A computerized tomography (CT) scan combines a series of X-ray images taken from different angles around your body and uses computer processing to create cross-sectional images of bones, blood vessels and soft tissues. It can be used to visualize nearly all parts of the body and is used to diagnose disease and injury. It’s particularly well-suited to quickly examine people who may have internal injuries.
What is a CT Scan? A computerized tomography scan (CT or CAT scan) uses computers and rotating X-ray machines to create cross-sectional images of the body. These images provide more detailed information than normal X-ray images. They can show the soft tissues, blood vessels, and bones in various parts of the body.
What Happens during the procedure? Depending on the body part that is being examined, the technologist may ask the patient to change into a medical gown. Not all exams require the patient to change into a gown. The patient will be asked to lay face up on a table that slides into the CT scanner. The technologist will then leave to the exam control room where they can see and hear the patient. They will be able to communicate with you via an intercom and guide you through the exam. The table will slowly move the patient into the scanner and the X-ray machine will rotate around them. The patient will hear subtle clicking, buzzing and whirring noises during the scan. The table will then move in a few millimeters at a time until the exam is finished. The exam may take anywhere between 15 to 30 minutes per body part. The duration may also vary if the patient’s exam requires contrast, as the patient may need to be injected or drink the liquid contrast. It is very important that the patient lay still while the CT images are being taken because the movement can cause blurry pictures. During the test, the technologist may ask the patient to hold their breath for a short period of time to prevent the chest from moving up and down.
What are contrast materials in a CT scan and how do they work? Contrast materials are used to improve the images inside of the body produced by x-rays, computer tomography (CT). Often contrast materials allow the radiologist to distinguish between normal and abnormal conditions. The contrast material does not harm or permanently discolor the organs. It simply amplifies the image clarity and detail and allows the radiologist to see certain structures or tissues that would appear different if there was no contrast media administered.
Contrast media is a liquid substance that is administered to the patient in one of two ways:
Injected into a blood vessel (vein or artery)
Swallowed (taken by mouth or orally)
How should I prepare for my imaging procedure with contrast material?
Because contrast materials carry a slight risk of causing an allergic reaction or adverse reaction, you should tell your doctor about:
Allergies to contrast materials, food, drugs, dyes, preservatives, or animals