-ray imaging is to diagnose issues of the skeletal system, different types of X-rays are used for different purposes.

For example, the doctor may order a mammogram to examine the patient’s breasts or they may order an X-ray with a barium enema to get a closer look at the gastrointestinal tract.

How is it performed?

• Based on the part of the body to be imaged, the technician may ask the patient to lie, sit or stand in several positions during the test.
• A specialised plate that contains an X-ray film or sensors is placed behind the area to be imaged and a large camera connected to a steel arm is moved over the patient’s body to capture the images.
• It is important for the patient to stay still while the images are being taken to provide the clearest images. The test is completed when the technician is satisfied with the images gathered.

• If the X-ray is done to diagnose or manage a painful condition, such as a broken bone, the patient may experience pain or discomfort during the test as they will need to hold their body in certain positions while the images are being taken.
• X-rays use small amounts of radiation to create images of the body. The level of radiation exposure is considered safe for most adults.