Final Review Flashcards
(114 cards)
1
Q
What is the study of objects at rest and objects in motion
A
Mechanics
2
Q
What is the unit for work called
A
Joule
3
Q
What is the kinetic energy of random motion of molecules called
A
Heat
4
Q
What are the fundamental particles of an atom
A
Proton
Neutron
Electron
5
Q
The binding energies or energy levels of electrons are represented by what?
A
Electron shells
6
Q
The rate of rise and fall of a sine wave is called
A
Frequency
7
Q
Does the velocity of electromagnetic radiation remain constant?>
A
Yes
8
Q
Photons with the highest frequencies have the longest wavelengths
True or false
A
False
9
Q
What is the smallest unit of electric charge
A
Electron
10
Q
What is the unit of electric potential
A
Volt
11
Q
What is electric power measured in
A
Watts
12
Q
Fairadays experiments proved that a current could be induced by a magnetic field only if the field is changing
True or false
A
True
13
Q
In a step up transformer which side has more windings, the primary or secondary
A
Secondary
14
Q
Mechanical motion produces an electric current in the electric generator
True or false
A
True
15
Q
What are variations in power distribution to the x-ray machine corrected by?
A
Line voltage compensator
16
Q
What is the first component to receive power in the x-ray circut?
A
Auto transformer
17
Q
Which circuit provides electrons for the X-ray tube circuit?
A
Filament circut
18
Q
The high voltage transformer, the filament transformer, and the rectifiers are all part of?
A
High voltage generator
19
Q
Which part of the cycle does current flow through the X-ray tube with half wave rectification
A
The positive
20
Q
Voltage across the tube is most constant with which type of generator?
A
High frequency
21
Q
Is the filament side of the tube positive or negative?
A
Negative
22
Q
What is the filament made of?
A
Tungsten
23
Q
In the tube, where is the actual source of radiation?
A
Focal spot
24
Q
Due to the heel effect, where is the x-ray intensity lower? Anode or cathode?
A
Anode
25
Which side of the tube should be toward the thicker part of the patient?
Cathode
26
Are the staters inside or outside the glass envelope of the tube?
Outside
27
Most of the kinetic energy of projectile electrons is converted to?
Heat
28
Useful k-shell x-rays are called?
Characteristic
29
Most of the x-rays produced at the target are called
Bremsstrahlung
30
X-rays produced by slowing electrons at the target are called
Brems
31
The quantity of brems radiation increases with an increase in
mAs
32
Doubling the mAs is the equivalent to doing what to the kVp
Increasing it by 15%
33
X-ray quantity increases in direct proportion to increases in
MAs
34
If x-ray quantity is doubled what happens to optical density?
Doubles
35
Penetrability of the x-ray beam is called x-ray
Quality
36
What factors affect beam quality
Filtration
| KVp
37
What is the main purpose of added filtration
Reduce patient dose
38
When an outer shell electron is ejected, and the atom is ionized, what type of interaction has occurred
Compton scatter
39
If kVp increases does the probability of photoelectric absorption increase or decrease?
Decrease
40
There is complete absorption of the incident x-ray photon with which interaction
Photoelectric
41
Give an example of tissue with high mass density
Bone
42
What type of scatter causes image fog
Compton
43
What makes barium a good contrast agent
High atomic number
44
What is the main purpose of the gelatin emulsion in radiographic film?
Holds the silver halide crystals
45
Does direct exposure film have thicker or thinner emulsion than screen film
Thicker
46
When there is a photon interaction in the silver haylide crystal, which atoms free their electrons
Bromide and iodide
47
The latent image is made of which atoms?
Silver atoms
48
Photon interaction on film can occur from exposure to x-rays and light
True or false
True
49
Why is film made with double emulsion
Enhance film speed
50
What important development led to the 90 second processing
Polyester
51
What agent in the developer hardens film and controls emulsion swelling
Gluderaldohide
52
When are the undeveloped silver crystals removed
In the fixer
53
Film can turn brown during storage due to the retention of which agent
Ammoniumtheosulfate
54
Which agent could be depleted if the film comes out wet
Gluderaldehide
55
If we are looking at a cross section of the intensifying screen, which layer of the screen lies closer to the film
Protective layer
56
Which layer of the screen improves light emitting efficiency?
Reflective layer
57
What type of material for a period of time after stimulation
Phosphorescent
58
What is it called when a screen emits light after an exposure is terminated
Screen lag
59
The use of screen greatly increases the tube life
True or false
True
60
What does the wire mesh test check for?
Good film screen contact
61
Does high or low kVp result in more scatter
High
62
Which type of x-ray interaction contributes to the clear parts of the image
Photoelectric
63
Compton scatter contributes to the useful information
True or false
False
It contributes to image noise
64
Does scatter increase or decrease as field size increases
Increases
65
What can we do to improve contrast resolution on a large patient
Collimation
Lower kVp
Compression
66
If you lower kVp what happens to patient dose and contrast
Dose goes up and contrast goes up
67
True or false
The use of colimation improves contrast and reduces patient dose
True
68
What beam restricting device is only accurate at a fixed SID
Aperature diaphragm
69
What could be defined as the degree of difference in optical densities between areas of an image
Contrast
70
Does image contrast improve when scatter radiation is removed`
Yes
71
The amount of scatter absorption in a grid depends on
Angle of scattered photon
The height of the grid strips
Width of the inner space material
72
What is the formula for grid ratio
Height/distance
73
The purpose of a grid is to reduce patient dose
True or false
False
Purpose is to improve contrast
74
Which grid type cannot be used off focus or upside down
Focused grid
75
If you increase mAs what happens to beam quality and beam quantity
Quality stays the same and quantity increases
76
What happens to patient dose when mAs is increased from 20 to 40
Patient dose doubles
77
Beam penetrability is increased if you increase
KVp
78
3 phase image systems provide the highest beam quantity available
True or false
False
High frequency does
79
How much inherent filtration do all general purpose X-ray tubes have?
0.5 mm/al
80
What is the size range of a general purpose X-ray tubes small focal spot
.5-1mm
81
The large focal spot can provide a beam of higher quantity and unchanged quality
True or false
True
82
Name a radiolucent tissue
Lungs
83
Name a radiopauqe tissue
Bone
84
Name a medical condition that may require a lower technique
Osteoporosis
| Emphysema
85
Name a medical condition that may require a higher technique
Pneumothorax
86
When only optical density needs to be changed, what technique factor should be adjusted
Mas
87
What change in mas is needed to see a noticeable change in optical density
30%
88
What change in kvp has the same effect on optical density as doubling the mas
15%
89
What is the most commonly used technique chart
Fixed kvp
90
A veriable mas technique chart has specific mas settings for every 6cm of thickness
True or false
False
2cm
91
The benefit of the fixed kvp chart is lower patient dose
True or false
True
92
What are some factors that are important to consider when developing a technique chart
```
Patient thickness
Kvp
Ma
Sec
Sid
Grid ratio
```
93
What body habitus are technique charts based on
Sthenic
94
What type of exams are high kvp technique charts used for
Contrast studies
95
What is the most important thing to remember when using AEC
Positioning
96
With AEC when is the exposure terminated
Optimal optical density is reached
97
When using anatomically programmed radiography, the tech selects the correct mas and kvp manually
True or false
False
You select part
98
A high quality radiograph should always demonstrate high contrast
False
99
Is spacial resolution improved with decreased screen blur
Yes
100
What can be defined as the ability to image two separate objects and visually detect one from the other
Resolution
101
What portion of the characteristic curve shows film contrast
Slope
102
Where do densities above 2.5 appear on the characteristic curve
Shoulder
103
What are the best ways to minimize magnification
Increase Sid
| Decrease OID
104
How can we reduce distortion
Parallel body part
105
How does patient thickness image quality
Magnification
Contrast down
Focal spot blur
106
What is the display image that occurs in a series of rows and columns
Matrix
107
Where is the latent image in CR formed
Photostimulable phosphor
108
What happens to the CR imaging plate before it can be reused
Exposed to intense light
109
What are the mathematical formulas used for digital reconstruction of a specific exam called
Algorithms
110
Which factor sets the midpoint of densities visible on the display monitor
Window level
111
Which factor corresponds to the radiographic contrast on the display monitor
Window width
112
The ratio of image to object as a function of spacial resolution is known as
Modulation transfer function
113
What is the graphic display of the distribution of pixel value of each individual image know as
Histogram
114
What is the overall efficiency of converting the information from x-ray intensities know as
Detective quantum efficiency
