Ch. 13 Test Flashcards
____ uses a photomultiplier tube or a photodiode coupled with a fluorescent screen.
phototimer
____ is a hollow air-filled cell connected to a timer circuit via wire.
ionization chamber
T/F - Phototimers use DAP meters to determine when to terminate the exposure.
false
____ are much less prone to failure, though they are not as accurate.
ionization chambers
T/F - Phototimers are the most commonly used form of AEC today.
false
Because AEC only controls the amount of radiation that reaches the IR, it has ____ on contrast.
no effect
Raising kVp when using AEC ____ exposure time.
decreases
Lowering kVp when using AEC ____ exposure time.
increases
Increasing or decreasing ____ will also effect exposure time when using AEC.
- SID
- part thickness
- mA
- all of the above
- none of the above
all of the above
T/F - AEC may not be appropriate for use with pediatric patients due to increased minimum response time.
true
____ is the maximum amount of time that an exposure will go before it is terminated.
backup time
In general, backup time should be set to terminate when the exposure has reached ____% of the desired exposure.
150-200
T/F - When using AEC, the part being examined can be placed anywhere on the receptor and still achieve ideal results.
false
T/F - Collimation has no effect on AEC.
false
When performing QA measures on an AEC system, the system should be able to provide multiple exposures with mR readings with __% of each other.
5
When performing QA measures on an AEC system, the system should be able to provide multiple exposures that result in images with pixel brightness levels that are __% from each other.
30
T/F - Exposure technique charts that are based around variable kVp are the best because they do not alter contrast.
false
T/F - Exposure technique charts that are based around fixed mAs are the best because they do not alter contrast.
false
T/F - The most ideal exposure technique charts are based around fixed kVp/variable mAs because they do not involve changing contrast in order to properly radiate the part being imaged.
true
When using a fixed kVp/variable mAs exposure technique chart, mAs needs to ____ for every additional 4-5cm of part thickness.
double
When using variable kVp/fixed mAs exposure technique charts, kVp is increased by __ for each additional cm of part thickness.
2
T/F - When creating technique charts, you only need one for the entire department.
false
T/F - When radiographing pediatric patients, you should opt for the longest exposure time possible.
false
T/F - Bariatric patients usually require less radiation to image than geriatric patients.
false
T/F - Geriatric patients often require less radiation to image due to diminished bone mineralization.
true
Plaster casts require ____ radiation to penetrate.
more
Fiberglass casts require ____ radiation to penetrate than plaster casts do.
less
This kind of pathology can require an increase in technical factors.
additive
This kind of pathology can require a decrease in technical factors.
destructive
Barium is a ____ contrast
positive
Air is a ____ contrast.
negative
Negative contrasts show up ____ on x-ray than the surrounding tissue
darker
Positive contrast shows up ____ on x-ray than the surrounding tissue.
lighter
Amorphous selenium is used in ____.
direct DR
Amorphous silicon is used in ____.
indirect DR
This is the most inferior piece of the sternum.
xiphoid process
T/F - SC joints are more lateral than AC joints.
false
The kidneys are ____
retroperitoneal
T/F - The hamate is a bone in the foot.
false
Which view is best for visualizing the ankle mortise.
15 degree oblique
