Radreview Image Processing and Quality Assurance 102 Flashcards

The process of "leveling and windowing" of digital images determines the image
A.
spatial resolution
B.
contrast
C.
pixel size
D.
matrix size

The relationship between the intensity of light striking a film and the intensity of light transmitted through the film is an expression of which of the following?
A.
Radiographic contrast
B.
Radiographic density
C.
Recorded detail
D.
Radiographic filtration

As the CR laser scanner/reader recognizes the phosphostimulated luminescence (PSL) released by the PSP storage plate, it constructs a graphic representation of pixel value distribution called a
A.
processing algorithm
B.
histogram
C.
lookup table
D.
exposure index

The function(s) of the developer in film processing is (are) to

remove the unexposed silver bromide crystals

change the exposed silver bromide crystals to black metallic silver

harden the emulsion

A.
1 only
B.
2 only
C.
1 and 3 only
D.
2 and 3 only

Cassetteless digital systems have a fixed spatial resolution determined by:
A.
The image plate laser divergence
B.
The focal spot size used
C.
The thin film transistor (TFT) detector element (DEL) size
D.
The proximity of the phosphor screen crystals

Which of the following statements regarding dual x-ray absorptiometry is (are) true?

Radiation dose is low.

Only low-energy photons are used.

Photon attenuation by bone is calculated.

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

Which section of the automatic processor shown in Figure 6–9 is associated with preservation of the x-ray image?

A.
Section 1
B.
Section 2
C.
Section 3
D.
Section 4

Figure 6–9.

Due to the high sensitivity of digital detectors to low intensity radiation (background, scatter and/or off-focus radiation), there is likely to be scatter and off-focus radiation contributing to the image outside the collimation margins. Since many radiologists find this distracting, the most appropriate radiographer action would be to:
A.
Use film-screen imaging only
B.
Apply a black border to the image before it is printed or sent to PACS
C.
Expose the anatomical parts as is; there is nothing that can be done to improve the presentation of the image(s) due to the inherent sensitivity of the system
D.
Reduce exposure factors by one-half to ensure minimal scatter and off-focus radiation

The luminescent light emitted by the PSP is transformed into the image seen on the CRT by the
A.
PSP
B.
scanner–reader
C.
ADC
D.
helium–neon laser

Which of the two film emulsions illustrated in Figure 4–11 requires more exposure to produce at density of 1.75?

A.
Emulsion 1 requires more exposure to produce a density of 1.75.
B.
Emulsion 2 requires more exposure to produce a density of 1.75.
C.
Emulsions 1 and 2 have identical characteristics.
D.
Density cannot be predicted from the illustration.

Figure 4–11.

A change from 400-speed screens to 200-speed screens would require what change in milliampere-seconds?
A.
mAs should be increased by 15%.
B.
mAs should be increased by 30%.
C.
mAs should be doubled.
D.
mAs should be halved.

Histogram data that is skewed relative to the values of interest (VOI) of the histogram analysis used for a particular exam may be caused by all of the following, except:
A.
Anatomical structures not centered to the IP
B.
Excessive windowing
C.
The X-ray beam is not correctly aligned to the edges of the IP
D.
The beam edge is irregular because of overlap of a radiopaque shadow, such as a gonadal shield

Which of the following affects both radiographic density and intensifying screen speed?

Thickness of phosphor layer

Type of phosphors used

Thickness of spongy screen support

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

An exposed image plate will retain its original image quality for about
A.
2 hours
B.
8 hours
C.
24 hours
D.
48 hours

The radiograph in Figure 6–12 could be improved in which of the following ways?
Courtesy of Stamford Hospital, Department of Radiology.

A.
The MSP should be 45 degrees to the plane of the IR.
B.
The MSP should be 90 degrees to the plane of the cassette.
C.
The chin should be elevated slightly.
D.
The head should be flexed slightly.
Figure 6–12.

The pre-contrast image used to subtract pixel values from the post-contrast image showing contrast-filled blood vessels in digital subtraction angiography is called the:
A.
Mask image
B.
Ghost (phantom) image
C.
Moiré image
D.
Latent image

What effect will a stained intensifying screen have on the finished radiograph?
A.
Blurring
B.
Magnification
C.
Decreased density
D.
Increased density

The presence of dust or scratches on intensifying screens will cause
A.
decreased density in those areas of the image
B.
increased density in those areas of the image
C.
decreased density in all areas of the image
D.
increased density in all areas of the image

Unopened boxes of radiographic film should be stored away from radiation and
A.
in the horizontal position
B.
in the vertical position
C.
stacked with the oldest on top
D.
stacked with the newest on top

An important feature of the pixel in a flat-panel TFT digital detector active matrix array is the:
A.
Nyquist frequency
B.
Fill factor
C.
Image lag
D.
Modulation transfer function

Which of the following is (are) tested as part of a quality assurance (QA) program?

Beam alignment

Reproducibility

Linearity

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

Which of the following is (are) methods used for x-ray film silver reclamation?

Photoelectric method

Metallic replacement method

Electrolytic method

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

Factors that contribute to film fog include

the age of the film

excessive exposure to safelight

processor chemistry

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

Silver reclamation may be accomplished in which of the following ways?

Metallic replacement cartridge

Electrolytic plating unit

Removal from used film

A.
1 only
B.
2 only
C.
1 and 2 only
D.
1, 2, and 3

In which section of the automatic processor shown in Figure 7–9 are the exposed silver halide crystals changed to black metallic silver?

Figure 7–9.

A.
Section 1
B.
Section 2
C.
Section 3
D.
Section 4

Which of the following possesses the widest dynamic range?
A.
High-speed screens
B.
Slow-speed screens
C.
AEC
D.
CR

Which of the following requires two exposures to evaluate focal-spot accuracy?
A.
Pinhole camera
B.
Slit camera
C.
Star pattern
D.
Bar pattern

Figure 4–24 is representative of

Figure 4–24.

A.
the anode heel effect
B.
the line-focus principle
C.
the inverse-square law
D.
the reciprocity law

Exposure-type artifacts include

poor screen–film contact

motion

chemical fog

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

The term windowing describes the practice of
A.
varying the automatic brightness control
B.
changing the image contrast and/or density
C.
varying the FOV
D.
increasing resolution

All of the following are potential digital pre-processing problems, except:
A.
Edge enhancement
B.
Defective pixel
C.
Image lag
D.
Line noise

Which of the following contribute(s) to base-plus fog?

Chemical fog

Base tint

Background radiation

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

While indirect digital detectors use a scintillator (phosphor) to convert X-ray energy, direct detectors use a:
A.
Photoconductor
B.
Scintillator
C.
Charged coupled device
D.
Histogram detector screen

A wire-mesh test is performed to evaluate screen
A.
lag
B.
contact
C.
resolution
D.
intensification

The term spectral matching refers to the fact that film sensitivity must be matched with the
A.
proper color screen fluorescence
B.
correct kilovoltage level
C.
correct milliamperage level
D.
proper developer concentration

Which of the following materials may be used as grid interspace material?

Lead

Plastic

Aluminum

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

What information, located on each box of film, is important to note and has a direct relationship to image quality?
A.
Number of films in the box
B.
Manufacturer's name
C.
Expiration date
D.
Emulsion lot

Boxes of film stored in too warm an area may be subject to
A.
static marks
B.
film fog
C.
high contrast
D.
loss of density

The function of the developer solution chemicals is to
A.
reduce the manifest image to a latent image
B.
increase production of silver halide crystals
C.
reduce the latent image to a manifest image
D.
remove the unexposed crystals from the film

When a slow screen–film system is used with a fast screen–film AEC system, the resulting images
A.
are too light
B.
are too dark
C.
have improved detail
D.
have poor detail

Geometric blur can be evaluated using all the following devices except
A.
star pattern
B.
slit camera
C.
penetrometer
D.
pinhole camera

Which of the two sensitometric curves shown in Figure 7–8 requires more exposure to produce a density of 2.0 on the finished radiograph?

Figure 7–8.

A.
Image 1
B.
Image 2

The X-ray scintillator layer used in in direct flat-panel digital detectors is usually either _____________ or ______________.
A.
Silicon dioxide, silver halide
B.
Cesium iodide, gadolinium oxysulfide
C.
Yttrium oxysulfide, barium fluoride
D.
Amorphous silicon dioxide, barium platinocyanide

The cause of films coming from the automatic processor still damp can be
A.
air velocity too high
B.
unbalanced processing temperatures
C.
insufficient hardening action
D.
developer underreplenishment

The functions of a picture archiving and communication system (PACS) include

storage of analog images

acquisition of digital images

storage of digital images

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

The changes between the images shown in Figure 4–7 represent changes made to

A.
pixel size
B.
matrix size
C.
window width
D.
window level
Figure 4–7.

Incorrect spectral matching between rare earth intensifying screens and film emulsion results in
A.
longer-scale contrast.
B.
insufficient density.
C.
decreased recorded detail.
D.
excessive density.

During measurement of blood pressure, which of the following occurs as the radiographer controls arterial tension with the sphygmomanometer?
A.
The brachial vein is collapsed.
B.
The brachial artery is temporarily collapsed.
C.
The antecubital vein is monitored.
D.
Oxygen saturation of arterial blood is monitored.

The purpose of the automatic processor's transport system is to
A.
monitor and adjust temperature
B.
agitate, mix, and filter solutions
C.
move the film and change its direction
D.
monitor the solution and replace it as necessary

Which of the lines indicated in Figure 7–1 correctly demonstrates the relationship between the exposure received by the PSP and its resulting luminescence as it is laser scanned?

Figure 7–1.

A.
Line A is representative of PSP exposure.
B.
Line B is representative of PSP exposure.
C.
Neither line is representative of PSP exposure.
D.
Both lines are representative of PSP exposure.

"Saturation" of an image in CR means that:
A.
The CR reader has difficulty converting insufficient exposure signals to produce a diagnostic image; all electronic enhancement mechanisms are maximized
B.
Beyond a certain exposure level, a large number of pixels will be at maximum digital value (black), resulting in loss of visibility of anatomical structures in that region.
C.
There is a large amount of scatter radiation that is contributing to loss of anatomical image detail due to loss of contrast, thus decreasing diagnostic quality of the image
D.
The CR image reader has adequately, and completely, read all the exposure intensities from the pixels resulting from the exposure

Which of the following can cause poor screen–film contact?

Damaged IR frame

Foreign body in IR

Warped IR front

A.
1 only
B.
2 only
C.
1 and 3 only
D.
1, 2, and 3

X-ray film emulsion is most sensitive to safelight fog
A.
before exposure and development
B.
after exposure
C.
during development
D.
at low humidity

Off-focus and scatter radiation outside of the exposure field when using CR can cause:
A.
Narrowing of the histogram
B.
Widening of the histogram
C.
Improper alignment of the exposure field
D.
High contrast

Inadequate collimation in CR imaging can result in an image that is too

light

dark

noisy

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

Exposed silver halide crystals are changed to black metallic silver by the
A.
preservative
B.
reducers
C.
activators
D.
hardener

Which of the following can affect the amount of developer replenisher delivered per film in an automatic processor?
A.
Developer temperature
B.
Amount of film exposure
C.
Film size
D.
Processor capacity

Before a flat-panel detector can be used for a radiographic exposure, it must be prepared. This preparation is referred to as:
A.
Propagation
B.
Initialization
C.
Augmentation
D.
Instrumentation

The device used to give film emulsion a predetermined exposure in order to test its response to processing is called the
A.
sensitometer
B.
densitometer
C.
step wedge
D.
spinning top

A fill factor of 80% in direct or indirect digital radiography means that:
A.
20% of the pixel area is occupied by the detector electronics with 80% representing the sensing area
B.
80% of the pixel area is occupied by the detector electronics with 20% representing the sensing area
C.
The saturation level will be unacceptable
D.
Only 20% of the image will be captured

A film emulsion having wide latitude is likely to exhibit
A.
high density
B.
low density
C.
high contrast
D.
low contrast

The chest radiograph shown in Figure 4–1 demonstrates

Figure 4–1.

Courtesy of Stamford Hospital, Department of Radiology.

A.
motion
B.
focal-spot blur
C.
double exposure
D.
poor screen–film contact

The optimal alignment of the anatomical part being imaged for all digital receptors should be:
A.
Field centered to IP with at least two collimation margins and parallel to the IP edges
B.
Centered anywhere on the IP, but having four distinct collimation margins, regardless of parallel orientation to the IP edges
C.
Centered to the IP with at least one collimation margin aligned to nearest edge of IP
D.
Field centered to IP with four collimation margins parallel to the IP edges

The x-ray tube used in CT must be capable of

high-speed rotation

short pulsed exposures

withstanding millions of heat units

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

Sampling frequency in computed radiography (CR) is expressed as:
A.
The TFT array size
B.
An inverse relationship between focal spot size and matrix size
C.
The light spread between the image plate and the light guide of the scanner
D.
Pixels/mm or pixel density

An unexposed and processed film will have a density of about
A.
zero
B.
0.1
C.
1.0
D.
2.5

With a given exposure, as intensifying screen speed increases, how is radiographic density affected?
A.
Decreases
B.
Increases
C.
Remains unchanged
D.
Is variable

Which of the following is the correct order of radiographic film processing?
A.
Developer, wash, fixer, dry
B.
Fixer, wash, developer, dry
C.
Developer, fixer, wash, dry
D.
Fixer, developer, wash, dry

If obtaining multiple images on one image plate, it is important to:
A.
Allow for X-ray tube cooling between successive exposures
B.
Avoid shielding of the image plate at all times to avoid field recognition errors
C.
Properly shield each exposed and unexposed area during the imaging of each individual image
D.
Expose the AP or PA projection in the right lower portion of the image plate

Base-plus fog is a result of

blue-tinted film base

chemical development

the manufacturing process

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

Component part(s) of x-ray film include which of the following?

Phosphor layer

Gelatin emulsion

Adhesive layer

A.
1 only
B.
1 and 3 only
C.
2 and 3 only
D.
1, 2, and 3

Resolution in CR increases as

laser beam size decreases

monitor matrix size decreases

PSP crystal size decreases

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

Pixel size and spacing determine the spatial resolution of the digital image. This is known as:
A.
Pixel pitch
B.
Focal resolution
C.
Nyquist resolution
D.
Frequency modulation

Which of the following digital post-processing methods remove high-frequency noise from the image?
A.
Edge enhancement
B.
Windowing
C.
Smoothing
D.
Aliasing

The safe approach to avoid an exposure field recognition error when using CR is to:
A.
Expose one image on the smallest IP available with collimation margins aligned parallel to the edges of the IP
B.
Expose multiple images on one IP, but make sure all collimation margins overlap
C.
Expose one image on the IP, but do not collimate
D.
Expose multiple images on one IP, but make sure all collimation margins are parallel to each other and do not overlap

A film emerging from the automatic processor exhibits excessive density. This might be attributable to the following

Developer temperature too high

Chemical fog

Underreplenishment

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

Film base is currently made of which of the following materials?
A.
Cellulose nitrate
B.
Cellulose acetate
C.
Polyester
D.
Glass

The device shown in Figure 4–16 is used for

Figure 4–16.

Courtesy of Gammex Inc.

A.
tomographic QA testing
B.
timer and rectifier testing
C.
mammographic QA testing
D.
kilovoltage calibration testing

Which of the following is an abnormal intensifying screen action?
A.
Fluorescence
B.
Luminescence
C.
Speed
D.
Lag

What information must be included on an x-ray image for it to be considered as legitimate legal evidence?

Name of facility where exam performed

Examination date

Date of birth

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

Characteristics of DR imaging include

solid-state detector receptor plates

a direct-capture imaging system

immediate image display

A.
1 only
B.
1 and 3 only
C.
2 and 3 only
D.
1, 2, and 3

Chemical fog may be attributed to

excessive developer temperature

oxidized developer

excessive replenishment

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

The artifacts on the radiograph shown in Figure 4–25 are called

A.
pi lines
B.
guide-shoe marks
C.
hesitation marks
D.
reticulation

Figure 4–25.

In digital imaging, the maximum spatial resolution is equal to:
A.
The Nyquist frequency, which is 1/2X the pixel pitch (mm)
B.
The wavelength of the detector system's analog-to-digital convertor's electrical signal
C.
The distance between the silver halide crystals in the image receptor
D.
The detective quantum efficiency of the imaging system; this should be at least 2X the frequency of the analog-to-digital convertor electrical signal

For the same FOV, spatial resolution will be improved using
A.
a smaller matrix
B.
a larger matrix
C.
fewer pixels
D.
faster screens

The processor rollers that are out of solution and function to transfer the film from one solution to another are the
A.
deflector plates
B.
guide shoes
C.
crossover rollers
D.
turnaround assembly

In which section of the automatic processor seen in the figure below are the unexposed silver halide crystals removed from the emulsion?

A.
Section 1
B.
Section 2
C.
Section 3
D.
Section 4

When radiographing a cross-table lateral hip or axial shoulder using CR, one method of creating a collimation margin at the bottom of the radiograph is to:
A.
Use a narrow lead strip at the bottom edge of the IP, but out of the anatomy
B.
Only one collimation margin is necessary, so this would not be necessary
C.
Make two exposures with suspended respiration; one for the uppermost anatomy, then a second for the dependent anatomy
D.
Expose the anatomy as is and use the post-processing cropping feature

The automatic film processor's recirculation system functions to

add quantities of solution as required.

maintain uniform temperatures.

mix and agitate solutions.

A.
1 only
B.
1 and 3 only
C.
2 and 3 only
D.
1, 2, and 3

The instrument that is used frequently in quality-control programs to measure varying degrees of x-ray exposure is the
A.
aluminum step wedge.
B.
spinning top.
C.
densitometer.
D.
sensitometer.

What determines the quantity of fluorescent light emitted from a fluorescent screen?

Thickness of the phosphor layer

Type of phosphor used

Phosphor size

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

What is the purpose of the thin layer of lead that is often located behind the rear intensifying screen in an IR?
A.
To prevent crossover
B.
To increase screen speed
C.
To diffuse light photons
D.
To prevent scattered radiation fog

All of the following are factors that cause low contrast in CR images, except:
A.
High kVp
B.
Inadequate grid efficiency or no grid
C.
Excessive beam limiting (collimation)
D.
Incomplete erasure of the image plate

The smallest digital detectors (approximately 100 microns) provide the best spatial resolution and, therefore, are best-suited for use in:
A.
Fluoroscopy procedures
B.
Mammography
C.
Pediatric radiography
D.
Long bone measurement to ensure measurement accuracy

IRs/cassettes frequently have a lead-foil layer behind the rear screen that functions to
A.
improve penetration
B.
absorb backscatter
C.
preserve resolution
D.
increase the screen speed

Objectionable widening of the histogram in CR can be caused by all of the following, except:
A.
Off-focus and scatter radiation outside of the exposure field
B.
Windowing
C.
Improper pre-exposure anatomical selection
D.
Subtraction

One reason why only one image is preferred per image plate is:
A.
To ensure that the anatomical part is properly centered to avoid undercutting of the image
B.
To allow the radiologist to split the PACS monitor and display the current image and a prior image side-by-side for comparison
C.
To ensure optimal radiation safety, since only one image is exposed on one image plate
D.
To reduce the chances of grid cutoff artifacts

A QA program serves to

keep patient dose to a minimum

keep radiographic quality consistent

ensure equipment efficiency

A.
1 only
B.
1 and 2 only
C.
1 and 3 only
D.
1, 2, and 3

As the conversion efficiency of intensifying-screen phosphors increases,

patient dose increases

noise increases

speed increases

A.
1 only
B.
1 and 2 only
C.
2 and 3 only
D.
1, 2, and 3

Which apparatus is needed for the construction of a sensitometric curve?

Penetrometer

Densitometer

Electrolytic canister

A.
1 and 2 only
B.
1 and 3 only
C.
2 and 3 only
D.
1, 2, and 3

In order to avoid background radiation artifacts when using CR, it is important to:
A.
Erase all image plates that have not been used for 48 hours
B.
Erase all image plates if there is any question about how long it has been since the plate has been erased
C.
Erase an image plate if there is any doubt as to when it was last erased, especially in the case of pediatric radiography
D.
A and B are correct actions
E.
B and C are correct actions
F.
All of these are correct actions
G.
None of these would be considered correct actions

Phosphors suitable for use in intensifying screens should have which of the following characteristics?

High conversion efficiency

High x-ray absorption

Afterglow

A.
1 only
B.
1 and 2 only
C.
3 only
D.
1, 2, and 3