Ch. 4 PPT Flashcards
Which is the old technology, computed radiography or direct radiography?
computed radiography
Picture elements are called:
pixels
Combination of rows and columns of small, square pixels:
matrix
Increasing the number of pixels improves ____.
spatial resolution
Pixel size is ___ related to FOV.
directly
Pixel size is ___ related to matrix size
inversely
Increasing the Field of View for the same matrix will ___ the size of the pixel. This will ___ spatial resolution.
increase , decrease
Increasing the matrix size for the same Field of View will ___ the size of the pixel. This will ___ spatial resolution.
decrease, increase
Increasing pixel density and decreasing pixel pitch ____ spatial resolution.
increases
___ is the pixel spacing or distance measured from the center of a pixel to an adjacent pixel
Pixel pitch
Decreasing pixel density and increasing pixel pitch ___ spatial resolution
decreases
A digital composite of the varying x-ray intensities exiting the patient.
Image matrix
The ability of a detector to accurately capture the range of photon intensities that exit the patient is called:
Dynamic range
___ have a wider dynamic range than ___.
Digital IRs (image receptors), film-screen detectors
___ represents the number of digital pixel values versus the relative prevalence of those values in the latent image.
- Amount of exposure is on the __-axis
- Incidence of pixels is on the __-axis
Histogram
- X
- Y
An image-processing technique commonly used to assess the raw data prior to image display.
Histogram Analysis
During histogram analysis, if you select a part other than the imaged one, a ____ may occur.
histogram-analysis error
___ is computer software operations available to you that allow manual manipulation of the displayed image
Postprocessing
___ sets the midpoint of the range of brightness visible in the image
Window level
Increasing the window level ___ the image brightness; decreasing the window level ___ the image brightness
increases, decreases
a control that adjusts the radiographic contrast
window width
Decreasing the window width (narrow) ___ the image contrast; increasing the window width (wide) ___ the image contrast
increases, decreases
Does windowing alter the original stored pixel values of an image?
No, it only alters how they are stored
CR or DR?
DR
