Chapter 10 & 12 Test Flashcards
What are the effects of scattered radiation on a radiographic image?
1.) it produces radiographic fog
2.) decreased image contrast
3.) it produces quantam mottle
a.) 2 only
b.) 1 only
c.) 1, 2 and 3
d.) 1 and 2 only
d.) 1 and 2 only
In CR, which layer of the image receptor is responsible for collecting the latent image?
a.) phosphor layer
b.) valence layer
c.) support layer
d.) reflective layer
a.) phosphor layer
Which situation is most likely to result in grid errors?
a.) stationary radiography at the table bucky
b.) table top radiography
c.) mobile radiography
d.) stationary radiography in an upright bucky
c.) mobile radiography
Increasing the anode angle will:
1.) decrease the anode heel effect
2.) increase the anode heel effect
3.) decrease IR exposure
4.) increase IR exposure
a.) 1 only
b.) 1 and 4 only
c.) 2 and 4 only
d.) 2 and 3 only
b.) 1 and 4 only
In CR what part of the phosphor layer traps electrons (latent image) prior to processing?
a.) conductive layer
b.) conduction band
c.) reflective layer
d.) valence band
b.) conduction band
Decreased patient thickness results in:
1.) increased IR exposure
2.) increased heel effect
3.) decrease distortion
4.) higher image contrast
a.) 1 and 4 only
b.) 1, 2, 3 and 4
c.) 1 only
d.) 1, 3 and 4 only
d.) 1, 3 and 4 only
Which of the following are factors that affect contrast in digital imaging?
1.) mA and/or time
2.) windowing
3.) kVp
4.) PACS
5.) look up table
a.) all choices are responsible
b.) 2, 3 and 5 only
c.) 2, 3, 4 and 5 only
d.) 3 only
e.) 3 and 5 only
b.) 2, 3 and 5 only
Which of the following factors affect image contrast? choose all that apply.
a.) collimation
b.) grid ratio
c.) motion
d.) kvp
e.) focal spot size
f.) mas
g.) scatter
h.) OID
I.) anode heel effect
j.) patient factors
a.) collimation
b.) grid ratio
d.) kvp
g.) scatter
h.) OID
j.) patient factors
Which device converts anologue signal into a digital signal?
a.) CMOS
b.) CCD
c.) ADC
d.) TFT
c.) ADC
Amorphus silicon is used as the:
a.) photoconductor for direct capture DR imaging
b.) photoconductor for indirect capture DR Imaging
c.) photodetector for direct capture DR Imaging
d.) photodetector for indirect capture DR imaging
d.) photodetector for indirect capture DR Imaging
Which type of grid error results from misplacement of the IR to the grid, causing the grid lines to run in the opposite direction of the xray beam?
a.) off level
b.) upside down focused
c.) off focus
d.) off center
b.) upside down focused
When processing a CR cassette, the term slow scan describes a laser light moving over a stationary IR.
a.) true
b.) false
b.) false
The greatest detail sharpness is obtained by using:
1.) a small focal spot
2.) the longest SID
3.) the smallest OID
4.) longer exposure times
a.) 4 only
b.) 1, 2, 3 and 4
c.) 1, 2 and 3
d.) 1 only
c.) 1, 2 and 3
Scatter radiation reduces radiographic quality by changing:
a.) contrast
b.) optical density
c.) blurring
d.) distortion
a.) contrast
A measure of the ability of a system to display contrast of anatomic objects varying in size describes.
a.) OID
b.) FOV
c.) MTF
d.) DQE
c.) MTF
As mAs increases, quality:
a.) increases by a factor of 4
b.) increases
c.) decreases
d.) is unaffected
d.) is unaffected
Amorphus selenium is used as the:
a.) photoconductor for direct capture DR imaging
b.) photodetector for indirect capture DR imaging
c.) photoconductor for indirect capture DR imaging
d.) photodetector for direct capture DR imaging
a.) photoconductor for direct capture DR imaging
Which grid error is the result of the CR not being aligned side to side with an IR?
a.) off level
b.) off center
c.) upside down
d.) off focus
b.) off center
Which of the following devices acts as a switch to release the electric charge collected by a detector element?
a.) photodiode
b.) TFT
c.) CCD
d.) scintillator
b.) TFT
The relationship between a DEL and spatial resolution is:
a.) directly proportional
b.) inversely proportional to the square
c.) inversely proportional
d.) directly proportional to the square
a.) directly proportional
In digital imaging, image brightness is primarily controlled by:
1.) kvp and mas
2.) monitor functions
3.) postprocessing functions
a.) 1 and 2 only
b.) 1, 2 and 3
c.) 2 and 3 only
d.) 1 only
c.) 2 and 3 only
Part of a PSP plate that reduces and carries away static electricity is the:
a.) conductive layer
b.) reflective layer
c.) turbid layer
d.) support layer
a.) conductive layer
Methods that help to reduce the production of scattered radiation include using:
1.) compression
2.) beam restriction
3.) a grid
a.) 1 and 3 only
b.) 1, 2 and 3
c.) 1 and 2 only
d.) 2 and 3 only
c.) 1 and 2 only
Which of the following grids will allow for the least amount of centering and or positioning latitude?
a.) 16 to 1
b.) 12 to 1
c.) 5 to 1
d.) no grid
a.) 16 to 1
The distance at which a focus grid can be used is most closely related to the:
a.) grid ratio
b.) convergence line
c.) grid frequency
d.) interspacing material
b.) convergence line
Misalignment of the tube-part-IR relationship results in:
a.) magnification
b.) size distortion
c.) shape distortion
d.) blur
c.) shape distortion
ALl of the following are related to SR except:
a.) OID
b.) focal spot size
c.) SID
d.) milliamperage
d.) milliamperage
what does the acronym pacs stand for?
Picture Archiving and Communication System
Which of the following statements is true concerning direct radiography (DR) systems?
a.) use storage phosphors to temporarily store energy representing the image signal
b.) require that the storage phosphor undergoes a process to extract the latent image
c.) have detectors that directly capture and read out an electronic image signal
d.) a and b
c.) have detectors that directly capture and read out an electronic image signal
What is the main effect of grid cut off?
a.) under exposure to the IR
b.) over exposure to the IR
c.) reduced image resolution
d.) decreased image contrast
a.) under exposure to the IR
What is the primary factor that influences contrast in digital imaging?
a.) smoothing
b.) kvp
c.) look up table
d.) histogram
c.) look up table
WHich of these processes corrects for slight under exposure or over exposure errors made by the technologists?
a.) look up table
b.) digitizer
c.) histogram analysis
d.) rescaling
d.) rescaling
In a direct radiography system, indirect capture provides the least amount of data loss.
a.) true
b.) false
b.) false
A light sensitive semiconducting device that generates an electrical charge when stimulated by light and stores this charge in a capacitor is the:
a.) cathode of the camera tube
b.) anode of the camera tube
c.) charge coupled device
d.) xray tube
c.) charge coupled device
In radiography of a large abdomen, which of the following are effective ways to minimize the amount of scattered radiation reaching the IR?
1.) use of close collimation
2.) use of low MAS
3.) use of low ratio grid
a.) 1 only
b.) 1 and 2
c.) 1 and 3
d.) 1, 2 and 3
a.) 1 only
Cassette less radiography systems do not use which of the following:
a.) photoconductors
b.) plate readers
c.) buckies
d.) xrays
b.) plate readers
Good collimation practices will do all of the following except:
a.) reduce visibility of recorded detail
b.) all options are correct
c.) decrease radiation dose
d.) affect the amount of scatter that reaches the IR
a.) reduce visibility of recorded detail
WHich of the following factors influence the production of scattered radiation?
1.) kilovoltage level
2.) tissue density
3.) size of field
a.) 1 and 3
b.) 1 and 2
c.) 1, 2 and 3
d.) 1 only
c.) 1, 2 and 3
A grid usually is used in which of the following circumstances?
1.) when radiographic a large or dense body body
2.) when using high kvp
3.) when a lower patient dose is required
a.) 1, 2 and 3
b.) 1 only
c.) 1, and 2 only
d.) 3 only
c.) 1 and 2 only
the phosphor layer of a CR plate is composed of:
a.) amorphus silicon and europium activators
b.) barium fluorohalide and amorphus silicon
c.) amorphus silicon and ceisum iodide turbid or structured
d.) barium flurohalide and europium activators
d.) barium fluorohalide and europium activators
The main purpose of a grid is to absorb scatter, and decrease patient dose.
a.) true
b.) false
b.) false
A decrease in kilovoltage will result in:
1.) a decrease in image resolution
2.) a decrease in photon energy
3.) a decrease in IR exposure
a.) 1 only
b.) 1 and 2 only
c.) 1, 2 and 3
d.) 2 and 3 only
d.) 2 and 3 only
How does adding filtration to the xray tube assembly change the characteristics of the xray beam?
a.) decrease quantity, decreases quality
b.) increases quantity, increases quality
c.) increases quantity, decreases quality
d.) decreases quantity, increases quality
d.) decreases quantity, increases quality
Types of grid errors include: choose all that apply.
a.) upside down focused grid
b.) right side up error
c.) off center error
d.) off level error
a.) upside down focused grid
c.) off center error
d.) off level error
Computed radiography acquires an image through ____________.
a.) the use of storage phosphor plate
b.) conventional film/screen processing using a digital scanner
c.) an electrically charged cassette
d.) the heating of a thermoluminescent device
a.) the use of a storage phosphor plate
As collimation increases, the quantity of scatter radiation decreases. T/F
true
Which of the following will result in increased scatter reaching the IR? choose all that apply.
a.) decreased tissue density
b.) compton scatter
c.) increased patient thickness
d.) high kvp
e.) decreased FOV
f.) decreased grid ratio
g.) decreased collimation
b.) compton scatter
c.) increased patient thickness
d.) high kvp
f.) decreased grid ratio
g.) decreased collimation
Which type of grid has lead strips situated parallel to the primary xray beam?
a.) focused grid
b.) stationary grid
c.) parallel grid
d.) non focused grid
a.) focused grid
Benefits of beam restriction include: choose all that apply.
a.) decreasing patient dose
b.) reducing the production of scatter
c.) increasing FOV
d.) limiting the are exposed to radiation
a.) decreasing patient dose
b.) reducing the production of scatter
d.) limiting the area expised to radiation
What describes the number of lead lines per unit length?
grid frequency
Which of the following factors have an affect on image receptor (IR) exposure?
a.) mas
b.) kvp
c.) patient factors
d.) motion
e.) SID
f.) focal spot size
g.) tube, IR, and or patient angel
h.) filtration
a.) mas
b.) kvp
c.) patient factors
e.) SID
h.) filtration
Which of the following options is the standard for communicating systems of PACS to other devices such as workstations and printers
a.) DICOM
b.) HIS
c.) PACS
d.) RIS
a.) DICOM
Compared with a low ratio grid, a high ratio grid will:
1.) allow more centering latitude
2.) absorb more scattered radiation
3.) absorb more primary radiation
a.) 1 only
b.) 2 and 3
c.) 1 , 2 and 3
d.) 1 and 2
b.) 2 and 3
The part of the PSP plate that includes a random distribution of crystal is the:
a.) relfective layer
b.) turbid layer
c.) structured layer
d.) conductive layer
b.) turbid layer
Graphical represention of a set of data that represents pixel values according to IR exposure.
Histogram
A process where the computer analyzes the histogram and compares it to a preestablished histogram.
Histogram Analysis
A digital process that adjusts the original histogram to match the expected histogram of a radiograph. This process adjusts for slight under or over exposure to an IR.
Rescaling
A processing function that will adjust the contrast of a radiograph.
Look Up Table
What are the primary parts of a CR imaging system?
Digitizer/Reader
Cassette Holder
PSP plate
Computer workstation
What type of grid design is used mainly in the xray suite?
a.) focused grid
b.) parallel (non focused) grid
c.) generally 6 to 1 grids
d.) grids with a lower ratio
a.) focused grids
Which type of grid cut off is the only one that can be demonstrated with both focused and nonfocused grids?
a.) off level grid
b.) off focus grid
c.) upside down grid
d.) off center grid
a.) off level grid
Which of the following will decrease the production of scatter?
a.) decreasing FOV
b.) increasing FOV
c.) increasing grid ratio
d.) increasing KVP
a.) decreasing FOV
Foreshortening can be caused by:
a.) excessive distance betweeen the object and the IR
b.) insufficient distance between the focus and the IR
c.) the radiographic object being placed at an angle to the IR
d.) excessive distance between the focus and the IR
c.) the radiographic object being placed at an angle to the IR
WHich of the following is not a type of beam limiting restrictor?
a.) aperture diaphragm
b.) lead shield
c.) PBL
d.) cylinder
b.) lead shield
The longer an image is stored in the CR cassette, the:
more energy is lost by the electrons.
Aluminum filtration has its greatest effect on:
low energy xray photons
Saturation indicates:
a.) overexposure of the IR
b.) underexposure of the IR
c.) quantam mottle
d.) fog
a.) overexposure of the IR
The primary effect of scatter radiation on radiographic image quality is:
a.) decreased brightness
b.) decreased receptor exposure
c.) decreased SR
d.) decreased contrast
d.) decreased contrast
Decreasing mas will:
a.) decrease SR
b.) increase contrast
c.) decrease IR exposure
d.) increase IR exposure
c.) decrease IR exposure
WHich of the following grid patterns will result in an image with the least amount of grid cutoff?
a.) cross hatched grid
b.) non focused grid
c.) parallel
d.) focused
d.) focused
The height of lead strips within a radiographic grid compared to the distance between them is described as the:
a.) grid ratio
b.) grid conversion
c.) grid frequency
d.) grid efficiency
a.) grid ratio
