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72 Cards in this Set
- Front
- Back
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Halation |
A special light absorbing dye used to reduce the reflection of light that is transmitted through the emulsion and base in order to counteract this effect |
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Manifest image |
The image after processing |
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EUROPE |
Electrons are used in reduction, oxidation produces electrons |
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Bushong's uses what theory to explain Latent Image Formation? |
Gurney-Mott |
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T or F: in the typical emulsion, 98% of the silver halide is silver bromide, the remainder is silver iodide |
True |
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Redox |
The term used to describe when oxidation and reduction occurs simultaneously |
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Reflective Layer |
This layer of the intensification screen intercepts light headed in other directions and redirects it towards the film |
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Sequestering Agents |
These agents help remove impurities from the emulsion and help stabilize the developing agents |
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The order of film bade development |
Glass, cellulose nitrate, cellulose triacetate, polyester, CR and Digital |
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Crossover racks |
Transports the film to the next assembly when it exits the top of the rack assembly |
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Fluorescence |
Visible light emitted ONLY while the phosphor is stimulated |
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6 Properties that affect screen speed that cannot be controlled by the Rad Tech |
1. Phosphor composition 2. Phosphor thickness 3. Dye 3. Crystal size 4. Reflective layer 5. Crystal concentration 6. Phosphor composition |
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Primary characteristics of radiographic intensifying screens a technologist should be concerned about |
1. Image noise 2. Screen Speed 3. Spatial Resolution |
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The purpose of the intensifying screen is to convert the _______ _______ into _________ _________ |
X-ray beam ; visible light |
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Characteristics of high quality base material |
1. Not prone to interact with phosphors 2. Rugged, moisture resistant 3. Resistant to Radiation "aging" (damage and discoloration) |
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Processing an X-ray changes silver ions into |
Black Metallic Silver |
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The active ingredient in the film's emulsion is: |
Silver Halide Crystals |
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3 conditions that affect the speed of the screen the CAN be controlled by the rad tech |
1. Radiation quality 2. Image processing 3. Temperature |
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High Conversion Efficiency can |
Increase noise |
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Calcium Tungstate is embedded into what layer of the intensifying screen? |
The phosphor layer |
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Image Forming Radiation |
X-rays that exit the body and interact with the image receptor |
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The overcoat protects the film from scratches, pressure and contamination during handling, processing, and storage which |
Allows for relatively rough manipulation of the film before exposure |
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Spectral matching |
When the light sensitivity of the xray film and the light emitting properties of the intensifying screens are the same |
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Earliest compound used in intensifying screens |
Calcium tungstate |
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Most common film used for general radiographt |
Double emulsion film |
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Proper sequence for processing film in an automatic processor |
Developer, fixer, rinse, dryer |
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Specific criteria for the use of laser sensitive film |
1. Handled in total darkness 2. Sensitive to red light |
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Conversion efficiency |
The phosphor should emit a large amount of light per photon interaction |
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Cellulose nitrate was replaced by cellulose triacetate primarily because of what reason? |
It was very flammable |
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In general, the higher the intensification factor, the ________ the spatial resolution |
Lower |
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What is the principle advantage of using intensifying screens? |
Less exposure to the patient |
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To reduce excessive radiation exposure to the patient, the following combination should be used: |
Cassette, rare earth screen, film combination |
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In an intensifying screen, the layer closest to the base is known as: |
The reflective layer |
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Light is emitted from what part of the intensification screen? |
The phosphor |
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Who is attributed with the discovery of xrays? |
Wilhelm Conrad Roentgen |
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Buffering agents contain these types of compounds which are caustic, very corrosive and can cause skin burns, they are called: |
Alkali |
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4 layers of the xray film |
Protective layer Emulsion Adhesive layer Base |
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The most significant affect that "crossover" has on the image is |
Blurring |
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The "heart" of the film is the |
Emulsion |
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The protective layer of film is also known by what two other common names? |
Overcoat and supercoat |
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Spatial resolution |
How small an object can be imaged |
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In reference to intensification screens, photoelectric absorption occurs with what electrons specifically? |
Inner |
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Spectral matching |
Light emitted from the intensification screen phosphors must be of proper wavelength so it will match the sensitivity of the xray film |
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Characteristics of the silver halide crystal that affect the film speed |
Size and concentration |
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Latent image |
The image after exposure but before processing |
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Typical shapes of a halide crystal |
Octahedral, polyhedral, tubular |
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Radiographic film is sensitive to |
Rough handling, chemicals, heat |
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Hypo retention is |
1. Excess fixer in the emulsion that has not cleared out 2. Can cause eventual degradation of the films quality long term 3. Is commonly manifested as a brownish color on the film over time |
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Terms associated with intensification screens |
Phosphor, antistatic screen cleaner, base, reflective layer, lanthanum |
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Intensification factor |
The ratio of the exposure required to produce a given OID with a screen, to that required to produce the same OID without a screen |
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Handling considerations of film |
Radiation, shelf life, heat and humidity |
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Isotropically |
Term used to describe light that is emitted with equal intensity in all directions |
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Two basic parts of the emulsion |
Gelatin and silver halide crystal |
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Replenishment system |
This system meters the proper amount of chemicals into each tank to maintain volume and chemical activity |
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Direct exposure film imaging typically has thicker emulsion, is rarely used today, was replaced by high detail film screen, is used with a cardboard holder and has a.. |
10-100 x's the patient exposure |
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Visible light is emitted after the phosphor is stimulated is known as |
Screen lag, after glow, phosphorescence |
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Line pair test |
A test for spatial resolution |
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Type of image receptors |
Fluoroscope, digital plate, cassette |
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Number that represents the "original" assignment of the par speed xray screen |
100 |
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Luminescent |
Any material that emits light in response to some outside stimulus |
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Conversion of the latent image to the manifest image is accomplished by? |
Radiographic processing |
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Charles Leonard |
Discovered that using two glass plates with the emulsion surfaces together enhanced the image and cut exposure time in half |
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The principle function of the gelatin is to |
Provide mechanical support for the silver halide crystal |
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If a radiograph is fogged, the radiographic density will |
Increase |
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Oxidation |
Produces electrons during the processing of film |
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Which film has the potential of greatest detail? |
Direct exposure |
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Circulation system |
Primary function: Agitation in the developer and fixer is necessary to continuously mix the chemicals |
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The back cover of the film cassette is made of a metal substance to |
Minimize backscatter |
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Rare Earth Crystals |
Lanthanum, gadolinium, yttrium |
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High contrast refers to |
Black and white images |
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The film base is tinted blue for 3 specific reasons |
To increase radiologist accuracy, to increase radiologist efficiency and to reduce eye strain and fatigue |
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T or F: the ability of the film base to maintain its size and shape during processing is known as demonstrated stability? |
False |
