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Glossary of KI 11

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________ is a cardboard coasted with:
1. a layer of light-emitting phosphor crystals mixed with a binder
2. a reflective layer that reflects light back toward the film
3. a cleanable protective surface
Intensifying screens
________ is inside a metal cassette on the front and back surface.
Intensifying screens
What does the intensifying screen do?
THe phosphor crystals convert the radiation energy into visible light, thereby intensifying the effect of the x-rays.
More than ____% of the exposure to the film is due to the light emitted from the intensifying screens, and ____% from the x-ray.
95
5
What is the main purpose for using screens?
To reduce the amount of radiation exposure required to produce a diagnostic radiograph.
3 properties that determine the efficiency of screen material
1. They must have a high level of x-ray absorption
2. They must have ahigh x-ray to light conversion with suitable energy and color
3. There must be little to no after glow once the radiation has stopped.
The light emitted from the screen may be in the ___, ___, or ____ spectrum
blue
green
violet
Ideally, the film's light sensitivity should matche the _______
color of light emitted by the phosphors
The use of screens results in ______, thus decreasing the dose of radiation to the patient and the chance of motion on the radiograph.
mAs
_____ exposure requires about 34 times as many photons as _______ to obtain the same density.
Direct film
film-screen combination
The most common type of screen is ________ mounted inside metal cassettes.
Calcium tungstate phosphor crystals
Calcium tungstate phosphor crystals emit light in the __ spectrum and ________ is very sensitive to this color.
blue
silver halide
__________ is strong and absorbs x-rays well, but doesn't convert to light very efficiently.
Calcium tungstate
Screens are rated by _____ & ____.
speed
efficiency
________ refers to the ability of a phosphor crystal to convert radiation to light.
Screen speed
5 factors affect screen speed
1. Crystal size
2. Thickness of phosphor layer
3. Reflective layer efficiency
4. Dyes in the phosphor layer
The x-ray-to-light conversion efficiency of __ phosphors is significantly greater than that of calcium tungstate.
rare-earth
Substance that can emit light
phosphor
Larger crystals emit _____ light and require ____ radiation for an exposure.
more
less
As the crystal size increases, the detail of the image ______.
decreases
Increased screen speed has led to a radiographic artifact known as ______.
quantum mottle
_______ gives a radiograph a spotty or mottled appearance.
Quantum mottle
Fast screen has ___ crystals.
larger
Slow screens have _____ crystals.
smaller
Smaller crystals emit _____ light and require ____ radiation.
less
more
______ crystals give fine detail.
small
Increased screen thickness ________ absorption and efficiency.
increases
________ layer of phosphor decrease detail.
Thick
Decreased phosphor layer thickness ________ absorption and efficiency.
decrease
______ phosphor layer increase detail.
Thin
4 Layers of an intesifying screen
1. plastic base
2. reflective layer
3. phosphor layer
4. protective coat
The reflective layer of a screen is positioned between the ______ and the ______.
base
phosphor layer
The purpose of the reflective layer is to _________
reflect all light emission from teh phosphor layer toward the x-ray film.
The reflective layer of a screen must has a ______ and a ________
high reflective capability
low absorption capacity
A ______ may be incorporated into the phosphor layer of some screens.
light-absorbing dye
The primary purpose of the dye in the phosphor layer of a screen is to ________
decrease lateral spreading of the light emitted from the phosphor crystals, thus decreasing the blurring of the image.
When dyes are added to the phosphor layer of the screen, the _______is reduced, and the _____ is decreased.
light intensity emitted by the screen
speed of the screen
Rare earth screens have greater _________ and greater _____, which lead to greater ________
x-ray absorption efficiency
light conversion
density at lower settings
Rare earth screens cut down exposure by ____%
70
Rare earth screens' phosphors emit light in the ______ spectrum, so it is best to use film that is sensitive to this light.
green
_________ cassettes used to be used for detail studies.
Non-screen
Non-screen cassettes required ________
a lot of radiation
With non-screen cassettes, you should use ________ film, but can use ____ film with reduced detail.
non-screen
screen
In care of screens, you should check for:
1. warping of the front
2. craked frame
3. worn or bent latches
4. thinning or absence of felt boarders
Warping of the front of a screen causes _______-
imcomplete contact between screen and film
What is acceptable to use in cleaning the screen?
Commercial screen cleaners
Mild soap and water solution
What do you need to produce a radiograph? (4 items)
1. electromagnetic energy in the form of x-rays
2. a subject
3. photosensitive film
4. a chemical process that makes the latent image visible and permanent
The purpose of x-ray film
To provide a permanent record containing essential diagnostic information
3 components of x-ray film
1. polyester base
2. emulsion
3. supercoat
The purpose of the polyester base of a x-ray film
provides a thin, flexible support base.
The emulsion of an x-ray film consists of a _____ suspension that contain __________
gelatin
silver halide crystals
The purpose of the supercoat of an x-ray film
to protect the emulsion layer
Describe the cross section of x-ray film

Cross section of x-ray film
_______ is an invisible image on the x-ray film after it is exposed to ionizing radiation or visible light before processsing.
Latent image
Explain how a latent image is formed on a x-ray film.
When x-ray or visible light strike the silver halide crystals, electron and silver molecules interact and form the latent imgage.
Explain what happens when an x-ray film is developed.
When the exposed silver halide crystals are treated with developer solution, a chemical reaction occurs that changes silver halide to metallic silver.
Metallic silver appears _____ on the film.
black
Explain what happens to the unexposed film when it is developed.
Silver halide crystals that were not exposed to x-rays are removed by fixer solution. This leaves the film clear, or nearly so.
Explain the relationship of the exposed silver halide and teh quality of the image.
The greater the number of silver halide crystals that were exposed to radiation, the more crystals were changed to metallic silver, the blacker the film.
3 most common film sizes
14 x 17
10 x 12
8 x 10
List 6 things x-ray film is sensitive to
1. x-rays and visible light
2. heat
3. moisture
4. aging
5. pressure
6. certain gasses
X-ray film should be stored in a ________
film bin
Ideal temperature of x-ray film
50-60F
Ideal humidity of x-ray film
40-50%
4 gasses x-ray film is sensitive to
1. H2S
2. ammonia
3. formalin
4. peroxide
3 things film identification should include
1. name & address of the hospital
2. Date the radiograph was taken
3. Patient identification
Film labeling system that utilizes a lead blocker placed on the outside of the cassette, an identification card, and a photoimprinter.
Photoimprinting label system
The best method of filing radiographs is in a _____
large, 14 x 17 inch file envelope, regardless of the film size.
The film envelopes should be labeles with:
1. patient description
2. name of the owner
3. date
4. type of radiograph taken
5. machine setting
______ refers to the amount of exposure to radiation a film requires to produce an image of adequate density.
Film speed
Film is rated as _____, _____, or ____
fast
slow
par
High detail film is ______ film
slow
______ film requires less exposure, but produces a grainier image that lacks definition
Fast
_______ film requires more radiation but produce a clearer image
Slow
_______ film is most widely used in veterinary medicine
medium
Screen films are categorized by the __________
color of light they are sensitive to
Film-screen combinations depend on:
1. available power and strenght of x-ray machine
2. desired level of image detail
The film-screen combined speed is called _______.
system speed
Low powered x-ray machine requires ______ systems
faster
Film screen combinations are assigned __________ values
numerical
Common film-screen combinations used in veterinary medicine
300-400
The ______ is a rigid frilm holder designed to hold the x-ray film and intensifying screens in close contact.
cassette
The most common causes of physical damage to cassettes are: (list 2)
1. dropping the cassette on a hard surface
2. leakage of fluid such as blood or urine into the cassette
A cassette should be cleaned on a regular basis with ________
mild soap & water
List the common phosphor types used in diagnostic intensifying screens
Calcium tungstate
Raer-earth
List the 2 general types of x-ray film
1. screen film
2. nonscreen film
_________ is manufactured with silver crystals that are sensitive to fluorescent light emitted from intensifying screens and less sensitive to ionizing radiation.
Screen film
_________ is exposed by the direct action of x-ray.
Nonscreen film
Speeds of radiographic films are determined from the ____________
exposures required to produce an image with adequate density
_______ is the exposure range of a film that will produce acceptable densities.
Film latitude
The primary function of the intensifying screen is to ________
reduce the amount of radiation exposure required to produce a diagnostic radiograph
The conversion of x-ray into visible light occurs via:
a. double-emulsion x-ray film
b. the processor
c. intensifying screens
d. the cassette
c
To absorb backscatter, the back of most cassettes is lined with:
a. lead
b. felt
c. intensifying screen
d. x-ray film
a
Intensifying screens allow:
a. higher kVp to be used
b. lower mAs to be used
c. longer exposure time to be used
d. higher mAs to be used
b
The main advantage of today's rare-earth-coated intensifying screens is:
a. its emission of light is in the blue region of the UV spectrum
b. its ability to convert a latent image into a visible image
c. they are easy and inexpensive to se
d
Which of the following statements is true?
a. Screen film is more sensitive to ionizing radiation
b. Nonscreen film produces poorer detail
c. Nonscreen film is highly sensitive to fluorescent light emitted from intensifying screens
d.
d
A processed film that has not been exposed to ionizing radiation or visible light will appear:
a. black
b. green
c. clear
d. blue
c
Which of the following are appropriate storage conditions for radiographic film?
a. 10-15C, 40-60% humidity, vertical
b. 1-15C, 40-80% humidity, vertical
c. 10-20C, 40-60% humidity, horizontal
d. 10-15C, 50-60% humidity, horizontal
a
Which of the following film-screen systems is most commonly used in veterinary medicine?
a. High-speed system
b. Low-speed system
c. Medium-speed system
d. The fastest system possible
c
_______ is the degree of blackness, or how much white light passes through the film
Film density
A very _____ film is very dark.
dense
A radiograph that lacks density appears ______.
light
______ density is the quantity of matter per unit of the volume.
Subject
Subject density affects ____ density.
film
X-ray cause silver halide to turn to ______ and turn _____ in the developing process.
silver
black
A dense subject produces a ____ area on the film underneath it.
light
A less dense subject will produce a _______ area on the film underneath it.
dark
_________ is a subject that absorbs x-ray and therefore produces a less dense radiograph.
Radiopaque
_______ is a subject that lets x-ray through and therefore produces a more dense image.
Radioluscent
The electrical current that heats the filament is measured in _________.
milliamperage (mA)
_____ affects the intensity of the x-ray beam and is the measure of quantity of x-ray produced.
mA
The total quantity of x-rays produced during a given exposure is also dependent onthe ______.
length of exposure
The period during which the x-rays are permitted to leave the x-ray tube is termed the _______.
exposure time
The quantity of x-rays required for a given exposure is expressed as the product of the ____ and the ____ in ____.
mA
time
milliamperage-seconds (mAs)
______ x _______ = mAs
mA
time
A higher mA setting allows for a ____
shorter time setting
With a shorter time setting, the possibility of _____ on a radiograph is decreased.
motion occurring
______ is considered the most common artifact in veterinary radiography.
Motion
Why would you want to change mA or the length of exposure without affecting the density of the film?
1. you may need to decrease the time b/c of patient motion.
2. you may want to increase your mA so that you can use a lower kVp
3. you may want to decrease your mA so that you cna use a higher kVp
An xray was taken at 200mA and 0.1 seconds. You want to decrease the exposure time to 1/30 seconds. What should your new mA be if you want to maintain the same film density?
600mA
What mA should you select if you want a 5mAs and your time is set at 1/60 second?
300mA
You took an x-ray at 300 mA and 1/15 seconds. Now you want a better detailed x-ray so you choose the 10mA setting so that you can take advantage of the smaller focal point. What time will you have to use to maintain film density?
1/5 seconds
The higher the kilovoltage, the faster the __________
electrons are accelerated
A change in kVp affects:
1. the beam's ability to penetrate an object
2. the amount of radiation reaching the film
3. film density, especially underneath objects
Higher kVp settings allow for lower ______ settings.
mAs
kVp must vary ________ with mAs in order to maintain film density.
inversely
At 40-50 kVp, if mAs is halved, ______.
add 4 kVp
At 40-50 kVp, if mAs is doubled, ______.
subtract 4 kVp
At 50-60 kVp, if mAs is halved, ______.
add 6 kVp
At 50-60 kVp, if mAs is doubled, ______.
subtract 6 kVp
At 60-70 kVp, if mAs is halved, ______.
add 8 kVp
At 60-70 kVp, if mAs is doubled, ______.
subtract 8 kVp
At 70-80 kVp, if mAs is halved, ______.
add 10 kVp
At 70-80 kVp, if mAs is doubled, ______.
subtract 10 kVp
At 80-90 kVp, if mAs is halved, ______.
add 12 kVp
At 80-90 kVp, if mAs is doubled, ______.
subtract 12 kVp
At 90-100 kVp, if mAs is halved, ______.
add 14 kVp
At 90-100 kVp, if mAs is doubled, ______.
subtract 14 kVp
If the original setting is 64 kVp and 10 mAs, what would the new kVp be if mAs was changed to 5 mAs.
72
If the original setting is 64 kVp and 5 mAs, what would the new kVp be if mAs was changed to 2.5 mAs.
82
If the original setting is 64 kVp and 2.5 mAs, what would the new kVp be if mAs was changed to 5 mAs.
70
Why would you want to double or halve the mAs and change kVp?
1. If you selected a shorter time and couldn't change the mA
2. If you wanted to alter the scale of contrast
3. If you needed ore or less density but were limited in mAs range.
________ is a method of estimating kVp
Santes' Rule
Santes' Rule formula
(2 x body part cm) + FFD = kVp
Dr. Davis has requested an x-ray of a goat's abdomen measuring 25 cm. What should your kVp setting be? FFD = 40.
(2 x 25) + 40 = 90 kVp
A change in patient density (cm) requires a _______ if similar film dentsity is desired.
change in kVp
Add ___ kVp per cm up to 80 kVp
2
Add ___ kVp per cm between 80-100 kVp
3
Add ___ kVp per cm over 100 kVp
4
If a 14 cm patient is taen at 66 kVp, a 17 cm be taken at ?
72 kVp
Margin of error is aka
exposure latitude
The distance between the source of x-rays and the film affects the _______.
intensity of the x-ray
Inverse Square Law says:
the intensity of the beam is inversely proportional to the square of the distance.
A formula to calculate the required mAs change when FFD is changed
old mAs x (new distance)2/(old distance)2 = new mAs
If an x-ray was taken at 10 mAs at 100 cm and now the FFD is changed to 50 cm, what will the new mAs be if density is to remain the same?
2.5 mAs
Ways to decrease the number of personnel in the radiology suite include:
a. using higher kVp setting
b. using longer time setting with a higher mA setting
c. sedating patients
d. none of the above
c
Ways to increase penetrating power of x-rays include:
a. increasing kVp
b. increasing the time setting
c. increasing thermionic emission
d. increasing mAs
a
The mAs for 1000 mA and 1/10 sec is:
a. 10 mAs
b. 10,000 mAs
c. 100 mAs
d. 1 mAs
c
According to Santes' rule, if a cat's abdomen measures 12 cm, kVp is:
a. 72
b. 64
c. 66
d. 52
b
The source-image distance:
a. is directly proportional to the intensity of the x-ray.
b. must be considered every time the control panel is set
c. changes only a few inches between patients and is negligible
d. most commonly ranges fr
b
1% of the energy produced at the anode is in the form of:
a. heat
b. x-rays
c. sound
d. none of the above
b
The temperature of the filament within the cathode is controlled by:
a. time setting
b. the source-image distance
c. kVp setting
d. mA setting
d
Which is a characteristic of x-rays?
a. Their total number produced is determined by kVp.
b. Longer wavelengths have more penetrating power.
c. Their intensity increases as SID decreases.
d. They diverge from a light source.
c
The potential difference between the anode and cathode is measure in:
a. kilovolts
b. calipers
c. milliamperes
d. centimeters
a
A higher kVp setting allows for a _____ mAs and ______ exposure time.
a. higher; lower
b. lower; higher
c. lower; lower
d. higher; higher
c
3 qualities that constitute a good darkroom
1. clean
2. organized
3. lightproof
_______ provides light without ruining film
Safelight
Use a _______ for safelight
frosted 6.5-10 watt bulb
Do not position safelight closer than __ feet to the work area
4
_____ is a chemical solution that converts the latent image to a visible image by converting the exposed silver halide crystals to silver metal.
Developer
Developer temperature affects the ________.
developing time
Developer consists of:
1. developing agents
2. accelerators
3. preservatives
4. restrainers
5. hardeners
6. solvent
_________ are composed of chemical compounds such as hydroquinone or phenidone, that can convert exposed grains of silver halide to black metallic silver.
Developing agents
Developing agents has little to no effect on _________.
unexposed crystals
__________ are chemicals that increase the activity of the developer.
Accelerators
Substances such as potassium carbonate or sodium carbonate are used to increase the _________ of developer.
pH
The increase in pH of developer causes the __________, allowing the developing agent to work more effectively.
emulsion to swell and soften
_______ prevent the rapid oxidation that can occur with alkaline developing agents.
Preservatives
Preservatives of developer maintain a stable development rate and prevent __________.
staining of the emulsion layer
Oxidated developer looks _______
brown
________ prevents the development of unexposed silver crystals.
Restrainers
________ of developer consists of water to dissolve the chemicals.
solvent
3 purposes of the rinse bath
1. Rinses the developing solution from the film
2. Stops the developing process
3. Prevents contamination of the fixer
2 purposes of the fixer
1. clears the unexposed silver halide crystals from the film
2. hardens the gelatin coating so that it can be dried without damaging the film surface
The process by which the unexposed silver halide crystals are removed from teh film and the gelatin is hardened.
Fixation
The film should be fixed for ____ the development time to ensure maximum hardening of the emulsion.
twice
A radiograph can be viewed briefly after it has been in the ________ and then returned after evaluation.
fix for 1 minute
The fixer consists of:
1. clearing or fixing agent
2. preservatives
3. hardeners
4. acidifiers
5. buffers
6. solvent
Purpose of clearing (fixing) agent of the fixer.
Dissolve and remove the unexposed silver halide crystals from the film emulsion
The 2 most common clearing agents are:
1. sodium thiosulfate
2. ammonium thiosulfate
The clearing agent changes the appearance of the friml from ____ to ___.
milky white
clear image
Clearing agent does not affect __________ portion of the film.
black metallic silver
______ preserves fixer.
Preservatives
Fixer preservatives agent is _____.
sodium sulfite
________ of the fixer prevents over swelling of the emulsion.
Hardeners
______ of fixer shorten the drying time by essentially preventing the film from getting too soggy.
Hardeners
________ accelerate action of the fix.
Acidifiers
_________ neutralize any developing solution that has gotten into the fixer
Acidifiers
_______ maintains desired pH of the fixer
Buffers
_______ stabilize the acidity of the fix
Buffers
___________ removes chemicals from the film.
Wash bath
________ prevents eventual discoloration and fading of x-rays.
Wash bath
A film should be washed in the wash bath for ________
20-30 min
The walls of the darkroom should be white or cream colored because:
a. it is easier to keep these colors clean.
b. these colors help to detect light leaks.
c. film can be held to the wall to determine quality.
d. more reflection of th
d
Which of the following is true regarding safelights?
a. They should be 20 watts or less.
b. They must be at least 4 feet from the work area.
c. The brown filter is for blue-light-sensitive film.
d. Film can be exposed to safelights in
b
What is the ideal pH at which to develop radiographs?
a. 9.8 to 11
b. 7.2 to 7.4
c. 2.0
d. 7.8 to 9.8
a
Unexposed silver halide crystals remaining on the film are removed at this stage.
a. rinsing or stop bath
b. washing
c. fixing
d. developing
c
Advantages of automated film processing include:
a. consistent quality of processed radiographs
b. dry radiographs are prodced in a very short time
c. a much smaller space is needed
d. All of the above
d
These two by-products of development contain silver that cannot be disposed in a septic system:
a. radiographs and developer
b. radiographs and fix solution
c. radiographs and rinse
d. fix and rinse
b
Which of the following is not required on the label ID of a radiograph?
a. initials of radiographer
b. date taken
c. patient name and owner name
d. name and address of hospital or veterinarian
a
All of the following are legally valid methods of labeling a radiograph except:
a. lead-impregnated tape
b. lead marker
c. permanent marker after development
d. photoimprinting label system
c
T or F:
The radiographer must recover silver in the veterinary clinic.
False: Gold and silver refiners exist who purchase fix solutions and films for reclamation of silver.
The most effective types of darkroom doors include:
a. doors that don't lock
b. revolving door system
c. double door system
d. both b and c are correct
d
List and describe the 3 qualities of a good darkroom.
1. Clean
2. Organized
3. Completely lightproof
Describe an organized darkroom
- Has a dry side and a wet side
- Dry side
Cassettes are unloaded and reloaded. Tabletop that allows frequent cleaning. Film hangers above the table
- Wet side
State the various methods of darkroom lightproofing
Locate the light leaks
Fit the door with strips of felt or rubber molding
Bolt lock or doorknob lock
White painted wall
State the correct safelight to be used with blue-light- and green-light-sensitive film
bulb <15 watts or less with a special dark red filter
Direct or indirect
List the 5 basic steps of film processing
1. developing
2. rinsing
3. fixing
4. washing
5. drying
Describe the primary function of the developer
To convert the exposed silver halide crystals to black metallic silver
List and describe the six developer components
1. Developing agents
2. Accelerators
3. Preservatives
4. Restrainers
5. Hardeners
6. Solvent
State the function of the rinse bath
1. To stop the developing process
2. Rinse teh developer from the film
3. Prevent carryover contamination to the fixer
State the two basic purposes of the fix bath
1. Clears the unexposed silver halide crystals from the film
2. Hardens the gelatin coating so that it can be dried without damaging the film surface
List and describe the 6 components that make up the fix solution
1. Clearning agents
2. Preservatives
3. Hardeners
4. Acidifiers
5. Buffers
6. Solvent
Describe the methods of recognizing exhausted chemicals
Developer solution turns brown to green
fogging for fixer
List and describe the nine steps in manual processing
1. Preparation
2. Unloading the cassette
3. Loading the film on a hanger
4. Developing the film
5. Rinsing the film
6. Fixing the film
7. Washing the film
8. Optional final rinse
9. Drying the film
Describe how an automatic processor works
Automatic processors involve roughly the same routine as manual processing, except they operate at much higher temperatures and have specially formulated
chemicals to speed developent.
List the basic maintenance procedures
1. Solution level check
2. Replenishment rate check
3. Temperature check
4. Roller operation check
5. Rinsing and wiping of all roller racks
6. Regular cleaning of tanks

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