IMAGE ARTIFACTS

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IMAGE ARTIFACTS
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What is an ARTIFACT

• Any irregularity on an image that is not
  caused by the proper shadowing of tissue by the
  primary beam.
• an undesirable optical density on radiograph

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How are they produced?

• Exposure
• Processing
• Handling Storage

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ARTIFACT FROM EXPOSURE

• Associated with conducting Exam
• Equipment
• Incorrect film screen match or poor
  contact
• Warped or dirty cassettes
• Grid misalignment
• Patient
• preparation or instruction (motion)
• positioning errors
• technical errors

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DR Exposure Artifacts

• More tolerant of exposure artifacts
• Underexposure causes loss of contrast and grainy
  appearance

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ARTIFACTS FROM PROCESSING

• Pressure marks from transport of film
• produced during processing and will usually
  appear with a higher OD
• Roller Marks
• Dirty Rollers
• Chemical Fog
• Wet-Pressure Sensitization

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ROLLER MARK

• Guide Shoes-mark on leading or trailing edge of
  film, found parallel to the film travel
  direction. Caused by improper positioned guide
  shoes or spring shoes
• pi lines- 3.1416 inch intervals
• dirt and chemical stains

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DIRTY ROLLERS

• Emulsion Pickoff
• Gelatin buildup-
• sludge
• Can appear as sharp positive or negative optical
  density on film

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CHEMICAL FOG

• Improper or Inadequate processing chemistry
• Chemical Fog- uniform dull grey
• Dichoic Stain- 2 colors
• yellow, green, blue, purple
• Curtain Effect-chemistry running up trailing edge
  or down leading edge

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WET PRESSURE SENSITIZATION

• Developer tank
• Irregular or dirty rollers
• Small circular increased optical density

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DR Processing Artifacts

• Electronic rather than chemical
• Artifacts caused by interference with electronic
  components

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HANDLING STORAGE

• Radiation and Light fog
• Rough Handling- kink marks
• Static
• Hypo retention
• Kinks
• Scratches

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ARTIFACTS FROM RADIATION AND LIGHT FOG

• Light leaks
• Safelight
• Radiation
• Heat/humidity
• below 68 degrees
• 40 to 60 humidity

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HANDLING

• Before or After processing
• Kink marks
• Scratches
• Fingerprints
• Darkroom environment
• clean dry surfaces

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STATIC

• Electron buildup on emulsion
• Low humidity
• Crown
• Tree
• Smudge

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HYPO RETENTION

• Hypo - fixing agent
• ammonium thiosulfate
• Improper washing
• Yellowish discoloration to stored
• radiograph

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DR Handling and Storage Artifacts

• Debris on image receptor
• Discoloration of fluorescent screens
• Fogging
• ghost images
• dead detector images