<human>: My doctor wants to do a CT scan on my chest. What is a CT scan?
<bot>: A CT scan is a type of medical imaging test that uses X-rays and computer technology to create cross-sectional images of the body. It can be used to diagnose and treat a variety of conditions, including cancer, heart disease, and neurological problems. The test involves the patient lying still while the machine rotates around them, taking pictures from different angles. The pictures are then combined into a 3D image of the area being scanned.