X-Ray Physics (Part II) (Irene Gold) Flashcards
1
Q
What three things are found inside the Cathode?
A
Large Filament
Small Filament
Focusing Cap
2
Q
What is the source of the electrons that produce the x-ray?
A
Filament
3
Q
What is the filament made out of?
A
Tungsten
4
Q
When does a Thermionic Emission happen?
A
When current is applied to a filament
5
Q
What controls the quantity of electrons (mA)?
A
Temperature of the filament
6
Q
What part of the cathode encases the two filaments?
A
Focusing/Filament Cup
7
Q
In what part of the Cathode does the Thermionic Emission occur?
A
Filament Cup
8
Q
What is the name of the positive electrode in the x-ray tube?
A
Anode
9
Q
In most x-ray machines is the anode stationary or rotating?
A
Rotating
10
Q
What is the reason for a rotating Anode target?
A
To dissipate the heat that is generated
11
Q
What is the focal area/spot of the Anode?
A
The exposed area of the tungsten target
12
Q
How is the focal spot determined?
A
By the size of the filament
13
Q
What does a Smaller filament produce as an outcome?
A
Better Detail
14
Q
What is it called when “The effect of making the actual focal spot size appear smaller when viewed for the position on the film”?
A
Line Focus Principle
15
Q
What give you a smaller effective spot on x-ray?
A
Smaller target angle
16
Q
What is the term used that “Heats the filament causing a boiling off of electrons”?
A
Millamperage (mA)
17
Q
How is the term Millamperage per Second defined (mAs)?
A
More Current=More Electrons produced= More x-ray produced= Greater Radiographic density (Darker)
18
Q
What is the term used for overall blackening on the film?
A
Density
19
Q
What does the term Radiolucent mean?
A
Structures produce more blackening on the film
20
Q
What term is used for “Structures that produce less blackening on the film”?
A
Radio-opaque
Whiter on X-ray
21
Q
The relationship between what two components of x-ray mAs and density?
A
They are directly proportional
22
Q
What is the primary way to control how black a film is?
A
mAs
23
Q
If the mAs is increased what does that mean in terms of film exposure?
A
The film exposure time is increased
24
Q
What is the minimum change in mAs to see a change in density on the film?
A
30%
25
What does it mean to the density if the mAs is either doubled or halved?
The density will be doubled or halved, they are directionally proportional
26
What is the definition of Kilovoltage (kVp)?
The force applied to accelerate the electrons from the cathode to the anode at the time of exposure
27
When will the greatest number of high energy x-ray photons be produced?
When a great force of Kilovoltage (kVp) is produced
28
What is the relationship between wavelength and frequency?
Inversely related
29
If there is a low kVp what kind of energy and penetration are produced?
Low energy
| Weak penetration
30
What kind of kVp would produce a high energy and a strong penetration?
High kVp
31
What kind of kVp produces shorter wavelengths with a greater ability to penetrate body tissue?
High kVp
32
What is the term that "is the difference in density between two structures"?
Contrast
33
What is the purpose of Contrast on an x-ray?
Makes detail visible
34
What is the relationship between kVp and contrast?
Inversely related
35
Does mAs or kVp control contrast?
kVP
36
In terms of Low kVp; what kind of contrast and scale are produced?
High Contrast=Short Scale
37
What kind of x-ray will be produced from a Low kVp setting?
Sharp difference in dark and light areas
A black and white film= underexposed (Bone Film)
38
Low kVp has what two effects?
Produces more scatter
| Increased amount of radiation is absorbed by the patient
39
Low Contrast=Long Scale is seen in what kind of kVp film?
High kVp
40
What is expected to be seen on an x-ray film of High kVp?
Very little differences between densities
More shades of grey (Soft Tissue Film)
41
High kVp films have what two effects?
More scatter produced
| Decreased amount of radiation is absorbed by the patient
42
How can you do the following on an x-ray film:
Lower Contrast
Longer Scale of Contrast
More Shades of Gray
Increase kVp by 15%
AND
Decrease mAs by 50%
43
How can you do the following on an x-ray film:
Higher Contrast
Shorter Scale of Contrast
Fewer shades of Grey (More Black and White)
Decrease kVp by 15%
AND
Increase mAs by 100%
44
What is the primary way to control density on an x-ray?
mAs
45
What is the relationship between kVp and density?
NOT proportional
46
What is the 15% Rule?
Increase the kVp by 15%=Double the film density
Decrease the kVp by 15%= Half the film density
47
Which tissue absorbs more x-ray?
Denser tissue
48
What two things are Black on x-ray?
Gas
| Fat
49
What three things appear Gray on x-ray?
Muscle
Water
Soft tissue
50
What two things will show up as white on x-ray?
Bone
| Metal
51
On which side of the x-ray is the intensity the greatest?
Cathode side
52
Towards what side do you place the thinner portion of the patient being x-rayed?
Anode Side (Anode Heel Effect)
53
Why is the thinner portion of the patient placed on the Anode Side of the x-ray tube?
Density and Intensity are Decreased
54
Which Side of the X-Ray machine produces less X-Ray?
Anode Side
55
What is the size of the Effective focal spot on the Anode Side of the X-Ray machine?
Smaller
56
What size of the X-Ray machine produces more Detail?
Anode Size
57
Where is the Anode side of the X-Ray machine placed?
Used on the thinner body part
58
On the Cathode side of the X-Ray machine:
Is there more or less X-Ray?
Effective focal spot, larger or smaller?
How much detail is produced, Less or More? Where do you place the Cathode on a patient during an X-Ray?
X-Ray: More
Focal Spot: Larger
Detail: Less
Use on the thicker body part
59
What term is used to determine "The length of space from the focal spot (tube) to the recording medium (film)?
Focal Film Distance (FFD)/Source Image Distance (SID)
60
What happens as you increase the Focal Film Distance (FFD)?
The image gets smaller and clearer
61
What two things happen when you decrease the Focal Film Distance (FFD)?
The image gets:
Bigger
Blurrier
62
What law explains how the intensity of the x-Ray beam is affected by the changes in the Source Imaging Distance?
Inverse Square Law
63
What varies inversely with the square of the distance from the source?
Intensity of Radiation
64
What happens if a 40 inch Focal Film Distance is doubled to 80 inches of Focal Film Distance?
The intensity at 80 inches of Focal Film Distance is 1/4 the intensity at 40 inches of Focal Film Distance, if no other factors are changed
65
What must happen to the mAs at 80 inches of Focal Film Distance?
It must be increased 4x the amount from 40 inches of Focal Film Distance, to maintain the same amount of Blackening
66
What kind of crystals are found in the Intensifying Screen for X-Ray?
Fluorescent
67
What are three findings with large crystals in the X-Ray screen?
More Light
Work quickly
Yield Less Detail
68
What is the "equation" of Large crystals in the X-Ray screen?
Faster Screen=Higher Contrast=Short Scale (Less Patient Exposure)
69
What part of the X-Ray is intensified using screens?
Density
70
What is the term used for "Clarity and Sharpness of a Film"?
Definition
71
What does the term Umbra mean?
Picture made by a useful beam
72
What term is "blurry halo part of the image"?
Penumbra
73
What three things can cause Penumbra?
Tube to close to the film (Short Focal Film Distance (FFD))
Patient to far from the film (Long Object Film Distance (OFD))
To large of a filament on the Cathode, making the focal spot to big
74
What is the term used for describing the distance between the patient and the film?
Object Film Distance (OFD)
75
What happens as you increase the Object Film Distance (OFD)?
Image has more Penumbra; becomes bigger and blurrier
76
What happens as you decrease the Object Film Distance (OFD)?
Image has better detail; becomes smaller and clearer
77
How do you get the best detail?
Place the patient as close to the film as possible
78
What is the term for the following definition: "Pressure exerted by the film holder as it encloses the X-Ray film"?
Screen-Film Contact
79
What is the outcome of poor screen-film contact?
Reduces the sharpness of the image
80
What are the two types of distortion that can happen on and X-Ray?
Size
| Magnification
81
What two things are distortion of an X-Ray effected by?
Object Film Distance (OFD)
| Focal Film Distance (FFD)
82
What three things happen when an X-Ray strikes an object?
Scatter
Absorption
Penetration
83
What four ways can Scatter Radiation be reduced?
Grids
Air gap technique
Collimators
Filters
84
Where is the grid placed?
Between the patient and the film
85
What is the sole purpose of the grid?
Improve the quality of the radiograph by absorbing scatter radiation
86
When using a grid, why must exposure factors be increased?
To maintain density
87
Does the use of a grid increase or decrease the patient's dose of radiation?
Increase
88
What is a Grid Ratio?
The height of lead strips to the distance of Lead strips
89
What Grid Ratio is used in Chiropractic offices?
12:1
90
What is the definition of the "Air Gap Technique"?
6-10 inch gap between the patient and the film
91
What happens to the X-Ray as there is an increase in the Air Gap Technique?
Scatter radiation diverges away from the film
92
Is the patient's radiation dose increased or decreased when there is an Air-Gap?
Decrease, but can distort or magnify the image
93
What is the main function of Collimation?
Limits the size of the beam to the body part being X-rayed
94
What is the best way to reduce scatter radiation to both the patient and the film?
Collimation
95
What are X-Ray filters made out of?
Aluminum
96
What is the preferred way to remove low energy photons from an X-Ray?
Filtration
97
What function does the filter play during X-Ray?
Stops weak photons (those not capable of getting all the way to the screen) from entering the patient's body, thus protecting from scatter radiation
98
What is the term used to "Measure the radiation energy absorbed"?
Radiation Absorbed Dose (RAD)
99
What is the term defined as "Biological effectiveness of the radiation absorbed"?
Radiation Equivalent Man (REM), Badges worn by Radiology Technicians
100
What is the safe number of Radiation Equivalent Man (REM) per year?
5
101
What is the term for "The number of Radiation Equivalent Man (REM) a person can get in a lifetime without getting radiation poisoning"?
Maximum Permissible Dose (MPD)
102
What is the Maximum Permissible Dose (MPD)?
Maximum Permissible Dose= 5(Age-18)
103
What is the name of the majority of the useful beam of an X-Ray?
Bremsstrahlung
AKA
Braking Radiation
104
What is the Characteristic of Bremsstrahlung Radiation?
High intensity electron hits an inner shell electron, which is knocked out of it's position in orbit. An out shell electron then fills it's spot
105
What is the primary form of scatter radiation?
Compton Scatter
106
What are two other names for Classic Scatter?
Thompson Scatter
| Coherent Scatter
107
What type of Scatter is "A low energy X-Ray that changes direction with no energy loss"?
Classic Scatter
108
How is Compton Scatter described?
A moderate energy X-Ray knows out an outcry shell electron, which causes loss of energy
109
What type of Scatter contributes to Film Fog?
Classic Scatter
110
What is it called when "A low energy photon is absorbed by the subject creating a latent image on the film"?
Photoelectric Effect
111
What is another name for Quantum Mottling?
Radiographic Noise
112
What type of screen produce the most Mottling?
Faster Screens
113
What two exposure factors will decrease Radiographic Noise?
High mAs
| Low kVp
114
When processing a film what will increase the density?
Solution temperatures that are to hot
115
What is the effect of film density if the solutions are to low when the film is being processed?
Density will be low/insufficient
116
What are the four factors of processing an X-Ray?
Developer
Rinse
Fixer
Wash
117
What factor of X-Ray processing "Brings out the latent image by exposing the Silver Halide crystals?
Developer
118
What is the purpose of the Rinse step in processing an X-Ray?
Removes the exposed Silver Halide crystals
119
What step of the making an X-Ray "Hardens the image, making it permanent on the film"?
Fixer
120
What step in making an X-Ray removes the Developer and Fixer?
Washing
121
What three things are indicated by Dark Films?
Light Leak
Overexposure
Developer Temperature too hot
122
What two things does a Light Film indicate?
Developer temperatures are to low
| Chemicals need to be changed/replaced
123
If the Developer is inadequate what color will the film be?
Brown
124
Milky Films indicated an inadequacy in what factor or the x-Ray processing?
Fixer
125
If a film is inadequately Washed how will it appear?
Greasy Film
126
What three things can cause an increase in Film Fog?
Hot Developer
Old Film
Contaminated Chemicals
127
What does a Soft Emulsion on a film indicate?
Insufficient Fixing
128
How should film/cassettes be stored?
Vertically to avoid pressure damage
129
What causes creases on an X-Ray film?
Nail Marks
130
What two colors can be added to the base of an X-Ray film to reduce glare?
Green
| Blue
131
What is the term when a "beam of radiation loses energy as it passes thru matter"?
Attenuation
132
What is the definition of Transducer?
One form of energy to another
133
What term is described as a "step up or step down in power"?
Transformer
134
What part of the X-Ray Machine changes Alternating Current (AC) to Direct Current (DC)?
Rectifier
135
What two things can be produced by Static Electricity, when removing the film quickly from the cassette?
Black film
| Branching lightening like likes on the film
