What you need to know Contrast Agents about…

Although bones show up clearly on contrast agents are harmlessly absorbed One of the most commonly used x-ray images, some other organs and by the body; others are excreted contrast agents is barium sulfate. tissues do not. Contrast agents, also through the urine or bowel movements. Barium blocks the passage of x-rays, known as contrast media, often are Contrast agents are not dyes; they do so barium-filled organs stand out used during medical imaging not permanently discolor internal better on x-ray exams. For an examinations to highlight specific organs. Instead, they temporarily examination of the esophagus or parts of the body and make them change the way x-rays or other imaging stomach, patients are asked to drink a easier to see. Contrast agents can be tools interact with your body. mixture of barium sulfate and water, used with many types of imaging If the exam your physician sometimes with vanilla or fruit examinations, including x-ray exams, requested for you requires a contrast flavoring added. This mixture usually computed tomography scans and agent, a radiologic technologist will is thick and white. magnetic resonance imaging. explain how it is used before the exam For an examination of the rectum or Contrast agents are administered in begins. Radiologic technologists are colon, barium is administered rectally different ways: Some are given as a skilled health professionals who have through an enema tube. After the exam drink, others are injected or delivered specialized education in the safe use of is finished, you can go to the bathroom through an intravenous line or an contrast agents as well as in radiation and expel the barium. It is a good idea enema. After the examination, some protection, radiographic positioning to increase your fluid intake after the and procedures. exam to help remove the contrast from The technologist your body. Your bowel movements may will answer any be white for a few days. questions you have Contrast agents containing iodine about the are used to image the gallbladder, examination or the urinary tract, blood vessels, spleen, liver contrast agent. and bile duct. Iodine contrast agents Some contrast are clear liquids and usually are agents carry a injected. Patients who are allergic to small risk of iodine should not receive this type of allergic reaction, so contrast agent. Be sure to tell the it is important to technologist which medications you are tell the radiologic taking and your current medical technologist who conditions before the exam begins. will perform your Some conditions and medications make examination if you the use of iodine contrast agents riskier. have any type of You may notice side effects allergy. Also, if you associated with the use of iodine- notice any unusual containing contrast agents. These or uncomfortable include a feeling of warmth or symptoms during flushing, a metallic taste in the mouth, the examination, light headedness, nausea, itching and be sure to tell the hives. Usually, these symptoms are technologist. It is mild and disappear quickly. However, his or her job to it is a good idea to tell the radiologic make you as technologist if you experience any of comfortable as them. In extremely rare instances, possible while these side effects can be serious. The An -ray film showing the large intestinge filled with barium, a obtaining the best technologist will monitor you carefully common contrast agent. image possible. for signs of side effects.

This patient education page provides general information concerning the radiologic sciences. The ASRT suggests that you consult your physician for specific information concerning your imaging exam and medical condition. Health care professionals may reproduce these pages for noncommercial educational purposes. Reproduction for other reasons is subject to ASRT approval.

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