Brainscape's Knowledge GenomeTM

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


See full index

SEM III - Radiation Biology > Radiation Protection/exposure Reduction > Flashcards

Radiation Protection/exposure Reduction Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
0
Q

Time

A

Minimizing the amount of time spent in the vicinity of the ionizing radiation source

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

The 3 cardinal rules for protection of personnel

A

Time

Distance

Shielding

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

Distance

A

Maximize the distance between your body and the source of ionizing radiation

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

Shielding

A

Interpose as much shielding material as possible between your body and the source of ionizing radiation

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

Two types of fixed barriers

A

Primary protective barriers

Secondary protective barriers

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

Primary protective barriers

A

Areas exposed to direct impact of the primary X-ray beam (up to 140 KVP). Requires 1/16 inch lead or equivalent and must extend up to a height of 7 feet from the floor.

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

Secondary protective barriers

A

Areas exposed to scattered and leakage radiation only. Require 1/32 inch lead or equivalent. Plaster or concrete ca. Serve as a secondary barrier.

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

Secondary protective barrier - control booth

A

X-rays must scatter at least 2 times before hitting the control booth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Secondary protective barrier - observation window

A

Obtained in lead equivalencies from .3-2mm. Average glass lead window consists of 1.5 mm lead.

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

Secondary protective barrier - miscellaneous protection

A

Exposure cord short enough so exposure is only possible when radiographer in the booth. Walls must be 7feet high and mounted to the floor. Door should be interlocked with control panel so it cannot be opened.

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

Protective tube housing

A

X-ray tube enclosed by a lead metal covering serves to reduce leakage radiation to an assigned safe level. Required shielding being approximately 1.5mm lead.

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

Leakage from X-ray tube housing should not exceed

A

100mR/hr at 3 feet or 1 meter.

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

During radiography and fluoroscopy procedures at 1 meter from the patient, beam intensity is reduced by a factor or 1000 or .1% the original beam intensity.

A

Yup.

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

Barrier thickness depends on the distance between radiation source and barrier.

A

The greater the distance between radiation source and barrier the less lead needed for the barrier.

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

Barrier thickness factors

A

Time of occupancy

Workload - radiation capacity - max KVP/mAs

Use - % of time beam is on

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

Time of occupancy factor

A

The amount of time a hospital area is occupied by people

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

Occupancy factors - 2 types

A

Controlled

Uncontrolled

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

Controlled area

A

Area occupied by radiation personnel
Occupancy factor of 1
Meaning radiation workers are always present

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

Uncontrolled area

A

Area occupied by the general public

Designated as full, partial or occasional

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

Uncontrolled occupancy

A

Stairways, unattended elevators, outside areas. Factor depends on use of the area.
Hallways - factor of 1/4
Unattended elevators - 1/16

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

Controlled area require barriers to reduce the exposure rate to less than 100 mrem/week

A

Yup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Uncontrolled area

A

Require barriers to reduce exposure rate to less than 10mrem/week.

Uncontrolled walls have 1/10 value layer of lead compared to controlled wall.

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

Workload depends on

A

Radiation level activity in that room, the more exams, the thicker the barrier.
Accounts for weekly average tube current and operating time, measured in milliampere minutes/week.

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

Workload for small office

A

Less than 100 mA-min/week

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

Workload for hospital

A

500 mA-min/week

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

Use factor

A

Percentage of time X-ray beam is energized and directed to a particular wall.

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

NCRP recommendations for use factor

A

Primary wall barriers and floor barriers - use factor of 1

Non primary wall -use factor of 1/4

Secondary barriers - user factor of 1

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

Secondary barrier

A

Struck only by scatter radiation from patient.

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

The primary barrier is located

A

Any wall which the primary beam is directed

Minimum 1/16 of an inch of lead equivalent

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

Secondary barrier is located

A

On any wall against which only scatter or leakage impacts (control console)

Minimum 1/32 of an inch lead equivalent.

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

Barriers do not have to be lead

A

But they must absorb X-rays as well as the lead equivalent. Examples are concrete, steel, brick, drywall, wood, glass, even air.

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

Barrier height must be at least

A

7 feet high.

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

Control console walls and leaded glass are

A

Secondary barriers and should never receive the primary beam

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

With modern X-ray rooms that have flexible mobile buckeys and image receptors

A

Every wall becomes a potential primary barrier

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

Why lead?

A

All matter attenuated X-ray energy
Lead is very efficient
High atomic number of 82 - 82 electrons per atom
X-ray interacts with electrons.
More electrons in the path of an X-ray means an increased probability of interaction.

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

Why lead 2?

A 
Plentiful
Cheap
Low melting temperature
Malleable
Inert
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

There’s nothing magical about lead…

A

Lead does not attract X-rays, electrons just get in the way of X-rays, absorbing energy.

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

Leaded sterile gloves

A

Lead protects from scatter radiation only, does not protect hands from primary X-ray.

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

If you can see phalanges on the C-arm monitor than the fingers

A

Are being penetrated

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

Leaded glasses

A

Prevent X-ray energy to the lens of the eye, reduce cataract formation

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

Lead gloves

A

To be used when required to place hands in or near the primary beam

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

Thyroid collar

A

Protect Thyroid tissue amongst the more radio sensitive tissues of the body

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

Leaded barriers see through barrier

A

Leaded glass

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

Leaded barriers - solid barriers

A

Come in mobile or fixed barriers

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

Lead underwear

A

Protect reproductive organs for both male and female.

Keep radiation IN - brachytherapy of prostate.

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

Protective garments contain

A

Lead due to high atomic number and absorbs most scattered photons.

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

Shields evaluated by half value layers (HVLs) - which refers to

A

Lead thickness that will reduce the intensity of radiation to 50%

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

Lead aprons are lead impregnated with vinyl or rubber, their thickness

A

Should be .25, .5 and 1 mm lead equivalencies.

When facing the primary X-ray beam approximately 3/4 of the body’s active bone marrow is covered.

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

Maternity aprons need to be a minimum

A

.5mm lead equivalent.

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

Lead gloves

A

Used for personnel when hands are in the beam.

Minimum lead equivalency of .25mm

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

Thyroid shield

A

Primarily used during fluoroscopy

Minimum lead equivalency of .5mm.

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

Mobile exams

A

Effective communication and assessment necessary, clear and protect all persons in area, announce X-ray loud/clear.

Distance oneself from patient and remember inverse square law.

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

A mobile unit switch should allow the technologist to obtain a distance of

A

At least 6 feet from the patient.

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

Fluoroscopic exams

A

Lead apron should be at least .5 mm if lead equivalent. The primary source of exposure is the patient.

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

The highest energy scatter occurs at a

A

90 degree angle to the incident beam.

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

Bucky slot cover - fluoroscopic exams

A

Located at gonad level, lead shield must cover this slot, strips of lead rubber form a drape between the patient and radiologist (absorbs a majority of the scatter).

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

Deadman switch - fluoroscopic exams

A

Fluoroscopic exposure switch, usually a foot pedal or hand switch only emits radiation when constant pressure is applied

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

Source to table top distance for mobile fluoroscopic exams must be a minimum

A

Of 12 inches for mobile fluoro units.

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

Source to tabletop distance for fixed fluoroscopic units is

A

15 inches

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

Total filtration of the fluoroscopic equipment must be at least

A

2.5mm aluminum equivalent.

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

Image intensifier component (primary barrier) lead equivalent must be

A

2mm

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

Cumulative timing device

A

Creates audible signal after 5 minutes of fluoro

Timer resets after 5 minutes and resets after each exam.

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

Fluoroscopic X-ray intensity at tabletop must not exceed

A

10R/min

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

High level control fluoroscopy (HLCF) must not exceed

A

5R/min

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

The radiologist should be trained to use intermittent or pulsed fluoroscopy

A

And should also Collimate to the area of interest only

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

Inverse square law

A

The intensity of radiation at a given distance from a source is inversely proportional to the square of the distance of the object from the source.

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

Inverse square law (2)

A

As distance from source goes down, your exposure goes up

As distance from source goes up your exposure goes down

I1/I2 = D2^2/D1^2

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

When involuntary motion is a factor

A

Use short exposure time and a high mA
Use positioning aides (sponges, sandbags, tape, etc)
Explain why immobilization is being used!

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

Holding of patients

A

Radiographer is last choice
- wear a lead apron, thyroid shield, gloves, glasses, etc

NO DH - designated holder

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

When X-ray enters matter one of three things will happen

A

X-ray energy will pass through without interaction

X-ray energy will be absorbed by matter

X-ray energy will be redirected due to interaction

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

An X-ray is a shadow image - a shadow is formed by

A

Energy absorbed, and energy passing through and around

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

Radiations to consider

A 
Primary
Secondary
Scatter
Remnant
Leakage
Off-focus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Primary radiation is sometimes referred to as

A

The useful beam.

Radiation produced in the X-ray tube

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

The focal spot is the “s” in the term

A

“SID”

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

Secondary radiation

A

X-ray produced at a point other than the focal spot of the anode, produced in the patient by classical/coherent interactions and photoelectric interactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Scatter

A

Redirected primary - produced in the tube

76
Q

Secondary

A

A brand new X-ray produced in patient

77
Q

Scatter radiation

A

Redirected primary beam radiation due to interaction with matter (Compton, collision)

The patient is the source of scatter.

78
Q

Effects of scatter

A

Increase in patient dose, tech dose.
Degradation of image quality - unwanted density
Decrease in image contrast - useless grays

79
Q

Remnant radiation

A

Portion of primary beam that survives the trip through the patient, passes through without interraction, good for the image formation.

80
Q

How can an X-ray pass through a solid object?

A

Bohr atom theory

  • mini solar system
  • mostly empty space
  • X-ray weaves through matter, sometimes without hitting anything
81
Q

Off focus radiation

A

X-ray produces at points of the anode other than the true/focal spot

82
Q

2 sets of lead shutters

A

A high set and a low set, dramatically decrease off focus radiation

83
Q

Leakage radiation

A

X-ray that escapes the tube housing at a point other than the tube window.

Must be less than 100mR/hr at 1 meter

84
Q

Radiation survey equipment is used to detect and measure ionizing radiation, two types:

A

Geiger-Muller aka Geiger counter - electrical conduction of inert gas within the detection chamber

Ionization Chamber Survey Meter aka cutie pie - ionization of air within the detection chamber

85
Q

Occupational Exposure Annual Dose Limits - whole body

A

5 rem (50mSv)

86
Q

Occupational Exposure Annual Dose Limits - lens of eye

A

15 rem (150 mSv)

87
Q

Occupational Exposure Annual Dose Limits - skin/extremities

A

50 rem (500 mSv)

88
Q

Occupational Exposure Annual Dose Limits - Whole body cumulative

A

Age x 1rem (age x 10 mSv)

89
Q

Occupational Exposure Annual Dose Limits - Fetus (nine month)

A

.5 rem (5mSv)

90
Q

Occupational Exposure Annual Dose Limits - Fetus (one month)

A

.05 rem (.5 mSv)

91
Q

Occupational Exposure Annual Dose Limits - Student less than 18 years of age

A

.1 rem (1mSv)

92
Q

Annual dose limits public exposure - infrequent exposure

A

.5 rem (5mSv)

93
Q

Annual dose limit public exposure - frequent exposure

A

.1 rem (1 mSv)

94
Q

ALARA

A 
A - as
L - low
A - as 
R - reasonably
A - achievable
95
Q

As patient exposure goes up…

A

Image quality goes up

96
Q

X-ray is…

A

Bundles of pure energy in transit through space, undetectable to human senses.
No mass, no charge, speed of light, waveform movement

97
Q

Characteristics of X-ray

A

Energy in transit through space (electromagnetic energy). Created on demand, polyenergetic, divergent, Isotropic, interacts with matter at the level of the atom.

98
Q

X-ray begins and ends with

A

Electrons

99
Q

The X-ray technologist controls

A

When X-rays are created (exposure switch)
The strength of X-rays created (KVP adjustment)
How many X-rays are created (mAs adjustment)
For how long the X-rays are crated (exposure timer)

100
Q

3 things for X-ray production

A

Source of free electrons (thermionic emission of the filament)
Acceleration of free electrons (application of KV)
Abrupt halting of high speed electrons (tungsten target)

101
Q

Reducing patient dose can be done by adjusting the following

A 
Filtration
Collimation
Shielding
High KVP/low mAs techniques
Beam projection
Motion control (voluntary/involuntary)
Get it right the first time (positioning/technique)
102
Q

Why filter the X-ray beam?

A

To selectively remove weaker X-rays that cannot penetrate patient and cannot contribute to image formation.

103
Q

Beam filtration is rated in

A

Aluminum equivalency - anything between the focal spot and the patient (glass, oil, plastic, mirror, air, etc)

104
Q

Federal guidelines require a minimum filtration of at least

A

2.5 mm Al/eq (aluminum equivalency).

105
Q

Inherent filtration

A

Built into tube and housing

106
Q

Added filtration

A

Between the housing and the patient

107
Q

Total filtration

A

Inherent + added

108
Q

Collimation

A

Controlling the size and shape of the beam, minimizing the amount of tissue irradiated.

109
Q

Shielding

A

All persons all the time, especially radiation sensitive tissues.

110
Q

Blood is the most sensitive body system.

A

Yup.

111
Q

Technical factors that are within the techs control

A 
KVP selection
MAs selection
Exposure time
Digital speed class
Grid selection
112
Q

Traditionally KVP has been used to control

A

Contrast

This is the dominant control factor with film/screen imaging

113
Q

With digital imaging

A

KVP is less critical to image contrast.

KVP can be increased while maintaining high contrast.

114
Q

As KVP increases, MAS decreases

A

To maintain image density (15%rule)

115
Q

MAs is the number of X-rays in beam

A

As mAs does down, patient dose goes down

116
Q

Fewer X-rays =

A

Less dose

117
Q

KVP is the photon strength in the beam

A

As KVP goes up patient does goes down

As KVP increases average X-ray strength increases.

118
Q

Stronger X-rays are more likely to pass through the patient, an X-ray that passes through

A

Does not deposit energy into tissue

119
Q

With digital imaging, KVP no longer

A

Controls contrast but is still needed for penetration of part.

120
Q

CR speed class controls

A

Size and speed of the laser

121
Q

DR speed class controls

A

Sampling rate of data

122
Q

As speed goes down, patient dose

A

Goes up

123
Q

Slow imaging speed

A

Requires an increase in mAs - increased dose

124
Q

Use of a grid

A

Requires an increase in mAs - increased dose

125
Q

Low KVP/high mAs

A

To establish high contrast/to minimize quantum mottle

Requires an increase in mAs - increased dose

126
Q

Increased SID

A

Requires an increase in mAs

Though not necessarily increased patient dose.

127
Q

Benefits of a higher ratio grid

A

More scatter absorbed

Higher contrast

128
Q

Benefits of a lower ratio grid or no grid at all

A

Lower mAs can be used - lower patient dose

Greater latitude - fewer grid errors/repeats

129
Q

Drawbacks of higher ratio grid

A

More mAs required - higher patient dose

Lower latitude -more grid errors/repeats

130
Q

Drawbacks of lower ratio or no grid

A

Less scatter absorbed

Loss of contrast - image can be very gray

131
Q

ESE

A

Entrance skin exposure

132
Q

AP vs PA projection

A

Radiation sensitive tissues tend to be anterior

  • thyroid
  • lens of eye
  • gonads
  • intestinal linings
133
Q

Maximum dose occurs where the

A

Beam enters the body

Attenuation results in decreased exposure

134
Q

Attenuation

A

Partial absorption and partial transmission of X-ray energy as it passes through matter

135
Q

Motion control

A

To minimize the risk of repeat exposure.

136
Q

Voluntary motion

A

Within control of the patient - wiggling, talking, breathing.

Best controlled by clear instruction.

137
Q

Involuntary motion

A

Not within the patients control - heartbeat, peristalsis, pulsation of vessels.

Best controlled by short exposure time.
Immobilization - as required.

138
Q

Patient immobilization

A

Use positioning aids (sandbags, sponges, straps, tape, etc)

Explain why immobilization is required! - especially to parents when a child is the patient

139
Q

Radiographs can only be performed on the

A

Order of a physician or licensed practitioner.

Evaluate and question orders as needed, be the expert.

140
Q

Understanding which tissues are sensitive is important to

A

Take special care to protect those tissues.

141
Q

The least mature and least specialized cells, high reproductive activity, and the longest mitotic phase as the most

A

Radiation sensitive cells

142
Q

Bergonie and Tribondeau discovered that

A

Discovered that radio sensitivity is a function of the metabolic state of the cell receiving the exposure.

143
Q

The law of Bergonie and Tribondeau states

A

The radio sensitivity of cells is directly proportional to the reproductive activity and inversely proportional to their degree of differentiation

144
Q

Stem cells are

A

Undifferentiated cells and are not yet specialized, these tend to be very sensitive to radiation.

145
Q

Lymphocytes are the most

A

Radiation sensitive tissue of the body.

146
Q

The hematopoietic system is the most

A

Radiation sensitive of all body systems.

147
Q

Radiation impact upon the circulatory system

A

Reduce the body’s ability to protect and heal itself,
decrease the number of blood cells in the bone marrow,
reduce the number of cells in circulation

148
Q

Radiation primarily affects

A

Immature erythrocytes

  • red bone marrow
  • stem cells for the hematopoietic system
149
Q

Once mature, erythrocytes are

A

Much less radio sensitive

150
Q

Erythrocytes

A

Red blood cells. - carry gasses within the blood

151
Q

Thrombocytes

A

Lifespan of only 30 days

Initiate clotting and prevent bleeding

AKA platelets

152
Q

Epi/endothelial tissue

A

Cells found in/on body, in lining of intestines, respiratory tract, pulmonary alveoli, lining of blood and lymphatic vessels.

Single cell thick, transport of materials across linings - short life span

153
Q

Because epi/endothelial tissue/cells are constantly regenerating

A

They are considered to be highly radio sensitive

154
Q

Crypt cells

A

Stem cells to produce spit helical and endothelial tissues

155
Q

Spermatogonia

A

Male genetic cells, both mature and immature exist within the male testes.

156
Q

Oocytes - ova

A

Female genetic cells that exist both maturely and immaturely in the female ovary. Genetic damage can occur is an irradiated ova is fertilized.

157
Q

Embryo-fetus nervous tissue

A

More radio sensitive than adult nerve cells.

158
Q

Embryo nervous tissue is most sensitive

A

8-15 weeks after gestation.

A lower risk exists until 25 weeks.

159
Q

Radioinsensitive cells

A 
Muscle
Nerve
Bone
Cartilage
Tendons
Ligaments
160
Q

Radium watch dial painters

A

1920-30’s

161
Q

Uranium miners, Navajo

A

1950-60’s

162
Q

Early medical radiation workers

A

1896-1910’s

163
Q

Thorotrast patients

A

1925-1945

164
Q

Infant thymus gland patients

A

1940-50’s

165
Q

Marshall Islanders

A

1954

166
Q

Hiroshima/Nagasaki

A

1945

167
Q

Chernobyl

A

1986

168
Q

Fukushima daiicchi

A

2011

169
Q

Natural radiation

A

Aka background

Cosmic
Terrestrial
Internal

170
Q

Man made radiation

A

Artificial

CT scanning
Nuclear medicine
Fluoro/X-ray
Consumer products, occupational/industrial

171
Q

Electromagnetic interaction

A

Charged particles influencing atoms/molecules

172
Q

The simplest way to ionize matter is to

A

Remove an electron

173
Q

In the X-ray room there are two sources of ionizing radiation to consider

A

The X-ray tube - primary created on demand

The patient - scatter production

174
Q

We protect ourselves and others from

A

Scatter

175
Q

When X-ray enters matter one of three things will happen

A

Pass through without interraction

Will be absorbed by matter

Will be redirected due to interaction

176
Q

What is scatter

A

Redirected primary beam radiation caused primarily by Compton interactions with tissue proceeding isotropically, carries NO anatomical info.

177
Q

Scatter is useless density into the image/receptor and also known as

A

“Veil of gray”

178
Q

Scatter variables - scatter produced dependent on…

A

X-ray beam field size - as area of tissue irradiated^ scatter^

Thickness of tissue irradiated - as thickness^ scatter^

Composition of tissue irradiated - lower density tissue scatters more and absorbs less

Kiliovoltage - as KVP^, scatter^

179
Q

Our job as imaging techs is to

A

Minimize the production of scatter

Minimize the impact of scatter on the radiograph

Using the tools of collimator and grid

180
Q

The primary tools used for minimizing scatter are

A

The collimator - minimize production of scatter

The Grid - minimize the impact of scatter

181
Q

Image gently - the society for pediatric radiology

Their goal:

A

To raise awareness in the imaging community of the need to adjust radiation dose when imaging children

182
Q

People are not one size fits all - X-ray technique should not be either

A

Use size appropriate settings for children and adults

183
Q

Image wisely is a combined effort of the

A

ACR - American college of radiology
PSNA - radiologic society of North America
AAPM - American association of physicists in medicine
ASRT - America society of radiologic technologist

184
Q

Image wisely goal

A

To address concerns about the surge of public exposure to ionizing radiation from medical imaging. To lower the amount of radiation used in medically necessary imaging studies, and to eliminate unnecessary procedures.

185
Q

Repeat analysis

A

What must be recorded and analyzed is which exam, why, who…

Not meant to be a witch hunt, the goal is patient safety and to minimize patient dose by minimizing repeats

186
Q

Rad techs are not just button pushers, they consider

A

Patient size
Patient condition
Patient pathology
Patient cooperation

All of these should be considered when imaging and should adjust setting to accommodate these factors.

187
Q

The dose creep phenomenon

A

Dose creep is when overexposure is purposefully done to obtain an optimal image in digital. Only under exposing will not provide an optimal image so why not overexposed ever time?

188
Q

We can fight dose creep by…

A

Understanding our systems exposure indicators and continuously evaluate exposure indicator values.

Use a high KVP and low mAs - as long as quantum mottle is under control.

SEM III - Radiation Biology (8 decks)

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