Clicker Q's Flashcards
(93 cards)
1
Q
Which X-Ray production process occurs when an electron shifts its shell?
A
Characteristic (5 very specific X-rays that are produced by this process)
2
Q
Which X-Ray production process occurs when an electron slows down or stops?
A
Bremmsstrahlung
3
Q
Which X-Ray production process is responsible for the majority of the x-rays in the beam?
A
Bremsstrahlung
4
Q
Which XRay production process requires at least 70 kVp in a tungsten target?
A
characteristic
5
Q
Which one is capable of producing HIGHER energies, greater than 70 keV
A
bremsstrahlung
6
Q
What is the type of current distributed by power companies?
A
AC power
7
Q
What type of current is necessary to produce X-Rays?
A
DC current
8
Q
14 X 36 Full spine
anode?
A
up
9
Q
AP Thoracic (T1-T12) anode?
A
up
10
Q
Lateral Lumbar
anode?
A
up
11
Q
Lateral Thoracic
anode?
A
down
12
Q
Lateral Cervical
anode?
A
doesn’t matter
13
Q
AP Femur
anode?
A
down
14
Q
REM =
A
RAD x QF
15
Q
20 RAD=
A
20 REM
16
Q
QF of X-ray =
A
1
17
Q
20mRAD=
A
20mREM
18
Q
1000mREM=
A
1 REM
19
Q
20 RAD of alpha exposure=
A
400 REM
20
Q
Occupational exposure unit —systems international nomenclature =
A
Sievert (SI)
21
Q
100 REM =
A
1 Grey = 1 Sievert
22
Q
Which will produce the most Radiographically Dense Image?
1) 20 mAs at 40” SID
2) 20 mAs at 72” SID
A
20 mAs at 40” SID
***because more xrays made it to the film – blacker image
23
Q
Which will produce the most geometric sharpness?
1) 30mAs, 73kVp, 36” SID
2) 120 mAs, 73kVp, 72” SID
A
120 mAs, 73kVp, 72” SID
***higher SID creates MORE geometric sharpness
24
Q
If 30 mAs used at 36” SID versus 120 mAs used at 72” SID
1) More Dense
2) Less Dense
3) No change in density
A
No change in density
(***only skin exposure reduced, deep tissue X-rays would not be affected
25
Which interaction causes the white areas in the image?
photoelectric effect
26
In which of these interactions is an x-ray totally absorbed when ionizing (in diagnosis)
photoelectric
27
Which interaction causes image contrast to be reduced?
fog == compton scatter
28
This x-ray interaction is more probable in high atomic number matter
photoelectric absorption
29
Which of these energy interactions is important in Diagnostic Radiology?
both photoelectric and compton scatter
30
Which interaction likely to occur at 10-60 keV?
photoelectric
31
What is the item that controls contrast?
kVp
32
Exposure factors that effect the sharpness of detail and the amount of of distortion in an image are known as
geometric factors
33
Occupational Exposure as reported on radiation dosimeters will be expressed in this classical unit of radiation exposure?
mREM or REM
34
The unit REM differs from RAD because it combines both occupational and personal exposure.
T/F?
false (they are separate and distinct)
35
The systems international unit that describes the quantity of patient exposure is:
grey
36
This x-ray interaction with matter produces the whites in the image
photoelectric absorption
37
This x-ray interaction causes “fog” in the image
compton scatter
38
This x-ray interaction occurs at high kVp in the diagnostic range
compton scatter
39
This x-ray interaction decreases image contrast?
compton scatter
40
When collimating from 14X17 to 10X12 area -- what do we do therefore?
increase mAs by 50%
41
An AP Lumbar spine exam is properly exposed using 40mAs, 73kVp and a 14X17 film. If a 4X4 spot film is needed, what are the exposure factors.
increase by 50% mAs = 60 mAs, 73kVp, and the spot view
42
What causes severe underexposure?
Backward Focused Grid -- I.E it was put in the wrong way in the Bucky...
43
Height of the Lead Strip divided by Width of the Interspace Strip:
grid ratio
44
High Frequency Radiographic Grid does this?
decreases the visibility of grid lines
45
What grid is on useful in Chiropractic??
crosshatch
46
This will be indicated on a Focused Grid?
tube side
47
The Ratio Grid adequate for large images (Gonstead)
12:1 or 16:1
48
When to use a radiographic grid?
Body part is > 10cm
When we are using > 60 kVp
(Radiographic Grid is also referred to as a “Bucky”)
49
What is the film BASE made of?
Polyester Plastic (Mylar)
50
What is the film emulsion made of?
Silver Halide crystals suspended in gelatin
51
The purpose of using intensifying screens is to:
Reduce Patient Exposure
52
What are intensifying screens made of?
Rare Earth Crystals --Lanthanum, Gadolinium, and Yttrium
53
You have a 200 speed film-screen system. The technique chart that is posted is posted works well for that system. What do we need to do with a 600 flim screen system??
Use 1/3X mAs Values
54
Density is correct when using a 20 mAs on a 1200 speed system. What mAs should be used if changing to a 200 speed system?
120 mAs
55
Density correct when using 60 mAs with a 300 Speed system. What is the mAs when we buy a new 600 speed system?
30 mAs
56
What does quantum mottle look like in an image?
graininess
57
Which of these systems will operate with the most quantum mottle?
1200 speed
58
Which of these system speeds would you use for detailed extremity images?
100 speed
59
Which of these would be the minimum speed used for spine imaging?
400 speed
60
Which of these would result in the most radiation exposure to the patient?
100 speed
61
Which of these speeds is most consistent with the ALARA concept?
1200 speed
62
What is film latitude?
range of error
63
How is film contrast related to film latitude?
inversely
64
What type of safelight is safe for rare earth screen combinations?
GBX (green blue X-ray)
65
As film speed system speed increases, geometric blur:
increases
66
The writing on the Safe-light fixture should be placed:
away from the bulb
67
The gelatin side of the safelight filter is placed away from the bulb so it will:
not melt
68
Safelight Bulbs should be in terms of watts:
15 Watts or Less
69
Safelights should be placed at least this far from the work surface?
4 feet
70
What is the relative humidity to store films at?
40-60% humidity
71
Dirty screens can cause these types of artifacts?
Sharp White Dots
72
These should be used to clean the intensifying screens:
Screen Cleaner and Gauze
73
Define the term “Latent Image”?
The Invisible Image on the Film Before Processing
74
Define the term “Manifest Image”?
The Visible Image on Film After Processing
75
What happens when we use film that is out of date?
FOG -- also caused by compton scatter
76
What is the function of the developer?
To convert the latent image into a manifest image
77
What is the function of the fixer?
To Clear and Harden the Emulsion
78
Why does the direction of film transport through the processor motor matter?
Chemical Replenishment
79
When image processed with oxidized developer what would it look like?
too light
80
An occupationally exposed person’s own, personal exposure is included in the REM unit?
T/F?
false
81
Which of these is the most likely to cause “fog” in an image?
1) Use of low kVp
2) Use of high kVp -- creates a longer “range”, higher kVp goes further into range of Compton Scatter which causes Fog. higher probability of Compton = higher fog
3) High mA and short exposure time
4) Low mA and long exposure time
Use of high kVp -- creates a longer “range”, higher kVp goes further into range of Compton Scatter which causes Fog. higher probability of Compton = higher fog
82
Which of these will reduce Compton Scatter?
1) Using High kVp (low will reduce)
2) Collimating Well
3) Compressing Tissue
4) Using shorted OID possible (longer = reduce compton)
Collimating Well Compressing Tissue
83
WHich of these grids is designed so that the strips coincide with the divergence of the x-ray beam:
focused
84
10:1 grid ratio compared to using no grid will require this change in exposure factors:
Use 4X the mAs
85
Scale of contrast is too long at 30mAs, and 80kVp. What change should be made to produce a shorter scale of contrast.
Key is to go DOWN in kVp and UP in mAs to compensate.
| This means 68kVp, and 60mAs
86
What is the annual whole body MPD for occupationally exposed persons?
5 REM (or 5000 mREM)
87
What is the MPD for a pregnant worker?
0.5 REM/gestation period
88
Which of these is not a cardinal priniciple of Radiation Protection?
1) kVp
2) Time
3) Distance
4) Shielding
kVp
89
Which of these would allow a greater amount of weekly radiation exposure?
1) Controlled Area
2) Uncontrolled Area
Controlled Area
90
State the cumulative MPD for a 55 year old occupationally exposed man using the NEW Formula (1 X the person’s age):
55 REM
91
How often must film badges be sent in for processing?
Once every month
92
What does the “m” mean on a dosimeter report?
That the exposure was so minimal it did not record
93
Which of these is allowed a greater amount of weekly exposure?
Controlled Area (Has a benefit to outweigh the risk)
