contrast medium


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Related to contrast medium: contrast material, contrast agent

medium

 [me´de-um] (pl. mediums, me´dia) (L.)
1. an agent by which something is accomplished or an impulse is transmitted.
3. a preparation used in treating histologic specimens.
contrast medium a radiopaque substance used in radiography to permit visualization of body structures. Called also contrast agent.
culture medium a substance or preparation used to support the growth of microorganisms or other cells; called also medium.
dioptric media refracting media.
disperse medium dispersive m.
dispersion medium dispersive m.
dispersive medium the continuous phase of a colloid system; the medium in which the particles of the disperse phase are distributed, corresponding to the solvent in a true solution.
refracting media the transparent tissues and fluid in the eye through which light rays pass and by which they are refracted and brought to a focus on the retina.

con·trast me·di·um

any internally administered substance that has a different opacity from soft tissue on radiography or computed tomography; includes barium, used to opacify parts of the gastrointestinal tract; water-soluble iodinated compounds, used to opacify blood vessels or the genitourinary tract; may refer to air occurring naturally or introduced into the body; also, paramagnetic substances used in magnetic resonance imaging.

contrast medium

n.
A substance, such as barium or air, used in radiography to increase the contrast of an image. A positive contrast medium absorbs x-rays more strongly than the tissue or structure being examined; a negative contrast medium, less strongly.

contrast medium

a substance that is injected into the body, introduced via catheter, or swallowed to facilitate radiographic imaging of internal structures that otherwise are difficult to visualize on x-ray films. Contrast media may be either radiopaque or radiolucent. Also called contrast agent.

contrast medium

Contrast, contrast agent Imaging A substance with a density–eg, a dye or signal differing from that of the organ or structure being imaged, which allows delineation of contour abnormalities; CMs that are more radiopaque–eg with barium or iodine—than the organ or structure being analyzed are known as positive CM, while those that are less radiopaque–eg, with air, are known as negative CM. See Radiopaque contrast.

con·trast me·di·um

(kon'trast mē'dē-ŭm)
Any internally administered substance that has a different opacity from soft tissue on radiography or computed tomography; used to opacify parts of the gastrointestinal tract, blood vessels, or the genitourinary tract.

contrast medium

Any substance offering greater resistance to the passage of X rays than soft tissues that can be introduced into a hollow organ so as to outline its interior during radiology. Contrast media include a suspension of a barium salt for the intestine (barium meal or enema) and iodine-containing fluids for the blood vessels and urinary tract.

Contrast medium

A chemical substance used to make an organ or body part opaque on x ray.
Mentioned in: Hysterosonography

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
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.
double contrast
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.
contrast materials
see contrast agents (above).
contrast medium
a substance used in radiography to permit visualization of internal body structures. Called also contrast agent, contrast material.
negative contrast
a contrast material that is not radiopaque such as air or carbon dioxide.
contrast pattern
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.
positive contrast
the use of a contrast material that is radiopaque such as barium sulfate and iodinated products.
triple contrast
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.

medium

pl. media, mediums [L.]
1. an agent by which something is accomplished or an impulse is transmitted.
2. a substance providing the proper nutritional environment for the growth of microorganisms; called also culture medium.

basic nutritive medium
one adequate for the growth requirements of most bacteria.
contrast medium
a radiopaque (positive) substance, or (negative) gases used in radiography to permit visualization of body structures.
culture medium
a substance used to support the growth of microorganisms or other cells.
dioptric medium
refracting medium (see below).
disperse medium, dispersion medium
the continuous phase of a colloid system; the medium in which a colloid is dispersed, corresponding to the solvent in a true solution.
enriched medium
modification of a basic medium for the growth of fastidious bacteria. Common additions are blood, serum or egg yolk.
indicator medium
a type of bacteriological medium which may contain a fermentable sugar plus a pH indicator that gives a color change. It is used to identify bacteria on the basis of a characteristic biochemical reaction.
refracting medium
the transparent tissues and fluid in the eye through which light rays pass and by which they are refracted and brought to a focus on the retina.
medium sausage
a technique for examining meat for bacterial contamination. The solid medium is made up in the form of a sausage and slices are removed from it after application of the exposed end to the suspect meat.
selective medium
formulated to facilitate the isolation of specific bacteria, they contain substances to inhibit growth of others.
transport medium
formulated to preserve a specimen, usually tissue or microbiological swab, and minimize bacterial overgrowth for the time necessary to transport it to the laboratory.

Patient discussion about contrast medium

Q. Has anyone had an allergic reaction to gadolinium dye, MRI contrast agents, I have had a severe reaction. I would like to know the long term effects of this dye. And if anyone else has had or heard of problems and reactions to it. Please answer me. Thank you

A. In 1969 I almost died from the IVP dye. I had no idea I was allergic and when I awoke I was in a "recovery room." The doctor told me to always tell any physicians/paramedics etc of my allergy status regarding the dye. I now have chronic back pain, have a history of cancer in the family and the doctor wants to do a scan (including dye) but when I emphasized that I was allergic he backed off. Now I am wondering if there is anything else that can be done to test the bone (scan) without the dye. Any answers? Thanks

More discussions about contrast medium
References in periodicals archive ?
All patients received the same amount of the same contrast medium thus avoiding variability regarding the medium.
36] have demonstrated, by in vivo experiments in rats, that the decrease in cortical and medullary microvascular blood flow induced by a contrast medium is partly accounted for by the downregulation of endogenous renal cortical and medullary NO synthesis.
Pulmonary and oil embolism after hysterosalpingography with oil soluble contrast medium.
In conclusion, our results showed that non ionic low osmolar contrast medium administration led to an increase in MDA levels indicating accelerated oxidant reactions, and a decrease in NO levels in rat kidney tissues.
An evaluation of myelography with non-ionic water-soluble contrast medium iohexol.
If a contrast medium is used, the radiologist or technologist will inject it into a vein, probably in your arm.
Neonatal thyroid function: effect of a single exposure to iodinated contrast medium in utero.
In a retrospective study analyzing 11,588 patients who underwent either CT without contrast or CT with a low-osmolar contrast medium (iohexol) or an iso-osmolar contrast medium (iodixanol), no significant difference in the overall incidence of CIN was observed between the isoosmolar contrast medium and the control groups for all baseline creatinine values.
Then, under a local anaesthetic, a contrast medium is injected.
About 80% to 90% of contrast medium is used for CT and 10% to 20% for cardiac catheterization procedures.