RADIOGRAPHIC FILM PROCESSING DARKROOM. THE PROCESSING AREA PROCESSING AREA VIEWING SECTION.
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Transcript of RADIOGRAPHIC FILM PROCESSING DARKROOM. THE PROCESSING AREA PROCESSING AREA VIEWING SECTION.
RADIOGRAPHIC FILM PROCESSING
DARKROOM
THE PROCESSING AREA
• PROCESSING AREA
• VIEWING SECTION
VIEWING AREA
PROCESSING AREA
VIEWING SECTION VIEWBOX ILLUMINATION INTENSITY-500-1000 FOOT CANDLES
PHOTOMETER IS USED TO MEASURE VIEWBOX
ILLUMINATION INTENSITY
VIEWING STATION
VIEWBOX LIGHT
IF ONE BULB IS BLOWN ALL BULBS HAVE TO REPLACED
VIWBOXES
• TO BE CLEANED ONCE EVERY 6 MONTHS
• IF USED 24/7 – BULBS CHANGES ONCE A YEAR
• IF USED 12/7 BULBS CHANGED ONCE EVERY TWO YEARS
VIEWING AREA HOT LIGHT
MOST OF MODERN MEDICAL IMAGING DEPARTMENTS USE AUTOMATIC PROCESSORS—
MOST OF THOSE ARE DAYLIGHT PROCESSORS
AUTOMATIC DAYLIGHT PROCESSORS
AUTOMATIC DARKROOM PROCESSORS
AUTOMATIC DARKROOM PROCESSORS
MANUAL PROCESSING
DARKROOM
BASIC COMPONENTS OF DARKROOM
STORAGE SHELVES
WORKBENCH
BASIC COMPONENTS:PROCESSOR
BASIC COMPONENTS:CHEMISTRY MIXING TANKS
BASIC COMPONENTS:FILM DUPLICATOR
DUPLICATING FILM EXPOSED TO ULTRAVIOLET RADIATION
BASIC COMPONENTS:FILM FLASHER
BASIC COMPONENTS:SILVER RECOVERY SYSTEM
BASIC COMPONENTSFILM BIN
FILM BIN AUDIO ALARM
FILM BIN ANATOMY
CONTAINS INDIVIDUAL SLOTS THAT HOLD FILMS OF DIFFERENT SIZES
TYPICAL DARKROOM FILM BIN
14 x 17
FRONT
11 x 14
10 x 12
8 x 10
OTHER FILMS
RADIOGRAPHIC FILM SIZES
• 14 X17 • 11 x 14• 10 x 12• 8 x 10• 7 x 17• 6 x 12• 14 x 36
• 35 x 43• 28 x 35• 25 x 30• 20 x 25• 18 x 43• 15 x 30• 35 x 91
DARKROOM LIGHT
• WHITE LIGHTS
• SAFELIGHTS
WHITE LIGHT IS USED FOR:
EQUIPMENT REPAIR AND DARKROOM CLEANING
SAFELIGHTS USED
DURING FILM PROCESSING
SAFELIGHT BULBSINCANDESCENT RECESSED WITHIN METALLIC LIGHT
FIXTURE• RED FILTER-- KODAK GBX-2 OR GS-1
• AMBER FILTER --WRATTEN 6B
SAFELIGHTS
• RED—GREEN LIGHT SENSITIVE FILM ORTHOCHROMATIC
• AMBER –BLUE LIGHT SENSITIVE FILM
• TOTAL DARKNESS FOR PANCHROMATIC FILM
FILM TRAY
7.5 W
AT LEAST 3 FEET FROM THE FILM TRAY
FILM TRAY
15 W
AT LEAST 4 FEET FROM THE FILM TRAY
LATENSIFICATION
INCCREASED SENSITIVITY TO SAFELIGHT ILLUMINATION AFTER FILM WAS EXPOSED
DARKROOM DESIGN
LEAD SHIELDING IF ADJACENT TO X-RAY ROOM
• 1/16 INCH OF LEAD IN THE WALLS ALL THE WAY TO THE CEILING.
IF ADJACENT TO X-RAY ROOMS
• PASS-BOXES NEEDED TO PASS FILMS DIRECTLY FROM THE X-RAY ROOM TO DARKROOM
VENTILATION
• SYSTEM MUST BE LIGHTPROOF AND ABLE TO FILTER OUT DUST
HUMIDITY
• 40-60%
• > 60%--FILM FOG
• <40% STATIC ARTIFACTS
SIZE
• BIG ENOUGH!!!?
COLOR
• WALLS AND CEILING CAN BE PAINTED IN ANY COLOR
TEMPERATURE
• 50-70 º F FOR FILM STORAGE– TO SLOW DOWN THE AGING PROCESS OF THE FILM
WOULD YOU STORE IT LIKE THIS???
STORE YOUR FILMS STANDING ON THE EDGE TO AVOID
PRESSURE MARKS. USE FILM STORAGE CARTS OR SHELVES
COLOR OF THE MAZE
DARK-- NOT OT REFLECT WHIT LIGHT INTO THE DARKROOM
DARKROOM TESTING
• WHITE LIGHT LEAKS
• SAFELIGHT FOG
SAFELIGHT TEST
SENSITOMETRY
SENSITOMETRY-QUANTITATIVE MEASUREMENT OF FILM RESPONSE
TO EXPOSURE & DEVELOPMENT
FILM DEVELOPMENT
SENSITOMETRIC STRIPS
PRODUCING STRIP WITH PENETROMETER
PRODUCING STRIP WITH PENETROMETER
X-RAY TUBE
PRODUCING STRIP WITH SENSITOMETER
PRODUCING STRIP WITH SENSITOMETER
VISIBLE LIGHT
MEASURING DENSITY WITH DENSITOMETER
MEASURING DENSITY WITH DENSITOMETER
VISIBLE LIGHT
I o
I t
OD OPTICAL DENSITY
OD= LOG Io/I t
0.3 = 2 X DENSITY
OD vs % OF LIGHT TRANSMISSION
• 0• 1• 2• 3• 4
• 100• 10• 1• 0.1• 0.01
OD % TRANSMISSION
Characteristic curveCharacteristic curve, a curve used to show the exposure properties of a film or a film screen system. The characteristic curve, which was described in 1890 by Hurter and Driffield, is a representation of how the exposure of the film is related to the measurable signal, i.e. the blackening of the film, or film density. The characteristic curve is different for different film types but has a general shape as shown in Fig.1. The base and fog density is measured on an unexposed film. The shape of the characteristic curve tells the user the contrast properties (slope of the linear part) and the useful exposure range (length of the linear part). It also will indicate the speed of the film (or film-screen system), which can be judged from the curve's position along the horizontal axis. The speed class can also be found from the characteristic curve
SENSITOMETRIC CURVE
• H & D CURVE
• D Log E CURVE
• CHARACTERISTIC CURVE
SOLARIZATION
SYNERGISTIC REACTION
PHENIDONE
HYDROQUINONE
SOLARIZATION
FILM DUPLICATION
EXPOSURE TIME DENSITY
Base Plus Fog ( GROSS FOG, D min 0.15 -.20 OD)
The density of the unexposed film base plus any chemical fogging that may occur during
processing
Inertia Point
TRESHOLD
The point at which the film has absorbed sufficient light energy to start forming a
latent image.
ToeA non-linear region where shadow detail is recorded in negative materials (Highlight
detail in print material). Compression of the density differences occur and contrast is
decreased.
Straight Line Portion( GAMMA, SLOPE)
The linear section where most of the information is recorded. This section is used
to determine the processed contrast of the film.
RANGE OF USEFUL DENSITIES
0.25-2.0
Shoulder
A non-linear section. Compression of density differences occur and contrast is decreased. It
is unusual to record information on this region of the curve, however this region may
be reached with overexposure or extended development such as push processing to
increase effective film speed
QUANTITATIVE DATA OBTAINED FROM H&D CURVE
• FILM SPEED
• FILM CONTRAST
• B+F ( BASE PLUS FOG)
• EXPOSURE LATITUDE
FILM SPEED
SLOWSLOW
FASTFAST
FILM CONTRAST AVERAGE GRADIENT
A.G.= (OD2 – OD1)/ (LRE2 –LRE1)
FILM CONTRAST
STEEPNESS OF THE SLOPE
FILM CONTRAST AVERAGE GRADIENT
D2D2
D1D1
LRE2LRE2LRE1LRE1
FILM LATITUDE
LATITUDELATITUDELATITUDELATITUDE
CONTRAST VERY HIGH VISIBILITY OF DETAIL
VISIBILITY OF DETAIL vs CONTRAST
HIGH CONTRAST
LOW CONTRAST
PROCESSOR MONITORING
• DEVELOPER TEMP
• DEVELOPMENT TIME
.
• SPEED
• FOG
• CONTRAST
• FOG
• SPEED
• CONTRAST
THE AUTOMATIC PROCESSOR
AUTOMATIC PROCESSOR DAYLIGHT SYSTEM
PROCESSOR
SECTIONS OF THE PROCESSOR
DF
W
D
ENTRANCE ROLLERS
ENTRANCEROLLER
ENTRANCEROLLER
FILMS ORIENTATION ON THE TRAY
14 X 1711 X 1410 X 128 X 107 X 17
PROCESSOR SYSTEMS & SUBSYSTEMS
• TRANSPORT
• TEMP. CONTROL
• RECIRCULATION
• REPLENISHMENT
• DRYER
• ELECTRICAL
TRANSPORT
TRANSPORT FILM THROUGH PROCESSOR, REGULATION OF
IMMERSION TIME, AGITATE SOLUTIONS
TRANSPORT
ROLLER
GUIDE SHOE
RACKS
TURNAROUND ASSEMBLY
MASTER
GUIDE SHOE
TURNAROUND ASSEMBLY
MASTER ROLLER
GUIDE SHOE
SQUEEGE ROLLER
TEMPERATURE CONTROL—DRYER AND SOLUTION
TEMPERATURE
ELECTRICAL HEATER
TEMPERATURE VARIATION +- 5 DEG. FARENHEIT
TEMPERATURE
• DEVELOPER
• FIXER
• WASH
• DRYER
• 95 DEG F
• 95 DEG. F
• 90-95 DEG. F
• 135 DEG. F
TEMP. CONTROL
DRYER TEMP.
DRYER BLOWER RECIRCULATION
RECIRCULATION –AGITATION OF SOLUTIONS+ FILTRATION
PUMP
FILTER
RECIRCULATION
REPLENISHMENT SYSTEM
REPLENISHMENT
REPLENISHMENT PUMP
D F
REPLENISHMENT RATESFOR EVERY 14 IN. OF FILM
• 60-70 ML OF DEVELOPER
• 100-110 ML OF FIXER
PROCESSING TIME
+- 2 % VARIATION
• 45 SEC-210 SEC.
• MOST PROCESSORS DROP TIME 90 SEC.
RADIOGRAPHIC ARTIFACTS
TYPES OF ARTIFACTS
• PROCESSING
• EXPOSURE
• HANDLING AND STORAGE
PROCESSING ARTIFACTS
• HYPORETENTION• PI-LINES• GUIDE SHOE MARK• STATIC • ENTRANCE ROLLER MARK• CRINKLE MARK• FINGER MARKS• EMULSION PICK-OFF• WATER STAIN
EXPOSURE ARTIFACTS
• MOTION• IMPROPER POSITIONING• POOR FILM SCREEN CONTACT• DOUBLE EXPOSURE• FOREIGN OBJECTS• BACK-SCATTER• CASSETTE UPSIDE-DOWN• BROKEN CASSETTE• IMPROPER USE OF GRID
HANDLING & STORAGE ARTIFACTS
• LIGHT FOG
• RADIATION FOG
• STATIC
• SCRATCHES
• HYPORETENTION
FILMS STUCK TO EACH OTHER DURING PROCESSING
HYPORETENTION
PI-LINE
GUIDE SHOE MARK
STATIC
STATIC
STATIC
ROLLER MARKS
FINGER MARKS
CRIMPING MARK
PICK-OFF
WATER STAIN
WATER STAIN
POOR FILM SCREN CONTACT
H.T. (High Voltage) CABLES
DOUBLE EXPOSURE
BACKSCATTER OR CASSETTE UPSIDE-DOWN
BACKSCATTER
BACKSCATTER OR CASSETTE UPSIDE-DOWN
MOIRE EFFECT
WARPED CASSETTE-LIGHT LEAK
HAIR BUN
CLOTHES RIBBING
GRID CUT-OFF
JEWELLERY
SCATTER FOG
SANDBAG
FOGGING
KYPHOSIS-CHIN
STRAP
Q.A. TESTS
• COLLIMATION
• FOCAL SPOT SIZE
• KVP CALIBRATION
• EXPOSURE LINEARITY
• EXPOSURE REPRODUCIBILITY
• FILM-SCREEN CONTACT
• PROTECTIVE APPAREL INTEGRITY
COLLIMATION(LIGHT FIELD/RADIATION
FIELD CONGRUENCY)
• SEMI-ANUALLY
• NINE PENNY TEST OR SPECIAL TOOL TEST
• +- 2% OF SID
FOCAL SPOT SIZE
• ANNUALLY
• PINHOLE CAMERA, SLIT CAMERA, STAR PATTERN
• +- 50%
STAR PATTERN
LINE PAIR TEST TOOL
KVP CALLIBRATION
• ANNUALLY
• KVP METER
• +- 10%
KVP METER
EXPOSURE LINEARITY
• ANNUALLY
• DOSIMETER
• +- 10%
EXPOSURE REPRODUCIBILITY
• ANNUALLY
• RADIATION DOSIMETER
• +-5%
FILM/SCREEN CONTACT
• ANNUALLY
• WIRE MESH
• NO DARK AREAS PRESENT ON THE FILM
WIRE MESH
HOW USE WIRE MESH TO TEST FILM SCRREN CONTACT
CASSETTE
PROTECTIVE APPAREL
• ANNUALLY
• FLUORO
• NO CRACKS OR HOLES