(artefact) n. 1. (in radiography) an appearance on an image that is not a true representation of the patient’s body part. The cause may be a problem with the radiographic technique or something more straightforward. For example, a movement artifact is blurring of the image due to movement of the patient or organ during the exposure. All imaging techniques, including CT and MRI, 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.
an apparent decrease in the visibility of a structure in a *cross-sectional imaging technique, such as CT or MRI, when either the thickness of the object is much less than that of the slice being used to make the image, or the object is only partially imaged within the slice. See artifact.... partial volume artifact