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Digital Img Final
Question | Answer |
---|---|
What type of wavelength do large objects have? | Long |
Does a long wavelength represent a low or high frequency? | Low |
The number of up and down cycles across an entire row of pixels | Frequency of the waveform |
Decomposing the original image into 8 or more frequency layers, performing various operations on selected individual layers and recomposing the image | Multiscale processing |
What type of mottle is band pass filtering best for? | electronic mottle |
While applying a kernel, if the numbers are both positive and negative, and the sum equals 1.0, what does that result in? | edge enhancement |
The radiographer should routinely reprocess an image under different algorithms to obtain the highest quality | False |
This post processing feature removes some of the smallest details and reduces noise | smoothing |
this post processing feature increases local contrast to better visualize small details | edge enhancement |
this post processing feature subjectively brings out details by changing black to white and white to black on the image | image reversal |
System A has a speed of 400, while system B has a speed of 200. Which system requires less exposure and reduces patient dose? | System A |
In digital radiography you can't rely on how dark or light your image looks as an exposure indicator. | True |
A high exposure indicator number represents an under exposed image | False |
mAs and kVp are controlling factors in digital imaging | false |
electrical phenomenon that occurs at the detector when the dexels in a particular area have reached the maximum electrical charge that they can store | saturation |
A DR unit can capture, process and display the initial image | true |
In DIRECT conversion DR, the dexel is made of amorphous selenium | True |
In INDIRECT conversion DR, the dexel is made of amorphous selenium | false, it's amorphous silicon |
Amorphous silicon better absorbs light than xrays | true |
at the bottom electrode plate, the positive charge accumulates and moves to the what? | capacitor |
lines connected to an address drive, which tracks location of each dexel in each row are | gate lines |
in CR, residual electrons can get trapped in molecular _____, causing the plate to flow a second time | F centers |
The direction in which the PSP plate moves, it sets the length of the pixel | slow scan |
The PSP plate has no defined pixels or dexels | True |
The distance from the center of one pixel to the center of another pixel | Pixel pitch |
How many pixels does it take to make a detail? | 2 |
In a row of 20 pixels, how many details can you make? | 10 |
In a hardware matrix the size of pixels or dexels can be subject to change | false |
geometric artifacts caused by certain sampling frequencies | moire patterns |
A computer terminal that can access images for display, but can also adjust image quality and permanently save those changes in PACS | workstation |
for accurate reading in the radiologist office the lux should not exceed | 25 |
picture archiving and communication system | PACS |
all of the associated database information behind each image and included details | metadata |
What are negative side effects of image compression | lose smaller image details, increases image noise |
a lossless compression ratio is a ratio less than | 8:1 |
diagnostic work stations have a higher storage capacity than acquisition units | true |
correctly orient displayed images according to type of exam and can be customized by each radiologist | intelligent hanging protocols |
the 3 basic elements of security | privacy, authentication and system integrity |
2 parts of HIS | clinical information system and administrative information system |
a set of rules that facilitate the exchange of data between the different anodes of a computer network | protocol |
2 most common types of modern fluoroscopes | dynamic flat panel and image intensifier |
early CMOS produced inferior image quality | true |
Moving the image receptor as close to the patient as possible in a fluoroscopy room _____ | reduces OID |
which type of fluoroscopy unit requires a recording camera to be mounted to the top of it | image intensifier |
What is the rate at which data can be transferred through any system | bandwidth |
What is the typical matrix size of a CCD | 2048x2048 |
CMOS sensor consists of individual dexels | true |
These are represented as black spots on your image/screen | stuck pixels |
these are represented as white spots on your image/screen | dead pixels |
statistical noise that is inherent to the DR detector | intrinsic noise |