Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Oral Radiology > Final Exam > Flashcards

Final Exam Flashcards

1
Q

Stochastic effects

A

Cell DNA injury
No threshold
-All or non response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In stochastic effects the greater the does

A

Increases the probability of occurrence

Any amount of radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Deterministic effect

A

High amount of radiation

  • Increased cell death
  • Threshold does
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Threshold dose

A

(Deterministic effect)

Clinical symptoms apparent at any dose above threshold

Severity is PROPORTIONAL to dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 types of effects from formation of free radicals

A

Direct effects

Indirect Effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Law of Bergonie and Tribondeau

A

Radiosensitivity of different tissues

  • Amount of undifferentiated cells
  • Mitosis activity
  • Length of active proliferation

Oocytes and lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What cells have the highest radiosensitivity

A 
Lymphoid tissues
Bone marrow
Testes
Ovaries
Small intestines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The more undifferentiated the more

A

Mitosis and more radiosensitive tissue that is

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Oocytes and lymphocytes are highly _______ but very _____

A

Differentiated

Sensitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Linear Energy Transfer

A

The rate at which energy from photons is imparted as they travel through matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

High LET

A

Densely ionizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Low LET

A

Sparsely ionizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

As energy is given off

A

Different damage is done

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Absorbed Dose

A

Measure of the total energy transferred from any type of radiation to matter

rad or Gy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

100 rads =

A

1 Gy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Equivalent Dose

A

Measure of how different types of radiation affect various tissues
-Sv

Radiation sighting factor (Wr)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

1 Sv=

A

1 Gy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Effective Dose

A

Measure of estimated risk in humans
-Sv

Tissue weighting factor (Wt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Acute Radiation Syndrome

A

Whole Body irradiation

Onset is ore rapid and severity increases with greater dose

Management depends on stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Mucositis

A

Second week of therapy

Erythematous mucosa
Sloughing of the irradiated tissue
Painful
Secondary infection
Difficulty consuming food
Heals within 2 months after completion of radiotherapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Xerostomia

A

Parenchuymal cells of salivary glands are radiosensitive

Reduced salivary flow

Pain/tenderness
Difficulty chewing and swallowing
May resolve in 6-12 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Taste Loss

A

Second/third week of therapy
Reduced salivary flow my a contributing factor

Reversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Trips us

A

Inflammation and fibrosis of musculature

Limited opening 2 months after completion of radiation therapy

PT

MOM affected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Radiation Caries

A

Rampant tooth decay
-mostly due to salivary gland changes

Maintenance and compliance
-daily fluoride varnish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Impeded Tooth Development

A 
Children receiving radiotherapy
-Incompletely formed teeth
—root development
-Malformed teeth
-Tooth bud destruction
-Microdontia

Restorative procedures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Osteoradionecrosis

A

50-60 Gy

Reduction of blood supply bone remolding capacity and mineralization

breakdown of oral mucosa

Mandible>maxilla

Debridemtn
Resection
Restorative procedures
Pre-Radiotherapy clearance when possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Is radiation induced cancer a stochastic effect of radiation?

A

True; even one does of radiation can cause cancer. More doses increase risk but the end result does not change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

All electromagnetic radiation can cause carcinogneis

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

The closer to the nucleus the higher the

A

Bonding energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Highest bonding energy shell

A

K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Lowest bonding energy shell layer

A

P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Z number

A

(Atomic number)

of protons

Same number of electrons in a neutral atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

A number (Atomic mass #)

A

of P+N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The binding energy of electrons in a specific end shell is higher in an element with

A

A high Z number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

T/F Radaiton induced cancer is a stochastic effect of radiation

A

True

No threshold increase amount increases risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

T/F All electromagnetic radiation can cause carcinogenesis

A

False

Not all is the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Which electrons have highest bonding energy

A

Closer to nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Which shell is closet to nucleus

A

K shell

Klmnopq

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Z number

A

The number of neutrons protons in a neutral atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Higher atomic number (z number)

A

Higher the bonding energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Z number is the same as # of

A

Electrons in a neutral atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

A number:

A

of Protons + neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Radiation is energy in

A

Motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Radiation moves

A

In a straight line from a central point

It diverges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

If the radiation beam is further away

A

More face face would be exposed because it is divergent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Radiation can be ___ or ___

A

Electromagnetic (waves) or particulate (particles )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Radiation can be _____ or ____ radiation

A

Ionizing

Nonionizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Ionization

A

Reaction that has sufficient energy to remove electrons from atoms it encounters in its path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Wave theory

A

Radiation is propagated as waves

Electric and magnetic fields are in planes at right angles

Travel at speed low light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

How far from source do you have to be away

A

6 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

_____ wavelength has higher energy

A

Shorter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Frequency and wavelength are _____related

A

Inversely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Wavelengths

A

Distance between 2 succcesive crests or troughs

Measured in meters or angstroms (X-rays)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Frequency

A

of oscillations vibrations or cycles per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Electromagnetic radiation

A

Transfers of energy through space as a combination of electrical and magnetic fields

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Quantum theory

A

Electromagnetic radiation is considered as bundles of energy called photons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Higher frequency _______ energy

A

Higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Longer wavelength

A

Lower energy

Lower frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Ionization

A

Gaining or losing an electron

y

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Ionization occurs when

A

Occurs when particulate or electromagnetic radiation energy is greater than binding energ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Threshold for ionization

A

10e

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Types of ionizing good radiation

A

Gamma rays x rays and some UV rays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

In ionization the ejected particle

A

Is a negative ion

The remainder of atom is positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

X rays are produced when

A

velocity electrons are suddenly declarations when they pass close to the nuclei of high Z# absorbing material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

3 requirements for X-ray production

A

Electrons
High velocity of electrons
High Z number absorbing material (tungsten )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

2 mechanism of X ray production

A

Electron to nucleus

Electron to electron interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Electron to nucleus interaction

A

Bermesstrahlung radiation
-the fast voting electrons either slow down or stop when they come close to the nucleus of the atoms and part of their energy is transferred as X rays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Electron to Electron interaction

A

Characteristic radiation

Few electrons interact with tungsten target originated electrons imparting enough energy to ionize the tungsten target

When electrons displace inner shell electrons, characteristic radiation is produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Electrons have different kinetic energies

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Homogenous radiation

A

AC converted to DC

All cathode electrons will have similar KE and the resulting radiation is more homogenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Which is less radiation to patient homogenous or heterogenous radiation

A

Homogenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Long wavelength radiation have more energy compared to short wavelength T/F

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Which shell of an atom has the greatest binding energy

A

K shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

X rays are produced when high velocity atoms are suddenly decelerated when they pass close to the nuclei of high Z # absorbing material

A

False

ELECTRONS not atoms

75
Q

PID

A

Position indicating device

In the tube head

76
Q

4 conditions to produce X-rays

A

1) Production of high speed electrons
2) Separation of electrons from tungsten filament at cathode
3) concentration of electrons: electrons are negatively charged and repel each other. We need to focus them on a small region on the anode known as the target
4) Sudden stoppage of electron stream

77
Q

How to form electron cloud

A

The cathode is the source for electrons made of tungsten filament. The filament is heated at low volatile and electrons are separated from the filament

-thermionic emission

78
Q

Focusing cap

A

Focuses the negative electrons to the positive anode which then results in characteristic bremstahlngasads radiation

79
Q

Anode

A

Tungsten target covered in copper

80
Q

Tungsten target

A

High atomic number
High melting point
Low vapor pressure
Good thermal conductivity

81
Q

X ray tube

A

A glass bulb with vacuum inside it. A metal housing surrounds the tube and protects the tube from accidental damage and prevents overheating of the tube by providing a space filled with oil

82
Q

Filtering the beam

A

Beam exiting the tube has different wavelengths

Removes lower energy X ray photons

83
Q

Inherent filtration

A

The glass covering and oil in the tube contribute to stopping low energy

84
Q

Total filtration

A

Aluminum + inherent filtration

85
Q

At 50-70 kVP

A

At least 1.5 mm total filtration must be used

86
Q

Above 70 kVP

A

At least 2.5 mm total filtration is required

X ray machines rated below 60kVp should not be used

87
Q

Filtration reduces patient skin exposure

A

TRUE

88
Q

Factors controlling X-ray beam

A 
Tube voltage
Exposure time
Tube current
Filtration
Collimating
Distance
89
Q

KVP affects

A

Both quality and quantity of radiation

90
Q

Higher kVP

A

1) Increase amount of radiation

2) determine the maximum energy of x rays produced

91
Q

An increase of 15% kVP should be accompanied by

A

A reduction of on half in mAs

92
Q

An increase of 15 kVP

A

Would require having the exposure time

Decrease of 15kVp doubling the exposure time

93
Q

Low kVp leas to X-rays with

A

Longer wavelength and lower energy and so they do not penetrate much in matter

94
Q

Higher kVp

A

Increases the energy of the X-ray photons which can now travel deep in tissues/matter

95
Q

The mA or tube current of an X-ray tube affects

A

Quantity of the X-rays produced

96
Q

Exposure time of an X-ray tube affects the

A

Quantity of X-rays produced

97
Q

____ and ____ both control the quantity of X-rays produced

A

Exposure time, mA

98
Q

MAs determine

A

The total number of X-ray photons produced in the beam

99
Q

Most effective beam limiting devices

A

Collimating

Lead

100
Q

Collimating

A

To minimize the amount of radiation to patients and reduce scatter radiation

101
Q

Collimating should restrict the beam diameter to no more than

A

7 cm (2.75 in)

102
Q

The intensity of radiation varies

A

Inversely as the square of the source film distance

103
Q

X-rays that pass all the way through

A

Dark or radioluscent

104
Q

X rays that are absorbed completely

A

Radiopaque or white

105
Q

Three means of beam attentuation

A

Coherent scattering
Photoelectric absorption
Comptons scattering

106
Q

Scattering interaction

A

Photons interact with absorber atoms but then are scattered in another direction

This allows us to see the different between enamel dentin bone and soft tissues

107
Q

Coherent scattering

A

Low energy photons interact with outer electrons

The incident photons interacts with he electron in the outer shell causing it to vibrate momentarily at the same frequency as the incoming photon

108
Q

Photoelectric absorption

A

Incident photon interacts with inner e usually k

Overcomes binding energy and ejects electron

Ejected electron acquires the remainer KE
The empty spot is usually filled

109
Q

Photoelctron/recoil electron

A

Overcomes binding energy and ejects electron

110
Q

The frequency of photoelectric interaction is inversely proportional to

A

Cube of photon energy

Higher energy photons are less likely to undergo absorption

111
Q

The frequency of photoelectric interaction varies directly with the third power of

A

The atomic number of the absorber more likely with inner shells

As z number increases there is more photoelectric absorption

112
Q

The probability that a photon will be absorbed by a photoelectric interaction in bone is approximately

A

6.5 times greater than in an equal thickness of soft tissue

113
Q

Comptons scattering

A

Incident photon interacts with an outer electron

Overcomes binding energy ejects election; ejected electron acquires part of KE

Remainder of energy given off as scattered photon

Major source of scatter radiation

114
Q

Compton probability greater in

A

Bone than soft tissue

115
Q

Secondary electrons give up energy by 2 processes

A

Collisional interaction
-resulting in ionization of atom
Radiatiavie interactions
-Bremsstrahlung

116
Q

% of scattering

A

Coherent 7%
Photoelectric 27%
Compton 57%

117
Q

HVL

A

Half value layer

Thickness of an absorber such as aluminum required to reduce by one half the number of x ray photons passing through it

118
Q

Beam Attenuation: Monochromatic beam

A

A constant fraction of the beam in attenuated as the beam moves through each unit thickness of an absorber

119
Q

The absorption of the beam depends primarily on the

A

Thickness and mass of the absorber and energy of beam

120
Q

In reality beams are

A

Polychromatic beams not monochromatic

121
Q

Polychromatic beams

A

Absorption of individual photons depends on their energy

Low energy photons are much more likely to be absorbed than high energy photons

122
Q

Beam hardening

A

As an X-ray beam passes through matter the intensity of the beam decreases as quantity decreases but the mean energy of the resultant beam increases

123
Q

Collimator size

A

Round 2.75

Retrunagler 2 inches

124
Q

Best collimator

A

Rectangular collimator

125
Q

A digital image

A

Is a representation of two dimensional image as a finite set of digital values called picture elements or pixels

126
Q

Pixel values

A

Typically represent gray levels colors heights opacities etc

127
Q

Do digital save from radiation

A

Reduction compared with current standard of F speed film

Increase in number of radiographs made

Increase in the number and ease of remakes

128
Q

Digital Imaging Chain

A

Image Acquistion
Image processing
Image Dispaly

129
Q

Why go digital

A

Efficient work flow
Image enhancement
Better case acceptance
Co-diagnosis

130
Q

Wired systems

A

CCD

CMOS

(Phosphors uses plates)

131
Q

Sensors are made of

A

Silicone

132
Q

CMOS each pixel

A

Has its own transistor does not go from one well to another

133
Q

Phosphor wireless sensor

A

Sensor is made from a plastic plate coated with a phosphor material sensitive to X-ray

PSP sensor is exposed to X-ray

The image is then digitized with a special scanner

Plate must be cleared by light exposure

134
Q

Digital Detector characteristics

A

Contrast resolution
Spatial resolution
Detector latitude
Detector sensitivity

135
Q

Contrast resolution

A

Ability to distinguish different desensities in the image

136
Q

8 bit

A

2^8=256

137
Q

Spatial resolution

A

Capacity to distinguish fine detail

138
Q

Detector latitude

A

Ability of a receptor to capture a range of exposure

Full range of human tissues from Gingiva to enamel

139
Q

Detector sensitivity

A

Ability to respond to small amts of radiation

No classification standards for dental detectors yet

140
Q

Detector Quantum effeciency

A

DQE is the measure of noise and contrast expressed as a function of object detail

141
Q

Bit depth at least

A

12

142
Q

Image processing

A

To restor enhance or analyze

-image restoration
-image enhancement
—brightness contrast
—sharpening and smoothing
—-color
—Digital subtraction

143
Q

Digital subtraction

A

Two radiographs are taken with identical exposure geometry over a timer interval and superimposed

144
Q

Monitor contrast

A

1000:1

145
Q

Maxillary central incisor

A

Receptor selection:

Size 1

Sensor vertical

Entire length of bite block should be used to position the sensor back in the palate

146
Q

Mandibular anterior

A

Place the sensor flat on top of the tongue. Insert hero tally to the lower first molar region

Root he sensor into an upright position making sure the bend in the metal bar is even with the center of the nostrils

147
Q

Maxillary Posteriors

A

Retract the cheek and guide the sensor into the mouth between teeth 8 9 this is where the vault is in the palate and will give you plenty of room

Push sensor back until it is level with the desired teeth

148
Q

Mandibular Posterior

A

Retract place sensor into mouth between tongue and teeth at a 45 degree downward angle for comfort

Slide sensor back toward themolar area centering the premolar/second molar on the center of the bite tab

149
Q

Mandibular molar receptor

A

Size 2

Sensor horizontal

150
Q

Premolar or molar Bitewing

A

Size 2

Horizontal or vertical

151
Q

Overlap erro

A

Incorrect horizontal angulation

152
Q

Incisal edge not visible

A

Incorrect sensor placement

153
Q

Elongation error

A

Decreased vertical angulation

154
Q

Foreshortening error

A

Increased vertical angulation

155
Q

Cone cut error

A

X ray beam not centered on the receptor

156
Q

Blooming

A

Each pixel cell of a ccd device converts photons to electrons during exposure

Electrons oversaturate the wells

157
Q

Auto firing

A

White blank images

Caused by static

158
Q

T/F photoelectric absorption is the primary contributor to the formation of a radiopgraphic image

A

True

159
Q

It is recommend that na indivula operating a handheld x ray deveined wear a lead apron T/F

A

True

160
Q

X ray tube length

A

Increasing the X-ray source to skin distance leads to a dose reduction of 10-25%

161
Q

Reducing personal exposure

A

6 feet away at an angle of 90-135

Inverse square law

162
Q

Effective dose

A

Occupational: 20 mSv

Public: 1 mSv

163
Q

Effective dose: lens of eye

A

20 mSV

15 mSv

164
Q

Effective dose skin hands and feet

A

500 mSv

50 mSv

165
Q

Which image best visualizes periodontal bone levels

A

Bitewing

166
Q

The greater the object receptor distance, the less magnification there will be

A

False

Because the beam is diverging the further away you are the larger the image will be

167
Q

Broad radiographic examinations of the maxillofacial region

A

Images lack fine detail
Less invasive
Rapid scan time
Relatively low radiation dose

168
Q

Panoramic indications

A 
Osseous components of TMJs
Impacted teeth
Eruption abnormalities 
Pathology
Trauma
169
Q

Focal trough

A

Where beam is centered (mandible)

170
Q

Closer to the panoramic beam means the image projects

A

Higher due to slight tilt

171
Q

Ghost images

A

Always on opposite side and blurry

172
Q

Head rotation

A

Whatever side the patient head is turned toward is more magnified

The focal trough goes to the left

173
Q

If too far forward

A

Anteriors blurred

174
Q

Too far back

A

Too much mandible

175
Q

Overexposed

A

KVP to high black image

176
Q

Underexposed

A

KVP too low brigh white

177
Q

Lateral cephalmoteric skull projection

A

Evaluations of craniofacial skeletal morphology developmental growth occlusal relationships and treatment progress

178
Q

PA cephalometric

A

Evaluation of facial asymmetry and orthographic surgery

179
Q

Tongue not on palate

A

Radiolucent cant see

180
Q

Too forward

A

Blurring of anterior teeth

A lot more spine

181
Q

To far back

A

Anterior look too large

No spine

Huge mandible

182
Q

Chin tilted down

A

Exaggerated smile line

Mandibular anterior teeth look too small

183
Q

Chin elevated

A

Flat smile line

Oral Radiology (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions