artifact

1. Anything, especially in a histologic specimen or a graphic record, that is caused by the technique used and not reflecting the original specimen or experiment. 2. A skin lesion produced or perpetuated by self-inflicted action, as in dermatitis artefacta. [L. ars, art, + facio, pp. factus, to make]

- chemical shift a. in magnetic resonance imaging, a dark band caused by a biochemical difference in resonant frequency of adjacent regions rather than a true anatomic separation.

- thermal a. distortion of microscopic structure in a tissue specimen, because of heat generated by the instrument ( e.g., loop electrocautery) used to obtain the specimen.

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ar·ti·fact or chiefly Brit ar·te·fact 'ärt-ə-.fakt n

1) a product of artificial character due to extraneous (as human) agency specif a product or formation in a microscopic preparation of a fixed tissue or cell that is caused by manipulation or reagents and is not indicative of actual structural relationships

2) an electrocardiographic and electroencephalographic wave that arises from sources other than the heart or brain

ar·ti·fac·tu·al or chiefly Brit ar·te·fac·tu·al .ärt-ə-'fak-chə(-wə)l, -'faksh-wəl adj

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(artefact)

n.

1. (in radiography) an appearance on an image reflecting a problem with the radiographic technique rather than representing the true appearance of the patient. For example, a movement artifact is blurring of the image due to movement of the patient or organ during the exposure. All imaging techniques are susceptible to a range of artifacts. See also partial volume artifact.

2. (in microscopy) a structure seen in a tissue under a microscope that is not present in the living tissue. Artifacts, which are produced by faulty fixation or staining of the tissue, may give a false impression that disease or abnormality is present in the tissue when it is not.

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ar·ti·fact (ahrґtĭ-fakt″) [L. ars art + factum made] 1. any artificial product. In histology or microscopy, any structure or feature that has been introduced by processing a tissue. In radiology, a substance or structure not naturally present in living tissue, but of which an authentic image appears in a radiograph. 2. distortion or fuzziness of an image caused by manipulation, such as during compression of a digital file.