Principles of Exposure Flashcards
If the mAs is increased, what happens to the IR exposure?
Increased
Does mAs have an effect on contrast, spatial resolution, or distortion?
No
If kVp is increased, what effect will it have on IR exposure and contrast?
Increased IR exposure, decreased contrast
If the SID is increased, what effect will it have on exposure and geometric factors?
Decreased IR exposure, Increased spatial resolution, decreased distortion
If the OID is decreased, what effect does it have on contrast, spatial resolution, and distortion?
Increased contrast, decreased spatial resolution, increased distortion
If the focal spot size is increased, what effect does it have on spatial resolution?
Decreased spatial resolution
If the tube filtration is increased, what effect does it have on IR exposure and contrast?
Decreased IR exposure, increased contrast
If the collimation is increased, what effect does it have on IR exposure and contrast?
Increased IR exposure, decreased contrast
If there is excess motion from the patient during a radiographic procedure, what would be the result?
Decreased spatial resolution
If patient factors (size, pathology) are increased, what would be the effect on exposure and geometric factors?
Decreased IR exposure, Increased contrast, Decreased spatial resolution, Increased distortion
What effect does the angle of the tube, part, or receptor have on spatial resolution and distortion?
Decreased spatial resolution, increased distortion
Which technical factors can affect IR exposure?
Grids, kVp, mAs, SID
When SID is increased, which change must be made to maintain IR exposure?
Increase mAs
How is gross exposure error demonstrated in a digital image?
Missing data points
The smallest exposure difference that can be detected and displayed by the imaging system is called
Contrast resolution
Increasing the FOV will have what effect on pixel size?
Increased pixel size
Scatter radiation does not affect
Recorded spatial resolution
What kind of effect is it when an incoming X-ray photon interacts with an outer orbital electron of an atom
Compton effect
As the kVp is increased, which interaction is also increased
Compton
In a photoelectric interaction, the incoming photon from the primary beam collides with an
Inner orbital electron
As kVp is increased, photoelectric effect is
Decreased
What effects on an image does scatter radiation have
It creates fog that reduces both contrast and spatial resolution
Why does higher kVp result in more scatter radiation fog
The high energy radiation is better able to escape the subject without being reabsorbed and more likely to cause fog on the radiograph
What is the principle method for reducing scatter radiation fog
Using a grid
