RAD 106 vocab
Ratio of the height of the grid line to the width of the interspace material.
Grid ratio.
Size of a pixel, directly related to the amount of spatial resolution or detail in the image
Pixel size
Image noise resulting from spatial frequency greater than the Nyquist frequency, grid line resulting from incorrect alignment of the grid to the laser scan direction.
Moire Pattern.
Ability of the imaging system to demonstrate small details of an object.
Spatial resolution.
Post processing high-pass filter that increases contrast to enhance large structures and soft tissues (can be noisy).
Edge Enhancement.
Number of lead strips/grid lines per inch
Grid frequency.
Square arrangement of numbers (pixel values) in columns or rows.
Matrix
Post processing technique that blacks out the white collimation borders, essentially eliminating veil glare.
Shuttering.
Reference histogram of luminance values derived during image acquisition based on anatomy selection.
Look-up table.
Oldest indirect digital radiography, flat panel based
Charged coupled device (CCD)
Dynamic range.
Graphical display of a digital image. X-axis referres to the amount of exposure, y-axis refers to the number of pixels for each exposure.
Histogram.
Refers to the range of exposure diagnostic image values the image detector is able to produce. The amount of error that can be made while still creating an image.
Latitude.
TFT, photosensitive array made of small pixels that converts light to electrical charge within flat panel detectors
Thin film transistor.
Picture Arching Communication System.
PACS
Noise.
Parameter that controls how bright or dark the screen image is.
Window level.
Measurement of how efficiently a system converts an x-ray input signal into a useful output image
Detective quantum efficiency (DQE).
Digital imaging and communication in medicine, standard that allow imaging modalities and PACS to communicate in the same language.
DICOM.
Noise, granny appearance caused by low mAs.
Quantum mottle.
parameter that controls the ratio of black and white, the contrast.
Window width.