Flashcards in Chapt Four Deck (48)
Milliamperage and exposure time have an ______ partly relationship when maintaining the same mAs
The minimum of change needed for a correct for a density error is determined by multiplying or dividing mAs by ______
If a screen is 2xs fast then the mAs should be cut _____
Making a visible change in density requires a minimum change in mAs by approx __1__.
What effects density because it alters amount and penetrating ability of the beam
Maintaining or adjusting density can be accomplished with kV by using what rule?
15% Rule states
A: changing kVp by 15% will have the same affects as __1__ or cutting it __2__
B: if you want to maintain density and you add 15% kVp, you must cut mAs ________.
C: if you subtract 15% kVp, you must _____ mAs
D: below 90 kV, work in factors of ______.
E: above the 90 kV work in factors of ______
As _______ is increased, the quality of xray production is raised, but the energy of the photons is not affected.
In order to see a visible change in radiographic density, the mAs should be increased or deceased by ___________.
The law that explains the relationship between SID and mAs is ________
Inverse Square Law
The amount of darkening/blackness which is seen on a radiograph is a measure of radiograph.
A radiograph is taken showing insufficient penetration. This could be corrected by _________
Increasing the kV
The quality of an X-ray beam is primarily controlled by the _________.
A radiograph is produced which shows a large amount of scatter radiation. One method that can be employed to decrease this scatter is:
Lower the kV
The use of low kV photons results in a radiograph with a small number of widely varying density values termed:
Short scale of contrast
The mAs values for an exposure will primarily effect the following:
An increase in mAs during an exposure with no other changes made will increase the:
Number of photons produced
Hardest to easiest to penetrate
Teeth, bone, muscle, fat, gas
The major function of the grid generally utilized in an X-ray department serves to:
Reduce the scatter reaching the IR
Which of the following would produce a radiograph with the longest scale of contrast?
A. 50 mA, 1 sec, 70kV
B. 100 mA, .5 sec, 80 kV
C. 200 mA, 1/4 sec, 90 kV
Which is not used as contrast?
Air, Saline, Barium, or Iodine?
Which would produce a longer scale of contrast, increasing kV or decreasing kV?
The greater the atomic number of the part, the ______ the resulting density on the radiograph.
If the distance tweet the tube and the pt. is cut in half and no adjustments we made to the technique, what happens to pt. dose?
It increases by 4 times
An example of an inorganic interspacer
Grids doesn't __1__ production of scatter. It __2__ overall quality of image.
SCATTER IS ______
Height of Pb strips/distance between Pb strips