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The administration of radiological contrast by three methods, typically orally, rectally, and intravenously.
See also: contrast
radiographically the degree of perceptible difference between two color tones. Black and white images on the one film is said to be high contrast; an all gray film has low or nil contrast.
contrast agents are used for injection into the vascular system for either a local visualization of a system or organ or for outlining an excretory system. Radiolucent (negative) contrast media are gases such as air, oxygen or carbon dioxide. The radiopaque (positive) contrast media include the insoluble salt barium sulfate and a variety of organic iodine compounds.
Barium is used for gastrointestinal studies. Water-soluble, iodinated contrast media excreted by the kidneys are used for many procedures, including all types of angiography and for intravenous and retrograde urography. Those excreted by the liver are used for oral or intravenous cholangiography or cholecystography. New, nonirritant iodine compounds have been developed for myelography. Oily iodinated media are used for lymphangiography and bronchography.
the use of two contrast agents or two routes of administration in the one patient. For example, radiopaque dye and then air in the urinary bladder.
see contrast agents (above).
a substance used in radiography to permit visualization of internal body structures. Called also contrast agent, contrast material.
a contrast material that is not radiopaque such as air or carbon dioxide.
the pattern made by the contrast agent. Includes confined extension patterns in diverticula and similar confined spaces, and unconfined extensions, e.g. in bladder rupture.
the use of a contrast material that is radiopaque such as barium sulfate and iodinated products.
the use of three contrast media or routes in the one patient at the one time.
water-soluble contrast agents
agents used for injection into the vascular system for either a local visualization of a system or organ or for outlining an excretory system. In the past these have consisted mostly of iodine preparations which are irritant and cause tissue damage so that they must be injected intravenously. However, there are now available some recently developed water-soluble iodine preparations that are nonirritant and which can be used in myelography. See also contrast.