Double-contrast barium enema Double-contrast barium enema A double-contrast barium enema is a form of contrast radiography in which x-rays of the colon and rectum are taken using two forms of contrast to make the structures easier to see. A liquid containing barium (that is, a radiocontrast agent) is put into the rectum. Barium is a silver-white metallic compound that outlines the colon and rectum on an x-ray and helps show abnormalities. Air is also put into the rectum and colon to further enhance the x-ray. Double-contrast barium enemas are less invasive than a colonoscopy and have comparatively fewer issues in a viable large
Period 5 element corrosion-resistant tin plating of steel. Because of its low toxicity, tin-plated metal is also used for food packaging, giving the name to tin cans, which are made mostly of steel. Antimony () is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite (SbS). Antimony compounds have been known since ancient times and were used for cosmetics, metallic antimony was also known but mostly identified as lead. For some time China has been the largest producer of antimony and its compounds,