Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
RADT 456 Img Acq/Eva
Unit 4 Image Acquisition and Evaluation
| 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 |
Created by:
lmdegraffe
Popular Radiology sets