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WorksheetsPrinciples final review
Total questions: 118
Worksheet time: 59mins
A radiograph that demonstrates minimal differences between gray shades is said to have
long scale
low contrast
decreased contrast
all of the above
When the tissue structure of the ankle joint is considered, the dramatic tissue differences between the muscles and bones of the ankle produce
low receptor contrast
high subject contrast
high receptor contrast
low subject contrast
Immediately after exposure and before a digitally acquired image is post-processed, the initial image shown demonstrates
a very low contrast
extremely high contrast
focal spot blur
the heel effect
As the lead content of a grid increases,
the contrast improvement factor decreases
the K-factor decreases
exposure to the image receptor increases
the ability of the grid to remove scatter increases
With increasing kVp levels, it is important to remember that with digital receptors and DR technologies
the differences between minimum and maximum incoming photon energies is reduced
more anatomical data can be recorded with a lower patient dose
less differential absorption occurs and a narrower histogram results
all of the above
For a grid to be properly focused, the x-ray tube must be located along the ____ line.
convergence
divergence
tangent
resolution
When an AEC is used for a lateral chest, which ionization chambers are utilized?
all three cells
the left and right outer cells
the left outer cell only
the center cell
The relationship between mAs and exposure is
directly proportional
exponential
a squared relationship
indirectly proportional
When exposure factor controls the penetration power of the x-rays?
kilovolts peak, kVp
mA
seconds
time
When the lead strips run in a single direction in a grid, the grid pattern is described as
linear
tangential
cross-hatched
criss-cross
A ghost image can occur in digital imaging because of ______.
supernatural phenomena
backscatter
image blur
incomplete erasure
Photon absorption within the body occurs as the result of
characteristic interactions
Bremsstrahlung interactions
Compton interactions
photoelectric interactions
Body thickness is measured in inches.
True
False
What size is the average CR or DR image file per image?
100 KB
10 KB
20 MB
200 MB
Prime exposure factors are variables the professional technologist controls as well as the patient.
True
False
The use of a radiographic grid requires
attention to central ray angulation
an increase in exposure factors
an awareness of the SID
all of the above
Lossy compression reduces data files greater than ____.
10:1
50:1
1000:1
100:1
Which statement about radiographic grids is INCORRECT?
The interspace strips are usually made of aluminum
The radiopaque strips are typically made of thin lead
Grids may have grid strips running in perpendicular directions
A grid is a series of lead strips that alternate with radiopaque interspace strips.
As kVp increases, the percentage of Compton interactions ____ and contrast ____
increases, decreases
decreases, decreases
increases, increases
decreases, increases
Factors affecting the quantity of emission x-rays
mAs, Kilovoltage, Distance
mAs and patient thickness
Kilovoltage and Distance
None of the above
Object artifacts in digital imaging can occur from errors in ____
patient positioning
x-ray beam collimation, histogram selection, and patient positioning
histogram selection
x-ray beam collimation
Pressing the jaws too tightly against the body part may result in an inaccurate measurement
True
False
When using an AEC, the radiographer loses control of
kVP
mAs
mA
distance
Battery powered Mobile (Portable) X-ray equipment takes 8 hours to charge if fully discharged
True
False
In digital imaging using a DR detector, image contrast decreases with
radiographic grids
mAs values that are too low
excessive kVp values
underexposure
Extremities portable studies require 2 projections at 45 degrees from each other
True
False
The amount of scatter radiation produced increases with a/an
larger field size
decrease in atomic number of the tissue
increase in patient thickness
all of the above
The recorded detail of a digital radiographic image is primarily visible because of
sufficient contrast
sufficient receptor exposure
both a and b
low signal to noise ratios (SNR)
A radiographic grid absorbs
scattered electrons
primary radiation
all scatter and secondary electrons
scattered radiation
The factor that affect x-ray emission under the direct control of the radiographer are called the ____ factors.
quantity
prime
principal
quality
What prime factor controls contrast?
kVp
mA
mAs
Seconds
Immediately after exposure and before a digitally acquired image is post-processed, the initial image shown demonstrates
extremely high contrast
the heel effect
focal spot blur
very low contrast
Angulation across the long axis of a linear grid causes
cross-hatched impressions
grid convergence
grid cut-off
grid shadowing
Lossless compression reduces data files to as low as ____
1000:1
50:1
100:1
10:1
As the lead content of a grid increases
the ability of the grid to remove scatter increases
the contrast improvement factor decreases
exposure to the image receptor increases
the K-factor decreases
As you are performing a KUB radiograph on a patient using AEC, you notice that your post-exposure readout is unusually high. A possible explanation for this high reading could be
the kVp was too high
the minimum response time was too long
the backup mAs was set too love
the detector was collimated out of the field of exposure
The difference between adjacent densities is defined as?
image detail
image quality
density change
contrast
An increase in x-ray beam filtration
reduces contrast
increases the average photon energy
increases the number of Compton interactions
all of the above
The primary factor controlling x-ray beam quantity is determined by
mAs
distance
filtration
kVp
The three classifications of digital imaging artifacts are ______
an image receptor, software, and object
processing, exposure, and handling/storage
software, object, and exposure
processing, image receptor, and exposure
When the lead strips run in a single direction in a grid, the grid pattern is described as
linear
criss-cross
cross-hatched
tangential
What type of artifact is seen in the image?
Image receptor artifacts
software artifacts
object artifacts
foreign object artifacts
The atomic interaction that produces scatter radiation is
photodisintegration
photoelectric
Bremsstrahlung
Compton
Artifacts are an acceptable part of digital imaging
True
False
A device that moves the grid during a radiographic exposure is called a(n)
oscillator
focussed grid
Porter-Bucky diaphragm
alterantor
Computed radiography cassettes can sit for _____ between exposures
a few days
an unlimited time
up to 1 yr
a few hours
The single function of an AEC is to eliminate the need to set
time
mA
all of the above
kVp
Which grid would most effectively reduce scatter
8:1
6:1
12:1
15:1
High contrast is directly related to
the number of photoelectric interactions
high kVp
the amount of Compton scatter
mAs
Grid suppression software is intended to
lower image contrast for the viewer, to reveal low contrast objects
blur out the grid lines through dynamic visual motion
remove the visibility of grid lines
amplify the visibility of the radiopaque grid strips
Backscatter radiation artifacts can occur more readily in digital imaging because of the ________
large data file sizes
techniques used
highly sensitive receptors
partitioning errors
Collimating light projected off IR reduces patient and technologist exposure
True
False
The primary purpose of using a radiographic grid is to
intercept remnant radiation
remove undesired primary photons
remove a percentage of scatter photons
decrease skin exposure to patients
The difference between two adjacent gray shades on a radiographic image is
quantum mottle
distortion
recorded detail
radiographic contrast
Standard power Mobile (portable) x-ray equipment DO NOT have a capacitor.
True
False
When an x-ray beam passes through the body
it will be absorbed by the body
it will pass through the body unaffected
it will interact with the body and change directions
all of the above
The principal controlling factor of radiographic contrast using film-screen technology is
anode angle
mAs
focal spot size
kVp
The number of grid lines per inch is the grid
ratio
speed
focus
frequency
A radiograph with few shades of gray exhibits
high contrast
long scale contrast
low contrast
medium contrast
The total AMOUNT of irradiated material is a function of
body position and focal spot size
tissue thickness and tissue density
body part thickness and area of exposure
field size and anode angle
Histogram selection is done _______
automatically during each exposure
by the radiographer during post-processing
by the radiographer before each exam
automatically during post-processing
Radiographic image contrast is a combination of
grid ratio and field size
data rescaling and look-up tables
receptor contrast and subject contrast
filtration thickness and field size
Automatic exposure devices provide a diagnostic quality radiograph when the
proper time is set
anatomy of interest is positioned directly above the appropriate ionization chambers
beam filtration is minimum
correct focal spot is selected
What exposure factor measure current
milliamps, mA
seconds or milliseconds
kVp
volts or kilovolts
The greatest source of scatter during a radiographic examination is the
table top material
AEC detector
patient
image receptor
What is the recommended distance for the technologist to be away from the patient for mobile radiography
no more than 6 ft
at 5 ft
6ft or more
if using an apron, no need to be away from the patient
The prime factors include all of the following EXCEPT
distance
mAs
kVp
filtration
As kVp _____, a, ______ range of photon energies is produced
increases, narrower
decreases, wider
decreases, longer
increases, wider
Automatic Exposure Control is commonly referred to as
phototiming
automatic
exposing
chambers
What artifact do you see on this picture? (Line on half of image)
Image receptor artifact
software artifact
object artifacts
grid cut off artifacts
Adjustments in mAs should be used to control IR
window level
contrast
resolution
density or exposure
Most modern AEC systems provide a minimum response time of
0.001 sec
1 millisecond
1/1000 sec
all of the above
When an AEC is used for PA chest, which ionization chambers are utilized?
the center cell
the left and right outer cells
all three cells
the right outer cell only
Radiographs of the fingers, hand, wrist, forearm, and foot are usually viewed with the proximal aspect pointing up
True
False
Increasing the kVp will result in the production of an x-ray photon with
more penetrability and greater energy
greater velocity and more electrons
less penetrability and less energy
greater charge and more photons
The primary purpose of using a radiographic grid is to
intercept remnant radiation
remove a percentage of scatter photons
remove undesired primary photons
decrease skin exposure to patients
Radiography density is defined as the overall blackness/blackening of the radiograph
True
False
As kVp increases
image receptor exposure increases
secondary radiation increases
scatter radiation increases
all of the above
Kilovoltage is the primary controlling factor of
x-ray beam quality
x-ray beam quantity
filtration thickness
x-ray beam intensity
U.S. public law requires the generators automatically terminate AEC exposure at _____ mAs above 50 kVp
100
900
300
600
The relationship between the intensity of radiation is the
15 percent rule
direct square law
inverse square law
reciprocity law
Kilovoltage is the primary controlling factor of
x-ray beam quality and contrast
filtration thickness and contrast
x-ray beam intensity
x-ray beam quantity
The radiopaque strips
absorb scatter
are made of radiodense material
have a high atomic number
all of the above
Radiographs are generally viewed "right side up," with the most superior aspect of the anatomy at the top
True
False
A radiograph that demonstrates considerable differences between gray is said to have
short scale
increase contrast
high contrast
all of the above
When more than one ionization chamber is used simultaneously during exposure, the signal is
multiplied
determined by the chamber with the highest exposure
average
amplified to the highest value
The primary factor controlling x-ray beam quantity is determined by
filtration
mAs
distance
kVp
In an emergency situation when a radiographic grid is unavailable, a convenient practice to employ, that creates a "grid-like image" when one was not used is
grid suppression software
all of the above
increase the OID to create an air-gap
to turn the digital detector over, to use the back of the detector as an absorber
SID stands for System to Image Receptor Distance
True
False
The size and number of digital images have to be compressed to permit _____
archiving
transmitting
transmitting and archiving
viewing
What factor controls time of exposure?
seconds or milliseconds
hours
kVp
none of the above
What prime factor controls density
kVp
mAs
seconds
distance
Most AEC consoles permit activation of
the outer cells when the center cell is inactivated
all three cells simultaneously
all three cells in any combination
the center cell and either outer cell
As a general rule, a radiographic grid is employed
for procedures below 60 kVp
for pediatric studies to improve contrast
for part thicknesses above 10 cm
in order to improve positioning latitude
Poor positioning skills results in increased repeat rate when using AEC
True
False
A graph of the frequency of occurrence versus digital value intervals is called a(n) ____
digitization
compression
histogram
algorithm
X-ray beam penetrability is primarily controlled by
mAs
kVp
focal spot size and dimension
filtration
A radiographer that demonstrates considerable differences between gray shades is said to
increased contrast
high contrast
short scale
all of the above
As the mA doubles, the number of electrons flowing from cathode to anode
increases twofold
decreases twofold
increases fourfold
increases by 50 percent
Modern equipment uses ________ _________ a the Automatic Exposure Control technology
ionizing boxes
detector chambers
ionization chambers
phototiming detectors
When using a radiographic grid with computed radiography (CR)
none of the above
higher frequency grids are undesirable
the Moire effect is a consideration
radiographic grids are unnecessary
The factors that DIRECTLY AFFECT x-ray quality are
focal spot size and anode angle
filtration and mAs
kVp and beam filtration
mAs and distance
The relationship between mAs and exposure is
exponential
indirectly proportional
directly proportional
a squared relationship
The software correction that equalizes the response of each pixel to a uniform exposure of x-rays is called____
flatfielding
lossless compression
histogram selection
lossy compression
As a general rule, a radiographic grid is employed
for procedures below 60 kVp
in order to improve positioning latitude
for part thicknesses above 10 cm
for pediatric studies to improve contrast
What is seen in the zoomed yellow rectangle area? (Left should area with clavicle)
Morie Pattern
Misalingment
cassette artifact
Grid cut off
Grid suppression software is intended to
blur out the grid lines through dynamic visual motion
lower image contrast for the viewer, to reveal low contrast objects
remove the visibility of grid lines
amplify the visibility of the radiopaque grid strips
Early versions of AEC technology were referred as
photometers
photosensors
phototimers
photomultipliers
The purpose of moving the grid during the radiographic exposure is to
blur out the radiopaque strips
activate the digital detector
activate the AEC detectors
remove unwanted contrast
As kVp increases
contrast decreases
contrast increases
contrast remains the same
density decreases
The ratio of the height of the lead strips to the distance between the lead strips is the grid
speed
frequency
selectivity
ratio
Grid replacement software is designed to
allow the radiographer to select a grid ratio for postprocessing
create a nongrid image that looks like a grid was employed
all of the following
hide the grid from the viewer
What type of artifact do you see in this picture? *software artifact*
image receptor artifact
software artifact
object artifacts
grid cut off artifacts
When AEC is used for an AP abdomen, which ionization chambers are utilized?
all three cells
the left outer cell only
the left and right outer cells
the center cell
Varying tissue thickness and densities is referred to as
subject contrast
image contrast
attenuation
differential absorption
With digital imaging technologies, the final brightness and contrast appearance of an image is due to
kVp
image rescaling
look-up table (LUT) application
window and level controls
Which of the following sets of exposure factors would best control involuntary motion?
200 mA, 0.045 sec
100 mA, 0.069 sec
300 mA, 30 ms
500 mA, 18 ms
If the primary beam is collimated from an activated chamber, the result is a
light radiograph
short exposure time
dark radiograph
decrease in radiographic density
