Comprehensive Final Flashcards
1
Q
Natural background radiation yields what amount of exposure per year?
A
300mR
2
Q
What is the annual exposure to cosmic radiation?
A
30mR
3
Q
What is the annual terrestrial radiation exposure?
A
30mR
4
Q
What is the annual Internal radiation exposure?
A
30mR
5
Q
What is the annual radiation exposure from radon gas?
A
100-200mR
6
Q
This is a natural by product of the transmutation of the decay of uranium.
A
Radon Gas
7
Q
Radon gas only exposes which type of lung tissue and is the 2nd leading cause of lung cancer?
A
Epithelial lining
8
Q
What is the annual radiation exposure for medical X-rays?
A
60mR
9
Q
What is the annual radiation exposure to man made background?
A
40mR
10
Q
This is narrowly defined as the intensity of radiation incident upon the surface of an object.
A
Exposure
11
Q
How is exposure best detected?
A
As an ionization event in the air just above the surface.
12
Q
This is the intensity of radiation entering through the surface of the body, not the amount absorbed by the body.
A
Entrance Skin Exposure
13
Q
This is a measure of ionizations in the air and only applies to X-rays.
A
Roentgen
14
Q
This is a unit of measure of absorbed dose and applies to all types of radiation. The patients dose is usually given in this unit.
A
Rad
15
Q
What is Rad?
A
Radiation Absorbed Dose
16
Q
This is a unit of measure of dose equivalent and of biological harm.
A
Rem
17
Q
What is Rem?
A
Radiation Equivalent in Man
18
Q
Wr and Wt are related to which unit of radiation measurement?
A
Rems
19
Q
What is Wr?
A
Relative Harmfulness
20
Q
What is Wt?
A
Relative Sensitivity
21
Q
What is the relative sensitivity of bone? Organs? Marrow, Colon, Lung? Gonads?
A
Bone- .01
Organs- .05
Marrow, Colon Lungs- .12
Gonads- .20
22
Q
1R=1rad=1rem for X-rays… for neutrons? Alpha?
A
Neutrons- 10rem
Alpha- 20rem
23
Q
This is 100 ergs per gram of tissue and is independent of collimation.
A
Rad dose
24
Q
What is the dose area product formula?
A
dose*field size
25
This is defined as 1 joule of energy deposited per kilogram of tissue.
Gray (Gy)
26
What is Gy(a)? Gy(t)?
Gy-a- energy absorbed in air
| Gy-t- energy absorbed in tissue
27
What is the conventional unit of measurement equivalent to Gy(a)? Gy(t)?
Roentgen
| Rads
28
What is the SI equivalent to rems?
Sievert
29
1 gray is equal to how many rads?
100
30
In order to convert from conventional to SI what do you do? From SI to conventional?
Multiply by .01
| Divide by .01
31
This type of interaction with matter requires 10kEv or less where the incident electron enters the atom causing excitation and then exits in a new direction with no loss of energy.
Coherent Scatter (classical/unmodified)
32
This type of interaction with matter uses moderate kEv where the incident X-ray removes the inner shell electron from orbit. An outer shell electron then drops down to fill that space. The extra energy given off is in the form of secondary (characteristic) radiation.
Photoelectric
33
This interaction with matter is a major cause of pt dose as well as a major part of the image formation.
Photoelectric
34
What is the relationship to photoelectric effect and the atomic number of an atom? The photon energy?
- it is directly proportional to the atomic #^3
| - it is inversely proportional to photon energy^3
35
This type of interaction with matter occurs at higher kEv ranges with outer shell electrons with a low binding energy. When this occurs it glances off the outer shell electron giving up energy in the form of scatter.
Comptons (modified)
36
How much energy does a compton scatter retain?
2/3 the original
37
This type of interaction with matter is therapeutic occurring at 1.02mEv or greater. It is influenced by the nucleus causing the photon to disappear and in its place are 1 positron and 1 negatron.
Pair Production
38
When a positron interfaces with a negative electron what is the outcome?
Annihilation where 2 photons are produced each with .5 mEv of energy
39
This type of interaction with matter is therapeutic and occurs at 10mEv or greater. The photon penetrates the nucleus and absorbs energy causing excitation that spits out a nuclear fragment.
Photodisintegration
40
Total Effective Dose Equivalent is based on what?
Whole body dose limiting organs
41
What are the 3 limiting organs for TEDE?
1. Gonads
2. Red Bone Marrow
3. Lens of the eye
42
What is DEL?
Dose Equivalent Limits
43
This type of DEL is for long term control and if it is exceeded action is required. It is age in years * 1rem.
Cumulative Lifetime Dose Equivalent Limits
44
This type of DEL restricts dose at early ages to allow flexibility in older ages. "looking ahead". It allows 5rem/yr
Prospective Dose Limits
45
This type of DEL is most commonly for nuclear power plant workers and allows 3rem/quarter.
Retrospective Dose Limit
46
This is a dose if given to every individual will cause the same genetic effects in the population as the existing distribution of radiation.
Genetically Significant Dose (GSD)
47
What are the 5 main tissues of the human body?
1. water
2. proteins
3. lipids
4. carbohydrates
5. nucleic acids
48
What percent does water make up in the body? Proteins? Lipids? Carbohydrates? Nucleic Acids?
```
Water- 80%
Proteins- 15%
Lipids- 2%
Carbohydrates- 1%
Nucleic Acids- 1%
```
49
This type of cell generates or builds tissues for specific organs.
-Blast cells
50
This type of cell destroys particular cells that are non functional or worn out.
-Clast Cells
51
This is a small bundle of reproductive or stem cells.
Blastula
52
This is a "body" cell of regular organ tissue.
Somatic Cells -soma
53
This is a "beginning" production cell such as a sperm or ova.
Genetic Cells -genesis
54
What is Mitosis?
The phase of active division of a cell
55
What are the 4 stages of Mitosis?
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
56
In which stage of mitosis does the nucleus swell?
Prophase
57
In which stage of mitosis does the nucleus elongate, chromosomes line up in the middle, and the spindle fibers attach to the centromere?
Metaphase
58
In which stage of mitosis do the double chromosomes split and get pulled to polar ends?
Anaphase
59
In which stage of mitosis does the new cell membrane divide the cell?
Telophase
60
Which stage of mitosis shows chromosomes visibly under a microscope?
Metaphase
61
What is Interphase?
The resting phase of a cell
62
What are the 3 phases of Interphase?
1. Gap 1
2. Synthesis
3. Gap 2
63
In this stage of interphase the cell duplicates organelles but not DNA.
Gap 1
64
In this stage of interphase the cell replicates DNA and 2 chromatids become 4 for all chromosomes.
Synthesis
65
In this stage of interphase enzymes and proteins are formed in preparation for cell division.
Gap 2
66
This is the most radiosensitive stage of interphase.
Synthesis
67
The Law of Bergonie and Tribondeau states what?
The most radiosensitive cells are young, fast growing, poorly or undifferentiated cells.
68
This type of cell is one that divides more frequently and has a longer "dividing future"
Prolific
69
This is another name for a young cell.
Primitive
70
Cells that are both prolific and primitive are highly radiosensitive, what are some examples.
Blast and Stem cells
71
The minimum dose delivered at the rate of 200rad/day that will produce a response is known as what?
Relative Radiosensitivity of tissues and organs
72
This graphs the degree of biological response to increasing doses of ionizing radiation.
Radiation Response Curve
73
What are the 2 types of radiation response curves?
1. # of cases occurring within a population
| 2. severity of a particular effect on a single organism
74
A proportional relationship on a response curve is known as what?
Linear
75
When the rate of response changes at different exposures on a radiation response curve this is known as?
Non-linear
76
This is the point you can see the first response on the radiation response curve.
Threshold
77
This type of radiation response curve shows no visible point of safe exposure for which we can be sure an effect will not occur.
Non-Threshold
78
What are the 2 main concerns at diagnostic radiology levels? What is the response curve? What does this mean?
1. Genetic and Carcinogenic effects
2. Linear, Nonthreshold
3. There is no completely safe level of exposure
79
The target molecule critical to the survival of the cell describes what?
The Target Theory
80
When non target molecules take a hit from radiation it results in what?
Sub-lethal hit
81
This is an unprepared functional damage to a chromosome resulting in deactivation of a portion of the genetic code.
"hit"
82
What is the survival code for cells?
Minimum threshold dose before cells begin to die.
83
What hits are non lethal?
Single target- single hit
| Single target- multi-hit
84
What hits are lethal?
Multi target- single hit
85
This type of hit occurs from the creation from water of chemical compounds which then attack the target molecule.
Indirect
86
This type of hit has a low probability compared to Indirect hits.
Direct
87
This is ionization causing the chemical breaking down of water into various ions and free radicals.
Radiolysis of water/Hydrolysis
88
HOH+, HOH- are types of what?
Ions
89
OH+, H+ are types of what?
Free Radicals
90
What is the most damaging free radical?
Hydroxl (OH+)
91
Hydroxl causes how much damage?
2/3 of call damage caused
92
What does Hydroxl attack?
1. tRNA in the endoplasmic reticulum
| 2. DNA and mRNA in the nucleus
93
An attack of hydroxyl on the DNA and mRNA in the nucleus can result in what?
changes in genetic code and metabolism of a cell.
94
Damage to the cell membrane can occur from what?
1. Ionizing radiation damage breaching the cell membrane
| 2. toxins enter and the cytoplasms dry out causing cel death
95
The cell membrane is composed of what?
Phospholipids
96
What are the 2 parts of a phospholipid?
1 phosphate and 2 lipids
97
Phosphates dissolve in what? Lipids?
1. dissolve in water
| 2. alcohol dissolves lipids
98
What are the 3 types of Irradiation of Macromolecules?
1. Main Chain Scission
2. Cross-Linking
3. Point Lesions
99
This breaks into smaller molecules decreasing viscosity.
Main Chain Scission
100
This chain attaches at middle points increasing viscosity.
Cross-Linking
101
These can become late effects of radiation.
Point Lesions
102
What are the 3 types of damage that can occur to DNA/RNA?
1. Main Chain Scission
2. Rung Damage
3. Frame Shift Mutations
103
What occurs to the DNA if damaged by Main Chain Scission?
There is a break in the sugar phosphate "rails" of molecule structure.
104
What occurs in main chain scission if 1 side rail is severed? Both side rails severed?
- If one is severed the damage is repairable
| - If both sides are severed it is caused by a direct hit which is rare
105
What occurs to DNA if rung damage occurs? Is it reparable?
There is a break in the nitrogenous base pairs that make up the "rungs".
Reparable because they are held in place by the rails.
106
What occurs to DNA if Frame Shift Mutation occurs?
There is actual change in the sequence of genetic code. Both side rails must be broken or one rung.
107
This is any unprepared changes to genetic code. It is recessive/hereditary.
Mutations
108
What is the radiation response curve for mutations?
Linear- Nonthreshold
109
What are the 3 types of single hit chromosome aberrations?
1. Acentric
2. Dicentric
3. Translocation
110
What are the 3 types of multi hit effects to chromosomes?
1. Deletions
2. Rings
3. Cross-Linking
111
This is the energy deposited per mm or micrometer of tissue as radiation penetrates into the body.
Linear Energy Transfer (LET)
112
LET is an indicator of what?
How harmful the radiation is.
113
LET is always inverse to what?
Penetration
114
What is the most appropriate LET unit of measure is what?
Kilovolts per micron
115
What is the LET for x-rays?
3kev per micrometer of tissue
116
This is the effectiveness of a certain type of radiation in causing a specified effect or disease.
Relative Biological Effectiveness (RBE)
117
What are the typical RBE's for X-rays? 10mev protons? 5mev alpha? Particle accelerators?
x-rays- 1
protons- 5
alpha- 20
particle- 30
118
This is a dose delivered continuously at a lower dose rate. This dose over an extended period of time reduces effectiveness therefore a higher dose must be calculated to compensate enough to still destroy the tumor.
Protraction of Dose
119
This is a dose that breaks the total dose into several separated or discrete portions. Therefore allowing time in between each exposure allowing for normal tissue to recover.
Fractionation of Dose
120
Fractionation reduced the effectiveness of the radiation due to what 2 factors?
1. Extended delivery time.
| 2. Separation of dose.
121
The increased pressure of O2 enhances the production of free radicals from radiation exposure describes what?
Oxygen Enhancement Ratio (OER)
122
OER applies to which type of damage?
Indirect
123
This is a theory stating small amounts of radiation may be salutary to cell viability.
Hormesis
124
What are the 3 ways of measuring risk?
1. Epidemiology
2. Extrapolation
3. Direct Experimentation
125
This is the study of disease in a population.
Epidemiology
126
This is projecting unknown results from known data.
Extrapolation
127
What are the 3 types of risk?
1. Absolute
2. Relative
3. Excess
128
This is #of cases per million per year.
Absolute Risk
129
This is the ratio of cases compared to a control population of identical size.
Relative Risk
130
This is the # of cases beyond the moral expected in a group.
Excess Risk
131
This is a type of effect that increases in severity with increasing dose above the threshold. It is certain to occur with large doses.
Deterministic Effects
132
Deterministic Effects are which type of effect and follow which type of response curve?
early effects following a non-linear threshold curve
133
This is a type of effect that increases in probability with increasing dose while the severity is independent of the dose level. It is random measured statistically in a population.
Stochasic Effects
134
Stochastic effects occur at what dose levels? What is the response curve?
- Low dose levels.
| - Linear Non threshold
135
Stochastic effects are early or late effects?
Late Effects
