1
Q
When x-rays interact with matter, what are the THREE possible outcomes?
A. Reflection, refraction, absorption
B. No interaction, photoelectric effect, Compton interaction
C. Transmission, diffraction, scattering
D. Absorption, emission, reflection
A
No interaction, photoelectric effect, Compton interaction
2
Q
Which interaction occurs when an x-ray photon passes through matter without any change?
A. Photoelectric effect
B. Compton interaction
C. No interaction
D. Pair production
A
No interaction
3
Q
Which interaction results in complete absorption of the x-ray photon?
A. Compton interaction
B. Photoelectric effect
C. Coherent scattering
D. Transmission
A
Photoelectric effect
4
Q
Which interaction is responsible for scatter radiation?
A. Photoelectric effect
B. No interaction
C. Pair production
D. Compton interaction
A
Compton interaction
5
Q
What is the primary purpose of a radiographic grid?
A. Increase patient dose
B. Improve radiographic contrast in the image
C. Reduce exposure time
D. Increase kVp
A
Improve radiographic contrast in the image
6
Q
How does a grid improve image contrast?
A. By increasing primary radiation
B. By absorbing scattered radiation before it reaches the image receptor
C. By increasing SID
D. By decreasing mAs
A
By absorbing scattered radiation before it reaches the image receptor
7
Q
What is the PRIMARY source of scatter radiation in radiography?
A. X-ray tube
B. Image receptor
C. Patient
D. Collimator
A
Patient
8
Q
Why is scatter radiation undesirable in radiographic imaging?
A. It increases image sharpness
B. It improves contrast
C. It increases density only
D. It has no diagnostic value
A
It has no diagnostic value
9
Q
As kVp increases, what happens to secondary radiation?
A. It decreases
B. It remains unchanged
C. It increases
D. It stops completely
A
It increases
10
Q
As kVp increases, what happens to scatter radiation?
A. It increases
B. It decreases
C. It remains unchanged
D. It is eliminated
A
It increases
11
Q
As kVp increases, what happens to image receptor exposure?
A. It decreases
B. It increases
C. It remains unchanged
D. It becomes zero
A
It increases
12
Q
As kVp increases, which of the following ALL increase?
A. Primary radiation only
B. Patient thickness and SID
C. Secondary radiation, scatter radiation, and image receptor exposure
D. Grid ratio and frequency
A
Secondary radiation, scatter radiation, and image receptor exposure
13
Q
Why are grids used in radiography?
A. To increase patient dose
B. To decrease SID
C. To reduce primary radiation
D. To improve contrast by absorbing scatter
A
To improve contrast by absorbing scatter
14
Q
What type of interaction is responsible for DARK areas on a radiograph?
A. Absorption
B. Scatter
C. Transmission
D. Compton interaction
A
Transmission
15
Q
What type of interaction is responsible for LIGHT areas on a radiograph?
A. Transmission
B. Absorption
C. Scatter
D. No interaction
A
Absorption
16
Q
How does scatter radiation affect image quality?
A. Improves contrast
B. Increases sharpness
C. Has no effect
D. Lowers contrast and contributes nothing useful
A
Lowers contrast and contributes nothing useful
17
Q
What is the GREATEST source of scatter radiation?
A. X-ray tube
B. Collimator
C. Image receptor
D. Patient
A
Patient
18
Q
What produces radiographic contrast in an image?
A. Absorbed photons
B. Scattered photons
C. Photons that pass through the body unaffected
D. Secondary radiation
A
Photons that pass through the body unaffected
19
Q
Which interaction contributes MOST to useful image formation?
A. Scatter
B. Transmission
C. Compton interaction
D. Absorption
A
Transmission
20
Q
Which of the following increases scatter radiation?
A. Decreased kVp
B. Increased atomic number
C. Increased field size
D. Decreased patient thickness
A
Increased field size
21
Q
As kVp increases, what happens to scatter radiation?
A. It decreases
B. It increases
C. It remains unchanged
D. It is eliminated
A
It increases
22
Q
How does patient thickness affect scatter radiation?
A. Increased thickness decreases scatter
B. Thickness has no effect
C. Increased thickness increases scatter
D. Scatter is eliminated
A
Increased thickness increases scatter
23
Q
What happens to scatter radiation when atomic number (Z#) increases?
A. Scatter increases
B. Scatter decreases
C. Scatter remains unchanged
D. Scatter doubles
A
Scatter decreases
24
Q
Which combination results in the MOST scatter radiation?
A. Low kVp, small field size, thin patient
B. High kVp, small field size, thin patient
C. Low kVp, large field size, thick patient
D. High kVp, large field size, thick patient
A
High kVp, large field size, thick patient
25
When is the use of a grid generally recommended?
A. Part thickness less than 5 cm
B. kVp below 50
C. Part thickness greater than 10 cm
D. Only during fluoroscopy
Part thickness greater than 10 cm
26
At what kVp is grid use generally recommended?
A. Below 40 kVp
B. Below 60 kVp
C. Above 60 kVp
D. Only at 100 kVp
Above 60 kVp
27
What does “cleaning up scatter” with a grid mean?
A. Improves contrast
B. Increases exposure time
C. Reduces SID
D. Decreases kVp
Improves contrast
28
What is the overall effect of using a grid on image contrast?
A. Contrast decreases
B. Contrast increases
C. Contrast remains unchanged
D. Contrast is eliminated
Contrast increases
29
“Results in greater contrast” is another way of saying:
A. Reduces density
B. Increases noise
C. Improves contrast
D. Decreases sharpness
Improves contrast
30
Which of the following BEST describes the effect of a grid?
A. Decreases patient thickness
B. Increases scatter radiation
C. Reduces primary radiation
D. Improves image contrast
Improves image contrast
31
“Improves contrast,” “increases contrast,” and “results in greater contrast” all mean:
A. Different effects depending on kVp
B. Only applies to digital imaging
C. The same effect
D. No effect on image quality
The same effect
32
Which of the following statements about grids is TRUE?
A. They reduce contrast
B. They clean up scatter and improve contrast
C. They increase scatter radiation
D. They eliminate primary radiation
They clean up scatter and improve contrast
33
What type of radiation is allowed to reach the image receptor when using a grid?
A. Scatter radiation
B. Secondary radiation
C. Primary radiation
D. Leakage radiation
Primary radiation
34
What type of radiation is MOSTLY absorbed by a grid?
A. Primary radiation
B. Scatter radiation
C. Transmission radiation
D. Coherent radiation
Scatter radiation
35
What is a PRIMARY disadvantage of grid use?
A. Increased contrast
B. Reduced exposure time
C. Increased kVp requirement
D. Grid lines may appear on the image
Grid lines may appear on the image
36
What can happen if a grid is used improperly?
A. Increased sharpness
B. Increased primary radiation transmission
C. Some primary radiation may be absorbed
D. Scatter radiation is eliminated
Some primary radiation may be absorbed
37
What is the main function of a grid?
A. Increase scatter radiation
B. Absorb most scattered radiation
C. Increase patient motion
D. Reduce primary radiation
Absorb most scattered radiation
38
Which of the following BEST describes proper grid function?
A. Blocks all radiation
B. Allows scatter to pass through
C. Absorbs primary radiation only
D. Allows primary radiation through while absorbing scatter
Allows primary radiation through while absorbing scatter
39
What material are grid strips made of?
A. Aluminum
B. Plastic fiber
C. Lead
D. Copper
Lead
40
What is the function of the lead strips in a grid?
A. Allow radiation to pass through
B. Absorb scattered radiation
C. Increase exposure time
D. Reduce SID
Absorb scattered radiation
41
What type of material is used between lead strips in a grid?
A. Radiopaque material
B. Dense metal
C. Lead foil
D. Radiolucent interspace material
Radiolucent interspace material
42
What is the function of the interspace material in a grid?
A. Absorb scatter radiation
B. Block primary radiation
C. Allow radiation to pass through
D. Increase grid ratio
Allow radiation to pass through
43
What materials are commonly used to encase a grid?
A. Lead and copper
B. Aluminum or plastic
C. Tungsten and steel
D. Glass and fiber
Aluminum or plastic
44
What best describes basic grid construction?
A. Radiolucent strips separated by radiopaque interspaces
B. Lead strips separated by radiolucent interspace material
C. Plastic strips with no spacing
D. Solid metal plate
Lead strips separated by radiolucent interspace material
45
Why is lead used for grid lines?
A. It is lightweight and transparent
B. It increases patient comfort
C. It is inexpensive, easy to shape, and moisture resistant
D. It allows scatter radiation to pass through
It is inexpensive, easy to shape, and moisture resistant
46
What type of material are grid lines classified as?
A. Radiolucent
B. Radiopaque
C. Transparent
D. Reflective
Radiopaque
47
What material is MOST commonly used for grid interspace?
A. Copper
B. Lead
C. Steel
D. Aluminum
Aluminum
48
Why is aluminum commonly used as interspace material?
A. It absorbs most radiation
B. It increases scatter radiation
C. It is easy to use and more durable
D. It blocks primary radiation
It is easy to use and more durable
49
What is the function of interspace material in a grid?
A. Absorb primary radiation
B. Increase grid ratio
C. Block all radiation
D. Should not absorb radiation
Should not absorb radiation
50
What does the symbol 'h' represent in grid construction diagrams?
A. Distance between strips
B. Height of lead strips
C. Thickness of patient
D. Image receptor size
Height of lead strips
51
What does the symbol 'D' represent in grid construction?
A. Distance between lead strips (interspace width)
B. Density of the patient
C. Diameter of the x-ray tube
D. Dose to the patient
Distance between lead strips (interspace width)
52
Which of the following materials may be used for grid encasement?
A. Plastic, aluminum, and carbon fiber
B. Lead and copper
C. Steel and tungsten
D. Glass and ceramic
Plastic, aluminum, and carbon fiber
53
What is a characteristic of lead strips in a grid?
A. Thick and flexible
B. Very thin foil thickness
C. Transparent to radiation
D. Made of plastic
Very thin foil thickness
54
What is the primary function of radiopaque lead strips?
A. Allow radiation to pass through
B. Increase SID
C. Absorb scatter radiation
D. Reduce patient motion
Absorb scatter radiation
55
Radiopaque strips in a grid are made of material with what property?
A. Low density
B. Low atomic number
C. Radiolucent composition
D. High atomic number
High atomic number
56
What type of material is used for grid interspace?
A. Radiopaque material
B. Metallic lead
C. Radiolucent material
D. Dense alloy
Radiolucent material
57
Which of the following is used as interspace material in low-dose grids?
A. Copper
B. Carbon fiber
C. Steel
D. Lead
Carbon fiber
58
What is the advantage of using carbon fiber in grid construction?
A. Increases scatter radiation
B. Increases grid ratio
C. Blocks primary radiation
D. Reduces patient dose
Reduces patient dose
59
In grid construction, what does the symbol 'H' represent?
A. Height of radiopaque strips
B. Distance between strips
C. Patient thickness
D. Image receptor size
Height of radiopaque strips
60
In grid construction, what does the symbol 'D' represent?
A. Density of the patient
B. Distance between strips (interspace width)
C. Diameter of the x-ray tube
D. Dose to the patient
Distance between strips (interspace width)
61
What does 'D' specifically refer to in grid dimensions?
A. Thickness of interspace material
B. Height of lead strips
C. Grid frequency
D. SID
Thickness of interspace material
62
What is the formula for grid ratio?
A. D / H
B. H × D
C. H / D
D. D + H
H / D
63
If the height of lead strips increases while distance remains constant, what happens to grid ratio?
A. It decreases
B. It increases
C. It remains unchanged
D. It becomes zero
It increases
64
If the distance between strips increases while height remains constant, what happens to grid ratio?
A. It increases
B. It remains unchanged
C. It becomes negative
D. It decreases
It decreases
65
Grid ratio is defined as:
A. Distance between strips divided by height
B. Number of grid lines per inch
C. Height of lead strips divided by distance between them
D. Thickness of patient divided by SID
Height of lead strips divided by distance between them
66
What is the effect of increasing grid ratio?
A. Less scatter is removed
B. No change in scatter removal
C. More efficient removal of scatter radiation
D. Scatter radiation increases
More efficient removal of scatter radiation
67
As grid ratio increases, what happens to required exposure?
A. It decreases
B. It increases
C. It remains unchanged
D. It becomes zero
It increases
68
Why do higher grid ratios require more exposure?
A. They absorb more primary radiation
B. They decrease scatter production
C. They increase SID
D. They reduce patient thickness
They absorb more primary radiation
69
What is the typical range for grid ratios?
A. 1:1 to 4:1
B. 3:1 to 10:1
C. 5:1 to 17:1
D. 10:1 to 25:1
5:1 to 17:1
70
Which grid ratio would MOST effectively reduce scatter radiation?
A. 5:1
B. 8:1
C. 12:1
D. 16:1
0.6673611111111111
71
Why are higher grid ratios more effective at removing scatter?
A. They allow more angled photons to pass through
B. They require less alignment
C. They limit the angle of scatter that can pass through
D. They increase field size
They limit the angle of scatter that can pass through
72
What is a disadvantage of using a high grid ratio?
A. Increased scatter radiation
B. Reduced image contrast
C. Decreased exposure needed
D. Increased patient dose due to higher exposure
Increased patient dose due to higher exposure
73
If a grid has lead strips 3 mm high and interspace of 0.5 mm, what is the grid ratio?
A. 3:1
B. 6:1
C. 1.5:1
D. 0.5:1
0.25069444444444455
74
What is the formula for calculating grid ratio?
A. D / h
B. h × D
C. h / D
D. D + h
h / D
75
If grid ratio increases, what happens to the distance between lead strips (assuming height is constant)?
A. It increases
B. It remains unchanged
C. It becomes zero
D. It decreases
It decreases
76
Which grid has the GREATER distance between lead strips?
A. 15:1
B. Both are equal
C. 6:1
D. Cannot be determined
0.25069444444444455
77
Why does a 6:1 grid have a greater distance between strips than a 15:1 grid?
A. It has taller lead strips
B. It has a smaller interspace distance
C. It has a larger interspace distance
D. It absorbs more primary radiation
It has a larger interspace distance
78
What happens to grid ratio if interspace distance increases while height stays the same?
A. It increases
B. It decreases
C. It remains unchanged
D. It doubles
It decreases
79
What is grid frequency?
A. Height of lead strips divided by distance
B. Number of lead strips per inch or centimeter
C. Thickness of the patient
D. Distance between lead strips
Number of lead strips per inch or centimeter
80
What is the typical range of grid frequency?
A. 10–50 lines/in
B. 30–60 lines/in
C. 60–200 lines/in
D. 200–500 lines/in
60–200 lines/in
81
What is the MOST common grid frequency range?
A. 10–20 lpi
B. 60–80 lpi
C. 120–150 lpi
D. 85–103 lpi
85–103 lpi
82
What is the approximate equivalent of 85–103 lines per inch in lines per cm?
A. 10–20 lines/cm
B. 20–30 lines/cm
C. 33–41 lines/cm
D. 50–60 lines/cm
33–41 lines/cm
83
What happens to lead strip thickness as grid frequency increases?
A. It increases
B. It decreases
C. It remains unchanged
D. It doubles
It decreases
84
Why are high-frequency grids less visible on images?
A. They absorb more scatter
B. They increase exposure
C. They have thicker strips
D. They have thinner lead strips
They have thinner lead strips
85
High-frequency grids are commonly used in which situation?
A. Mobile radiography
B. Low kVp procedures
C. Stationary grid use
D. Pediatric imaging only
Stationary grid use
86
As lead content of a grid increases, what happens to its ability to remove scatter?
A. It decreases
B. It remains unchanged
C. It becomes unpredictable
D. It increases
It increases
87
What grid frequency is considered very high for digital imaging systems?
A. 60–80 lpi
B. 85–103 lpi
C. 120–150 lpi
D. 178–200 lpi
178–200 lpi
88
What is the approximate equivalent of 178–200 lines per inch in lines per cm?
A. 20–30 lines/cm
B. 33–41 lines/cm
C. 50–60 lines/cm
D. 70–80 lines/cm
70–80 lines/cm
89
Why are very high-frequency grids recommended for digital imaging?
A. They increase patient dose
B. They minimize grid line appearance
C. They increase scatter radiation
D. They reduce SID
They minimize grid line appearance
90
Very high-frequency grids are compatible with which imaging system?
A. Film-screen only
B. Fluoroscopy only
C. Computed radiography
D. Ultrasound
Computed radiography
91
What is the primary advantage of using high-frequency grids in digital systems?
A. Increased scatter radiation
B. More visible grid lines
C. Reduced image sharpness
D. Reduced visibility of grid lines
Reduced visibility of grid lines
92
What determines the total lead content of a grid?
A. kVp and mAs
B. Number of grid strips and thickness of grid strips
C. Patient thickness only
D. SID and OID
Number of grid strips and thickness of grid strips
93
Lead content is considered the most important factor in determining what?
A. Patient comfort
B. Grid efficiency
C. Exposure time
D. Image size
Grid efficiency
94
How is lead content measured?
A. Lines per inch
B. Millimeters
C. Mass per unit area (g/cm²)
D. Kilovoltage peak
Mass per unit area (g/cm²)
95
Which type of grid tends to have the HIGHEST lead content?
A. Low ratio, high frequency
B. High ratio, high frequency
C. Low ratio, low frequency
D. High ratio, low frequency
High ratio, low frequency
96
What happens to grid efficiency as lead content increases?
A. It decreases
B. It remains unchanged
C. It increases
D. It becomes unpredictable
It increases
97
Which factor increases lead content in a grid?
A. Decreasing strip thickness
B. Increasing number of strips
C. Increasing SID
D. Decreasing kVp
Increasing number of strips
98
In general, which type of grid has the greatest lead content?
A. Low ratio, high frequency
B. High ratio, low frequency
C. Low ratio, low frequency
D. High ratio, high frequency
High ratio, low frequency
99
As lead content increases, what happens to scatter removal?
A. It decreases
B. It remains unchanged
C. It increases
D. It becomes unpredictable
It increases
100
As scatter removal increases, what happens to image contrast?
A. It decreases
B. It increases
C. It remains unchanged
D. It disappears
It increases
101
What is grid cut-off?
A. Increase in scatter radiation
B. Improved contrast
C. Increase in primary radiation
D. Undesirable absorption of primary beam photons by the grid
Undesirable absorption of primary beam photons by the grid
102
Why is grid cut-off undesirable?
A. It increases contrast
B. It increases scatter radiation
C. It reduces image receptor exposure
D. It improves image quality
It reduces image receptor exposure
103
Which of the following best describes the relationship between lead content and contrast?
A. Increased lead content decreases contrast
B. Lead content has no effect on contrast
C. Increased lead content increases contrast
D. Lead content only affects density
Increased lead content increases contrast
104
What is a criss-cross grid also known as?
A. Linear grid
B. Parallel grid
C. Cross-hatched grid
D. Focused grid
Cross-hatched grid
105
What type of grid has lead strips running in ONE direction only?
A. Linear grid
B. Criss-cross grid
C. Focused grid
D. Cross-hatched grid
Linear grid
106
What type of grid pattern has lead strips running in TWO directions?
A. Linear grid
B. Focused grid
C. Parallel grid
D. Criss-cross grid
Criss-cross grid
107
What are the TWO main types of grids?
A. Linear and criss-cross
B. Parallel and focused
C. High and low frequency
D. Stationary and moving
Parallel and focused
108
Which grid type has lead strips that run parallel to each other?
A. Focused grid
B. Linear grid
C. Parallel grid
D. Criss-cross grid
Parallel grid
109
Which grid type is designed to match the divergence of the x-ray beam?
A. Parallel grid
B. Linear grid
C. Criss-cross grid
D. Focused grid
Focused grid
110
What is a cross-hatched grid made of?
A. Two focused grids stacked together
B. Two parallel grids placed one on top of the other
C. One grid with thicker lead strips
D. A single linear grid
Two parallel grids placed one on top of the other
111
In a cross-hatched grid, lead strips run in which directions?
A. Diagonal only
B. Vertical only
C. Horizontal only
D. Both horizontal and vertical directions
Both horizontal and vertical directions
112
How must the primary beam be directed when using a cross-hatched grid?
A. At any angle
B. Parallel to the grid
C. Centered perpendicular to the grid
D. At a 45-degree angle
Centered perpendicular to the grid
113
What is a requirement when using a cross-hatched grid?
A. The grid must be tilted
B. The grid must remain flat
C. The grid must be rotated
D. The grid must be angled
The grid must remain flat
114
What is a major advantage of cross-hatched grids?
A. Reduced patient dose
B. Easier positioning
C. Lower cost
D. Outstanding clean-up of scatter
Outstanding clean-up of scatter
115
Why are cross-hatched grids NOT widely used?
A. They do not remove scatter
B. They increase image sharpness
C. Positioning limitations and increased dose
D. They are only used in fluoroscopy
Positioning limitations and increased dose
116
What is a key advantage of linear grids?
A. They allow angulation of the primary beam along the direction of the grid lines
B. They eliminate all scatter radiation
C. They allow angulation in all directions
D. They require no alignment
They allow angulation of the primary beam along the direction of the grid lines
117
In a typical x-ray table, linear grid strips run in which direction?
A. Across the short axis of the table
B. Diagonally across the table
C. Along the long axis of the table
D. Randomly positioned
Along the long axis of the table
118
When using a linear grid, tube angulation is allowed in which direction?
A. Side to side (left to right)
B. Toward the head or feet of the patient
C. In all directions
D. No angulation is allowed
Toward the head or feet of the patient
119
What happens if the x-ray tube is angled across the grid lines of a linear grid?
A. Increased contrast
B. No effect
C. Increased sharpness
D. Grid cutoff occurs
Grid cutoff occurs
120
Why are linear grids more commonly used than cross-hatched grids?
A. They remove more scatter
B. They are less expensive only
C. They allow limited tube angulation
D. They eliminate the need for alignment
They allow limited tube angulation
121
What is a limitation of linear grids?
A. They cannot absorb scatter
B. They allow angulation in all directions
C. They increase patient dose only
D. They cannot be angled across the grid lines
They cannot be angled across the grid lines
122
What is the key feature of focused linear grids?
A. Lead strips are parallel to each other
B. Lead strips are angled to match the divergence of the x-ray beam
C. Lead strips run in two directions
D. Lead strips are thicker than usual
Lead strips are angled to match the divergence of the x-ray beam
123
In a focused grid, where does the primary beam travel?
A. Through the lead strips
B. Through the interspace material
C. It is completely absorbed
D. It is scattered
Through the interspace material
124
In a focused grid, what happens to scatter radiation?
A. It passes through unchanged
B. It increases
C. It is absorbed by the lead strips
D. It is reflected back to the tube
It is absorbed by the lead strips
125
Why must focused grids be used within a specific SID range?
A. To increase patient dose
B. To match beam divergence and avoid grid cutoff
C. To increase grid frequency
D. To reduce exposure time
To match beam divergence and avoid grid cutoff
126
What happens if a focused grid is used outside its recommended SID range?
A. Improved contrast
B. Increased sharpness
C. No effect
D. Grid cutoff occurs
Grid cutoff occurs
127
Which statement best describes focused grid function?
A. Blocks all radiation
B. Allows scatter to pass
C. Aligns with beam divergence for optimal primary transmission
D. Eliminates need for collimation
Aligns with beam divergence for optimal primary transmission
128
What is the convergence line in a focused grid?
A. The path of scattered radiation
B. The line where lead strips would meet if extended
C. The center of the image receptor
D. The direction of grid movement
The line where lead strips would meet if extended
129
What does “narrow positioning latitude” mean for focused grids?
A. They are easy to position
B. They allow angulation in all directions
C. They require precise alignment and positioning
D. They eliminate grid cutoff
They require precise alignment and positioning
130
What is the result of improper centering when using a focused grid?
A. Increased contrast
B. Peripheral grid cutoff
C. Increased exposure
D. Improved sharpness
Peripheral grid cutoff
131
Focused grids are only useful under which condition?
A. Any SID distance
B. Very low kVp
C. Mobile procedures only
D. At the preset SID distance
At the preset SID distance
132
Why do higher grid ratio focused grids require more careful alignment?
A. They allow more scatter through
B. They increase image noise
C. They are more sensitive to misalignment
D. They reduce contrast
They are more sensitive to misalignment
133
What is a key limitation of focused grids?
A. They cannot remove scatter
B. They require precise SID and alignment
C. They increase image brightness
D. They eliminate primary radiation
They require precise SID and alignment
134
What is a defining feature of parallel linear grids?
A. Lead strips angled to match beam divergence
B. Lead strips run in two directions
C. Lead strips are parallel to one another
D. Lead strips are curved
Lead strips are parallel to one another
135
Parallel grids are considered what type of grid?
A. Focused
B. Non-focused
C. Cross-hatched
D. Moving grid
Non-focused
136
What is a disadvantage of parallel grids?
A. They do not absorb scatter
B. They increase image contrast too much
C. They require higher kVp only
D. They absorb some primary radiation causing grid cutoff
They absorb some primary radiation causing grid cutoff
137
Why can grid cutoff occur with parallel grids?
A. They increase scatter radiation
B. They are too expensive
C. They absorb some of the primary beam
D. They eliminate all radiation
They absorb some of the primary beam
138
What is an advantage of parallel grids?
A. They remove all scatter radiation
B. They are least expensive
C. They allow unlimited angulation
D. They eliminate grid cutoff
They are least expensive
139
Why are parallel grids not commonly used?
A. They are too complex
B. They increase patient dose
C. They cannot absorb scatter
D. Positioning limitations and cutoff issues
Positioning limitations and cutoff issues
140
What is the Potter-Bucky diaphragm commonly called?
A. Collimator
B. Grid holder
C. Bucky
D. Cassette tray
Bucky
141
What is the function of the Potter-Bucky diaphragm?
A. Increase scatter radiation
B. Hold and move the grid during exposure
C. Reduce SID
D. Increase patient dose
Hold and move the grid during exposure
142
Where is the grid positioned in relation to the cassette in a Bucky system?
A. Below the cassette
B. Inside the cassette
C. Behind the patient only
D. Above the cassette
Above the cassette
143
What is a common mounting size for grids used in a Bucky?
A. 8 x 10 inches
B. 10 x 12 inches
C. 14 x 17 inches
D. 17 x 19 inches
17 x 19 inches
144
Why is the grid moved during exposure in a Bucky system?
A. To increase exposure
B. To blur grid lines
C. To increase scatter radiation
D. To reduce patient motion
To blur grid lines
145
What are the two types of grid movement in a Bucky system?
A. Linear and cross-hatched
B. Parallel and focused
C. Reciprocating and oscillating
D. Stationary and mobile
Reciprocating and oscillating
146
What type of grid movement is associated with the Potter-Bucky diaphragm?
A. Oscillating
B. Linear
C. Reciprocating
D. Rotational
Reciprocating
147
What describes reciprocating grid movement?
A. Grid rotates in a circular motion
B. Small motor drives grid back and forth during exposure
C. Grid remains stationary
D. Grid moves only once during exposure
Small motor drives grid back and forth during exposure
148
What mechanism is used in oscillating grid movement?
A. Small motor only
B. Hydraulic system
C. Gravity only
D. Electromagnet and spring activation
Electromagnet and spring activation
149
What happens during oscillating grid movement?
A. Grid is fixed in place
B. Grid is pulled to one side and released during exposure
C. Grid rotates continuously
D. Grid moves only upward
Grid is pulled to one side and released during exposure
150
In what direction does the grid move during exposure?
A. Parallel to grid lines
B. Random direction
C. Perpendicular to the direction of the grid lines
D. Along the SID
Perpendicular to the direction of the grid lines
151
Why is grid movement important during exposure?
A. To increase patient dose
B. To eliminate primary radiation
C. To increase scatter radiation
D. To blur grid lines on the image
To blur grid lines on the image
152
What happens to image receptor exposure when a grid is placed in the beam?
A. It increases
B. It decreases
C. It remains unchanged
D. It doubles
It decreases
153
Why does image receptor exposure decrease when using a grid?
A. More primary radiation reaches the receptor
B. The grid increases kVp
C. The grid absorbs some radiation
D. The grid increases SID
The grid absorbs some radiation
154
What must be done to compensate for reduced image receptor exposure when using a grid?
A. Decrease exposure factors
B. Increase exposure factors
C. Change patient position
D. Decrease SID
Increase exposure factors
155
Which of the following best describes grid use and exposure?
A. Grid increases exposure naturally
B. Grid eliminates need for technique changes
C. Grid has no effect on exposure
D. Grid requires increased technique to maintain exposure
Grid requires increased technique to maintain exposure
156
What is the PRIMARY reason exposure factors must be increased when using a grid?
A. To reduce scatter radiation
B. To increase patient comfort
C. To compensate for radiation absorbed by the grid
D. To decrease image contrast
To compensate for radiation absorbed by the grid
157
If exposure factors are NOT adjusted when using a grid, what will happen?
A. Image will be overexposed
B. Image will be underexposed
C. Image will be unchanged
D. Image will have increased contrast
Image will be underexposed
158
What does GCF (Grid Conversion Factor) represent?
A. The decrease in exposure due to scatter
B. The required increase in technique when using a grid
C. The distance between grid lines
D. The number of lead strips per inch
The required increase in technique when using a grid
159
What is another name for Grid Conversion Factor (GCF)?
A. Exposure index
B. Scatter factor
C. Bucky factor
D. Grid ratio
Bucky factor
160
What is the formula for calculating GCF?
A. mAs without grid / mAs with grid
B. kVp / mAs
C. SID / OID
D. mAs with grid / mAs without grid
mAs with grid / mAs without grid
161
If mAs without a grid is 10 and mAs with a grid is 40, what is the GCF?
A. 2
B. 3
C. 4
D. 5
4
162
What does a GCF of 4 mean?
A. Decrease mAs by 4
B. Multiply mAs by 4 when using a grid
C. Divide mAs by 4
D. No change in mAs
Multiply mAs by 4 when using a grid
163
GCF is dependent on which factor?
A. SID
B. Patient thickness
C. kVp
D. Grid frequency
kVp
164
What is the formula for grid conversion between two grid ratios?
mAs2 = (mAs1 × GCF2) / GCF1
165
Exposure is 20 mAs with an 8:1 grid at 85 kVp. What is the new mAs when switching to a 12:1 grid?
25 mAs
166
What type of grid error occurs when using an SID outside the focal range?
A. Off-center error
B. Off-focus error
C. Upside-down grid error
D. Crooked grid error
Off-focus error
167
What is the radiographic effect of using an incorrect SID with a focused grid?
A. Increased central density
B. Uniform exposure across the image
C. Loss of exposure at the periphery
D. Increased scatter radiation
Loss of exposure at the periphery
168
Why does off-focus error occur in grid use?
A. The grid is tilted incorrectly
B. The central ray is not centered
C. The grid is placed upside down
D. The SID does not match the grid’s focal range
The SID does not match the grid’s focal range
169
What is the appearance of off-focus grid cutoff on an image?
A. Complete white-out of the image
B. Sharp lines across the image
C. Dark center with lighter edges
D. Even exposure throughout
Dark center with lighter edges
170
What causes the moire effect in digital radiography?
A. Grid lines are perpendicular to scan lines
B. Grid lines are parallel to scan lines
C. Grid ratio is too high
D. SID is incorrect
Grid lines are parallel to scan lines
171
In which imaging system is the moire effect most commonly seen?
A. Film-screen radiography
B. Fluoroscopy
C. Digital systems (computed radiography)
D. Ultrasound
Digital systems (computed radiography)
172
What is the appearance of the moire effect on an image?
A. Increased sharpness
B. Uniform brightness
C. Wavy or repeating pattern artifacts
D. Dark center only
Wavy or repeating pattern artifacts
173
How can the moire effect be prevented?
A. Use lower kVp
B. Increase SID
C. Use lower grid ratio
D. Use high-frequency grids designed for digital systems
Use high-frequency grids designed for digital systems
174
What is the air-gap technique?
A. Decreasing SID to reduce scatter
B. Increasing kVp to improve contrast
C. Increasing OID to reduce scatter and create a grid-like effect
D. Using a lower grid ratio
Increasing OID to reduce scatter and create a grid-like effect
175
What happens to scatter radiation in the air-gap technique?
A. It increases
B. It is lost in the air space between patient and receptor
C. It is absorbed by the grid
D. It remains unchanged
It is lost in the air space between patient and receptor
176
A 10-inch air gap provides scatter cleanup similar to which grid ratio?
A. 5:1
B. 8:1
C. 10:1
D. 15:1
0.6256944444444446
177
What must be adjusted when using the air-gap technique to maintain image resolution?
A. Decrease SID
B. Increase SID
C. Decrease mAs
D. Increase grid ratio
Increase SID
178
What is the main advantage of the air-gap technique?
A. Eliminates need for proper positioning
B. Increases scatter radiation
C. Reduces scatter without using a grid
D. Increases patient motion
Reduces scatter without using a grid
179
What is a disadvantage of increasing OID in the air-gap technique?
A. Increased image sharpness
B. Reduced magnification
C. Increased magnification
D. Decreased distortion
Increased magnification
180
Why are higher kVp values recommended with digital imaging systems?
A. To increase patient dose
B. To improve image contrast only
C. To allow for reduced mAs while maintaining exposure
D. To eliminate scatter radiation
To allow for reduced mAs while maintaining exposure
181
What happens to mAs when using digital imaging with higher kVp?
A. It increases
B. It decreases
C. It remains unchanged
D. It doubles
It decreases
182
What rule is commonly applied when adjusting kVp and mAs in digital imaging?
A. Inverse square law
B. 10% rule
C. Grid ratio rule
D. 15% rule
15% rule
183
Why is exposure latitude reduced when using lower mAs in digital imaging?
A. Increased scatter radiation
B. Increased grid ratio
C. Reduced signal due to lower photon quantity
D. Increased SID
Reduced signal due to lower photon quantity
184
Why are grid cutoff artifacts more noticeable in digital imaging?
A. Digital systems increase scatter
B. Digital systems reduce resolution
C. Digital systems amplify contrast errors
D. Digital systems have less tolerance for exposure errors
Digital systems have less tolerance for exposure errors
185
Even a small degree of grid cutoff in digital imaging will result in:
A. No visible change
B. Slight increase in brightness
C. A visible artifact on the final image
D. Increased sharpness
A visible artifact on the final image
186
Are grids still needed in digital imaging systems?
A. No, they are completely replaced by software
B. Only in fluoroscopy
C. Yes, to control excessive scatter radiation
D. Only for pediatric imaging
Yes, to control excessive scatter radiation
187
What primarily determines final image contrast in digital imaging?
A. Grid ratio
B. mAs settings
C. kVp selection
D. Look-up tables (LUT) in digital software
Look-up tables (LUT) in digital software
188
What is the purpose of grid replacement software?
A. Removes scatter radiation completely
B. Produces a grid-like image without using a physical grid
C. Increases patient dose
D. Adjusts SID automatically
Produces a grid-like image without using a physical grid
189
What does grid suppression software do?
A. Increases contrast
B. Removes scatter radiation
C. Removes grid lines from the final image
D. Increases exposure
Removes grid lines from the final image
190
Which of the following best describes digital grid replacement?
A. It eliminates the need for collimation
B. It physically removes the grid
C. It simulates the effect of a grid using software
D. It increases image noise
It simulates the effect of a grid using software
191
Why are grids still important even with digital imaging?
A. Digital systems cannot process images
B. Software cannot fully eliminate scatter radiation
C. Digital systems increase scatter production
D. LUTs require grid use
Software cannot fully eliminate scatter radiation
__Exposure
flashcards
Decks in class (13)
# Cards
-
EXPOSURE - ch07_Automatic Exposure Control (AEC) - FIXED64
-
EXPOSURE - ch11_Filtration - FIXED33
-
EXPOSURE - ch15_Beam_Restriction - FIXED21
-
quizlet_deck-2122
-
Ch18 - Grids191
-
ch 20 - Digital Radiography117
-
Quiz 2 study guide ch18 & ch2035
-
ch18 & ch20 study guide A35
-
ch18 & ch20 study guide B35
-
ch18 & ch20 study guide C35
-
ch21 - Computed Radiography - DECK125
-
ch22 - Digital Radiography and Flat Panel - DECK144
-
ch23 _Technical_Considerations_DECK192
