Terms and Definitions
A binary number is called
What is a bit?
Common PSP phosphors are
In regards to spatial domains, small structures have _____ frequency and ______ contrast
high & high
Point processing
local processing
geometric processing
What are the 3 types of image processing operations?
The practice of over exposing the patient to ensure all of the data is captured is called
What is exposure creep?
An 8 bit word is called a
What is a byte?
A pixel size that has an 8 bit depth displays _____ shades of gray
What is 256 shades of gray?
The problem with manipulating the image prior to sending it to PACs is
It limits the information that the radiologist receives and can manipulate...don't do it:)
This processing operation allows for rotation and magnification of the image
What is geometric processing?
DQE and MTF have this relationship
What is directly proportional?
The information that is valuable on a histogram is called
What is the value of interest?
A matrix of 2048 x 1536 has _____ pixels.
What is 3,145,728 pixels?
Professional organizations have asked for a universal system for this parameter to standardize across manufacturers and make it more user friendly for technologists.
Exposure Indicators
Gray scale bit depth controls
What is the # of shades of gray or density resolution?
Resolution is controlled by
What is pixel size
The measurement of the sensitivity and accuracy of the IR to produce the image is known as the
What is the DQE-Detective Quantum Efficiency
Atomic #
thickness of material
density
What factors affect x-ray absorption?
The range of the IR's ability to respond to different exposure levels
What is the dynamic range?
This processing operation is used to visualize bony cortical changes, micro calcifications, and bony trabeculae
What is edge enhancement?
System
ambient
quantom mottle
Are all examples of
What is noise
Refers to the receptors ability to respond to different exposure levels
What is the dynamic range?
This preprocessing step adjusts for contrast
What is the look up table (LUT)
The range of over exposure or under exposure that can occur in producing an acceptable image
What is exposure latitude?
An under or over exposed image can be modified to achieve an acceptable image through a histogram analysis. This is done by the digital processing technique of:
What is histogram stretching, histogram modification, or rescaling
A high SNR would indicate
What is low noise
as noise increases, contrast decreases...think of it as scatter