A barium enema is an x-ray examination of the colon and rectum to find abnormalities such as polyps, diverticulosis, cancer, or inflammatory disease.
Liquid barium is administered through a small tube inserted into the rectum. In case of an air-contrast or double-contrast barium enema, the added air improves the evaluation of the lining of the large intestine.
Barium enemas require a bowel preparation with laxatives, starting one day before the examination.

See also Colonoscopy and Virtual Colonoscopy.

The company is developing and making specialized medicines for treating multiple sclerosis, dermatological disorders, female health concerns, cancer and is creating new diagnostic imaging techniques. Berlex, Inc. is a pioneer in the imaging market. It has introduced a broad range of imaging agents. Its contribution began in 1988 with the introduction of the world's first magnetic resonance imaging agent, Magnevist® (gadopentetate dimeglumine) injection. Berlex is headquartered in New Jersey and the U.S. affiliate of Bayer Schering Pharma AG, Germany.

Henri Becquerel demonstrated beta particles in 1900. Identical with electrons is there negative charge at -1. Their mass is 549 millionths of one AMU, 1/2000 of the mass of a proton or neutron. Beta particles consist of high energetic electrons emitted by radioactive nuclei or neutrons. By the process of beta decay, one of the neutrons in the nucleus is transformed into a proton and a new atom is formed which has one less neutron but one more proton in the core. Beta decay is accompanied by the emission of a positron (the antiparticle of the electron), a positive charged antineutrino. Beta particles have a greater range of penetration than alpha particles but less than gamma rays or x-rays. The name beta was coined by Rutherford in 1897. The traveling speed of beta particles depends on their energy. Because of their small mass and charge beta particles travel deep into tissues and cause cellular damage and possible cancer.

See also Radiation Shielding.

The molecular structure of some iodinated contrast agents makes them suitable for the computer-tomographic examination of the biliary tract. Organic iodine compounds increase the attenuation of x-rays and the contrast between body tissues containing iodine and those tissues that do not contain iodine. The degree of opacification is directly proportional to the concentration and volume of the iodinated contrast agent (the total amount of iodine).
Biliary contrast agents can be taken orally, for example calcium iopodate, or intravenous meglumine iotroxate. The contrast media are excreted by the liver and concentrate in the gallbladder after passing the intrahepatic biliary tree and cystic duct.
Oral biliary contrast agents usually opacify the gallbladder after a few hours. If the gallbladder is removed, an intravenous cholegraphic agent is required and gallbladder CT can start 60 minutes after the beginning of contrast medium infusion.
The main limitation of the use of biliary contrast agents is the high rate of allergic reactions and of renal or hepatic toxicity. Caused by the potential for systemic toxicity with intravenous cholangiography, ultrasonography should be the preferred method for evaluation of the gallbladder and the bile ducts.

Biliscopin® Infusion, an iodinated contrast medium for intravenous cholecystography is secreted actively by the hepatocytes. The biliary excretion rate of a biliary contrast medium is determined by the binding to plasma proteins and liver receptor proteins, and by its transport maximum for the liver. Because of its high hepatocellular transport rate, Biliscopin® Infusion leads rapidly to high grade contrast density in the intra-hepatic and extra-hepatic biliary ducts as well as in the gallbladder.
Computed tomography with biliary contrast agents provides maximum quality preoperative imaging of the biliary tract.