A CT scan uses a narrow beam of x-rays to take a series of pictures of the body from different angles. These pictures are then used to create 2-D and 3-D images of the body’s organs, bones, blood vessels, and soft tissues. 

CT scans can help diagnose diseases and injuries, plan treatments, and monitor the effectiveness of treatments. They can be used to identify conditions such as bone fractures, tumors, pulmonary embolisms, emphysema, and pneumonia. 

During a CT scan, you lie on a table that slides into a doughnut-shaped machine. You may be given a contrast agent to help certain parts of your body show up more clearly. The scan may take a few minutes to over 30 minutes. 

CT scans expose you to ionizing radiation, but the low doses used are not expected to cause long-term harm. However, repeated scans may slightly increase your lifetime risk of cancer.