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28 Cards in this Set
- Front
- Back
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alternating current |
produces one positive pulse and then one matching negative pulse. |
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amperage |
the current of the circuit |
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anode heel effect |
because of the angle of the anode target, the x-ray beam has greater intensity (number of x-rays) on the cathode side of the tube, with the intensity diminishing toward the anode side |
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anode |
a positively charged electrode within the x-ray tube. It consists of a target and in rotating anode tubes, a stator and rotor |
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cathode |
a negatively charged electrode within the x-ray tube. It comprises a filament and a focusing cup |
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direct current |
requires a source situated very close to the end user. |
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ground |
an alternate route for electricity to flow if the circuit is broken inappropriately. |
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hertz |
German scientist, cycles per second of the oscillations of alternating current (one positive and one negative) |
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rectifier |
redirect current flow on the negative portion of the cycle to become positive, making use of the full 60 cycles, instead of the x-ray tube only using half the power. |
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rotor |
rotates the anode in an x-ray tube. rotating part of an electromagnetic induction motor contained within the glass envelope of the x-ray tube. |
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target |
a metal that abruptly decelerates and stops electrons at the anode, thereby allowing the production of x-rays |
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transformer |
receive power from the incoming power lines and literally transform the power to the x-ray tube, to either increase or decrease the voltage in the circuit |
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x-ray tube |
consists of a glass enclosure, made of heat resistant glass, that houses a specialized anode and cathode |
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Chapter 4 notes |
-x-ray machines operate with three transformers: 1. the autotransformer - increases the incoming voltage, kv selector 2. high-voltage transformer - boosts voltage to the x-ray tube, for successful exposure the voltage must be raised from the original incoming 220 volts to a maximum of 125,000 volts 3. filament transformer - produces the voltage to the filament of the x-ray tube, produces the temperature that the filament in the cathode needs to reach to produce the cloud of electrons to send to the anode.
-the x-ray tube can only receive positive pulses, resulting in the need for a rectifier. |
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artifacts |
any accidental or unintentional image on a radiograph |
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cassette |
a film holder containing a pair of intensifying screens which the film is placed between |
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crossover effect |
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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emulsion |
the radiation-sensitive and light-sensitive layers of film and intensifying screens spread evenly across a polyester or mylar base |
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film base |
material that holds the emulsion of the film |
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film/screen contact |
the amount of direct contact between the film and intensifying screens |
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image receptor |
a device that receives the remnant radiation and produces the image |
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intensification factor |
a formula that represents the degree to which exposure factors are reduced when intensifying screens are used |
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intensifying screens |
a device found in radiographic cassettes that consists of an emulsion spread on a polyester base containing phosphors that convert -ray energy into light, which then exposes the radiographic film |
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latent image |
the invisible image that exists on the exposed film before it has been chemically produced |
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luminescence |
the emission of light from the screen when it is stimulated by radiation |
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manifest image |
the visible image on film after processing |
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resolution |
the ability of the imaging system to resolve or distinguish between two adjacent structures |
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supercoat |
a durable protective layer on film that is intended to prevent damage to the sensitive emulsion layer underneath it. |
