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Radiation chp6
Question | Answer |
---|---|
Most Common Cassette Sizes | 14x17, 10x12, 8x10 |
Anode | postive side of the x-ray tube |
Cathode | negative side of the x-ray tuibe contains the filament and focusing cup |
Collimator | controls the size and shape of the x-ray field coming out of the x-ray tube |
What is Generator | a coil of wire rotating through a magnetic field produces an electric current |
Kilvotage Peak | a measure of electrical presssure forcing the current through the tube also affects the energy QUALIlty of the x-ray photons produced |
When the kVp is decreased the quality of the beam and the quality of the radiograph change | Decreasing will: give a shorter scale of contrast, longer wavelength, decrease in intensity |
Latitude | range of x-ray exposure over which a radiograph is acceptable |
Wide latitude | long gray scale or low contrast |
Narrow latitude | short gray scale or high contrast |
Film latitude is influenced primarily by | inherent characterisctics of the film |
1 millampere equals | 1/1000 of an ampere |
The overall blackness of the film | Density |
ma controls the QUANITITY of the | x-ray beam |
If the image lacks density then its | underexposed |
mAs must be increased by 30% to see a | noticeable change |
Density of a radiograph is determined by the amount of | silver developed |
The best way to reduce unwanted density caused by scatter radiation is | collimattig (restricting the beam) |
If SID is to low equals | overexposed film detail will also change |
Density greatly effects | quality |
The light emitted from a screen contributes to 95% of the overall film | density |
Automatic exposure controls are useful for: | density must remain constant, Faulty density causes repeats, and density greatly affects quality |
The source to image distance standard is | 40 inches from the film to the radiographic tube |
An icrease in SID without any compensation in exposure factors equals | a visible radiographic image of HIGH CONTRAST |
WHat is detail | the degree to which the smallest structural lines of the anatomy can be recorded on film 1. based on sharpness of the image boundary 2. and the visiblilty of detail |
A small focal spot will give you | Better detail |
A Quantum Mottle is the | Result of an insufficent number of x-rays |
As radiation exits the tube primary radiation is | emitted from the tube |
As radiation exits the tube absorbed radiation | enters the patient adn is absorbed |
As radiation exits the tube Remnant Radiation | passes through the patient and the cassette |
As Radiation exits the tube secondary scatter | Bounces off the patient |