special subjects
X Rays
Variations of X Rays
X-rays can be done after a Radiopaque Contrast Agents (sometimes inaccurately called dye) is given, usually by injection into a vein, by mouth, or injected through a tube into the rectum. The radiopaque contrast agent makes the tissue or structure being imaged appear more radiopaque (whiter) than surrounding tissues, so that it can be better seen on an x-ray. In Angiography , x-rays are taken after a radiopaque contrast agent is injected into blood vessels. Before x-rays of the gastrointestinal tract, people may be asked to swallow barium or gastrografin (which are radiopaque contrast agents) in a liquid or food. The x-rays then show the esophagus, stomach, and small intestine outlined by the barium or gastrografin. Or, an examiner may inject barium through a tube inserted into the anus (barium enema), then carefully pump air into the lower part of the intestine (colon) to expand it. Barium makes ulcers, tumors, blockages, polyps, and diverticulitis easier to detect. A barium enema may cause mild to moderate crampy pain and an urge to defecate. For imaging of the esophagus, stomach, and upper intestinal tract, Endoscopy has largely replaced x-rays taken after barium or gastrografin is used. Fluoroscopy uses continuous x-ray images to show motion, similar to those of a video camera. Fluoroscopy can show organs or structures as they function: the heart beating, the intestines moving food along, or the lungs inflating and deflating. Fluoroscopy is commonly used During Electrophysiologic Testing (for abnormal heart rhythms) and during With a radiopaque contrast agent (such as barium), usually given by mouth, to evaluate the gastrointestinal tract During evaluation of musculoskeletal injuries to observe movement of bones and joints 