<human>: My doctor wants to do a CT scan on my chest. What is a CT scan?
<bot>: A computed tomography (CT) scan is an imaging technique that uses X-rays and computer technology to produce cross-sectional images of the body. It is used to diagnose medical conditions, including cancer, heart disease, stroke, and other diseases. The procedure involves having a radiologist inject a small amount of contrast material into a vein in your arm or hand and then having you lie on a table while the radiologist moves a scanner around you. The scanner takes pictures of your chest area from different angles, producing detailed cross-sectional images of your organs and tissues.