summer 2006 Flashcards
If you make an exposure at 100 mAs with 80 kV and the radiographic density is good, and a second exposure with 50 mAs and 92 kV, which film would have the higher contrast?
the first film would have the higher contrast
What is the undesirable with magnification distortion?
borders of the object will be blurred
What is the outcome of reducing the mAs by 1/2 and keeping the kV and the distance constant?
the film density would be decreased
What percentage in mAs would you expect to see the slightest change in density?
30%
If you took 4 A-P lumbar films…first with 9 kV and 6.25 mAs, second with 106 kV and 3.75 mAs, third with 58 kV and 60 mAs, fourth with 85 kV and 8 mAs…which would have the lowest contrast?
second
Osteoporosis will usually require you to do what with tube output?
reduce the tube output
What would produce the same film density as 200 mAs for 0.5 seconds?
100 mAs for 1 second
To double the density of a film by using kV what would you do?
increase kV by 15%
If you compared 2 films of a cervical spine with one having bee taken at 40” ad the other at 72” with the appropriate change in the radiographic technique…which image would be smaller and clearer?
72” (40” = larger/unclear)
If your x-ray tube was laterally shifted from the center of the film what would be the problem with the image?
shape distortion
The number of electrons will be doubled if you make what changes to the film?
increasing the mAs by 2x
T/F. When using an “air-gap” technique in a cervical series, it usually doesn’t require the use of a grid.
T
The higher the kV, what type of radiation is produced?
Compton’s
What is the range of body part thickness when a grid should first be considered to use?
12cm
If you wanted a film with more BLACKS and whites and less gray, what would you do?
use low kV and high mAs technique
Generally speaking, adding 4 kV to a film with a single phase machine would be the equivalent to what?
increasing mAs by 30%
T/F. Using a grid increases patient radiation
T
T/F. Using a high kV and low mAs technique would produce a very grainy film
T
What the recommend optimal kV range for an A-P thoracic film?
75-85
What is the primary factor for density? Contrast?
mAs = density kV = contrast
T/F. Using a high mAs technique would cause the most absorption of X-rays in a patients body
T
T/F. Using a stationary grid with 10:1 with 100 lines per inch is recommended for spinal filming?
T
How much increase in mAs is need to maintain the same density when reducing the X-ray field from 14”x17” to 8”x10”?
60%
