artifact Artefact A structure not normally present, but produced by some external action something artificial the distortion of a substance or signal, which interferes with or obscures the interpretation of a study, or a structure that is not representative of a specimen's in vivo state, or which does not reflect the original sample, but rather the result of an isolation procedure, its handling or other factors artifacts in electronic readout devices–eg, EEG, EKG, and EMG, may be due to loose leads or electrical contacts Cardiac pacing An electrical impulse of noncardiac origin which is recorded as a vertical spike on an EKG or other ECG monitor–eg a pacemaker pulse electrical signals from muscle contractions, or myopotentials, are called muscle artifacts Imaging The artifact seen depends on the procedure–eg, barium enema, where zones of inconstant segmental contractions of the colon may be confused with organic constrictions or anatomic variations, due to mucosal or intramural tumors, or a metal surgical clip that obscures an anatomical structure. For example, in a barium enema, where zones of inconstant segmental contractions of the colon may be confused with organic constrictions or anatomic variations due to mucosal or intramural tumours, or a metal surgical clip that obscures an anatomical structure. The artefact seen depends on the procedure. Artefacts in electronic readout devices (e.g., EEG, EKG, and EMG) may be due to loose leads or electrical contacts.Īn electrical impulse of noncardiac origin which is recorded as a vertical spike on an EKG or other ECG monitor (e.g., a pacemaker pulse) electrical signals from muscle contractions, or myopotentials, are called muscle artefacts.Īny change in tissue that occurs during tissue processing which may alter a tissue’s appearance and possibly the diagnosis. (2) The distortion of a substance or signal which interferes with or obscures the interpretation of a study, or a structure that is not representative of a specimen’s in vivo state, or which does not reflect the original sample, but rather is the result of an isolation procedure, its handling or other factors. artefact (1) A structure not normally present, but produced by some external action something artificial. However, as the tube ages further, resulting in images with more pronounced artifacts.The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. In the early stages the arcing may be infrequent, and small artifacts begin to appear in the images. The arcing causes a momentary loss of xray output, which contaminates the xray signal collected at the detectors, affecting proper image reconstruction and hence producing artifacts. Once an xray tube starts to arc, a cascade -type effect may occur that sets event in motion that contribute to yet more frequent arcing. Some of the increase may reflect valuation effects due to price and exchange rate movements and some may be an artifact of better measurement but much of it is real largely the result of increased international migration and declining transfer costs. Arcing can also occur through the oil in the xray tube housing. This method of dating organic material in ancient artifacts is based on measurement of the radioactive carbon that is formed by cosmic rays in the atmosphere and taken up by plant life. As an xray tube ages, the tendency to arc often increases owing to such factors as degradation of the vacuum within the tube, which results in increased gas pressure. In a xray tube, arcing can occur through residual gas molecules present within the evacuated envelop of the xray tube. Arcing tends to occur whenever there is a large difference in electrical potential, such as the case between the anode and cathode in an xray tube. This is referred to as either high voltage arcing or tube arcing.

A common cause of equipment induced artifact occurs when there is a undesired surge of electrical current like a short-circuit, within the xray tube.

Measurement artifact meaning