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92 Cards in this Set
- Front
- Back
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Absorbing layer
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A light-absorbing dye used in the screen to absorb light directed toward it by the phosphor layer.
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Base
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The bottom layer of the intensifying screen, found farthest from the film.
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Base layer
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Polyester (plastic) that gives the film physical stability.
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charge-coupled device (CCD)
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Detectors used in direct digital radiography that record flashes of light produced by the exit x-rays interacting with a screen that scintillates.
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Crossover
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Refers to light that has been produced by an intensifying screen that exposes one emulsion and then crosses over the base layer of the film to expose the other emulsion.
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direct-exposure film
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Single emulsion, nonscreen film that is significantly thicker than screen film and requires more development time.
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double-emulsion film
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Radiographic film having an emulsion coating on both sides of the base.
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Emulsion
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The radiation-sensitive and light-sensitive layer of the film that consists of silver halide crystals suspended in gelatin.
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film-screen contact
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The amount of direct contact between the film and intensifying screens
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flat panel direct capture detector
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An image receptor used in direct digital radiography that absorbs radiation and converts the energy into electrical signals.
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fluorescence
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Refers to the ability of phosphors to emit visible light only while exposed to x-rays.
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imaging plate (IP)
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The flexible plate inside the computed radiography cassette where the photon intensities are absorbed by the photostimulable phosphor.
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intensifying screen
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a device found in radiographic cassettes that contains phosphorus that convert X-ray energy into light that then exposes radiographic film.
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latent image
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The invisible image that exists on the exposed film before it has been chemically processed
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Latent image center
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Several sensitivity specks with many silver ions attracted to them.
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luminescence
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The emission of light from the screen when stimulated by radiation.
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Manifest image
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The visible image on film after processing.
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mAs conversion formula for screens
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A formula used in determining how to compensate or adjust mAs when changing intensifying screen system speeds.
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phosphor
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A chemical compound that emits visible light when struck by radiation.
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Phosphor layer
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Active layer of the screen that contains the phosphor material that absorbs the transmitted x-rays and converts them to visible light.
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Phosphorescence
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Occurs when screen phosphors continue to emit light after the x-ray exposure has stopped.
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Protective layer
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The outermost layer of the screen, found closest to the film and made of plastic to protect the fragile phosphor material beneath it
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Quantum mottle
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The statistical fluctuation in the quantity of x-ray photons that contribute to image formation per square millimeter which results in a radiographic image that is grainy, or noisy, in appearance.
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Rare earth elements
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A common phosphor material that consists of some element that ranges in atomic number from 57 to 71 on the periodic table.
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Reflecting layer
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Either a magnesium oxide or titanium dioxide material used in the screen to reflect all of the light toward the film.
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Relative speed
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The ability of the screen to produce visible light, and therefore density. Relative speed results from comparing screen-film systems based on the amount of light (and density) produced for a given exposure.
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Screen film
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Film more sensitive to light and less sensitive to x-rays and is intended to be used with one or two intensifying screens.
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Screen speed
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The capability of a screen phosphor to produce visible light. A faster screen produces more light than a slower screen for the same radiation exposure.
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Silver halide
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The material that is sensitive to radiation and light in the film's emulsion.
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Single-emulsion screen film
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Radiographic film having only one emulsion layer that is used with a single intensifying screen.
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Spectral emission
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Refers to the color of light produced by a particular intensifying screen.
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Spectral matching
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Refers to correctly matching the color sensitivity of the film to the color emission of the intensifying screen.
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Spectral sensitivity
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Refers to the color of light to which a particular film is most sensitive.
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Film speed
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The degree to which the film emulsion is sensitive to x-rays or light and indicates the amount of optical density produced for a given amount of radiation exposure
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Supercoat
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A durable protective layer on film that is intended to prevent damage to the sensitive emulsion layer underneath it.
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1. The radiation- and light-sensitive layer of radiographic film is the __________ layer.
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B. emulsion
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2. Crossover is a radiographic problem because it decreases
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C. recorded detail.
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3. Spectral sensitivity refers to the color sensitivity of
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A. radiographic film.
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4. According to the Gurney-Mott theory of latent image formation, electrons liberated by radiation or light exposure are attracted to the
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B. sensitivity speck.
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5. Silver halide crystals are found in the film's
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C. emulsion.
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6. Which of the following is the most common type of film for general radiographic examinations?
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C. Screen, double-emulsion
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7. Poor film-screen contact results in a loss of
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C. recorded detail.
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8. The purpose of intensifying screens is to
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D. decrease patient dose.
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9. The most common phosphor material used in today's intensifying screens is/are
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B. rare earth elements.
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10.The speed of an intensifying screen can be reduced by adding
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D. dye to the phosphor layer.
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12. If 25 mAs is used with a 500 speed film-screen system to produce an optimal image, how much mAs is needed to produce the same density with a 100 speed system?
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C. 125 mAs
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13. Typically, as screen speed decreases, ___________ decreases.
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A. density
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14. Which of the following strategies reduces quantum mottle?
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C. Reducing kVp and increasing mAs
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15. The wire mesh test tool is used to evaluate
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D film-screen contact.
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16. The image receptor for computed radiography (CR) is composed of
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D. barium fluorohalide.
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17. Both types of DR flat panel detector digital imaging systems convert x-ray energy into
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A. electric charges.
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18. The latent image that consists of electrons trapped in the phosphor layer is found with
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D. CR.
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19.Exposed CR imaging plates should be processed within __________ hour(s) to avoid any loss of image quality because of fading.
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A. 1
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20. Thin film transistors (TFTs) are used in DR systems to
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C. temporarily store the electric charge.
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artifact
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Any unwanted image on a radiograph.
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automatic processor
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A device that encompasses chemical tanks, a roller transport system, and a dryer system for the processing of radiographic film.
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crossover roller
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An assembly that moves the film from one tank to another and into the dryer assembly.
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developing or reducing agents
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The purpose of the developing or reducing agents is to reduce exposed silver halide to metallic silver and to add electrons to exposed silver halide. Two chemicals are used to accomplish this purpose: phenidone and hydroquinone. (not in back matter)
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diffusion
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The process used to remove fixing solution from the surface of the film by exposing the film to water that contains less thiosulfate than the film does.
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entrance roller assembly
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Rollers that are covered with corrugated rubber to assist in straightening out the path of the film so that it moves through the processor efficiently.
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feed tray
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A flat metal surface with an edge on either side that permits the film to enter the processor easily and correctly aligned.
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FIFO
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An acronym for first in/first out. This system requires that film received first be the film that is first rotated into the working film supply.
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fixing agent
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Chemical used in the fixer to clear undeveloped silver halide from the film.
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flood replenishment
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The replenishment of solutions that occurs at timed intervals, independent of the size or number of films processed.
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guide plates
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Slightly curved metal plates that properly guide the leading edge of the moving film through the roller assembly.
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immersion heater
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A heating coil that is immersed in the bottom of the developer and fixer tank. It is thermostatically controlled to heat the solution to its proper temperature and maintain that temperature as long as the processor is turned on
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latent image
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The invisible image that exists on the exposed film before it has been chemically processed.
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manifest image
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The visible image on film after processing.
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processing cycle
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The amount of time it takes to process a single piece of film..
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processor capacity
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The number of films that can be processed per hour.
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recirculation system
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Acts to circulate the solutions in each tank by pumping solution out of one portion of the tank and returning it to a different location within the same tank from which it was removed.
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replenishment
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The replacement of fresh developer and fixer solutions after the loss of chemicals during processing.
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silver recovery
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The removal of silver from used fixer solution.
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standby control
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An electric circuit that shuts off power to the roller assemblies when the processor is not being used.
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superadditivity
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Chemicals produce a greater effect together than they would individually.
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transport rollers
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Rollers on each side of a roller assembly to move the film through the chemical tanks and dryer assembly.
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turnaround roller
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B, Turnaround rollers at the bottom of the assembly turn the film from moving down to moving up. (not in the back matter)
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1. Conversion of the latent image to the manifest image is accomplished by
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B. radiographic processing.
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2. The sequential order for processing radiographic film is
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C. developing, fixing, washing, drying.
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3. Which of the following solutions are responsible for reducing the exposed silver halide crystals to black metallic silver: (1) ammonium thiosulfate, (2) hydroquinone, or (3) phenidone?
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C. 2 and 3 only
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4. The pH environment required for proper development of the exposed film is
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A. alkaline
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5. The fixing agent used to clear the undeveloped silver halide crystals is
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D. ammonium thiosulfate.
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6. Staining or fading of the permanent image results when too much ________ remains on the film with improper washing.
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C. thiosulfate
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7. Finished radiographs should retain what percentage of their moisture?
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B. 10% to 15%
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8. The type of roller responsible for moving the film from the bottom of the tank upward is a(n) ________ roller
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C. turnaround
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9. The type of roller responsible for moving the film from one tank to another is a(n) ________ roller.
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D. crossover
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10. Processing chemicals must be replenished to maintain activity and volume when depleted primarily by
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A. exhaustion.
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11. Decreasing the developer temperature
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C. decreases density.
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12. Under what environmental conditions should radiographic film be stored?
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D. Temperature between 50° and 70° F and relative humidity between 40% and 60%
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13. Safelight filters are chosen based on the
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C. film sensitivity.
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14. The type of silver-recovery unit that uses an electrically charged drum to attract the silver is called a(n) ________ unit.
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B. electrolytic
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15. A common plus-density artifact caused from bending the film is
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A. half-moon marks.
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