Scatter
Which interaction contribute most to noise?
Compton scatter
As grid ratio increases, Bucky Factor...
Increases
True or False: Increasing kVp increases image contrast
False
What is spatial resolution most directly affected by?
Pixel size
Increasing OID leads to _________ magnification and blur.
Increased
Does pixel pitch affect scatter production?
Nope!
The number of grid lines per centimeter is...
Grid frequency
What does window leveling control?
Image brightness
The primary reason for using small pixel IRs in extremity imaging is to...
Improve spatial resolution
What is a ghost artifact?
Incomplete erasure of a previous image overlapping your new image; only on CR
How does the Air-Gap technique reduce scatter?
Increasing OID so that the patient is closer to the tube, so the patient is the one reducing the scatter reaching the IR
How do you get less visible grid lines?
By using a high grid frequency
What determines the dynamic range of an imaging system?
Bit depth
Which monitor would have the highest spatial resolution? 2 MP or 5 MP?
5 MP
What are the 3 geometric factors that affect image quality?
Magnification, distortion, focal-spot blur
Increasing patient thickness will _______ scatter radiation.
Increase
Which grid ratio requires you to increase mAs by 5 times?
12:1 grid
What happens to subject contrast when patient thickness increases?
It decreases
What two things does the fill factor of the DEL affect?
Spatial resolution and signal strength
What is partitioning?
Imaging multiple exams on one IR with collimated fields
What helps limit the x-ray field size?
Beam-restricting devices like collimators
Contrast improvement factors for most grids fall between...
1.5 and 2.5
What can shape-induced contrast do?
Enhance or reduce contrast depending on the projection/position of the part
What does the Nyquist frequency define?
The limit of spatial resolution
What happens when you choose the incorrect histogram setting?
Exposure field recognition will fail