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.
- 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
- 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.
- _____ exposure requires about 34 times as many photons as _______ to obtain the same density.
- Direct film
- 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.
- __________ is strong and absorbs x-rays well, but doesn't convert to light very efficiently.
- Calcium tungstate
- Screens are rated by _____ & ____.
- ________ 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.
- Substance that can emit light
- Larger crystals emit _____ light and require ____ radiation for an exposure.
- As the crystal size increases, the detail of the image ______.
- 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.
- Slow screens have _____ crystals.
- Smaller crystals emit _____ light and require ____ radiation.
- ______ crystals give fine detail.
- Increased screen thickness ________ absorption and efficiency.
- ________ layer of phosphor decrease detail.
- Decreased phosphor layer thickness ________ absorption and efficiency.
- ______ phosphor layer increase detail.
- 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 ______.
- 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
density at lower settings
- Rare earth screens cut down exposure by ____%
- Rare earth screens' phosphors emit light in the ______ spectrum, so it is best to use film that is sensitive to this light.
- _________ cassettes used to be used for detail studies.
- Non-screen cassettes required ________
- a lot of radiation
- With non-screen cassettes, you should use ________ film, but can use ____ film with reduced detail.
- 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
- 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 __________
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.
- 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
6. certain gasses
- X-ray film should be stored in a ________
- film bin
- Ideal temperature of x-ray film
- Ideal humidity of x-ray film
- 4 gasses x-ray film is sensitive to
- 1. H2S
- 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
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 ____
- High detail film is ______ film
- ______ film requires less exposure, but produces a grainier image that lacks definition
- _______ film requires more radiation but produce a clearer image
- _______ film is most widely used in veterinary medicine
- 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
- Film screen combinations are assigned __________ values
- Common film-screen combinations used in veterinary medicine
- The ______ is a rigid frilm holder designed to hold the x-ray film and intensifying screens in close contact.
- 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
- 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
- To absorb backscatter, the back of most cassettes is lined with:
c. intensifying screen
d. x-ray film
- 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
- 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
- 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
- A processed film that has not been exposed to ionizing radiation or visible light will appear:
- 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
- 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
- _______ is the degree of blackness, or how much white light passes through the film
- Film density
- A very _____ film is very dark.
- A radiograph that lacks density appears ______.
- ______ density is the quantity of matter per unit of the volume.
- Subject density affects ____ density.
- X-ray cause silver halide to turn to ______ and turn _____ in the developing process.
- A dense subject produces a ____ area on the film underneath it.
- A less dense subject will produce a _______ area on the film underneath it.
- _________ is a subject that absorbs x-ray and therefore produces a less dense radiograph.
- _______ is a subject that lets x-ray through and therefore produces a more dense image.
- 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.
- 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 ____.
- ______ x _______ = mAs
- 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.
- 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?
- What mA should you select if you want a 5mAs and your time is set at 1/60 second?
- 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.
- kVp must vary ________ with mAs in order to maintain film density.
- 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.
- If the original setting is 64 kVp and 5 mAs, what would the new kVp be if mAs was changed to 2.5 mAs.
- If the original setting is 64 kVp and 2.5 mAs, what would the new kVp be if mAs was changed to 5 mAs.
- 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
- Add ___ kVp per cm between 80-100 kVp
- Add ___ kVp per cm over 100 kVp
- 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
- Ways to increase penetrating power of x-rays include:
a. increasing kVp
b. increasing the time setting
c. increasing thermionic emission
d. increasing mAs
- The mAs for 1000 mA and 1/10 sec is:
a. 10 mAs
b. 10,000 mAs
c. 100 mAs
d. 1 mAs
- According to Santes' rule, if a cat's abdomen measures 12 cm, kVp is:
- 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
- 1% of the energy produced at the anode is in the form of:
d. none of the above
- 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
- 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.
- The potential difference between the anode and cathode is measure in:
- A higher kVp setting allows for a _____ mAs and ______ exposure time.
a. higher; lower
b. lower; higher
c. lower; lower
d. higher; higher
- 3 qualities that constitute a good darkroom
- 1. clean
- _______ provides light without ruining film
- Use a _______ for safelight
- frosted 6.5-10 watt bulb
- Do not position safelight closer than __ feet to the work area
- _____ is a chemical solution that converts the latent image to a visible image by converting the exposed silver halide crystals to silver metal.
- Developer temperature affects the ________.
- developing time
- Developer consists of:
- 1. developing agents
- _________ 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.
- Substances such as potassium carbonate or sodium carbonate are used to increase the _________ of developer.
- 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 of developer maintain a stable development rate and prevent __________.
- staining of the emulsion layer
- Oxidated developer looks _______
- ________ prevents the development of unexposed silver crystals.
- ________ of developer consists of water to dissolve the chemicals.
- 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.
- The film should be fixed for ____ the development time to ensure maximum hardening of the emulsion.
- 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
- 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
- Clearing agent does not affect __________ portion of the film.
- black metallic silver
- ______ preserves fixer.
- Fixer preservatives agent is _____.
- sodium sulfite
- ________ of the fixer prevents over swelling of the emulsion.
- ______ of fixer shorten the drying time by essentially preventing the film from getting too soggy.
- ________ accelerate action of the fix.
- _________ neutralize any developing solution that has gotten into the fixer
- _______ maintains desired pH of the fixer
- _______ stabilize the acidity of the fix
- ___________ 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
- 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
- What is the ideal pH at which to develop radiographs?
a. 9.8 to 11
b. 7.2 to 7.4
d. 7.8 to 9.8
- Unexposed silver halide crystals remaining on the film are removed at this stage.
a. rinsing or stop bath
- 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
- 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
- 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
- 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
- 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
- List and describe the 3 qualities of a good darkroom.
- 1. Clean
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
- 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
- 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
- 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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