Radiographic exposure test 2
Terms
undefined, object
copy deck
- kVp affects ______/_______ of the beam
- quality/penetrability
- You must select optimum kVp for adequate ________ and thus adequate _______ and ________
- penetration; density; contrast
- No amount of ___ will compensate for insufficient ___
- mAs; kVp
- Extremely low mAs->_______ can occur
- Quantum mottle
- kVp inc->Penetrability ___->Density ___
- inc; inc
- __% change in kVp yields a visible change in image density
- 5
- __% change in kVp will change image density by a factor of 2 (doubles or halves density)
- 15
- At 70 kVp, a 15% change is about __ kVp
- 10
- To maintain density if you increase kVp by 15%:
- Decrease mAs by 50% (1/2 mAs)
- To maintain density if you decrease kVp by 15%:
- Increase mAs by 100% (double mAs)
- Using kVp to maintain density is possible but not desirable because:
- Changing kVp also changes contrast and noise
- 15% rule for kVp and density (formula)
- [(kVp2)^4]/[(kVp1)^4] = D2/D1
- The ____ the kVp, the less change you need to see a visible difference in density
- lower
- What would have a greater effect on image density, a 50% change in kVp or a 50% change in mAs?
- 50% change in kVp
- kVp inc->Noise ___
- inc
- kVp inc->Photoelectric effect ___ and Compton interactions ___->Scatter ___->Fog density ___
- dec; inc; inc; inc
- kVp inc->Light output from intensifying screen ___->Density ___
- inc; inc
- kVp inc->Energy of light from intensifying screen ___
- stays the same
- kVp inc->Contrast ___
- dec
- High kVp->_____-scale contrast->______ exposure latitude
- long; wide
- Low kVp->_____-scale contrast->______ exposure latitude
- short; narrow
- Hand/wrist
- 54 kVp
- Elbow/foot
- 60-62 kVp
- Ankle
- 64 kVp
- Knee
- 70 kVp
- Iodine procedures (IVP, cystogram)
- 70-76 kVp
- Femur
- 74-76 kVp
- Shoulder
- 74-76 kVp
- Sinus
- 74-76 kVp
- Ribs
- 74-76 kVp
- Cervical spine
- 74-76 kVp
- Thoracic spine
- 74-76 kVp
- Pelvis
- 76-80 kVp
- Abdomen
- 76-80 kVp
- Lumbar spine
- 76-80 kVp
- Non-grid chest
- 80 kVp
- Air contrast/barium studies
- 90-94 kVp
- Esophagram
- 90 kVp
- Solid-column barium studies
- 116-120 kVp
- Grid chest
- 110-120 kVp
- Intensifying screen speed inc->Density ___ and contrast ___
- inc; inc
- film that is particularly sensitive to fluorescent light of x-ray intensifying screens
- screen-type x-ray film
- type of film that reacts more to radiation than to light
- direct exposure film (no-screen film)
- Film that is used with intensifying screens reacts more to ______, especially to a certain ________ of _______
- light; color; light
- What is it called when film reacts to a specific color of light?
- spectral matching
- The film emulsion is designed to be chemically sensitive to a specific ______ or _______ of light
- frequency; wavelength
- 2 common color-specific films (for a specific intensifying screen)
- Blue-sensitive film and green-sensitive film
- What type of intensifying screens emit a blue light?
- Calcium tungstate
- What type of intensifying screens emit a green light?
- Rare earth screens
- __________ film is sensitive to all colors except red
- Orthochromatic
- What colors is orthochromatic film sensitive to?
- All except red
- What is the most common type of film used today?
- Orthochromatic film
- What color are safety lights?
- Red
- Orthochromatic film should be used with ________ screens
- rare earth
- X-ray film consists of an emulsion of ______ _______ crystals suspended in gelatin that is coated on both sides of a transparent blue-tinted polyester ______
- silver bromide; base
- What is the innermost layer of the film?
- Film base
- What provides support for the emulsion and also provides a degree of stiffness for handling?
- Film base
- What is the film base made of?
- Polyester material, dyed a blue tint
- Why is the film base tinted blue?
- To help visualize contrast in the image
- What is on both sides of the film base?
- Adhesive subcoating
- What is the purpose of the adhesive subcoating on both sides of the film base?
- To help emulsion adhere to the film base
- What occurs when the emulsion is exposed by light from the opposite side intensifying screen?
- Crossover
- What is the part of the film that contains light-absorbing dye to eliminate crossover?
- Crossover control layer
- What is the film emulsion made of?
- Silver bromide crystals suspended in gelatin
- Silver is added to ____ acid to produce _______ ______->Then combined with ________ ______ to form silver bromide crystals
- nitric; silver nitrate; potassium bromide
- What is it called when emulsion is placed on both sides of the film base, and why is it done?
- "Dual-emulsion film;" for a more efficient exposure
- How thick is the emulsion layer?
- 1/1000th of an inch
- What is the purpose of the emulsion layer?
- To absorb radiation and produce a latent image
- An important aspect of the emulsion is its ability to _______ during processing
- swell
- Why is it important for the film emulsion to swell during processing?
- So the processing chemicals can interact with the silver in the emulsion
- What color is the gelatin in the emulsion, and why?
- Clear/transparent, so no optical impairment of the image occurs (otherwise it would alter the color and contrast of the image)
- What is the outermost layer of the film?
- Protective coating (tough coat; T-coat; supercoat)
- What protects the emulsion layer from scratches?
- A thin coat of varnish called the protective coating (T-coat; tough coat; supercoat)
- Does the protective coating of the film have to be thin or thick, and why?
- Thin, because when the film is processed the protective coating must be removed so chemicals can get to the emulsion
- Is mammography film usually single-emulsion or double-emulsion?
- Single-emulsion
- Film is stored enclosed in what type of bag?
- Photo-inert or metal-foil (light tight and air tight)
- Radiographic film has to be kept in a cool, dry place. What temperature and humidity level should radiographic film be stored in?
- Temp range of 50-70 degrees F. Humidity level of 40-60%
- Even though film is stored in a light-tight, air-tight package, it is still exposed to...
- natural background radiation and becomes fogged the longer it is stored
- Does film have an expiration date?
- Yes
- Use film by the ________________ principle. Does the older film or newer film get used first?
- First In, First Out. Oldest film gets used first
- Darkrooms (and other film storage areas) should be lined with...
- lead
- Where should you handle film to reduce the chance of finger marks and smudges on the film?
- As close to the edge as possible
- Before handling film, your hands should be...
- clean and dry
- Name the layers of double-emulsion film in order from one side to the other
-
Protective coating
Emulsion
Film base
Emulsion
Protective coating - What type of marks can occur when you remove film from a cassette or when you remove film from a box of film?
- Static marks
- Static marks can occur from rubbing on material such as...
- silk, nylon, or rayon
- Is static more likely when humidity is low or high?
- Low
- 3 basic types of static
- Crown, tree, smudge
- Generally, a high speed film is _____ as fast as a medium speed film
- twice
- Film speed inc->Density ___, contrast slightly ___, and sharpness of detail ___
- inc; inc; dec
- Why is detail reduced when using a higher speed film?
- Because of the increased amount or thickness of the emulsion or larger crystal size
- How can film be made more sensitive or "faster"? What is the preferred method for changing film speed?
- By increasing crystal size, crystal concentration, or emulsion thickness. Changing emulsion thickness
- Is reciprocity law failure more pronounced when using low-speed films or high-speed films?
- High-speed films
- Films may be designed for a specific scale of contrast. For example, _____ contrast film may be used with a detail/extremity/slow screen
- high
- How do you determine total system speed?
- Multiply film speed by screen speed and divide by 100
- the inherent ability of the film emulsion to react to radiation and record a range of densities
- film contrast
- the inherent ability of the film to record a long range of density levels on the radiograph
- film latitude
- What will result in higher contrast, exposing film directly to x-rays or exposing film to x-rays in combination with intensifying screens?
- Using intensifying screens
- High latitude film will produce a _____ scale of contrast (____ contrast)
- long; low
- Low latitude film will produce a _____ scale of contrast (____ contrast)
- short; high
- ______ image is formed by exposing silver halide crystals
- Latent
- To contribute to the image, a crystal in the film emulsion must meet 3 requirements:
-
1-Crystal must contain a sensitivity speck
2-Crystal must be struck with photons of energy (light or x-ray)
3-Crystal must be struck repeatedly with photons of energy to record patient info and contribute to image - What is a sensitivity speck?
- An impurity in the crystal that allows the crystal to turn black; development center
- Do all crystals have a sensitivity speck?
- No. That is why gelatin in emulsion layer is saturated with crystals, so there is a greater probability of crystals with sensitivity specks being exposed
- More photons strike crystal->The _______ the crystal becomes
- blacker
- What does the Gurney-Mott theory relate to?
- Latent image formation
- Crystal is struck by photon->__ are given off by crystal and then go to the _____________, where they attract ____________
- e-; sensitivity speck; positive silver ions
- After crystal is struck by x-ray, crystal gives off e-, e- go to sensitivity speck, and e- attract positive silver ions, the crystal is considered ______
- broken
- After crystal is broken, chemicals can...
- react with crystal and make it turn black
- Is a silver bromide crystal more sensitive to light/x-ray before or after it is broken?
- After it is broken
- Is film more sensitive to light/x-ray before or after it is exposed?
- After
- What is the processing room also called?
- Darkroom
- What is the light-tight area where films can be inserted into and removed from cassettes?
- Darkroom (processing room)
- What type of processor is cheap and used in smaller places?
- Desktop processor
- After you place film into a desktop processor...
- you can turn on the light or open the door because the inside of the processor is light-tight
- What is another name for a multiloader?
- Daylight processor
- Multiloader (daylight processor) is similar to...
- a CR reader
- Multiloaders are manufactured to be used with one specific type of ______
- cassette
- Darkroom must be well _________ because of chemicals. Optimal _____ and _______ ranges must also be maintained
- ventilated; temp; humidity
- Where is film kept?
- Film bin
- What is the box that opens from the outside of the darkroom to the inside?
- Pass box
- Can both sides of the pass box be open at the same time?
- No
- Are safelights 100% safe?
- No; eventually safelights can fog film
- An exposed film is __x more sensitive to safelight than unexposed film
- 8
- What type of safelights should be used, if possible?
- Indirect
- How are safelights named? What are 2 names of safelights?
- By name of safelight filter. Kodak GBX and Wratten 6B
- Development of film changes silver bromide crystals into...
- black metallic silver
- What part of processing removes unexposed and undeveloped silver bromide from the emulsion?
- Fixing process
- What part of processing hardens the soft gelatin emulsion containing the metallic silver image?
- Fixing process
- What part of processing removes the fixing bath and silver salts from the film emulsion, and what does it use for removal?
- Washing process; water
- The transport system moves the film through different _____ in the processor
- tanks
- What turns the silver crystals black?
- Chemicals in the developer
- What is the solvent in the developer and fixer?
- Water
- Chemical reactions require that the chemicals...
- be dissolved in water
- the actual chemical that turns the exposed silver into black metallic silver
- reducer
- chemical that reduces silver bromide crystals to black metallic silver
- reducer
- What are the 2 types of reducers?
- Hydroquinone and phenidone
- Which reducer is responsible for the gray tones in the image?
- Phenidone
- Which reducer is responsible for the black tones in the image?
- Hydroquinone
- What softens the emulsion so reducers can interact with silver?
- Activator
- What acts as an alkaline catalyst for reducers?
- Activator
- What chemicals are included in the developer tank?
-
-Solvent
-Reducer
-Activator
-Preservative
-Restrainer
-Hardener - What chemicals are found in the fixer tank?
-
-Solvent
-Acidifier
-Clearing agent
-Hardener
-Preservative - What chemicals are found in both the developer tank and in the fixer tank?
- Solvent, preservative, and hardener
- What controls the activity of the reducing agents?
- Preservative
- What helps control oxidation?
- Preservative
- What maintains the life of the solutions in the developer tank and in the fixer tank?
- Preservative
- When solutions in the developer or fixer tanks are exposed to oxygen, the life of the solution is...
- shortened
- Developer solution is _______ as it ______ the film emulsion
- oxidized; reduces
- What limits the reducers to reacting with only those crystals that have been exposed?
- Restrainer
- What checks the action of the reducers and prevents over-development fog?
- Restrainer
- What limits the amount of softening of the emulsion caused by the activator?
- Hardener
- What neutralizes remaining developer solution in the emulsion?
- Acidifier
- What acts as an acid catalyst for clearing and hardening agents?
- Acidifier
- What changes the underexposed or unexposed/undeveloped crystals into silver salts that are removed from the emulsion?
- Clearing agent
- What removes unexposed silver bromide crystals from the emulsion?
- Clearing agent
- What restrains the swelling of the emulsion and completely hardens it so film can be handled?
- Hardener
- What shrinks and hardens emulsion for extended durability?
- Hardener
- What assists in clearing film and also helps prevent oxidation in the fixer?
- Preservative
- What are some processing variables?
- Time, temp, and solution in developer; time, temp, and solution in fixer
- Time in developer inc->Image density ___
- inc
- Temp in developer inc->Density ___
- inc
- If developer solution is weak or old, will film be underdeveloped (light) or overdeveloped (dark)?
- Underdeveloped
- If fixer solution is in the developer, will film be underdeveloped (light) or overdeveloped (dark)?
- Underdeveloped
- If developer solution is very strong or concentrated, will film be underdeveloped (light) or overdeveloped (dark)?
- Overdeveloped because of chemical fog
- Increasing development time, temp, or concentration increases image _____ and also image ______ (up to a certain point, past which excessive development time will turn the entire film black and destroy contrast)
- density; contrast
- Increasing development _____, ______, or ________ increases image density and image contrast up to a point
- time, temp, concentration
- Excessive time in fixer->Film will be too _____ and may become _____ and crack
- hard; brittle
- Fixer temp inc->Speed of fixation ___
- inc
- If fixer solution is old, weak, or insufficient, film will come out...
- sticky and wet
- If fixer solution is underconcentrated, film will come out...
- sticky and wet
- If fixer solution is too concentrated, film will come out...
- overhardened
- Insufficient fixation time, temp, and concentration can result in...
- emulsion damage and discoloration
- Excessive fixation time, temp, or concentration makes film...
- brittle
- Does film processing affect geometrical factors of the image?
- No, just photographic (visibility) functions
- Automatic processors allow more ________ results to be obtained in much ____ time
- consistent; less
- What type of processors greatly reduce time for film development?
- Automatic processors
- What tanks are included in an automatic processor?
- Developer, fixer, washer, and dryer compartment
- How long does it take an automatic processor to develop a film?
- 1-4 min (many take 90 sec)
- Systems within the automatic processor
- Transport, electrical, recirculation, replenishment, temperature control, silver reclamation
- How should you place film in the feed tray of the processor?
- Crosswise
- Orientation of the film in the feed tray controls how much ________ is going to occur
- replenishment
- After film is completely inside processor, a ______ goes off and then you can...
- buzzer; open door of darkroom
- What is placed over the tanks in the processor to help prevent oxidation?
- Dust covers
- What is the first set of rollers the film comes into contact with?
- Detection rack (feed rack)
- When film passes through the rollers of the ___________, the rollers are pushed apart which activates a microswitch that turns on ____________
- detection rack (feed rack); replenishment
- Replenishment system pumps fresh replenisher solution into both _______ and _____ tanks
- developer; fixer
- When does replenishment stop?
- After film has passed through rollers and rollers come back together, turning off the microswitch
- What is at the top of the detection rack (feed rack) to direct the film down into the developer tank?
- Guide shoes
- Whenever film must turn in the processor, ______ are there to direct the film
- guide shoes
- What transports film up and down through the tanks?
- Planetary rollers
- What is the large roller at the bottom where the film turns back up?
- Solar roller
- What squeezes most of the solution off the film before it reaches the next tank in the processor?
- Squeegee rollers
- After squeegee rollers, what is located at the top of each tank?
- Crossover rack
- What is crossover rack made of?
- Roller and 2 guide shoes
- What is found in the dryer rack?
- Rollers alternated with air tubes
- What part of the automatic processor provides power to operate the motors, pumps, blowers, and heaters?
- Electrical system
- What part of the automatic processor has a dedicated pump and tubing lines that carry the tank solutions through a heat exchanger and back into the tanks?
- Circulation system
- What does the heat exchanger in the circulation system do?
- Maintains temp, since it is best to keep the solutions at a certain temp
- Recirculation lines of the developer solution have a special ________ to prevent debris from accumulating in the developer tank
- filter
- What will happen if dirt and debris accumulate in the developer tank?
- Every time a film goes through the developer, dirt and debris on the rollers will stick to the film
- As film goes through the automatic processor and uses up solution, the __________ puts new solution in the tank
- replenishment system
- What is the visual indicator that replenishment is taking place?
- Replenishment indicator (black balls)
- For one 14x17 CW film, the replenishment rate for the developer is _____ ccs and the replenishment rate for the fixer is _____ ccs
- 60-70; 110-120
- Where are the replenishment tanks?
- External to the processor
- A float is on top of the developer solution to prevent...
- oxidation
- The water tank must also be replenished, since it uses about ____ gallons per minute. The water must also be mixed up or it will become...
- 1-3; stagnant and develop algae
- The temperature gauge is on the front of the processor to tell the temperature of the ________. There may also be a temperature gauge for the _______
- developer; dryer
- Normal temp in processor is usually between ____ degrees Fahrenheit
- 92-96
- Anything that heats up solution in the processor is part of the _______________ and is used to maintain a constant temperature for the solution
- temperature control system
- Why do we save the silver that is washed off the film?
-
-Worldwide supply of silver is dwindling
-Silver can be sold since it has monetary value
-Some states have laws that say you must save silver - Film that has been totally exposed is called _____ film, and it has ____ of the silver available to recover
- black; some
- Film that has been partially exposed is called _____ film, and it has ____ of the silver available to recover
- exposed; some
- Which has the most silver available to recover: green, clear, black, or exposed film?
- Green
- Where is the silver reclamation system?
- Attached to processor
- 3 approaches to recovering silver from processor
-
-Metallic replacement
-Electrolysis
-Chemical precipitation - In ____________, the solution goes through a canister that contains iron. Silver in the solution reacts with iron and remains in the tank
- metallic replacement
- In _________, solution passes through a canister with an electric current. Silver attaches to cathode
- electrolysis
- In _____________, chemicals are mixed with the silver solution. A chemical reaction occurs and the silver drops to the bottom of the tank. The remaining solution is washed out of the tank
- chemical precipitation
- When a film is scratched, it appears like...
- little white lines on film because of the emulsion that has been removed
- Guide shoe marks appear like...
- vertical white lines on film
- What are the artifacts that occur because of dirt/debris on the planetary roller?
- Pi lines (since they appear at 3.14" apart on the film)
- the measurement of the response of x-ray film (emulsion) to exposure and processing
- sensitometry
- the quantitative measurement of film response to exposure and processing conditions
- sensitometry
- We measure sensitometric properties with...
- a characteristic curve (H&D curve)
- What is H&D?
- Hurter and Driffield
- H&D curve is a graph produced by exposing a film and plotting various _____ levels against the logarithm of ________ that produced them
- density; exposures
- 2 different ways to make an H&D curve:
-
-Expose a regular film with a step wedge
-Expose a film with a sensitometer - Which is preferred for sensitometry, a sensitometer or a step wedge? Why?
- Sensitometer. Sensitometer creates a uniform exposure each time you expose the film
- What is D-min (minimum density) for an H&D curve?
- Toe (bottom curve of graph)
- The toe would represent the _________ part of the step wedge or the ______ step of the sensitometer
- thickest; lightest
- What is the slope of an H&D curve, and what does it represent?
- The body or straight line portion. The slope represents film contrast
- What is D-max (maximum density) on an H&D curve?
- Shoulder (at top curve of graph)
- The shoulder would represent the _________ part of the step wedge or the ______ step of the sensitometer
- thinnest; darkest
- Will the densitometer reading (optical density) of a film ever be zero?
- No. The blue tint of the base and background radiation add density to the film
- Where does base+fog density come from?
- The blue tint of the film base and the background radiation
- What are normal base+fog values?
- 0.18-0.22
- Base+fog should never exceed...
- 0.25 (since the useful range of densities is 0.25-2.5)
- What is the primary value of the H&D curve?
- To compare different types of films or different processing conditions
- the relative exposure required to produce a density of 1.0 + base+fog
- film speed
- The less exposure required to produce density on the film, the _____ the film
- faster
- On a graph of H&D curves, is the film furthest to the right or the film furthest to the left faster?
- Left
- the point where 1.0 + base+fog will interact with the H&D curve
- speed point
- On a graph of H&D curves, whichever film has a speed point furthest to the ______ is faster
- left
- Contrast formula
-
Contrast = (OD2-OD1)/(LRE2-LRE1)
-OD2 represents optical density of 2.0 + base+fog
-OD1 represents optical density of 0.25 + base+fog
-LRE is log relative exposure - The contrast of a line at a __ degree angle will always be 1
- 45
- The contrast of a line at a 45 degree angle is always...
- 1
- If the slope is steeper than 45 degrees, the contrast will be ____ than 1 (_____ contrast)
- more; high
- If the slope is less steep than 45 degrees, the contrast will be ____ than 1 (_____ contrast)
- less; low
- contrast that is measured between 2 points on the H&D curve (1 point being 0.25 + base+fog; the other point being 2.0 + base+fog)
- average gradient
- exposure range over which the IR responds with diagnostically useful optical density
- film latitude
- If H&D curve has a steep slope, film latitude is ______
- wider
- IGNORE CARD BEFORE THIS ONE! If H&D curve has a steep slope, film latitude is...
- narrower
- If H&D curve has a less steep slope, film latitude is...
- wider
- You must use _________ to create processor control charts
- sensitometry
- To compare different processing conditions, you must have a...
- processor control chart
- The processor control chart is a...
- quality control method
- 4 components of a processor control chart
-
-Speed
-Contrast
-Fog
-Temperature (is also recommended) - To make a processor control chart, you should record speed, contrast, fog, and temp at the same time on a _______ basis for at least ______
- daily; 1 week