Image Production- image acquisition, and evaluation Flashcards
What may be the cause of an over exposed image?
SID too low
If the KVP is increased 15 percent, how much must the mAs be reduced in order to maintain the same receptor exposure?
50 percent
What distance would produce the lease distortion?
72 in
The longer the SID, the less size distortion
A non-great exposure requires 15 mAs. How much mAs is needed if a 5:1 ratio grid is used?
30 mAs
Which of the following will occur on the tube angle is decreased?
Shape distortion will decrease
Special resolution can be improved by reducing which of the following?
Focal spot size
If the mA is set at 400 and the mAs obtained is 80, what is the exposure time?
0.2 seconds
To calculate time, divide the mAs by the mA
SID should be reduced by 1 inch for every ————— degrees or CR angle?
5
How are mA and seconds related to eachother when used to maintain receptor exposure?
Inversely proportional
The ratio of SID to SOD represents which of the following?
Magnification ratio
What is the greatest advantage of digital imaging?
Contrast resolution
What is the best method to reduce scatter radiation which causes fog?
Collimation
Spatial resolution can be improved by?
Maximum SID
What is an advantage of the air gap technique?
Eliminates the need for a grid
How will be in filtration affect the primary beam?
Make it more homogeneous
If the S ID is increase the same as the OID, what will the resultant radiograph show?
An increase in size distortion
Magnification formula SID/SOD
How much mAs will be generated if the control panel is set at 200 mA and 1/5 second?
40 mAs
mAs= 200 mA x 1/5 second
Geometric and sharpness is directly proportional to which of the following?
OID
Time can be decreased by half if the KVP is increased by what percentage?
15%
What condition would be considered easy to penetrate?
Degenerative arthritis
What are the two types of distortion that can reduce the quality of a radiograph?
Size and shape
Density was the term used to describe the overall blackening of a film screen radiograph. What term is used in digital imaging to describe this radiographic quality?
Receptor exposure
Wavy pattern that results when to geometrically parallel lines are super impose is referred to as what?
Moire effect
What is the correct name for loss of sharpness due to the use of a large focal spot?
Unsharpness
Which of the following technique adjustment should be made on radio graphing a geriatric patient with osteoporosis?
Decrease kvp
(Osteoporosis is easy to penetrate)
Because of the anode Hill affect where is the intensity of the x-ray being the greatest?
At the cathode end
Which of the following would be used to minimize size distortion?
Shortest Possible OID
Longest SID
And underexpose radiograph may because by what?
Grid cutoff
When using AEC, which method can be used to control motion by reducing exposure time?
Increase mA
Which of the following is not one of the three elements that affect shape distortion?
SID
(SID effects size distortion not shape)
What condition would be considered hard to penetrate
Osteosclerosis
If a technique of 300 mA, 1/10 second and 60 kVp is to be changed to 69 kVp what would the new time be?
1/20 second
(Cut time in half to compensate for 15% increase in kvp)
Spatial resolution is not affected by which of the following?
kVp
Which of the following radiographic qualities determines the sharpness of detail in the finish radiograph?
Spatial resolution and distortion
A flat panel detectors DEL size determines what of the following?
Spatial resolution
