Question | Answer |
When a structure is angled within the body and not parallel to the IR | Foreshortened |
Occurs when x-ray tube is angled | Elongation |
When image details placed away from the path of CR will be exposed to more divergent rays | Rotation distortion |
The smaller the focal spot, the _______ the geometrically recorded detail. | Better |
The finite area on the tungsten target that is actually bombarded by electrons from the filament. | Actual Focal Spot |
The foreshortened size of the focus as it is projected down toward the IR is | The Effective Focal Spot |
In 1986, Thomas Edison developed the _______ ______ intensifying screen that reduced the required exposure to a fraction of that needed without screens. | Calcium Tungstate |
List rare earth phosphors: | Gadolinium, lanthanum, and yttrium |
A particular phosphor's ability to absorb x-ray energy and convert it to fluorescent light energy | Conversion Efficiency (CE) |
Phosphors with a _____ atomic number have a greater likelihood of interacting with and x-ray photon and therefore possess a greater speed. | High |
Calcium tungstate emits _______ fluorescence. | Blue |
Rare earth screens emit ________ fluorescence. | Blue or green |
Refers to luminescence from fluoroscopic screen phosphors | Phosphorescence |
Phosphors used in fluoroscopy | cesium iodide and zinc cadmim sulfide |
As phosphor size increases, more surface area is available for x-ray photon capture, resulting in an _________ in screen speed. | Increase |
Screen speed and phosphor layer are _______ related. | directly |
Slower (detail) screens are commonly used for _______ exams. | Extremity |
Faster screens are used for ________ _________. | general radiography |
A related problem with screens and resolution. | Quantum mottle |
Most laser film must be handled | in total darkness |
Windowing describes the practice of | changing the image contrast and/or density |
Unopened boses of film should be stored away from radiation and | in vertical position |
The purpose of automatic processor's transport system is to | move the film and change its direction |
Misalignment of the tube-part-IR relationship results in | Shape distortion |
Small cresent-shaped artifacts on the processed x-ray film usually are a result of | Acute bending of the film before or after exposure |
Using a 48 inch SID, how much OID must be introduced to magnify an object 2 times? | 24 inches |
The direction of the electron travel in the x-ray tube is | Cathode to anode |
For the same FOV, spatial resolution will be improved using | a larger matrix |
The reduction in x-ray photon intensity as the photon passes through material is called | Attenuation |