RADIOGRAPHIC FILM & PROCESSING THE FILM Flashcards
(187 cards)
1
Q
What are image-forming X-rays?
A
X-rays that exit the patient and interact with the image receptor.
2
Q
What is the exit beam?
A
X-rays that remain as the useful beam exits the patient.
3
Q
The medium that converts the x-ray beam into a visible image.
A
Image receptor
4
Q
What are the basic parts of radiographic film?
A
Base and emulsion.
5
Q
What are the additional parts of radiographic film?
A
Adhesive layer and overcoat.
6
Q
What is the thickness range of radiographic film?
A
150-300 μm.
7
Q
What is the purpose of the adhesive layer in radiographic film?
A
To allow the emulsion and base to maintain proper contact and integrity.
8
Q
What is the purpose of the overcoat in radiographic film?
A
To protect the emulsion from scratches, pressure, and contamination, allowing rough manipulation before exposure.
9
Q
What is the base of radiographic film designed for?
A
To provide a rigid structure for the emulsion.
10
Q
Describe the characteristics of the base in radiographic film.
A
Flexible, fracture-resistant, maintains size/shape (dimensional stability), uniformly lucent, tinted with blue dye to reduce eyestrain.
11
Q
What was the original film base made from?
A
Glass plate.
12
Q
What is cellulose nitrate, and what characteristic does it have?
A
It is the standard base for radiographic film, and it is flammable.
13
Q
What base was introduced in the mid-1920s as a safety alternative?
A
Cellulose triacetate, which is less flammable than cellulose nitrate.
14
Q
What is the film base of choice in radiographic film today, and why?
A
Polyester, because it is more resistant and has superior dimensional stability.
15
Q
What are the two main components of the emulsion in radiographic film?
A
Gelatin and silver halide crystal.
16
Q
What is the thickness of the emulsion layer?
A
3-5 μm.
17
Q
What is the principal function of gelatin in the emulsion?
A
To provide mechanical support for silver halide crystals.
18
Q
What are the characteristics of gelatin?
A
Clear and sufficiently porous.
19
Q
What is the active ingredient of the emulsion?
A
Silver halide crystal.
20
Q
Why is a high atomic number significant in silver halide crystals?
A
It contributes to the crystal’s high sensitivity to radiation, aiding in image formation.
21
Q
What are the two primary chemical components of silver halide crystals
A
Silver bromide (98%) and silver iodide (2%).
22
Q
List the possible shapes of silver halide crystals.
A
Tabular (mostly used), cubic, octahedral, polyhedral, and irregular shapes.
23
Q
What is double emulsion film?
A
Film coated with emulsion on both sides.
24
Q
What is silver sulfide’s role in silver halide crystals?
A
Acts as a chemical contaminant that creates physical imperfections in the crystals.
25
What are the main factors affecting radiographic film performance?
number of sensitivity centers per crystal
crystal concentration in the emulsion,
size/distribution of the crystals.
26
Why is radiographic film manufactured in total darkness?
To prevent exposure and ensure the integrity of the film's sensitivity.
27
An invisible change induced in the silver halide crystal.
latent image
28
What is the photographic effect in radiographic film?
The formation of the latent image.
29
The accepted, although incomplete, explanation of latent image formation.
Gurney-Mott Theory
30
An inherent defect in the structure of silver halide crystals.
Frankel Defect
31
How does photon interaction with silver halide crystals contribute to the latent image?
Through photoelectric (total absorption) and Compton (partial absorption) interactions.
32
What are the steps in latent image production?
1) Radiation releases electrons,
2) electrons migrate to the sensitivity center,
3) atomic silver forms,
4) silver buildup creates the latent image.
33
What is the latent image center?
A cluster of silver atoms within the emulsion crystal.
34
List the types of film used in medical imaging.
Screen-film
laser printing
copy/duplicating
dental
radiation monitoring
dry transfer films.
35
What are the characteristics of screen-film in radiography?
Dual emulsion, blue or green sensitivity, used in general radiography, reduces technique and dose, but causes some image blur.
36
Single emulsion with antihalation backing, pre-exposed to Dmax, and used for duplicating radiographs.
copy/duplicating film
37
Dual emulsion packed in a sealed envelope with lead foil to reduce backscatter;
dental film
38
Dual emulsion packed in a sealed envelope; one emulsion can be removed to adjust the optical density scale; used for radiation monitoring.
radiation monitoring film
39
Single emulsion, thermally sensitive, used for “dry” printers.
dry transfer film
40
What must be considered when selecting screen-film?
Contrast, speed, spectral matching, anticrossover/antihalation dyes, and safelight requirements.
41
What is contrast in radiographic film?
degree of difference between the light and dark areas of a radiograph.
42
Describe high contrast film.
Produces black and white images with smaller grains.
43
Describe low contrast film.
Produces images with shades of gray and has larger grains.
44
What is latitude in radiographic film?
The range of exposure techniques (kVp and mAs) that produce an acceptable image.
45
The sensitivity of the screen-film combination to x-rays and light.
film speed
46
What determines film speed for direct exposure?
Concentration and number of silver halide crystals.
47
What determines film speed for screen-film?
Silver halide grain size and shape.
48
The efficient use of silver in the emulsion.
covering power
49
Exposure of one emulsion by light from the opposite radiographic intensifying screen, leading to image blur.
crossover
50
What are ways to reduce crossover?
Tabular grain emulsions, light-absorbing dyes, and IS that emits short-wavelength light (Blue or UV).
51
What are the three critical characteristics of crossover control layer?
Absorbs most crossover light
doesn’t diffuse into emulsion
is removed during processing.
52
The color of light emitted by the screen must match the response of the film.
spectral matching
53
States that optical density is proportional to the total energy imparted to the film
reciprocity law
54
What is the formula for the reciprocity law?
Exposure = Intensity x Time = Constant Optical Density.
55
Provides enough light to work without exposing the film, composed of an incandescent lamp with a filter.
SAFELIGHT
56
Film used without intensifying screens, thicker emulsion, higher silver halide concentration, and a clear gelatin coating on the backside.
direct-exposure film
57
Single emulsion with antihalation backing.
mammography film
58
Reflection of screen light transmitted through the emulsion and base.
halation
59
An absorbing dye that reduces reflection of screen light, used in single emulsion screen-films.
ANTIHALATION
60
Silver halide film sensitized to red light emitted by lasers, with single emulsion and antihalation backing; used in CT, MRI, and ultrasound printers.
laser film
61
What is the purpose of laser beam modulation in radiographic film?
To vary the laser beam intensity in direct proportion to the strength of the image signal.
62
What is cine film, and what is its application?
35mm film used in cinefluorography.
63
Static image in small-format intensifier screen taken during fluoroscopy, with sizes ranging from 70 to 105 mm.
spot film
64
What are artifacts in radiographic film?
Marks or spurious images that sometimes appear on processed radiographs.
65
An artifact caused by creasing of the film.
line artifact
66
An artifact caused by dirt on the hands or on the intensifying screens (IS).
specular artifact
67
An artifact caused by a dry environment.
static
68
What are the ideal storage temperature conditions for radiographic film?
Less than 20°C (68°F) for regular storage and 10°C (50°F) for refrigeration.
69
Caused by high temperatures, leading to reduced contrast on the film.
fog effect
70
What is the recommended humidity range for film storage?
Between 40% and 60% relative humidity.
71
What happens if humidity falls below 40% during film storage?
It can cause static artifacts on the film.
72
What happens if humidity exceeds 60% during film storage?
It can cause fog on the film.
73
How does light exposure affect film fog?
Low-level, diffuse light exposure increases fog, while bright light exposure can cause artifacts or partial exposure of the film.
74
How does radiation exposure affect stored film?
It increases fog and reduces contrast on the film.
75
What happens to film as it ages past its expiration?
It loses speed and contrast, and fog increases.
76
How should film boxes be stored to prevent pressure artifacts?
vertically
77
What is the recommended supply schedule for film storage?
every 5 weeks
78
What is the purpose of film processing?
To convert the latent image on the film into a visible image through a sequence of chemical steps.
79
When was the first automatic film processor introduced?
In 1942 by Pako, with a 120 films per hour rate and a 40-minute dry-to-drop time.
80
What significant development occurred in film processing in 1956?
Eastman Kodak introduced the first roller transport system processor with a 6-minute dry-to-drop time.
81
What advancement in film processing was made in 1965?
Eastman Kodak introduced a 90-second rapid automatic film processor, becoming the standard.
82
What are the steps in the standard processing sequence for radiographic film?
Wetting
Developing
Stop Bath
Fixing
Washing
Drying.
83
What is the dry-to-drop time in manual film processing?
70 minutes and 45 seconds.
84
What is the dry-to-drop time in automatic film processing?
90 seconds.
85
What is the purpose of wetting in film processing?
To swell the emulsion for chemical penetration.
86
How long does manual wetting take in film processing?
15 seconds.
87
What is the purpose of developing in film processing?
To create a visible image from the latent image on the film.
88
How long does manual developing take?
5 minutes.
89
What is the purpose of the stop bath in film processing?
To terminate development and remove excess chemicals from the emulsion.
90
How long does manual stop bath take?
30 seconds.
91
What is the purpose of fixing in film processing?
To remove remaining silver halide and harden the gelatin to stabilize the image.
92
How long does manual fixing take?
15 mins
93
What is the purpose of drying in film processing?
To remove water from the film and prepare it for viewing.
94
How long does manual drying take?
30 minutes.
95
What is the main agent used in the wetting stage?
Water, to swell the gelatin and allow chemical penetration.
96
What is the principal action of the developing stage in film processing?
To reduce silver ions of exposed crystals into metallic silver.
97
What is the primary component of the developing agent?
Hydroquinone, which acts as a reducing agent.
98
What is the function of Phenidone in the developer?
To rapidly produce shades of gray and control the toe of the characteristic curve.
99
What is the role of hydroquinone in the developer?
To slowly produce black tones and control the shoulder of the characteristic curve.
100
What are the chemicals used in the activator or buffering agent in the developer?
Sodium carbonate and sodium hydroxide, which help swell the gelatin, produce alkalinity, and control pH.
101
What is the strongest alkali used in the developer, and what is its other name?
Sodium hydroxide, also known as lye.
102
What is the purpose of potassium bromide in the developer?
It acts as an antifog agent, protecting unexposed crystals and preventing development fog.
103
What chemical acts as the preservative in the developer, and what is its role?
Sodium sulfite, which controls oxidation and maintains balance among developer components.
104
What is aerial oxidation, and how is it controlled in film processing?
It occurs when air mixes with the developer, turning it brown; it is controlled with close-fitting floating lids.
105
What is the primary chemical in the hardener for the developer, and what is its role?
Glutaraldehyde, which controls emulsion swelling and enhances archival quality.
106
What happens if glutaraldehyde is depleted?
It causes damp film to emerge from the processor.
107
The permanence of the radiograph, meaning the image does not deteriorate with age.
archival quality
108
What is the purpose of a sequestering agent in the developer?
To remove metallic impurities and stabilize the developing agent, using chelates.
109
What are the three physical factors affecting film development?
Time, temperature, and concentration of the developer.
110
What causes underdevelopment in radiographic film?
When the crystals containing a latent image are not fully reduced, resulting in a dull radiograph.
111
What causes overdevelopment in radiographic film?
Partial reduction of unexposed crystals, which also results in a dull radiograph.
112
What is development fog, and what causes it?
Increased developer time, temperature, and concentration cause unwanted fog on the film.
113
What causes radiation fog in radiographic film?
Unintentional exposure to radiation or improper storage at high temperature and humidity.
114
What are the principal actions of the fixing stage?
To treat the film so that the image remains permanent and to achieve archival quality.
115
What chemicals are used as fixing agents in the fixer?
Ammonium thiosulfate and sodium thiosulfate, which remove undeveloped silver bromine.
116
What is hypo retention, and how does it affect film quality?
The undesirable retention of fixer in the emulsion, resulting in a brownish film.
117
What is the most common cause of poor archival quality in radiographs?
Silver sulfide staining, often from hypo retention or improper fixing.
118
What is the purpose of the hardener in the fixer?
ensure the film is properly transported and to allow rapid, complete drying.
119
List the chemicals used as hardeners in the fixer.
Potassium alum, aluminum chloride, and chromium alum, which stiffen and shrink the emulsion.
120
What is the preservative in the fixer, and what is its role?
Sodium sulfite, which maintains chemical balance in the fixer.
121
What is the function of the buffer in the fixer?
To maintain the proper pH level in the fixer, using acetate.
122
What is the role of the sequestering agent in the fixer?
To remove aluminum ions, with boric acid or boric salts, which are the principal impurities at this stage.
123
What is the purpose of washing in film processing?
To remove any residual chemicals from the emulsion, particularly hypo, to maintain archival quality.
124
What is the wash agent in film processing?
water
125
What is the recommended wash water temperature in automatic film processing?
3°C/5°F lower than the developer temperature (typically 35°C/95°F).
126
What are the effects of inadequate washing on film quality?
Causes excessive hypo retention, resulting in poor archival quality and a brownish radiograph.
127
What is the purpose of drying in the film processing sequence?
To remove water used in washing and prepare the film for viewing.
128
What are the principal components of an automatic processing system?
Transport system
temperature control system
circulation system
replenishment system
dryer system.
129
What are the three subsystems of the transport system?
Roller, transport rack, and drive subsystems.
130
It is where the transport system begins, allowing the film to enter the processing cycle
feed tray in automatic processor
131
They grip the film to initiate its journey through the processor.
entrance rollers
132
Controls the replenishment rate of processing chemicals.
microswitch
133
They convey the film along its path through the processor.
transport rollers
134
3-inch rollers used when the film makes a turn in the processor.
master/solar rollers
135
Positioned around the master roller and guide shoes to support film movement around bends in the processor.
planetary rollers
136
What is the purpose of the transport rack assembly?
To move and change the direction of the film through rollers and guide shoes.
137
What are guide shoes, and what is their purpose?
Components used to steer the film around bends in the transport rack assembly.
138
A structure at the bottom of the transport rack that consists of the master roller, planetary roller, and guide shoes, guiding the film's path.
turnaround assembly
139
A structure made of rollers and guide shoes that transports film from one tank to the next in the processing sequence.
crossover track
140
What is the purpose of the drive subsystem in automatic processing?
To provide power to turn the rollers at a precise rate, controlling the film's movement through the processor.
141
What provides power for the transport system in an automatic processor?
A fractional horsepower drive motor.
142
List the three main mechanical devices in the drive subsystem.
A belt and pulley, a chain and sprocket, and gears.
143
What is the purpose of the temperature control system in film processing?
To monitor and adjust the temperature at each stage of the processing sequence.
144
What is the most critical temperature in film processing, and what is the standard value?
The developer temperature, typically set at 35°C (95°F).
145
What device monitors temperature in film processing?
A thermocouple or thermistor.
146
What is the purpose of the circulation system in automatic processing?
To agitate fluids to maintain a consistent temperature and ensure uniform exposure of the emulsion to chemicals.
147
What is the minimum flow rate for wash water in the wash tank circulation system?
12 liters per minute (3 gallons per minute).
148
What is the purpose of the replenishment system in film processing?
To meter the correct quantity of chemicals into each tank, maintaining volume and chemical activity.
149
What is the standard replenishment rate for developer solution?
60-70 mL per 14 inches of film.
150
What is the standard replenishment rate for fixer solution?
100-110 mL per 14 inches of film.
151
What is the effect of increasing the replenishment rate on film contrast?
It slightly increases film contrast.
152
What is the effect of decreasing the replenishment rate on film contrast?
It significantly decreases film contrast.
153
What is the purpose of the dryer system in an automatic processor?
To remove moisture from the film and vent exhaust.
154
What components make up the dryer system?
Blower, ventilation ducts, drying tubes, and exhaust system.
155
A 30-second dry-to-drop processing method essential in angiography, surgery, emergency rooms, and special procedures.
rapid processing
156
What temperatures are used for rapid processing chemicals?
Higher developer and fixer temperatures than standard processing.
157
A 3-minute dry-to-drop processing method used primarily in mammography.
extended processing
158
What are the advantages of extended processing in mammography?
Greater image contrast (15% increase) and lower patient dose (30% increased IR sensitivity).
159
What are the disadvantages of extended processing in mammography?
A longer dry-to-drop time.
160
What type of film is used in extended processing?
Single-emulsion film only
161
A method that allows radiographers to process films without a darkroom, providing uninterrupted patient care.
daylight processing
162
What are the advantages of daylight processing?
No darkroom needed, speed, and a 2-minute dry-to-drop time.
163
Monitors the unloading and reloading of the cassette.
microprocessor
164
Development of images without wet chemistry, eliminating the need for handling and disposal of chemicals, saving space, and reducing costs and maintenance.
dry processing
165
List two methods used in dry processing.
Photothermography (PTG) and thermography (TG).
166
Uses a laser to form a latent image and heat to process it, offering precise laser modulation with short dwell time.
photothermography
167
What are the advantages of photothermography (PTG)?
Short dwell time (15 seconds) and accurate laser modulation over short intervals (1 μm).
168
Uses heat (printhead) to produce a visible image directly.
thermography
169
What are the disadvantages of thermography (TG) in radiography?
Increased image blur and a pixelated appearance.
170
What chemical compound classically refers to "hypo" in radiographic processing?
Sodium thiosulfate.
171
What is the appearance of a radiograph affected by hypo retention?
The radiograph appears brown.
172
What are the two main functions of the hardener in the fixer?
To stiffen and shrink the emulsion, ensuring proper drying and transport through the processor.
173
What is the function of the acetic acid in the fixer?
It acts as a stop bath by neutralizing the developer and stopping its action.
174
What does a close-fitting floating lid prevent in the developer solution?
Prevents aerial oxidation.
175
What chemical is sensitive to aerial oxidation in the developer?
Hydroquinone.
176
What term describes the combination of two agents in developing, making them more effective than each alone?
Synergism.
177
Why is the length of exposure time crucial in the developer?
Longer exposure increases reduction of silver in each grain, affecting density.
178
How are oxidation and reduction reactions remembered in radiographic processing?
Electrons are Used in Reduction (EUR), Oxidation Produces Electrons (OPE).
179
What is the temperature tolerance in the transport system controlled by?
The motor speed and the gear reduction system.
180
What is a common cause of damp film emerging from the processor?
Depletion of glutaraldehyde in the developer solution.
181
Why must the shorter dimension of the film be placed against the side rail during processing?
To ensure the proper replenishment rate is maintained.
182
What is the relationship between contrast and exposure latitude in radiographic film?
Contrast is inversely proportional to exposure latitude.
183
A dye that absorbs crossover light, reducing image blurring by keeping light within its layer.
anticrossover dye
184
Describe the difference between orthochromatic and panchromatic film.
Orthochromatic is green-sensitive, while panchromatic is sensitive to the entire visible spectrum.
185
What is the minimum light wavelength required for safelight filters for green-sensitive film?
Greater than 600 nm (red filter).
186
What is the primary purpose of silver sulfide in the emulsion?
To create a physical imperfection that acts as a sensitivity center for the latent image.
187
What is meant by “manifest image” in radiographic film?
The visible image created after processing the latent image through chemical reactions.
