contrast medium

= contrast agent
a substance administered to enhance the visibility of structures (i.e. increase the contrast) during imaging. In radiography a positive contrast agent (e.g. barium sulphate or a water-soluble iodine-containing compound) increases the density of a structure. Gas is a negative contrast agent. Positive and negative contrast media can be used together (e.g. barium sulphate and gas in a double-contrast barium enema). Magnetic resonance (MR) contrast agents contain either a positive contrast atom (usually gadolinium) to increase the signal or a negative contrast atom (such as iron) to decrease it. Ultrasound contrast medium consists of tiny (1–10 μm diameter) bubbles of gas, which reflect back the sound waves strongly. They can also be made to resonate or rupture to increase the signal to the ultrasound probe.

The new mediacal dictionary. 2014.

Look at other dictionaries:

  • contrast medium — n a substance (as a solution of iodine or suspension of barium sulfate) comparatively opaque to X rays that is introduced into the body (as by injection or swallowing) to contrast an internal part (as the gastrointestinal tract, kidneys, or blood …   Medical dictionary

  • Contrast medium — A medical contrast medium (or contrast agent) is a substance used to enhance the contrast of structures or fluids within the body in medical imaging.[1] It is commonly used to enhance the visibility of blood vessels and the gastrointestinal tract …   Wikipedia

  • contrast medium — Med. a radiopaque substance injected into a part of the body, as the stomach or duodenum, to provide a contrasting background for the tissues in an x ray or fluoroscopic examination. [1950 55] * * * Substance comparatively opaque to X rays, which …   Universalium

  • contrast medium — noun a substance that is opaque to x rays; when administered it allows a radiologist to examine the organ or tissue it fills • Syn: ↑contrast material • Hypernyms: ↑medium …   Useful english dictionary

  • contrast medium — noun Any substance, such as barium sulfate, used in radiography to increase the visibility of internal structures …   Wiktionary

  • contrast medium — noun Medicine a substance introduced into a part of the body in order to improve the visibility of internal structures during radiography …   English new terms dictionary

  • contrast medium — con′trast me dium n. med a radiopaque substance introduced into a part of the body to provide a contrasting background for the tissues in an x ray examination • Etymology: 1950–55 …   From formal English to slang

  • Вещество Контрастное (Contrast Medium) — любое вещество, применяемое для улучшения видимости структур организма во время проведения рентгенологического обследования. Барий, принимаемый внутрь или вводимый клизмой и позволяющий увидеть на рентгенограмме пищеварительный тракт, является… …   Медицинские термины

  • contrast agent — contrast medium …   The new mediacal dictionary

  • Contrast-enhanced ultrasound — (CEUS) is the application of ultrasound contrast medium to traditional medical sonography. Ultrasound contrast agents rely on the different ways in which sound waves are reflected from interfaces between substances. This may be the surface of a… …   Wikipedia

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