Fluoroscopy is an imaging technique that renders real-time "live" images of the internal structures of a patient through the use of a fluoroscope. A fluoroscope consists of an x-ray source and a fluorescent screen between which a patient is placed. The fluorescent screen is linked to an image intensifier and a video camera which allows the images to be played and recorded on a monitor.

Fluoroscopy is used in many types of examinations and procedures, such as barium x-rays, cardiac catheterization, and placement of intravenous (IV) catheters (hollow tubes inserted into veins or arteries). In barium x-rays, fluoroscopy allows the physician to see the movement of the intestines as the barium moves through them. In cardiac catheterization, fluoroscopy enables the physician to see the flow of blood through the coronary arteries in order to evaluate the presence of arterial blockages. For intravenous catheter insertion, fluoroscopy assists the physician in guiding the catheter into a specific location inside the body.