What is a CT scan?
Computerized tomography (CT scan) — also called CT — combines a series of X-ray views taken from many different angles and computer processing to create cross-sectional images of the bones and soft tissues inside your body.
The resulting images can be compared to looking down at single slices of bread from a loaf. Your doctor will be able to look at each of these slices individually or perform additional visualization to view your body from different angles. In some cases, CT images can be combined to create 3-D images. CT scan images can provide much more information than do plain X-rays.
A CT scan can be used to visualize nearly all parts of the body. The strength of the CT scan for the ENT specialist is in its ability to demonstrate contrasts of tissues vs. bone. It is therefore very useful when evaluating the sinuses for inflammatory changes as well as fractures in the facial bones. It can pinpoit the location of a tumor, infection or blood clot. It can help to guide procedures such as biopsies, radiation therapy or even the course of surgery. A CT scan can detect conditions such as cancer. thyroid nodules, neck masses and internal injury or bleeding.
During a CT scan, you’re briefly exposed to much more radiation than you would be during a plain X-ray. This radiation from imaging tests has a very small potential to increase your risk of cancer. Still, CT scans have many benefits that may outweigh potential risks. Doctors use the lowest dose of radiation whenever possible. Newer machines and techniques may expose you to less radiation. Talk with your doctor about the benefits and risks of your CT scan.
Harm to unborn babies
Tell your doctor if you’re pregnant. Another type of exam may be recommended, such as ultrasound or magnetic resonance imaging (MRI), to avoid the risk of exposing your fetus to the radiation.
Reactions to contrast material
In certain cases, your doctor may recommend you receive a special dye called a contrast material through a vein in your arm before your CT scan. Although rare, the contrast material can cause medical problems or allergic reactions. Most reactions are mild and result in a rash or itchiness. In rare instances, an allergic reaction can be serious and potentially life-threatening. Tell your doctor if you’ve ever had a reaction to contrast material.
A CT scan typically takes only a few minutes to complete. Before the test, the radiology technician may insert an IV line to administer a contrast agent if the CT was ordered “with contrast”. Contrast agents help to demonstrate blood vessels among other tissues on the final images.
CT scanners are shaped like a large doughnut standing on its side. You lie on a narrow table that slides into the “doughnut hole” but you are not enclosed (in contrast with the MRI). The table will move slowly as the CT scan proceeds.