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26 Cards in this Set
- Front
- Back
- 3rd side (hint)
Geometric Processing Operations |
Changing position or orientation of pixels, allows rotation and magnification |
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Kernel |
Calculations applied to small group of pixels |
*High-pass filtering: edge enhancement *low-pass filtering: smoothing *unsharp masking or blurring *spatial location filtering |
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Point processing |
Operation performed between the receipt of the input image from the image receptor and the output image that is viewed on the monitor |
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Matrix |
Made up of pixels and voxels |
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Point Processing Operations |
Grayscale processing Histogram LUT windowing, contrast and brightness rescaling, stretching |
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Spatial resolution |
Controlled by matrix size and how many pixels displayed on monitor. Direct relationship between matrix and spatial resolution |
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Quantum mottle |
Undesirable signal from digital system itself Fixed by doubling mAs |
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DQE (detective quantum efficiency) |
Measure of how sensitive and accurate incoming data is converted to output viewing 0.3-0.7 average range |
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Exposure index |
Provides info about exposure to image receptor |
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PSP- photostimulable imaging plates |
Several layers Records and transmits image from x-ray beam |
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Latent image |
Image before processing |
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Manifest image |
Image after processing |
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CR reading data |
IP scans with a finely focused neon-helium laser beam in rastor pattern |
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Pixel pitch |
Inversely related to spatial resolution Dependent on matrix size and image receptor |
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Data manipulation |
Ability to adjust histogram into visible diagnostic density range |
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Data clipping |
Clinically irrelevant data not included in the image display |
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Collimater edge identification |
Algorithm that detects edges of exposure versus nonexposure |
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LUT - look-up table |
Graph of processed pixel values that permit changes in density or contrast |
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Imaging stitching |
Combine several images into one |
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Moire effect |
Grid frequency matches frequency of laser beam |
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DR dectectors |
Direct- use photoconductor Indirect- use scintillator |
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Direct detectors |
*Converts ionization from x-rays to electronic signal *Signal received by thin film transistors (TFT) and sent to computer |
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CCD (charge-coupled device) |
Photoelectric typically used with screen scintillator |
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Electronic masking |
Removes undesirable info to improve image quality |
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Veil Glare |
Black background for better visualization |
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Histogram |
Data set that reveals the edges of an image fixing under and over exposure |
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