Here are some common types of artifacts in general radiography:
1. Patient Motion: Patient movement during the exposure can result in blurred or distorted images. Minimizing patient motion through proper immobilization techniques is essential for sharp and accurate images.
2. Grid Cut-off: When using a grid (a device placed in front of the detector to reduce scattered radiation) in chest radiography, portions of the image may appear underexposed if the grid is not properly centered or if the patient's body parts, such as the shoulders, extend out beyond the edge of the grid.
3. Grid Lines: Lead grid lines may be visible in radiographic images and are part of the equipment design to reduce scattered radiation. However, pronounced or misaligned grid lines can sometimes interfere with image interpretation.
4. Cassette Artifacts: Improper handling or damage to the cassette holding the radiographic film or image detector can result in scratches, marks, or lines appearing on the image.
5. Processing Artifacts: Improper processing of radiographic films or poor-quality developing techniques can lead to artifacts such as streaks, spots, or uneven densities.
6. Electrical Interference: Electrical disturbances or fluctuations during the imaging process can cause random lines, dots, or streaks on the image.
7. Radiation Scatter: Scattered radiation, if not adequately controlled, can result in reduced contrast and increased background fog, affecting image quality.
8. Clothing and Jewelry: Metallic buttons, zippers, jewelry, or other objects on or near the patient's body can block the X-ray beam and create shadows or artifacts on the image.
9. Foreign Objects: Any materials or substances not related to the patient's anatomy that may be present during imaging, such as surgical instruments or medical supplies, can create unexpected shadows or superimpositions.
10. Movement of Bowel Gas or Contrast Medium: Movement of gas or contrast agents within the gastrointestinal tract can cause unpredictable patterns or obscured details.
11. Image Distortion: Improper positioning of the X-ray tube or detector can lead to image distortion, where structures may appear elongated or compressed.
12. Over- or Under-Exposure: Improper exposure settings can result in too much or too little radiation reaching the detector, leading to either a washed-out or underexposed image.
13. Artifacts from Medical Devices or Implants: Certain medical devices, such as pacemakers or metal plates, can produce characteristic artifacts due to their density and X-ray attenuation properties.
14. Beam Hardening: This occurs when the X-ray beam becomes harder (higher average energy) as it passes through denser tissues, resulting in non-uniform darkening of certain areas of the image.
It is important for radiographers to be familiar with the potential causes of artifacts and take appropriate measures to minimize their impact. Good quality control procedures and regular maintenance of imaging equipment are crucial to reducing artifacts and ensuring accurate diagnostic images.