Contrast
Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.
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1. A comparison in which differences are demonstrated or enhanced. 2. In radiology, the difference between the image densities of two areas is the c. between them; this is a function of the number of x-ray photons transmitted or the strength of the signals emitted by the two regions and the response of the recording medium. [L. contra, against, + sto, pp. status, to stand]
- simultaneous c. the enhancement of the visual sensation of white when a white object is viewed adjacent to a black object; the black object also appears blacker as a result of the contiguity of white. Adjacent complementary colors also appear brighter; e.g., green appears a brighter green and red a brighter red if these two colors are viewed side by side.
- successive c. the visual effect caused by viewing a brightly colored object and then a gray surface; the latter appears tinged with the complementary color of the object. Viewing a surface colored in the complementary color of the object rather than in gray enhances the color intensity of the surface.

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n.
1. short for contrast medium, e.g. post-contrast CT scan.
2. the difference in the shade of grey between different tissues on a diagnostic image, such as radiograph or CT scan (see grey scale).

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con·trast (konґtrast) [contra- + L. stare to stand] 1. the degree to which light and dark areas of an image differ in brightness or in optical density. 2. in radiology, the difference in optical density in a radiograph that results from a difference in radiolucency or penetrability of the subject. Called also radiocontrast.

Medical dictionary. 2011.

Synonyms:

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  • Contrast — may refer to: Contrast (vision), the difference in color and light between parts of an image Contrast (linguistics), expressing distinctions between words Contrast (statistics), a combination of averages whose coefficients add up to zero, or the… …   Wikipedia

  • contrast — 1. Contrast is pronounced with stress on the first syllable as a noun and on the second syllable as a verb. 2. In current use, the verb is normally constructed with with or and, and is used transitively and intransitively: • Data is sometimes… …   Modern English usage

  • contrast — CONTRÁST, contraste, s.n. 1. Opoziţie puternică între două sau mai multe lucruri, stări, acţiuni etc. 2. Diferenţa dintre înnegrirea maximă şi cea minimă a unei imagini fotografice. ♢ Contrastul imaginii = mărime caracteristică pentru variaţia… …   Dicționar Român

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  • Contrast — Con*trast , v. t. 1. To set in opposition, or over against, in order to show the differences between, or the comparative excellences and defects of; to compare by difference or contrariety of qualities; as, to contrast the present with the past.… …   The Collaborative International Dictionary of English

  • Contrast — Con*trast , v. i. [imp. & p. p. {Contrasted}; p. pr. & vb. n. {Contrasting}.] [F. contraster, LL. contrastare to resist, withstand, fr. L. contra + stare to stand. See {Stand}.] To stand in opposition; to exhibit difference, unlikeness, or… …   The Collaborative International Dictionary of English

  • Contrast — Con trast (k[o^]n tr[.a]st), n. [F. contraste: cf. It. contrasto.] 1. The act of contrasting, or the state of being contrasted; comparison by contrariety of qualities. [1913 Webster] place the prospect of the soul In sober contrast with reality.… …   The Collaborative International Dictionary of English

  • Contrast — Contrast, das Abstechende, der Abstich, ist nicht reiner Gegensatz, sondern das Nebeneinanderstellen mehrerer Gegenstände zum Zwecke der Vergleichung, des Hervorhebens Eines oder des Andern. Häßlich ist z. B. der Contrast von schön; wird nun ein… …   Damen Conversations Lexikon

  • contrast — n *comparison, collation, parallel, antithesis Analogous words: distinction, difference, divergence, divergency, *dis similarity, unlikeness: conflict, *discord contrast vb *compare, collate …   New Dictionary of Synonyms

  • contrast — [n] difference adverse, antithesis, comparison, contradiction, contradistinction, contraposition, contrariety, converse, differentiation, disagreement, disparity, dissimilarity, dissimilitude, distinction, divergence, diversity, foil,… …   New thesaurus

  • contrast — [kən trast′; ] for n. [ kän′trast΄] vt. [Fr contraster < It & VL * contrastare, to withstand < L contra, against + stare, to STAND] to compare so as to point out the differences; set off against one another vi. to show differences when… …   English World dictionary

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