X-ray Equipment   The X-ray machine          Grids   Film and cassettes       Processing
X-ray FilmTypes of filmHandling of filmChoosing film   Depends on size, subject, machine
X-ray FilmPurpose:    provides permanent record of x-ray image   Fluoroscopy/ultrasound traditionally transient   Newer ...
X-ray FilmComposed of silver halide crystals onplastic sheetCrystals interact with:   Ionizing radiation (including x-ray...
X-ray FilmComposition   Similar to photographic film   Silver halide emulsion on both sides of    polyester base   Most...
X-ray FilmLatent image   Formed by absorption of light photon by    silver halide crystal   Energy of photon dislodges a...
X-ray FilmLatent image formation   Br > Br+ e-   e- attracts Ag +   Ag+ Ag+ > Ag atoms
X-ray Film CharacteristicsFilm density   Measure of film blackening   Equals log of incident light intensity    divided ...
X-ray Film CharacteristicsFilm contrast   Difference between two densities on a    radiograph
X-ray Film CharacteristicsFilm contrast   Dependant upon:     Characteristic curve of the film       Film gamma refers t...
X-ray Film CharacteristicsFilm gamma refersto steepest part ofcurve
X-ray Film CharacteristicsFilm contrast   Dependant upon:     Film density
X-ray Film CharacteristicsFilm contrast   Dependant upon:     X-ray exposure       Higher kVp = greater gamma =        l...
X-ray Film Characteristics                        High kVpHigher kVp =greater gamma =low contrast(more visibleshades of gr...
X-ray Film CharacteristicsFilm contrast   Dependant upon:     Film processing       Longer developing times = lower     ...
X-ray Film CharacteristicsFilm latitude   Exposure range that produces    acceptable densities (0.25-2.0)
X-ray Film CharacteristicsFilm speed   Fast films      Larger crystals      Require less exposure      Produces a grainie...
X-ray Film CharacteristicsFilm speed   Slow films      Smaller crystals      Require greater exposure      Higher definit...
X-ray Film CharacteristicsFilm speed   Based upon size of    silver halide    crystals
X-ray Film TypesTwo general types   Non-screen film   Screen film
X-ray Film TypesNon-screen film   More sensitive to ionizing radiation      Allows for finer detail      Requires more ex...
X-ray Film TypesScreen film   Crystals also sensitive to fluorescent light    from intensifying screens   Less sensitive...
X-ray Film TypesScreen film   Blue sensitive film      Film responds to ultra-violet, violet and blue light      emitted ...
X-ray Film Types   Blue and green screen can be used with    either blue or green sensitive film      But most efficient ...
X-ray Film TypesScreen film   Standard silver halide crystals absorb violet to    blue light   “Ortho” film      Thin la...
X-ray Film TypesScreen film   Crossover or punch-    through effect      Decreased detail of      radiograph due to      ...
X-ray FilmCommon sizes   14 x14   14 x17   7 x17   8 x 10   10 x 12   11 x 14
Intensifying screensThin cleanable sheet of phosphor crystalswhich lies adjacent to the film within thecassettePurpose:  ...
Intensifying screens4 layers of a screen   Base      Substrate for phosphor crystals   Reflecting layer      To reflect ...
Intensifying screens
Intensifying screens   Intensification factor      Direct film requires roughly 34 times more      exposure than screen f...
Intensifying screens   Screen speed     Larger crystal = faster screen = more grainy     Thicker phosphor layer = faster ...
Intensifying screens   Phosphor layer      Calcium tungstate and barium lead sulfate      emit blue light      Rare earth...
Film holdersCassettes   Must be rigid, durable, light-proof and    transparent to x-rays on at least one face   Provide ...
Cassettes
Film holdersCardboard or light-proof paper   Use for non screen films   Light-weight   Low/no maintenance
Manual Film ProcessingDark room   Must be light-proof      Tight seal of door      Stray light may fog film   Must be no...
Manual Film Processing   Dry area      Film storage          Use lightproof cabinet      Cassette loading      Safelight...
Manual Film Processing   Wet area     Solution tanks     Sink     Viewer     Hangers
Manual Film Processing
Manual Film ProcessingDeveloping   Developer solution reduces silver bromide    crystals to black metallic silver
Manual Film ProcessingDeveloping   Chemical process dependant upon time and    temperature      Ideally 5 minutes in deve...
Manual Film ProcessingRinse bath   Water   About 30 seconds
Manual Film ProcessingFixer   Converts undeveloped silver bromide crystals    into a solution that is washed away      Bl...
Manual Film ProcessingMinimum fixing time   Determined by change in film appearance    from cloudy to clear (clearing time)
Manual Film ProcessingAfter clearing, film should be left in fortwice that amount of time   Ex. 2 minutes to clear = keep...
Manual Film ProcessingWashing   Removes residual silver and fixer   20 minutes if water changes 10 times per hour
Manual Film ProcessingDrying   Perform in clean cabinet      Avoid dust artifacts, water spots
Automatic Film ProcessingBenefits   Compact size   Faster   More consistent   Time and temperature controlled   Produ...
Film ProcessingSolutions need to be specially disposeddue to contents   Treated as hazardous waste in many    including C...
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03 xray film etc

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03 xray film etc

  1. 1. X-ray Equipment The X-ray machine Grids Film and cassettes Processing
  2. 2. X-ray FilmTypes of filmHandling of filmChoosing film Depends on size, subject, machine
  3. 3. X-ray FilmPurpose: provides permanent record of x-ray image Fluoroscopy/ultrasound traditionally transient Newer technology allows video capture
  4. 4. X-ray FilmComposed of silver halide crystals onplastic sheetCrystals interact with: Ionizing radiation (including x-rays) Visible light Pressure Bending Moisture
  5. 5. X-ray FilmComposition Similar to photographic film Silver halide emulsion on both sides of polyester base Most film bases are blue tinted Pleasing to the eye
  6. 6. X-ray FilmLatent image Formed by absorption of light photon by silver halide crystal Energy of photon dislodges an electron The electron causes positively charges silver ions to join into a silver atom
  7. 7. X-ray FilmLatent image formation Br > Br+ e- e- attracts Ag + Ag+ Ag+ > Ag atoms
  8. 8. X-ray Film CharacteristicsFilm density Measure of film blackening Equals log of incident light intensity divided by transmitted light intensity
  9. 9. X-ray Film CharacteristicsFilm contrast Difference between two densities on a radiograph
  10. 10. X-ray Film CharacteristicsFilm contrast Dependant upon: Characteristic curve of the film  Film gamma refers to steepest part of curve
  11. 11. X-ray Film CharacteristicsFilm gamma refersto steepest part ofcurve
  12. 12. X-ray Film CharacteristicsFilm contrast Dependant upon: Film density
  13. 13. X-ray Film CharacteristicsFilm contrast Dependant upon: X-ray exposure  Higher kVp = greater gamma = lower contrast (more visible shades of gray, smaller steps between grays)
  14. 14. X-ray Film Characteristics High kVpHigher kVp =greater gamma =low contrast(more visibleshades of gray,smaller steps)
  15. 15. X-ray Film CharacteristicsFilm contrast Dependant upon: Film processing  Longer developing times = lower gamma = less contrast
  16. 16. X-ray Film CharacteristicsFilm latitude Exposure range that produces acceptable densities (0.25-2.0)
  17. 17. X-ray Film CharacteristicsFilm speed Fast films Larger crystals Require less exposure Produces a grainier image Less latitude
  18. 18. X-ray Film CharacteristicsFilm speed Slow films Smaller crystals Require greater exposure Higher definition image/less grainy Greater latitude
  19. 19. X-ray Film CharacteristicsFilm speed Based upon size of silver halide crystals
  20. 20. X-ray Film TypesTwo general types Non-screen film Screen film
  21. 21. X-ray Film TypesNon-screen film More sensitive to ionizing radiation Allows for finer detail Requires more exposure Requires thicker emulsion and thus manual processing  Ex.: dental films
  22. 22. X-ray Film TypesScreen film Crystals also sensitive to fluorescent light from intensifying screens Less sensitive to direct ionizing radiation Benefits Less exposure Drawbacks Loss of image definition
  23. 23. X-ray Film TypesScreen film Blue sensitive film Film responds to ultra-violet, violet and blue light emitted from screen Green sensitive film Respond to screens that emit 60% green and 25% blues Relatively newer technology using rare earth phosphors
  24. 24. X-ray Film Types Blue and green screen can be used with either blue or green sensitive film But most efficient if film is sensitive to light emitted by screen
  25. 25. X-ray Film TypesScreen film Standard silver halide crystals absorb violet to blue light “Ortho” film Thin layer of green absorbing dye transfers energy to silver halide crystals Therefore extends sensitivity of film into green wavelengths “Pan” film Red absorbing dye
  26. 26. X-ray Film TypesScreen film Crossover or punch- through effect Decreased detail of radiograph due to additional exposure to light from screen on opposite side
  27. 27. X-ray FilmCommon sizes 14 x14 14 x17 7 x17 8 x 10 10 x 12 11 x 14
  28. 28. Intensifying screensThin cleanable sheet of phosphor crystalswhich lies adjacent to the film within thecassettePurpose: To decrease amount of radiation required for a diagnostic radiograph Able to use lower mAs (faster exposure)
  29. 29. Intensifying screens4 layers of a screen Base Substrate for phosphor crystals Reflecting layer To reflect light back toward film Phosphor layer Must be uniform and flexible (to avoid cracking) Protective coating
  30. 30. Intensifying screens
  31. 31. Intensifying screens Intensification factor Direct film requires roughly 34 times more exposure than screen film A 0.1 second exposure on screen film would require 3.4 seconds on non-screen film
  32. 32. Intensifying screens Screen speed Larger crystal = faster screen = more grainy Thicker phosphor layer = faster screen = decreased detail
  33. 33. Intensifying screens Phosphor layer Calcium tungstate and barium lead sulfate emit blue light Rare earth screens more green light emitted Extremely important to keep screens clean and undamaged
  34. 34. Film holdersCassettes Must be rigid, durable, light-proof and transparent to x-rays on at least one face Provide housing for intensifying screens and film Must be maintained well
  35. 35. Cassettes
  36. 36. Film holdersCardboard or light-proof paper Use for non screen films Light-weight Low/no maintenance
  37. 37. Manual Film ProcessingDark room Must be light-proof Tight seal of door Stray light may fog film Must be not be exposed to radiation Adjacent x-ray machine may cause fogging of film
  38. 38. Manual Film Processing Dry area Film storage  Use lightproof cabinet Cassette loading Safelight  Must be of visible spectrum that will not fog film  Red part of spectrum
  39. 39. Manual Film Processing Wet area Solution tanks Sink Viewer Hangers
  40. 40. Manual Film Processing
  41. 41. Manual Film ProcessingDeveloping Developer solution reduces silver bromide crystals to black metallic silver
  42. 42. Manual Film ProcessingDeveloping Chemical process dependant upon time and temperature Ideally 5 minutes in developer tank at 68 degrees Fahrenheit High temperature causes reticulation  Artifact caused by slipping of emulsion layer
  43. 43. Manual Film ProcessingRinse bath Water About 30 seconds
  44. 44. Manual Film ProcessingFixer Converts undeveloped silver bromide crystals into a solution that is washed away Black metallic silver left on film Also hardens film
  45. 45. Manual Film ProcessingMinimum fixing time Determined by change in film appearance from cloudy to clear (clearing time)
  46. 46. Manual Film ProcessingAfter clearing, film should be left in fortwice that amount of time Ex. 2 minutes to clear = keep film in 4 additional minutes Clearing time should not exceed 2-3 minutes
  47. 47. Manual Film ProcessingWashing Removes residual silver and fixer 20 minutes if water changes 10 times per hour
  48. 48. Manual Film ProcessingDrying Perform in clean cabinet Avoid dust artifacts, water spots
  49. 49. Automatic Film ProcessingBenefits Compact size Faster More consistent Time and temperature controlled Produces dry radiograph immediately
  50. 50. Film ProcessingSolutions need to be specially disposeddue to contents Treated as hazardous waste in many including California
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