Final Exam Part 1 - Density/KVP/DETAIl
Card Set Information
Final Exam Part 1 - Density/KVP/DETAIl
How will an increase in kvp affect radiographic density?
Increase because more penetration means more scatter photons hitting the IR.
How will decrease in over all mAs affect radiographic density?
Decrease because less photons are created.
How does an increaes in patient thickness affect radiographic density?
Decrease it because less photons will make it through the patient and onto the IR.
How does an increase in OID affect density?
Decrease because OID acts like a grid that takes away scatter.
How does an Increase in SID affect density?
Decrease because less radiation hits the IR.
Decreasing grid ratio will do what to density?
Increase because less photons get absorbed in lead strips hence more scatter is added to your image.
Decrease in focal spot size will do what to density?
Not affect is because focal spot size only affects recorded detail.
How does an increase in temperature of the processor affect density?
Increase in density because reducing agents over react and turns all crystals into black metallic silver.
Decreasing the amount of filtration will affect density how?
Increase it because less filtration will allow more photons to get trhough.
How does an increase in collimation affect density?
Decrease it because less scatter is being created because less tissue is being exposed.
How does increasing speed of intensifyng screen affect radiographic density?
Increase because faster screens will create more light photons.
How much do you need to increase mAs in order to see a visible change in density?
25-35 percent changes.
Which side in anode heel effect comes out darker? cathodeor anode side?
Cathode side bec ause more photons hit hte cathode side due to absorption of the beam in the heel of the anode.
How does an increase in kvp affect the amount of photoelectric absorption interactions that occur?
It decreases the amount of PE absopriton interactions because an increase in kVp will increase its PENETRABILITY hence less absorption.
How does a decrease of mAs by 30% affect contrsat?
It doesnt affect it.
How does an icnrease in focal spot size affect contrast?
It does not affect contrast.
What will an increase in filtration do to contrast?
It will decrease contrast because an increase in filtration will increase the average energy of kVp.
Higher kVp would mean more scatter.
Scatter REDUCES contrast. Hence it is a decrease.
How does an INCREASE in collimation affect contrast?
An increase in collimation would result in a INCREASE in contrast.
Increasing in collimation would mean smaller area being exposed.
Smaler area means there will be less tissue exposed = less scatter.
Less scatter = INCREASE in contrast
How does a decrease in thickness affect contrast?
A thinner patient thickness would result in increase in contrast because like before, less tissue = less scatter = increase in contrast.
How does an increase in grid ratio affect contrast?
As you increase grid ratio, you are increasing radiographic contrast because the grids take away scatter.
How does an increase in sspeed of intensifying screens affect contrast?
It increases contrast because according to the H&D curve, films with increased speed generally have higher contrast.
How does a DECREASE in processing temperature affect contrast?
It will DECREASE contrast because any change that does niot provide optimal processing conditions will decrease film contrast.
How does an increase in OID affect contrast?
An icnrease in OID will INCREASE contrast mainly because OID acts like a grid. It angles scatter away hence it increases contrast.
How does an increase in processing time affect contrast?
Longer processing time decreases contrast because it would result it more chemical fog which decreases contrast.
How does an angle in the x-ray beam affect contrast?
It will decrease contrast because as you angle, youre going through more tissue. If you're going through more tissue, you will have more scatter. Scatter REDUCES contrast.
How does poor film screen contact affect detail?
It decreases detail due to light diffusion.
Increasing the size of the focal point willl do what to detail?
An increase in the size of the focal point will DECREASE detail.
Smaller focal point = better detail
Will a decrease in mas affect detail?
No it doesnt affect detail.
A decrease in SID will affect detail how?
A decrease in SID will decrease detail because with a smaller SID, you have a smaller straighter beam.
The straighter beams will provide more detail.
How does a decrease in kvp affect detail?
kvp does NOT affect detail.
Increasing OID will affect detail how?
An increase of OID will decrease recorded detail because you are gonna be farther from the IR causing magnification.
How does increasing film speed affect recorded detail?
This will result in a decrease of recorded detail because faster film speed = Larger crystals/thicker layer.
You want smaller crystals in order tro get the best detail.
How does motion affect detail?
More motion = decrease in detail
How does an increase in film processing temperature affect recorded detail?
It does not affect it.
Increase in grid ratio affects detial in what way?
It doesnt affect detail
Increase in filtration will affect recorded detal how?
FIltration does NOT affect recorded detail
How does compression sffect detail?
Compression increases detail
Increase in SID will affect detail how?
Incdreases detail because the farther you, you have an area of much larger and STRAIGHTER beam that will give you better detail.
Going from .5 to 1.25 focal spot sixze will affect detail howe?
It will decrease detail as focal spot size goes up.
How does an icnrease in SID affect size distortion?
It doecreases size distortion.
How does an increase in OFD affect size distortion?
It increases size distortion.
How odes an increase in focal spot size affect size distortion?
It does NOT affect size distortion.
Improper central alignemtn will affect shape distortion how?
It will increase shape distortion.
Decreaseing OFD will affect shaep distoriton how?
OID does not affect shape distortion.