MOdule 7

  1. Increased chemical concentration in a film/screen processor can cause increased density on a radiographic film.  
    • True
    • Increased chemical concentration over-processes the image and increases radiographic density.
  2. Increased filtration increases radiographic density.
    • False
    • Increased filtration results in more attenuation of the primary beam and decreased radiographic density.
  3. Low kVp causes excessively high radiographic contrast.
    • True
    • Low kVp weakens the x-ray beam, which causes the body to absorb more x-ray photons and leads to increased contrast. 
  4. The increased scatter that reaches the image receptor also increases contrast.  
    • False
    • Increased scatter degrades radiographic contrast by decreasing the different densities in an image.
  5. Motion is the largest contributing factor to blur in radiographic images.  
    • True
    • Although geometric factors cause blur in images ─ motion, particularly patient movements, is a major cause of blurring in radiographic images.
  6. A decrease in radiation intensity always causes increased image brightness in a digital image
    • False
    • Increased image brightness is almost always the result of a processing error.
  7. When collimation fields are not recognized, a rescaling error may occur and cause the image to display improperly.
    • True
    • One way to determine whether the collimation borders have been recognized is to assess the unexposed areas of the image. If they are pure white, then the borders were recognized.
  8. An image that doesn't display with the correct brightness must be repeated.
    • False:
    • Sometimes the image can be reprocessed to correct the processing errors and properly display the image. This prevents exposing the patient to additional radiation
  9. Geometric factors are the most common reason for image blur.
    • False
    • The major cause of image blur is usually patient motion.
  10. Motion is difficult to see on a technologist's workstation monitor.

    Motion is often difficult to see on the monitors used by technologists,but easier to see on the radiologists' higher quality monitors. Therefore, technologists should magnify images and examine them for motion before they are sent to be interpreted.
  11. Everything possible should be done to limit image distortion.
    • False:
    • Sometimes distortion is necessary in order to see specific anatomy or to project an anatomic structure free of superimposition
  12. Noise in a digital image can generally be reduced by increasing the intensity of an x-ray beam.
    • True
    • Noise is the result of too little signal reaching the image receptor. This can usually be improved by increasing the intensity of the x-ray beam.
  13. Exposure indicators only change when the intensity received by the image receptor changes.
    • False
    • Exposure indicators will also change due to exposure field recognition errors, unexpected structures in the exposure field, and excessive scatter.
  14. Most artifacts caused by dirt and dust are found in cassetteless rather than cassette-based image receptors.
    • False
    • Cassette-based image receptors are removed for processing and have a better chance of picking up dust and dirt.
  15. Individual DELs or rows of DELs can be replaced when they fail.
    • False:
    • The entire panel must be replaced when a single DEL or a row of DELs fail and produce an artifact on the image.
  16. Most artifacts appear bright or white on a digital image.
    • True
    • Most digital artifacts occur when the signal is prevented from reaching the processing unit.
Card Set
MOdule 7