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33 Cards in this Set
- Front
- Back
Quality |
(Wavelength) Mean energy or penetrating ability of the x-ray beam, controlled by kilovoltage |
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Voltage |
Measurement of force (higher force, higher penetrating power), |
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Volts/Kilovolts |
Unit of measurement describing the potential that drives an electrical current through a circuit 1 Kilovolt= 1000 Volts |
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Kilovoltage Peak |
Maximum or peak voltage, regulates the speed and energy (quality) of the electrons and determines the penetrating ability of the x-ray beam |
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Filtration |
Removes the low energy x-rays |
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Half-Value Layer |
Thickness of a specified material that when placed in the path of the x-ray reduces the intensity by 1/2 |
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Density |
Overall blackness or darkness of the film |
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When the kVp is increased... |
the FILM exhibits and increased density, appears darker |
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When the kVp is decreased |
the FILM exhibits a decreased density, appears lighter |
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High density tissue areas |
Will stop x-rays completely, appear white on x-ray film |
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Medium density areas |
Partially block the x-ray, appear as shades of gray (bone, dentin) |
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Low density areas |
Allow x-rays to pass thru completely, appear black on the film (pulp) |
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Contrast |
How sharply light and dark areas are differentiated in an image, determined by the kVp |
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High contrast image |
Produced by a low kVP, has distinct black and white areas with few shades of gray, good for detecting dental caries |
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Low contrast image |
Produced from a high kVp setting and the resulting film will have many shades of gray, good for perio disease |
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Exposure time |
Interval of time during which x-rays are produced, measured by impulses |
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Impulse |
One occurs every 1/60 of a second |
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Relationship of exposure time and kVP |
Inversely related |
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Kilovoltage Peak Rule |
When kVp is increased by 15, exposure time should be decreased by 1/2. When kVp is decreased by 15, exposure time should be doubled |
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Quantity |
The number of x-rays produced |
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Amperage |
Determines the amount of electrons passing through the cathode filament |
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Ampere |
Unit of measure that describes the number of electrons (or current flowing through the cathode filament) |
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Milliampere |
mA, equal to 1/1000 of an ampere |
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Milliamperage |
Regulates the temperature of the cathode filament |
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Relationship between density and mA |
Increase in mA increases the density of the radiograph (darker image) |
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Relationship between exposure time and mA |
Inversely related |
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Intensity |
Product of the quantity and quality per unit of area per unit exposure rate |
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Target-surface distance |
From source of radiation to the patient's skin |
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Target-object distance |
The source of radiation to the tooth (object) |
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Target-film distance |
From the source of radiation to the film |
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Inverse Square Law |
Intensity of radiation is inversely proportional to the square of the distance from the source of radiation |
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Labial Mount |
Raised (convex) dot is towards the viewer, viewed as if looking directly at the patient |
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Lingual Mount |
Depressed dot is mounted away from the viewer, as if viewed from inside the patient's mouth |