Histogram
wide Histogram results in ___ _____?
What is SNR
Sound to noise ratio
What does the imaging process consist of?
Image acquisition, image processing, & image display
What does the neon laser beam do?
Causes phosphor to release latent image in the form of light photons
What are the preprocessing operations?
Exposure field recognition, histogram analysis, and grayscale analysis
True or False:
an excessive overexposed image can be altered to a align with reference image.
False, highly overexposed image can not be fixed
What types of noise affect the image
-system noise
-Ambient
-Quantum mottle
What is the active layer in PSP?
Phosphorus layer
What is pixel pitch?
Physical distance between pixels & its measured center to center.
What is data clipping?
Not all data is sent & data that is deemed clinically irrelevant is eliminated.
What determines the shape of the histogram
Anatomy & exposure
High SNR means _____ in image
Little noise
What is the purpose a PSP imaging plate?
records and enhances transmission of image
What is a ghost artifact?
A plate that is grossly overexposed so data from previous image does not completely erase.
Why is it important to choose the correct exam before exposing?
reduces need for retakes & image may not have correct brightness/contrast due to histogram errors.
___ is done when the image was over/underexposed.
Rescaling
What is quantum mottle?
A grainy image produced due to improper exposure factors.
What happens during image acquisition ?
Xray photons interact w/ imaging plate creating the latent image
What does a photodetector do?
Converts visible light to electrical signal
What is crucial to getting a good image with CR?
Good positioning & collimation
What happens when an image doesn't match reference histogram?
Histogram analysis error
What type of relationship does image noise have on contrst?
Inverse
What does light do to the PSP?
decreases spatial resolution & erases data from plate
What is photo stimulated luminescence?
When the red laser beam frees trapped electrons allowing them to return to a lower energy state.
What is used to develop a histogram?
Data within the collimated edges.