X-Ray Physics (Part II) (Irene Gold) Flashcards Preview

Boards Part II and III (Irene Gold) > X-Ray Physics (Part II) (Irene Gold) > Flashcards

Flashcards in X-Ray Physics (Part II) (Irene Gold) Deck (135):
1

What three things are found inside the Cathode?

Large Filament
Small Filament
Focusing Cap

2

What is the source of the electrons that produce the x-ray?

Filament

3

What is the filament made out of?

Tungsten

4

When does a Thermionic Emission happen?

When current is applied to a filament

5

What controls the quantity of electrons (mA)?

Temperature of the filament

6

What part of the cathode encases the two filaments?

Focusing/Filament Cup

7

In what part of the Cathode does the Thermionic Emission occur?

Filament Cup

8

What is the name of the positive electrode in the x-ray tube?

Anode

9

In most x-ray machines is the anode stationary or rotating?

Rotating

10

What is the reason for a rotating Anode target?

To dissipate the heat that is generated

11

What is the focal area/spot of the Anode?

The exposed area of the tungsten target

12

How is the focal spot determined?

By the size of the filament

13

What does a Smaller filament produce as an outcome?

Better Detail

14

What is it called when "The effect of making the actual focal spot size appear smaller when viewed for the position on the film"?

Line Focus Principle

15

What give you a smaller effective spot on x-ray?

Smaller target angle

16

What is the term used that "Heats the filament causing a boiling off of electrons"?

Millamperage (mA)

17

How is the term Millamperage per Second defined (mAs)?

More Current=More Electrons produced= More x-ray produced= Greater Radiographic density (Darker)

18

What is the term used for overall blackening on the film?

Density

19

What does the term Radiolucent mean?

Structures produce more blackening on the film

20

What term is used for "Structures that produce less blackening on the film"?

Radio-opaque
(Whiter on X-ray)

21

The relationship between what two components of x-ray mAs and density?

They are directly proportional

22

What is the primary way to control how black a film is?

mAs

23

If the mAs is increased what does that mean in terms of film exposure?

The film exposure time is increased

24

What is the minimum change in mAs to see a change in density on the film?

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