Chapter 10 & 12 Quiz Flashcards
Amorphous silicon is used as the:
a.) photoconductor for indirect capture DR imaging
b.) photoconductor for direct capture DR imaging
c.) photodetector for direct capture DR imaging
d.) photodetector for indirect capture DR imaging
d.) photodetector for indirect capture DR imaging
What are the effects of scattered radiaiton on a radiographic image?
1.) it produces fog
2.) it increases contrast
3.) it increases grid cutoff
a.) 1 and 2 only
b.) 1, 2 and 3
c.) 1 only
d.) 2 only
c.) 1 only
A latent image describes:
a.) the number of photons leaving the patient
b.) interactions with xray photons and an imaging plate
c.) release of energy from fluorohalides
d.) stored energy with flurohalides
d.) stored energy with flourohalides
Which grid error is the result of the CR not being aligned side to side with an IR?
a.) upside down
b.) off level
c.) off focus
d.) off center
d.) off center
What type of grid design is used mainly in the xray suite?
a.) focused grids
b.) generally 6:1 grids
c.) grids with a lower ratio
d.) parallel (non focused) grids
a.) focused grids
Characteristics of high ratio focused grids, compared with lower ratio grids include which of the following?
1.) they allow more positioning latitude
2.) theyre more efficient in collecting detail (SR)
3.) they absorb more of the useful beam
a.) 1 and 2 only
b.) 1, 2 and 3
c.) 2 and 3 only
d.) 1 only
c.) 2 and 3 only
According to NCRP regulations, leakage radiation from the xray tube must not exceed:
a.) 10mR/h
b.) 10 mR/min
c.) 100mR/h
d.) 100 mR/min
c.) 100 mR/h
Which of the following grid patterns will result in an image with the least amount of grid cutoff?
a.) cross hatched grid
b.) parallel grid
c.) focus grid
d.) crossed grid
c.) focus grid
Which of the following are considered beam restricting devices? (choose all that apply)
a.) a cone
b.) a cylinder
c.) flat lead sheilding
d.) diaphragm aperture
a.) a cone
b.) a cylinder
d.) diaphragm aperture
What is the main advantage of the use of a moving over a stationary grid?
a.) grid lines will be more visible with a moving grid
b.) grid lines will be blurred and not visible with a moving grid
c.) a moving grid will produce higher contrast images
d.) a moving grid is more efficient at absorbing scatter radiation
b.) grid lines will be blurred and not visible with a moving grid
Which situation is most likely to result in grid errors?
a.) mobile radiography
b.) stationary radiography at the table bucky
c.) table top radiography
d.) stationary radiography in an upright bucky
a.) moble radiography
Benefits of beam restrictions include: (choose all that apply)
a.) decreasing patient dose
b.) increasing FOV
c.) reducing the production of scatter
d.) limiting the area exposed to radiation
a.) decreasing patient dose
c.) reducing the production of scatter
d.) limiting the area exposed to radiation
The fill factor of a detector element is the:
a.) full dimensions of the detector
b.) xray sensitive portion of the detector
c.) TFT of a detector
d.) storage capacitor of the detector
b.) xray sensitive portion of the detector
An image demonstrating many brightness levels, or shades of gray, with only slight differences between the levels/shades is said to possess:
1.) long scale contrast
2.) low contrast
3.) short scale contrast
a.) 1 and 2 only
b.) 1 only
c.) 2 only
d.) 2 and 3 only
a.) 1 and 2 only
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.) 1 only
b.) 1, 2 and 3
c.) 4 only
d.) 1, 2, 3 and 4
b.) 1, 2 and 3
Types of grid errors include:
a.) off center error
b.) upside down focused grid
c.) off focus error
d.) off level error
a.) off center error
b.) upside down focused grid
c.) off focus error
d.) off level error
The height of the lead strips within a radiographic grid compared to the distance between them is described as the:
a.) grid conversion
b.) grid ratio
c.) grid frequency
d.) grid efficiency
b.) grid ratio
What is the main effect of grid cut off?
a.) overexposure to the IR
b.) reduced image resolution
c.) decreased image contrast
d.) under exposure to the IR
d.) under exposure to the IR
Decreasing mAs will:
a.) increase IR exposure
b.) decrease spatial resolution
c.) decrease IR exposure
d.) increase contrast
c.) decrease IR exposure
How does adding filtration to the xray tube assembly change the characterisitics of the xray beam?
a.) decreases quantity, increases quality
b.) increases quantity, decreases quality
c.) decreases quantity, decreases quality
d.) increases quantity, increases quality
a.) decreases quantity, increases quality
WHich of the following types of grids will allow for the least amount of centering and or positionign latitude?
a.) 16 to1
b.) 12 to 1
c.) 5 to 1
d.) no grid
a.) 16 to 1
What describes the number of lead lines per unit length?
a.) grid ratio
b.) grid height
c.) grid frequency
d.) grid convergence
c.) grid frequency
Graphical representation 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 lsight under or over exposure to an IR.
Rescaling
A processing function that will adjust the contrast of a radiograph.
Look Up Table
The primary purpose of an analogue to digital converteer (ADC) to convert:
a.) xrays into a light signal
b.) electrical signals into digital signals
c.) electrical signals to xray energy
d.) light photons into an electrical signal
b.) electrical signals into digital signals
Which term is used to describe the recommended range of SIDs that can be used with a specific grid?
a.) convergent point
b.) convergent line
c.) focal range
d.) focal distance
c.) focal range
The primary cause of scatter radiation within a radiographic image is :
a.) photon transmission
b.) compton interactions
c.) photoelectric interactions
d.) classical interactions
b.) compton interactions
A grid usually is used in which of the following circumstances?
1.) when radiographing a large or dense body part
2.) when using a 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
Which type of grid cutoff is the only one that can be demonstrated with both focused and non focused grids?
a.) upside down grid
b.) off center grid
c.) off focus grid
d.) off level grid
d.) off level grid
As collimation increases, the quantity of scatter radiation decreases.
a.) true
b.) fasle
a.) true
Which of the following statements best describes a focused grid?
a.) lead strips are perpendicular to each other
b.) lead strips are closer together in focused grids
c.) lead strips are angled to match the divergence of the xray beam
d.) two sets of lead strips are present at 90 degrees to each other
c.) lead strips are angled to match the divergence of the xray beam
the relationship between a DEL and SR is:
a.) inversely proportional to the square
b.) inversely proportional
c.) directly proportional to the square
d.) directly proportional
d.) directly proportional
