Quiz 3 C14 (Bush) 23 (C&A) Flashcards
The two principal characteristics of a medical image are _______________________.
spatial resolution and contrast resolution
Spatial frequency is used to describe the quality of spatial resolution in terms of _____________.
line pairs
In digital imaging, spatial resolution is ultimately limited by ___________________.
pixel size
As spatial frequency increases, the object size _____ and the spatial resolution _____.
decreases; increases
If there were such thing as a perfect imaging system, the MTF would be equal to ________.
one
A _______________ test tool is used to acquire data for an MTF curve.
bar pattern
The human visual system can distinguish ________ shades of gray.
30
The number of gray shades that an imaging system can reproduce is called its ________________.
dynamic range
Screen-film radiography has a dynamic range of __________. Digital Imaging has a dynamic range > ______________.
1000____65,00
The bit capacity of each pixel identifies the ___________ of a digital imaging system.
dynamic range
The ________________ digital imaging system uses the highest dynamic range.
mammography
The portion of useful image-forming x-rays is referred to as the ___________.
signal
Recent studies have shown that denser breast tissue is best imaged with _____________________.
digital mammography
As mAs is increased the signal-to-noise ratio is ____________.
increased
Image detail is also called _______________________.
spatial resolution
Of all radiographic imaging systems, _____________ has the best contrast resolution.
computed tomography
It is __________of the scope of practice of a radiologic technologist to use post-exposure shuttering, cropping, electronic collimation or electronic masking to eliminate any anatomical information.
outside
T or F: Electronic masking to improve image viewing conditions should be applied in a manner that demonstrates the actual exposure field edge to document appropriate collimation.
true
T or F: Masking should be applied over anatomy that was contained in the exposure field at the time of image acquisition.
false
Any part of the radiographic image that is not part of the signal is known as what?
noise
