Test 1 C11-16 (Bush) 20-23 (C&A) Flashcards
A CD, DVD, hard drive, flash drive, or cloud-based is used to _____________.
archive files
The _____ represents zero or one.
bit
In computer language, a byte is _________.
8 bits
MAC-OS and Windows are two different __________ systems.
operating
A computer first uses its ________________ program when it is turned on.
bootstrap
What is the form of radiology that allows for the transfer of images to remote sites for interpretation?
teleradiology
T or F: Word, Excel, iTunes, and Spider Solitaire are application programs.
true
T of F: In computer language a single binary digit, 0 or 1, is called a byte.
false
Computed radiography screens respond to radiation with ______________________.
photostimulable luminescence
A photostimulable phosphor in a metastable state will emit light ________________.
immediately, when stimulated by light, and over time
The computed radiography cassette is called a(n) ______________ receptor.
imaging
The four steps of creating an image with computed radiography are ______________.
metastable state, stimulate, read, and erase
The output signal from the photostimulable phosphor plate is converted from analog to digital by the ________________.
computer controls
The principal source of noise in computed radiography is ____________________.
scatter radiation
The computed radiography image has _____________________.
wide exposure latitude and improved contrast resolution
The laser beam must be less than 100 µm in diameter in order to maintain ________.
high spatial resolution
_____________ is prevented by flooding the erased imaging plate with bright light.
ghosting
T or F: IPs should be used soon after the erase cycle has been completed.
true
Digital radiography is best described by which three elements?
Capture, coupling, and collection
In digital radiography, the visible image results when the _______________ is scanned by a laser beam.
pixel detector
In digital radiography, the brightness of the image is determined by _______________.
pixel values
In CR, the capture element is the _____________.
photostimulable phosphor (PSP)
What is the most recent development in digital radiography image receptors?
Direct capture solid state devices
In digital radiography, spatial resolution is improved with increased _____________.
matrix size
The dynamic range determines the degree of __________________ in the image.
contrast resolution
Spatial resolution is determined by the ratio of ________________ to ____________.
field of view; matrix size
One advantage of DR over scanned projection radiography is __________________________.
shorter exposure time
T or F: Digital radiography is best described by three elements—capture, archiving, and storage.
false
T or F: CsI/CCD is an indirect DR process by which x-rays are converted first to light and then to an electronic signal.
true
T or F: CsI/a-Si is an indirect DR process by which x-rays are converted first to light and then to an electronic signal.
true
T or F: Spatial resolution in DR is pixel unlimited.
false
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
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
any part of the radiographic image that is not part of the signal is known as what?
noise
What are the prime exposure factors?
kVp, mAs, and SID
Changes in kVp affect all of the following, except _______________.
number of electrons boiled off the filament
An increase in mAs causes ______________ in beam quality and ___________ in beam intensity.
no change; an increase
There is a direct relationship between the quantity of x-rays and the _______________.
milliamperage
If mAs is increased from 20 mAs to 40 mAs, the patient dose will _____________.
be doubled
Beam penetrability is increased if ________ is/are increased.
kVp
At least a _____% change in mAs is necessary to produce a visible change in the image.
30
Patient thickness should be measured with the _______.
caliper
The small focal spot will provide a _______.
finer detail of image
Added filtration has the effect of __________ the beam quality and ________ patient dose.
increasing; reducing
List the following tissues in order from the most radiolucent to the most radiopaque.
lung, fat, muscle, bone
Which medical condition may require a lower technique?
emphysema
When only the intensity needs to be changed, only the _______ should be adjusted.
mAs
Sharpness of detail can be improved by increasing _________.
SID
Foreshortening is caused by a(n) _________________________________.
angled body part when the beam is perpendicular to the image receptor
With automatic exposure techniques the exposure is terminated when the optimum _____ is reached.
OD (optical density)
Patient factors include ___________________.
anatomical thickness and body composition
Which body habitus indicates an average patient?
sthenic
Patient thickness affects radiographic technique by affecting ____________.
mAs and kVp settings
A high quality radiographic image should always demonstrate ____________.
structures and tissues
_________ is defined as the ability to image two separate objects and visually detect one from the other.
Resolution
What is the formula for the magnification factor?
MF = (SID/SOD)
Subject contrast is affected by ___________.
patient thickness
T or F: Radiographic technique charts embedded in the operating console are based on hypersthenic patients.
false
T or F: Patient thickness should not be guessed.
true
T or F: Foreshortening of the image is when the anatomical part appears smaller than normal.
true