Week #10 Review Flashcards
-picture element
-smallest element in a digital image
Pixel
The process of associating the pixels with discrete values
Contrast resolution
What is the size of the pixel directly related to the amount of?
Spatial resolution OR detail in the image
Number of bits within a pixel
Pixel bit depth
= 2^n (n= number of bits)
What will the gray level be a factor in determining?
Image contrast resolution
What are the typical number of pixels in a matrix?
512 x 512
1024 x 1024
2500 x 2500
How does pixels affect resolution?
Smaller pixels = more resolution
Larger pixels = less resolution
How can the number of bits affect the shades of grey?
Lower bits = lower # of different shades of grey
Display devices used for the interpretation of images by radiologists and other physicians
Primary electronic display devices
Displayed devices used by general medical staff for purposes other than medical interpretation
Secondary electronic display devices
What is the number of megapixels used for mammography?
- Megapixels
What is the number of megapixels used for general radiography?
5.2 megapixels
What is the pixel size for a primary electronic display device?
Approximately 0.15mm - 0.05mm respectively
What is the matrix range for a secondary electronic display device?
1.3 megapixels - 2 megapixels
What is the pixel size for a secondary display device?
Approximately 0.3 mm
Mapping of an image of one matrix size to display of another size
Interpolation
The distance between the pixels on the screen
Pixel pitch
Ratio of the width of the display to the height of the display
Aspect ratio
What aspect ratio do primary display monitors usually have?
5:4
Generally 5 megapixel
How many times each second that the monitor rewrites or updates the image on the display
Refresh rate
What is the testing frequency for grid uniformity stated by SC35?
Annually
What is the standard for cassette IP cleaning from SC35?
Monthly
Testing evaluates the horizontal and vertical performance of the laser optics and transport systems
Laser Jitter test
Slug by irregular movements and variations in laser readings
Jitter
The ability to resolve different objects from the background when the difference in attenuation between the objects and the background is small compared to noise
Contrast resolution
