Test 4 Contrast Flashcards
1
Q
Few shades of grey
A
High contrast
2
Q
The principal controlling factor of contrast is
A
Kvp
3
Q
A radiograph that demonstrates considerable differences between densities is called
A
Short scale
High contrast
Increased contrast
4
Q
Minimal differences between densities
A
Long scale
Low contrast
Decreased contrast
5
Q
Contrast decreases with
A
Excessive density (all black) Inadequate density (all white) A wider range of densities
6
Q
Contrast increases with
A
Decreased kvp
Decreased field ️size
Decreased part ️thickness
7
Q
High contrast is directly related to
A
The number of photoelectric interactions (absorption)
8
Q
Increased contrast
A
Black and white
9
Q
T/f increasing the amount of irradiated tissue increases contrast
A
False
10
Q
As KVP increases the percentage of Compton interactions ______ and contrast ______
A
⬆️⬇️
11
Q
When the tissue structure of the ankle joint is considered, the dramatic differences between the muscles and bones of the ankle produce
A
High subject contrast
12
Q
A fluoro examination that uses barium as a contrast material would typically produce images with
A
Short scale contrast
13
Q
Short scale contrast
A
High contrast
Low kVp
Black and white
14
Q
Long scale contrast
A
Low contrast
High kvp
Many shades of grey
15
Q
The total amount of irradiated material is a function of
A
Body part ️thickness and body position
16
Q
Depending upon the kvp range a visible change in contrast will not be seen unless kvp is minimally changed
A
4-12%
17
Q
In order to reduce or entrance skin exposure (ESE) higher kvp exposures are a consideration. It is important to remember that
A
Kvp values that are too high produce more scatter and reduce contrast
18
Q
Kvp controls the proportional relation between
A
Compton (scatter) and photoelectric interactions (absorption)
19
Q
What should you expect to occur with a decrease in kvp
A
More photoelectric interactions
20
Q
An increase in xray beam filtration
A
Increases scatter
Reduces contrast
Increases the average photon energy
21
Q
Contrast is directly influenced by the xray
A
Photon wavelength used
22
Q
An image with a long range of slightly different translucent densities possesses
A
Low contrast
23
Q
Low kvp
A
High contrast
24
Q
A radio lucena anatomical structure is one that
A
Easily transmits X-rays to the image receptor
25
Scatter radiation will affect radiographic density and contrast in what matter
Density will increase and contrast will decrease
26
Radiographic contrast
Produces sharper structural lines in the image
| Allows visibility of anatomical structures
27
When different tissues in the area being images have different absorption characteristics
There will be radiographic contrast
28
The range of densities visible defines
Scale of contrast
29
A radiograph that has densities that are very different from each other
Has high contrast
30
A radiograph that has densities that are very similar to each other
Has low contrast
| Has long scale contrast
31
Subject contrast includes the
Quality of the xray beam
| Absorption characteristics of the anatomy being imaged
32
An area that has low subject contrast
Lowest breast
| Next lowest chest
33
An area of anatomy that has high subject contrast is the
Femur
34
Using a kvp xray beam results in
Increased transmission (penetration)
Higher energy x Ray photons
A film image with low contrast
35
A low kvp xray image of the chest results in a film image with
Short scale contrast
| Few but very different densities
36
Te difference between two adjacent densities is
Radiographic contrast
37
______ kvp results in the intensities of radiation exiting the pt being very ______
Low
| Different
38
Low kvp produces ______ radiograic contrast and high kvp produces ______
Higher
| Lower
39
Low kvp produces _______ radiographic contrast and high kvp produces ______
Long scale
| Short scale
40
Reducing the amount of scatter radiation reaching the IR results in
Higher radiographic contrast
41
When introducing a grid and increasing mAs
You get a cleaner image with more detail
| Increased contrast
42
Opening collimation has what effect on contrast
Increases scatter and decreases contrast
43
⬆️OID and ⬇️ SID has what effect on magnification
⬆️magnification
44
For every inch of OID the SID needs to increase by how much
7 inches to decrease ️magnification
45
When the tube or IR is angled what happens to the appearance of the body part
Elongation
46
When the body part is angled what happens to the appearance of the body part
Foreshortening
47
What two factors have no effect on density
Focal spot and anode hill effect
48
What two factors have a direct relationship with density
MAs and kvp
49
Filtration has what kind of relationship with density? Contrast?
Inverse
| Inverse
50
️thickness of body part has what kind of relationship with density? Contrast?
Both are inverse
51
What three control factors have no effect on contrast
MAs
SID
Focal spot size
52
What kind of relationship does grid ratio have with density? Contrast?
Inverse
| Direct (contrast)
53
What relationship does screen and contrast have
Direct
54
What relationship does collimation (beam restriction) have with contrast
Direct
55
When SID is divided by SOD What is the result called
️Magnification factor
56
The property of the xray beam that impacts the unsharpness on the radiographic beam
Divergence
57
Using a small focal spot ️size may be prohibited due to the
Amount of heat produced
58
️magnification is affected by
️OID and SID
59
SOD can be determined by
Subtracting ️OID from SID
60
What effect will increasing SID have on recorded detail
Increased recorded detail
61
What is the radiographer determining when selecting the focal spot ️size
Actual size of the filament used
62
The visibility of recorded detail
Photographic properties
63
The sharpness of recorded detail
Geometric properties
64
A distance created between the object and image receptor is called
Air gap principal/technique
65
When part ️thickness increases the amount of scatter production _______
Increases
66
Distortion is associated with what
️size and shape
67
T/F there is a % of ️magnification in every radiographic image
True
68
As the percentage of ️magnification increases the level of geometric unsharpness __________
Increases
69
Distinctness or sharpness of the structural lines that make up the recorded image is called
Recorded detail or ️resolution
70
What tech factors affect sharpness
SID
️OID
SOD
Motion
71
The controlling factor of sharpness
Focal spot ️size
72
The hazy edge of the "true" image
Penumbra
73
The "true anatomical image
Umbra
74
In general radiography te ️size of the focal spot usually ranges from
.5-1.2
75
As focal spot ️size increases unsharpness ______ and recorded detail _______
Increases
| Decreased
76
T/F a longer SID creates a larger penumbra
False
| Short SID = larger penny drs
77
The avg visual acuity of the human eye when inspecting a rad image at the normal viewing distance of 18" -24" is
5Lp/mm
78
What instrument records lines pairs/mm
Line pair test tool
79
______ kvp results in the intensities of radiation exiting the pt being very ______
Low
| Different
80
Low kvp produces ______ radiograic contrast and high kvp produces ______
Higher
| Lower
81
Low kvp produces _______ radiographic contrast and high kvp produces ______
Long scale
| Short scale
82
Reducing the amount of scatter radiation reaching the IR results in
Higher radiographic contrast
83
When introducing a grid and increasing mAs
You get a cleaner image with more detail
| Increased contrast
84
Opening collimation has what effect on contrast
Increases scatter and decreases contrast
85
⬆️OID and ⬇️ SID has what effect on magnification
⬆️magnification
86
For every inch of OID the SID needs to increase by how much
7 inches to decrease ️magnification
87
When the tube or IR is angled what happens to the appearance of the body part
Elongation
88
When the body part is angled what happens to the appearance of the body part
Foreshortening
89
What two factors have no effect on density
Focal spot and anode hill effect
90
What two factors have a direct relationship with density
MAs and kvp
91
Filtration has what kind of relationship with density? Contrast?
Inverse
| Inverse
92
️thickness of body part has what kind of relationship with density? Contrast?
Both are inverse
93
What three control factors have no effect on contrast
MAs
SID
Focal spot size
94
What kind of relationship does grid ratio have with density? Contrast?
Inverse
| Direct (contrast)
95
What relationship does screen and contrast have
Direct
96
What relationship does collimation (beam restriction) have with contrast
Direct
97
When SID is divided by SOD What is the result called
️Magnification factor
98
The property of the xray beam that impacts the unsharpness on the radiographic beam
Divergence
99
Using a small focal spot ️size may be prohibited due to the
Amount of heat produced
100
️magnification is affected by
️OID and SID
101
SOD can be determined by
Subtracting ️OID from SID
102
What effect will increasing SID have on recorded detail
Increased recorded detail
103
What is the radiographer determining when selecting the focal spot ️size
Actual size of the filament used
104
The visibility of recorded detail
Photographic properties
105
The sharpness of recorded detail
Geometric properties
106
A distance created between the object and image receptor is called
Air gap principal/technique
107
When part ️thickness increases the amount of scatter production _______
Increases
108
Distortion is associated with what
️size and shape
109
T/F there is a % of ️magnification in every radiographic image
True
110
As the percentage of ️magnification increases the level of geometric unsharpness __________
Increases
111
Distinctness or sharpness of the structural lines that make up the recorded image is called
Recorded detail or ️resolution
112
What tech factors affect sharpness
SID
️OID
SOD
Motion
113
The controlling factor of sharpness
Focal spot ️size
114
The hazy edge of the "true" image
Penumbra
115
The "true anatomical image
Umbra
116
In general radiography te ️size of the focal spot usually ranges from
.5-1.2
117
As focal spot ️size increases unsharpness ______ and recorded detail _______
Increases
| Decreased
118
T/F a longer SID creates a larger penumbra
False
| Short SID = larger penny drs
119
The avg visual acuity of the human eye when inspecting a rad image at the normal viewing distance of 18" -24" is
5Lp/mm
120
What instrument records lines pairs/mm
Line pair test tool
