X-ray EquipmentX-ray EquipmentThe X-ray machineThe X-ray machine
GridsGridsFilm and cassettesFilm and cassettes
ProcessingProcessing
X-ray FilmX-ray Film
Types of filmTypes of film
Handling of filmHandling of film
Choosing filmChoosing film Depends on size, subject, machineDepends on size, subject, machine
X-ray FilmX-ray Film
Purpose: Purpose: provides permanent record of x-ray imageprovides permanent record of x-ray image
Fluoroscopy/ultrasound traditionally transientFluoroscopy/ultrasound traditionally transient
Newer technology allows video captureNewer technology allows video capture
X-ray FilmX-ray Film
Composed of silver halide crystals on Composed of silver halide crystals on plastic sheetplastic sheetCrystals interact with:Crystals interact with: Ionizing radiation (including x-rays)Ionizing radiation (including x-rays) Visible lightVisible light PressurePressure BendingBending MoistureMoisture
X-ray FilmX-ray Film
CompositionComposition Similar to photographic filmSimilar to photographic film Silver halide emulsion on both sides of Silver halide emulsion on both sides of
polyester basepolyester base Most film bases are blue tinted Most film bases are blue tinted
Pleasing to the eyePleasing to the eye
X-ray FilmX-ray Film
Latent imageLatent image Formed by absorption of light photon by Formed by absorption of light photon by
silver halide crystalsilver halide crystal Energy of photon dislodges an electronEnergy of photon dislodges an electron The electron causes positively charges The electron causes positively charges
silver ions to join into a silver atomsilver ions to join into a silver atom
X-ray FilmX-ray Film
Latent image formationLatent image formation Br > Br+ e-Br > Br+ e- e- attracts Ag +e- attracts Ag + Ag+ Ag+ > Ag atoms Ag+ Ag+ > Ag atoms
X-ray Film CharacteristicsX-ray Film Characteristics
Film densityFilm density Measure of film blackeningMeasure of film blackening Equals log of incident light intensity Equals log of incident light intensity
divided by transmitted light intensitydivided by transmitted light intensity
X-ray Film CharacteristicsX-ray Film Characteristics
Film contrastFilm contrast Difference between two densities on a Difference between two densities on a
radiographradiograph
X-ray Film CharacteristicsX-ray Film Characteristics
FilmFilm contrastcontrast Dependant upon:Dependant upon:
Characteristic curve of the filmCharacteristic curve of the film Film gamma refers to steepest part of Film gamma refers to steepest part of
curvecurve
X-ray Film CharacteristicsX-ray Film Characteristics
Film gamma refers Film gamma refers to steepest part of to steepest part of curvecurve
X-ray Film CharacteristicsX-ray Film Characteristics
FilmFilm contrastcontrast Dependant upon:Dependant upon:
Film densityFilm density
X-ray Film CharacteristicsX-ray Film Characteristics
Film contrastFilm contrast Dependant upon:Dependant upon:
X-ray exposureX-ray exposure Higher kVp = greater gamma = Higher kVp = greater gamma =
lower contrast (more visible shades lower contrast (more visible shades of gray, smaller steps between of gray, smaller steps between grays)grays)
X-ray Film CharacteristicsX-ray Film Characteristics
Higher kVp = Higher kVp = greater gamma = greater gamma = low contrast low contrast (more visible (more visible shades of gray, shades of gray, smaller steps)smaller steps)
High kVp
X-ray Film CharacteristicsX-ray Film Characteristics
Film contrastFilm contrast Dependant upon:Dependant upon:
Film processingFilm processing Longer developing times = lower Longer developing times = lower
gamma = less contrastgamma = less contrast
X-ray Film CharacteristicsX-ray Film Characteristics
Film latitudeFilm latitude Exposure range that produces Exposure range that produces
acceptable densities (0.25-2.0)acceptable densities (0.25-2.0)
X-ray Film CharacteristicsX-ray Film Characteristics
Film speedFilm speed Fast filmsFast films
Larger crystalsLarger crystals
Require less exposureRequire less exposure
Produces a grainier imageProduces a grainier image
Less latitudeLess latitude
X-ray Film CharacteristicsX-ray Film Characteristics
Film speedFilm speed Slow filmsSlow films
Smaller crystalsSmaller crystals
Require greater exposureRequire greater exposure
Higher definition image/less grainyHigher definition image/less grainy
Greater latitudeGreater latitude
X-ray Film CharacteristicsX-ray Film Characteristics
Film speedFilm speed Based upon size of Based upon size of
silver halide silver halide crystalscrystals
X-ray Film TypesX-ray Film Types
Two general types Two general types Non-screen filmNon-screen film Screen filmScreen film
X-ray Film TypesX-ray Film Types
Non-screen filmNon-screen film More sensitive to ionizing radiationMore sensitive to ionizing radiation
Allows for finer detailAllows for finer detail
Requires more exposureRequires more exposure
Requires thicker emulsion and thus manual Requires thicker emulsion and thus manual processingprocessing
Ex.: dental filmsEx.: dental films
X-ray Film TypesX-ray Film Types
Screen filmScreen film Crystals also sensitive to fluorescent light Crystals also sensitive to fluorescent light
from intensifying screensfrom intensifying screens Less sensitive to direct ionizing radiationLess sensitive to direct ionizing radiation BenefitsBenefits
Less exposureLess exposure DrawbacksDrawbacks
Loss of image definitionLoss of image definition
X-ray Film TypesX-ray Film Types
Screen filmScreen film Blue sensitive filmBlue sensitive film
Film responds to ultra-violet, violet and blue light Film responds to ultra-violet, violet and blue light emitted from screenemitted from screen
Green sensitive filmGreen sensitive filmRespond to screens that emit 60% green and 25% Respond to screens that emit 60% green and 25% bluesblues
Relatively newer technology using rare earth Relatively newer technology using rare earth phosphorsphosphors
X-ray Film TypesX-ray Film Types
Blue and green screen can be used with Blue and green screen can be used with either blue or green sensitive filmeither blue or green sensitive film
But most efficient if film is sensitive to light But most efficient if film is sensitive to light emitted by screenemitted by screen
X-ray Film TypesX-ray Film Types
Screen filmScreen film Standard silver halide crystals absorb violet to Standard silver halide crystals absorb violet to
blue lightblue light ““Ortho” filmOrtho” film
Thin layer of green absorbing dye transfers energy Thin layer of green absorbing dye transfers energy to silver halide crystalsto silver halide crystalsTherefore extends sensitivity of film into green Therefore extends sensitivity of film into green wavelengthswavelengths
““Pan” filmPan” filmRed absorbing dye Red absorbing dye
X-ray Film TypesX-ray Film Types
Screen filmScreen film Crossover or punch-Crossover or punch-
through effectthrough effectDecreased detail of Decreased detail of radiograph due to radiograph due to additional exposure to additional exposure to light from screen on light from screen on opposite sideopposite side
X-ray FilmX-ray Film
Common sizesCommon sizes 14 x1414 x14 14 x1714 x17 7 x177 x17 8 x 108 x 10 10 x 1210 x 12 11 x 1411 x 14
Intensifying screensIntensifying screens
Thin cleanable sheet of phosphor crystals Thin cleanable sheet of phosphor crystals which lies adjacent to the film within the which lies adjacent to the film within the cassettecassette
Purpose:Purpose: To decrease amount of radiation required for To decrease amount of radiation required for
a diagnostic radiographa diagnostic radiographAble to use lower mAs (faster exposure)Able to use lower mAs (faster exposure)
Intensifying screensIntensifying screens
4 layers of a screen4 layers of a screen BaseBase
Substrate for phosphor crystalsSubstrate for phosphor crystals Reflecting layerReflecting layer
To reflect light back toward filmTo reflect light back toward film Phosphor layerPhosphor layer
Must be uniform and flexible (to avoid cracking)Must be uniform and flexible (to avoid cracking) Protective coatingProtective coating
Intensifying screensIntensifying screens
Intensifying screensIntensifying screens
Intensification factor Intensification factor Direct film requires roughly 34 times more Direct film requires roughly 34 times more exposure than screen filmexposure than screen film
A 0.1 second exposure on screen film A 0.1 second exposure on screen film would require 3.4 seconds on non-screen would require 3.4 seconds on non-screen filmfilm
Intensifying screensIntensifying screens
Screen speedScreen speedLarger crystal = faster screen = more grainyLarger crystal = faster screen = more grainy
Thicker phosphor layer = faster screen = Thicker phosphor layer = faster screen = decreased detaildecreased detail
Intensifying screensIntensifying screens
Phosphor layerPhosphor layerCalcium tungstate and barium lead sulfate Calcium tungstate and barium lead sulfate emit blue lightemit blue light
Rare earth screens more green light Rare earth screens more green light emittedemitted
Extremely important to keep screens Extremely important to keep screens clean and undamagedclean and undamaged
Film holdersFilm holders
CassettesCassettes Must be rigid, durable, light-proof and Must be rigid, durable, light-proof and
transparent to x-rays on at least one facetransparent to x-rays on at least one face Provide housing for intensifying screens and Provide housing for intensifying screens and
filmfilm Must be maintained wellMust be maintained well
CassettesCassettes
Film holdersFilm holders
Cardboard or light-proof paperCardboard or light-proof paper Use for non screen filmsUse for non screen films Light-weightLight-weight Low/no maintenanceLow/no maintenance
Manual Film ProcessingManual Film Processing
Dark roomDark room Must be light-proofMust be light-proof
Tight seal of doorTight seal of door
Stray light may fog filmStray light may fog film Must be not be exposed to radiationMust be not be exposed to radiation
Adjacent x-ray machine may cause fogging of filmAdjacent x-ray machine may cause fogging of film
Manual Film ProcessingManual Film Processing
Dry areaDry areaFilm storageFilm storage
Use lightproof cabinetUse lightproof cabinet
Cassette loadingCassette loading
SafelightSafelight Must be of visible spectrum that will not fog filmMust be of visible spectrum that will not fog film Red part of spectrumRed part of spectrum
Manual Film ProcessingManual Film Processing
Wet areaWet areaSolution tanksSolution tanks
SinkSink
ViewerViewer
HangersHangers
Manual Film ProcessingManual Film Processing
Manual Film ProcessingManual Film Processing
DevelopingDeveloping Developer solution reduces silver bromide Developer solution reduces silver bromide
crystals to black metallic silvercrystals to black metallic silver
Manual Film ProcessingManual Film Processing
DevelopingDeveloping Chemical process dependant upon time and Chemical process dependant upon time and
temperaturetemperatureIdeally 5 minutes in developer tank at 68 degrees Ideally 5 minutes in developer tank at 68 degrees Fahrenheit Fahrenheit
High temperature causes reticulationHigh temperature causes reticulation Artifact caused by slipping of emulsion layerArtifact caused by slipping of emulsion layer
Manual Film ProcessingManual Film Processing
Rinse bathRinse bath WaterWater About 30 secondsAbout 30 seconds
Manual Film ProcessingManual Film Processing
FixerFixer Converts undeveloped silver bromide crystals Converts undeveloped silver bromide crystals
into a solution that is washed awayinto a solution that is washed awayBlack metallic silver left on filmBlack metallic silver left on film
Also hardens filmAlso hardens film
Manual Film ProcessingManual Film Processing
Minimum fixing timeMinimum fixing time Determined by change in film appearance Determined by change in film appearance
from cloudy to clear (clearing time)from cloudy to clear (clearing time)
Manual Film ProcessingManual Film Processing
After clearing, film should be left in for After clearing, film should be left in for twice that amount of timetwice that amount of time Ex. 2 minutes to clear = keep film in 4 Ex. 2 minutes to clear = keep film in 4
additional minutesadditional minutesClearing time should not exceed 2-3 minutesClearing time should not exceed 2-3 minutes
Manual Film ProcessingManual Film Processing
WashingWashing Removes residual silver and fixerRemoves residual silver and fixer 20 minutes if water changes 10 times per hour20 minutes if water changes 10 times per hour
Manual Film ProcessingManual Film Processing
DryingDrying Perform in clean cabinetPerform in clean cabinet
Avoid dust artifacts, water spotsAvoid dust artifacts, water spots
Automatic Film ProcessingAutomatic Film Processing
BenefitsBenefits Compact sizeCompact size FasterFaster More consistentMore consistent Time and temperature controlledTime and temperature controlled Produces dry radiograph immediatelyProduces dry radiograph immediately
Film ProcessingFilm Processing
Solutions need to be specially disposed Solutions need to be specially disposed due to contentsdue to contents Treated as hazardous waste in many Treated as hazardous waste in many
including Californiaincluding California