Imaging Ch7 Flashcards
(100 cards)
1
Q
What is the primary effect of scatter radiation on a radiographic image
A
It decreases radiographic contrast
2
Q
Which of the following will increase scatter production?
A. decreasing patient thickness
B. Increasing collimation
C. Decreasing kVp
D. increasing x-ray field size
A
Increasing x-ray field size
3
Q
What is the primary function of a radiographic grid?
a. to increase patient exposure
b. to reduce scatter radiation reaching the image receptor
c. to reduce primary radiation reaching the image receptor
d. to increase the field size
A
to reduce scatter radiation reaching the image receptor
4
Q
Which of the following is true when increasing collimation
a. it increases the field size
b. it reduces scatter radiation produced
c. it decreases the exposure to the image receptor
d. B and C
A
both b and c
5
Q
Which of the following is a disadvantage of using a grid?
A. it increases patient exposure
B. it increases image contrast
C. it reduces scatter radiation
D. It decreases radiographic density
A
it increases patient exposure
6
Q
A grid ratio of 16:1 will clean up more scatter than a grid ratio of:
A: 5:1
B.6:1
c. 12:1
D. all of the above
A
All the above
7
Q
Which of the following devices limits the size and shape of the primary x-ray beam
A. collimator
b. aperture diaphragm
c. grid
d. cylinder
A
collimator
8
Q
A grid with lead strips that run at right angles to each other is referred to as a:
A. linear grid
b. crossed grid
c. parallel grid
d. focused grid
A
crossed grid
9
Q
What is the effect of using an upside-down focused grid?
A. increase in exposure at the edges of the image
b. decrease in exposure along the lateral edges of the image
C. no effect of on image quality
D. increase in contrast
A
decrease in exposure along the lateral edges
10
Q
Which grid ratio would be best suited for imaging anatomy over 10 cm and using high kVp techniques?
a. 5:1
b.6:1
c.8:1
d. 12:1
A
12:1
11
Q
Which of the following grid patterns allows for tube angulation along the length of the lead lines?
A. crossed grid
B. focused grid
C. parallel grid
D. linear grid
A
linear grid
12
Q
Which type of grid cut-off occurs when the x-ray tube is angled across the lead strips?
A. off-level grid cut off
B. off-focus grid cut-off
C. off-center grid cut-off
D. upside-down focused grid cut-off
A
off-level grid cutoff
13
Q
Grid cut-off that results in a loss of exposure at the periphery of the image is caused by:
a. off-level grid alignment
b. upside- down grid placement
c. off-focus grid usage
d. lateral decentering
A
off-focus grid usage
14
Q
Which factor describes the number of lead lines per unit length in a grid?
a. grid ratio
b. grid frequency
c. grid conversion factor
d. focal range
A
grid ratio
15
Q
Which of the following describes a grid with lead lines running parallel to one another?
- A. Focused grid
- B. Crossed grid
- C. Parallel grid
- D. Reciprocating grid
A
parallel grid
16
Q
Which grid ratio would provide the greatest scatter radiation cleanup but require a significant increase in mAs
A. 5:1
B. 6:1
C. 8:1
D. 16:1
A
16:1
17
Q
The air gap technique improves image contrast by:**
A. Decreasing scatter production
B. Increasing OID so scatter misses the image receptor
C. Increasing collimation
D. Decreasing SID
A
increasing OID so scatter misses the image receptor
18
Q
What is the grid ratio when the lead strips are 2.0 mm high and spaced 0.2 mm apart?
A. 5:1
B. 8:1
C. 10:1
D. 16:1
A
10:1
19
Q
A Potter-Bucky diaphragm is used to:
- A. Focus the x-ray beam
- B. Hold the x-ray cassette
- C. Move the grid during exposure to blur grid lines
- D. Restrict the size of the x-ray field
A
Move the grid during exposure to blur grid lines
20
Q
Which of the following can reduce the visibility of grid lines on a radiograph?
- A. Using a stationary grid
- B. Increasing kVp
- C. Using a reciprocating grid
- D. Decreasing grid ratio
A
using a reciprocating grid
21
Q
Which grid ratio is likely to require the highest increase in mAs for maintaining image density?
- A. 5:1
- B. 6:1
- C. 12:1
- D. 16:1
A
16:1
22
Q
What is the main disadvantage of using a grid during imaging?**
- A. Decrease in scatter radiation
- B. Increase in patient dose
- C. Increased image contrast
- D. Decreased image noise
A
increase in patient dose
23
Q
Which of the following grid patterns is more prone to grid cut-off if the x-ray tube is angled?**
- A. Focused grid
- B. Crossed grid
- C. Parallel grid
- D. Linear grid
A
crossed grid
24
Q
Which of the following is the typical focal range for a grid with a 72-inch SID?**
- A. 36-42 inches
- B. 66-74 inches
- C. 40-48 inches
- D. 100-120 inches
A
66-74 inches
25
Grid cut-off caused by misalignment between the central ray and the center of the grid is called:**
- A. Off-center cut-off
- B. Off-level cut-off
- C. Off-focus cut-off
- D. Upside-down grid cut-off
off-center cut-off
26
Which of the following is true about increasing the grid ratio?**
- A. It decreases the risk of grid cut-off
- B. It reduces the need for higher mAs
- C. It improves scatter cleanup and increases image contrast
- D. It decreases patient exposure
it improves scatter cleanup and increases image contrast
27
The air gap technique can be used as an alternative to a grid to improve image contrast. However, a disadvantage of this technique is:**
- A. Increased image contrast
- B. Increased patient exposure
- C. Increased OID, which decreases spatial resolution
- D. Decreased scatter reaching the image receptor
increased OID, which increases spatial resolution
28
**Which of the following is an advantage of using collimation?**
- A. Increased patient dose
- B. Increased scatter radiation
- C. Improved radiographic contrast
- D. Increased field size
improved radiographic contrast
29
What is the result of using an off-level grid?**
- A. Increased image contrast
- B. Uniform exposure across the image receptor
- C. Loss of exposure across the entire image
- D. Overexposure of the image
loss of exposure across the entire image
30
A grid with 12:1 ratio will provide greater:**
- A. Exposure to the patient
- B. Flexibility in tube angulation
- C. Absorption of scatter radiation
- D. Magnification
absorption of scatter radiation
31
Which of the following will decrease scatter radiation production?**
- A. Increasing field size
- B. Increasing collimation
- C. Increasing patient thickness
- D. Decreasing collimation
increasing collimation
32
Which of the following is true of a parallel grid?**
- A. It has lead strips that converge to match the x-ray beam divergence
- B. It can cause grid cut-off, especially at shorter SID
- C. It allows more angulation of the x-ray tube compared to a linear grid
- D. It is commonly used in focused grid applications
It can cause grid cut-off, especially at shorter SID
33
Which type of beam-restricting device uses lead shutters to adjust the x-ray field size?**
- A. Cylinder
- B. Aperture diaphragm
- C. Collimator
- D. Cones
collimator
34
A high-frequency grid is preferred in digital imaging to:**
- A. Increase image brightness
- B. Reduce scatter and avoid Moiré patterns
- C. Increase patient exposure
- D. Increase the divergence of the x-ray beam
reduce scatter and avoid Moire patterns
35
Which type of grid pattern can tolerate some tube angulation along its length?**
- A. Crossed grid
- B. Parallel grid
- C. Linear grid
- D. Focused grid
linear grid
36
What type of grid cutoff occurs when the grid is used outside
of its focal range?**
- A. Off-level grid cutoff
- B. Off-focus grid cutoff
- C. Upside-down grid cutoff
- D. Off-center grid cutoff
off-focus grid cutoff
37
The function of the Potter-Bucky diaphragm is to:**
- A. Restrict the size of the x-ray beam
- B. Eliminate scatter radiation production
- C. Reduce scatter reaching the image receptor by moving the grid during exposure
- D. Increase the size of the x-ray field
reduce scatter reaching the image receptor by moving the grid during exposure
38
A grid with a ratio of 8:1 will remove approximately what percentage of scatter radiation from the image?**
- A. 80%
- B. 85%
- C. 90%
- D. 95%
90%
39
What is the effect of using an upside-down focused grid?**
- A. Underexposure at the center of the image
- B. Overexposure at the center of the image
- C. Underexposure along the edges of the image
- D. Overexposure along the edges of the image
underexposure along the edges of the image
40
Which of the following grids is most likely to cause a zebra or Moiré effect in computed radiography?**
- A. A high-frequency moving grid
- B. A low-frequency stationary grid
- C. A focused grid
- D. A parallel grid
a low-frequency stationary grid
41
When using a grid, which factor needs to be adjusted to maintain adequate exposure to the image receptor?**
- A. mAs
- B. SID
- C. kVp
- D. OID
mAs
42
Which of the following best describes the function of beam-restricting devices?**
- A. Reduce scatter production
- B. Increase image magnification
- C. Increase patient exposure
- D. Improve spatial resolution
reduce scatter production
43
**The term “grid ratio” refers to:**
- A. The number of lead strips per inch
- B. The height of the lead strips to the distance between them
- C. The number of lead lines per centimeter
- D. The number of grid lines visible on the image
the height of the lead strips to the distance between them
44
What is the main function of the grid in radiographic imaging?**
- A. To increase scatter production
- B. To reduce primary beam exposure
- C. To reduce scatter radiation reaching the image receptor
- D. To improve patient positioning
to reduce scatter radiation reaching the image receptor
45
What is the grid frequency if there are 80 lead strips per centimeter?**
- A. 80 lines per inch
- B. 40 lines per inch
- C. 80 lines per centimeter
- D. 60 lines per inch
80 lines per cm
46
Which of the following is true regarding the use of a grid in pediatric imaging?**
- A. It should always be used regardless of part thickness
- B. It is generally not used if the body part is less than 10 cm thick
- C. It reduces the need for collimation
- D. It decreases patient dose
it is generally not used if the body part is less than 10 cm thick
47
The “focal range” of a grid refers to:**
- A. The SID at which the grid is effective
- B. The maximum OID allowable with the grid
- C. The amount of scatter absorbed by the grid
- D. The total number of grid lines
the SID at which thegrid is effective
48
In the air gap technique, increasing the object-to-image distance (OID) will:**
- A. Improve spatial resolution
- B. Decrease magnification
- C. Increase image contrast by reducing scatter
- D. Increase patient exposure
increase image contrast by reducing scatter
49
**Which of the following best describes grid cut-off?**
- A. Excessive scatter reaching the image receptor
- B. Reduced transmission of primary x-ray photons to the image receptor
- C. Enhanced image contrast and density
- D. Increased patient dose
Reduced transmission of primary x-ray photons to the image receptor
50
When using a 16:1 grid, what adjustment is typically needed?**
- A. Increase in kVp
- B. Increase in mAs
- C. Decrease in SID
- D. Decrease in exposure time
increase in mAs
51
Which type of grid pattern has the least flexibility for tube angulation?**
- A. Focused grid
- B. Crossed grid
- C. Linear grid
- D. Parallel grid
crossed grid
52
When using the air gap technique, which of the following must be adjusted to maintain image sharpness?**
- A. Increase in kVp
- B. Decrease in SID
- C. Increase in SID
- D. Decrease in mAs
increase SID
53
The term "grid cutoff" is best described as:**
- A. A reduction in image contrast
- B. A decrease in primary radiation reaching the image receptor
- C. An increase in scatter radiation production
- D. An improvement in spatial resolution
a decrease in primary radiation reaching the image receptor
54
In which situation would using a grid be unnecessary?**
- A. When imaging body parts larger than 10 cm
- B. When imaging with kVp greater than 60
- C. When imaging a thin pediatric patient
- D. When imaging with a large field size
when imaging a thin pediatric patient
55
Grid ratio is calculated by which of the following formulas?**
- A. h/D
- B. SID/OID
- C. Grid frequency/grid lines
- D. mAs/kVp
h/D
56
The most common type of grid pattern used in diagnostic imaging is:**
- A. Focused grid
- B. Parallel grid
- C. Crossed grid
- D. Linear grid
linear grid
57
Which of the following factors contributes to grid cutoff when using a focused grid?**
- A. Using the grid at the wrong SID
- B. Using a high-frequency grid
- C. Using the grid with too much OID
- D. Using a grid with high kVp
using the grid at the wrong SID
58
**What is the purpose of the interspace material in a grid?**
- A. To absorb scatter radiation
- B. To allow primary radiation to pass through to the image receptor
- C. To reduce patient exposure
- D. To restrict the size of the x-ray field
to allow primary radiation to pass through to the image receptor
59
Grid lines can be made less visible by:**
- A. Using a low-frequency grid
- B. Using a stationary grid
- C. Using a moving grid
- D. Decreasing mAs
using a moving grid
60
A grid is typically recommended for body parts that measure more than:**
- A. 4 cm
- B. 6 cm
- C. 10 cm
- D. 15 cm
10 cm
61
Which of the following occurs when a focused grid is placed upside down on the image receptor?**
- A. Even exposure across the image
- B. Increased density on the edges of the image
- C. Loss of density on the edges of the image
- D. Increased image contrast
loss of density on the edges of the image
62
Which of the following is an advantage of using a focused grid over a parallel grid?**
- A. Improved scatter cleanup at long SIDs
- B. Allows more flexibility in tube angulation
- C. Less chance of grid cutoff at short SIDs
- D. Requires lower mAs for optimal exposure
improved scatter cleanup at long SIDs
63
What is the purpose of the lead strips in a radiographic grid?**
- A. To reduce patient dose
- B. To absorb scatter radiation before it reaches the image receptor
- C. To increase the field size
- D. To improve spatial resolution
to absorb scatter before it reaches the image receptor
64
Which of the following grid types is most suitable for mobile radiography?**
- A. Crossed grid
- B. Parallel grid
- C. Focused grid with a short focal range
- D. Linear grid with a long focal range
focused grid with a short focal range
65
Which of the following grid ratios would typically be used for higher kVp examinations?**
- A. 5:1
- B. 6:1
- C. 8:1
- D. 12:1
12:1
66
When using an air gap technique, increasing the SID is recommended to:**
- A. Reduce scatter reaching the image receptor
- B. Compensate for magnification caused by increased OID
- C. Decrease exposure time
- D. Increase image contrast
compensate for magnification caused by increased OID
67
What effect does increasing grid frequency have on grid lines?**
- A. Grid lines become more visible on the image
- B. Grid lines become less visible on the image
- C. It has no effect on the visibility of grid lines
- D. Grid lines become thicker
grid lines become less visible on the image
68
Which type of cutoff is most likely to occur with a focused grid if the SID is too short or too long?**
- A. Off-center cutoff
- B. Off-focus cutoff
- C. Upside-down cutoff
- D. Off-level cutoff
off-focus cut off
69
Using a higher grid ratio will generally result in:**
- A. Decreased image contrast
- B. Increased risk of grid cutoff
- C. Decreased mAs requirement
- D. Increased field size
increased risk of grid cutoff
70
What is one reason to use a short-dimension grid in imaging?**
- A. To allow flexibility in angling the tube along the short axis
- B. To reduce exposure time
- C. To reduce scatter radiation production
- D. To allow increased field size
to allow flexibility in angling the tube along the short axis
71
A parallel grid is more likely to cause grid cutoff at:**
- A. Long SIDs
- B. Short SIDs
- C. Low kVp
- D. High grid frequency
short SIDs
72
A grid with lead strips parallel to the long axis of the grid is called a:**
- A. Short-dimension grid
- B. Crossed grid
- C. Long-dimension grid
- D. Focused grid
long-dimension grid
73
The Bucky factor is used to determine the required increase in which factor when using a grid?**
- A. OID
- B. SID
- C. mAs
- D. Focal spot size
mAs
74
What is the effect of collimating to a smaller field size?**
- A. Increased scatter production
- B. Decreased patient dose
- C. Increased exposure to the image receptor
- D. Decreased image contrast
decreased patient dose
75
The Moiré effect is most commonly associated with which of the following?**
- A. High grid frequency
- B. Low grid frequency in stationary grids used in CR
- C. High kVp
- D. Low OID
low grid frequency in stationary grids used in CR
76
Which of the following is used to describe the orientation of lead lines in a grid?**
- A. Grid pattern
- B. Grid ratio
- C. Grid conversion factor
- D. Grid frequency
grid patter
77
What is the main advantage of using a reciprocating grid?**
- A. It reduces patient exposure
- B. It reduces visibility of grid lines on the image
- C. It increases scatter production
- D. It increases contrast
it reduces visibility of grid lines on the image
78
Increasing the object-to-image distance (OID) as part of the air gap technique will have what effect on image quality?**
- A. Decreased spatial resolution
- B. Decreased contrast
- C. Increased grid cutoff
- D. Increased field size
decreased spatial resolution
79
Which of the following adjustments is necessary when switching from a 5:1 grid to a 12:1 grid?**
- A. Decrease in SID
- B. Increase in OID
- C. Increase in mAs
- D. Increase in kVp
Increase in mAs
80
What is the primary disadvantage of using a cross-hatched grid pattern?**
- A. It requires a decrease in kVp
- B. It reduces image contrast
- C. It restricts tube angulation
- D. It reduces scatter cleanup
it restricts tube angulation
81
The purpose of the air gap technique is to:**
- A. Increase patient dose
- B. Reduce scatter reaching the image receptor
- C. Increase exposure to the image receptor
- D. Increase SID requirements
reduce scatter reaching the image receptor
82
What is the result of using an off-focus grid?**
- A. Uniform exposure across the image receptor
- B. Loss of exposure at the edges of the image
- C. Improved contrast throughout the image
- D. Increased scatter reaching the image receptor
loss of exposure at the edges of the image
83
Which factor directly influences the amount of scatter radiation produced during an exam?**
- A. SID
- B. Field size
- C. Image receptor type
- D. Grid pattern
field size
84
Which grid ratio is most likely to be used in exams that require lower kVp?**
- A. 5:1
- B. 8:1
- C. 10:1
- D. 16:1
5:1
85
Which of the following will improve radiographic contrast?**
- A. Using a higher kVp
- B. Using a low-ratio grid
- C. Increasing collimation
- D. Decreasing mAs
increasing collimation
86
When using a focused grid, how should it be positioned relative to the x-ray beam?**
- A. With the grid lines perpendicular to the beam
- B. With the grid lines parallel to the beam divergence
- C. Upside-down on the image receptor
- D. Placed directly at the focal range SID
placed directly at focal range SID
87
**The purpose of a convergent point in a focused grid is to:**
- A. Minimize grid cutoff at any SID
- B. Align lead strips with the primary beam
- C. Increase the number of lead lines per unit length
- D. Enable cross-hatched grid patterns
align lead strips with the primary beam
88
Which factor is primarily responsible for determining the focal range of a focused grid?**
- A. Lead strip width
- B. Grid ratio
- C. Convergent line
- D. Grid frequency
convergent line
89
Grid conversion factors help determine the necessary increase in what when using a grid?**
- A. SID
- B. kVp
- C. mAs
- D. OID
mAs
90
Which of the following results when the grid is angled relative to the central ray?**
- A. Increased image density
- B. Uniform exposure across the image receptor
- C. Grid cutoff
- D. Increased scatter radiation production
grid cutoff
91
What is the purpose of the radiolucent material used between lead strips in a grid?**
- A. To absorb scatter radiation
- B. To increase image contrast
- C. To allow primary x-rays to pass through to the image receptor
- D. To enhance the visibility of grid lines
to allow primary x-rays to pass through to the image receptor
92
When using a grid with a higher grid frequency, which adjustment is often necessary?**
- A. Decrease in OID
- B. Decrease in SID
- C. Increase in mAs
- D. Increase in kVp
increase in mAs
93
Grid lines appear on an image when:**
- A. Using a focused grid within the focal range
- B. Using a stationary grid with digital imaging
- C. Using a high grid ratio
- D. Using a moving grid
using a stationary grid with digital imaging
94
Which of the following will most reduce the likelihood of a Moiré pattern?**
- A. Increasing grid ratio
- B. Using a grid with a low frequency
- C. Using a moving grid with high frequency
- D. Decreasing SID
using a moving grid with high frequency
95
The convergent line of a focused grid determines which of the following?**
- A. SID range
- B. Grid ratio
- C. Grid frequency
- D. Grid cutoff
SID range
96
What is the primary reason for using a grid in radiographic imaging?**
- A. To reduce scatter radiation reaching the image receptor
- B. To increase patient dose
- C. To increase scatter radiation production
- D. To decrease image density
to reduce scatter radiation reaching the image receptor
97
Which grid ratio would most likely be used for high kVp exams, such as a chest x-ray?**
- A. 5:1
- B. 6:1
- C. 8:1
- D. 16:1
16:1
98
When a grid is improperly positioned and the central ray is not aligned, what type of cutoff may occur?**
- A. Upside-down cutoff
- B. Off-level cutoff
- C. Off-center cutoff
- D. Off-focus cutoff
off-center cutoff
99
Which of the following will decrease when increasing the collimation?**
- A. Image contrast
- B. Scatter reaching the image receptor
- C. Radiographic density
- D. Exposure time
scatter reaching the image receptor
100
What is the effect of using a high-ratio grid on patient dose?**
- A. It decreases patient dose
- B. It increases patient dose
- C. It has no effect on patient dose
- D. It decreases scatter radiation production
it increases patient dose
