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Front 1

Name the types of Ionization Radiation

Back 1

1. Particulate Radiation
Source: disintegration of the nucleous of radioactive atoms. Particles travel through space as alpha or beta particles

2. Electromagnetic Radiation
Source: gamma rays originates from disintegration of the nucleus of radioactive atom. X-rays originate from X-ray tube production. Gamma and X-ray travel through space at the speed of light and have no mass or charge.

Front 2

The amount of exposure an individual receives depends on 4 factors:

Back 2

1. type of radiation

2. amount of radiation received

3. length of time exposed

4. specific parts of the body
exposed.

Front 3

Absorption
(absorbed dose)

Back 3

the interaction between the x-ray photons and the living mtter resulting in energy transfer

Front 4

Attenuation

Back 4

>any process thatprevents X-ray photons from reaching the patient or the radiographic film.

> absorption & scatter (loss of intensity) of the x-ray beam as it passes through the patient.

Front 5

Coherent (Classical/Thompsons)
(Type of Interactions)

Back 5

1. Coherent(Classical/Thompsons)
-produced by low-energy
X-ray photons
-electrons not removed but
vibrate
-emit energy equal to the
incoming photon
-non-ionization

Front 6

Photoelectric
(Type of Interactions)

Back 6

-photon absorption interaction
-incoming X-ray photon strikes K-shell electron
-vacant hole in K-shell is filled by electrons from outer shells releasing energy w/c creates low-energy characteristic photons
-this type of interaction results in increased patient ration dose

Front 7

Compton (Modified Scattering)
(Type of Interactions)

Back 7

-scatter of X-ray photons in the atoms of the body

-incoming x-ray photon strikes a loosely bound, outer shell electron

X-ray photon transfers part of its energy to the electron

- electron is removed form orbit as a scattered electron

- ejected electrons may ionize other atoms or recombine with an ion needing an electron

- photon scatters in another direction w/less energy

-compton scatter radiation does not contribute to the diagnostic image rather it cases radiographic film fog & requires uf of lead shieling for protection o foperator and patient

Front 8

Pair Production

Back 8

Ionization does not occur but the photon has scattered

Does not occur in diagnostic radiography

Involves an interaction between the incoming photon and the nucleus of the atom

Front 9

Cell

Back 9

is the basic component of all living organisms.

Front 10

Cell has 3 Basic Parts

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1. membrane-permeable sustance to pass into and out of the cell

2. cytoplasm-watery substance inside the cell

3. nucleus-separated from the cytoplasm by a doubled wall membrane.

Front 11

What is RNA and DNA

Back 11

RNA=Ribonucleic Acid

DNA = Deoxyribonucleic

Front 12

What are the 2 types of cell division

Back 12

1. Mitosis - cell divides to form two cells.Occur in 5phase
interphase,prophase,metaphase,
anaphase & telophase

2. Meiosis-reduction division

Front 13

Law of Bergonie & Tribondeau

Back 13

1. Radiosensitivity varies inversely with the degree of cell differentiation - immature, nonspecialized cells are the most radiosensitive

2. Radiosensitivity varies direlty with the level of metabolic activity

3. Radiosensitivity varies directly with the rate of cell proliferation-rapidly growing or dividing cells are more radiosensitive.

Front 14

Linear Energy Transfer (LET)

Back 14

is the unit of measurement of the amount of the avearage energy deposited in tissue per unit of track or path length

This concept is important in determining potential biologic tissue damage from ionizing radiation.

Front 15

Stochastic Effects

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1. randomly occurring effects of radiation.

2. the probability of such effects is proportional to the dose (increased dose equals increased probability, not severity of effects.

Front 16

Nonstochastic Effects

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1. effects that become more server at high levels of radiation exposure

2. do not occur below a certain threshold dose

Front 17

Linear-nonthreshold relationship

Back 17

1. no level of radiation can be considered completely safe.

2. a response occurs at every dose

3. the degree of response to exposure is directly propotional to the amount of radiation received

Front 18

Linear-threshold relationship

Back 18

1. lower doses of radiation exposure (to the left of the line intersecting the x-axis), no response is expected

2. when threshold dose is exceeded the response is directly proportional to the dose recd.

3. Example, cataractogenesis does not occur at low levels of radiation exposure: therefore there is a threshold dose below w/c cataractogenesis will not occur

Front 19

Nonlinear-threshold

Back 19

1. indicates that at lower doses of radiation exposure (to the left of the curve intersecting the x-axis), no response is expected

2. when that threshold dose is exceeded the response is not directly proportional to the dose received and is increasingly effective per unit dose

Front 20

Nonlinear-nonthreshold relationship

Back 20

1. indicates that no level of radiation can be considered completely safe

2. a response occurs at every dose

3. the degree of the response is not directly proportional to the dose received

4. the effect is large even with a small increase in dose.

Front 21

Direct Effect

Back 21

photons hits DNA in the cellular nucleus

Front 22

Indirect Effect

Back 22

photons hits water molecules in the cytoplasm of a cell

Front 23

Radiolysis

Back 23

occurs when a water molecule is ionized resulting in free ions capable of recombining with other free radicals to form new molecules.

Front 24

Biologic Effects

Back 24

Short-term or long term effects

Front 25

Short Term Effects

Back 25

are found in the ARS (Acute Radiation Syndrome) w/c includes but is not limited to gonadal dysfunctions, epilation (hair loss), depression of the WBC and even death. (happens quickly)

Clinical signs/symptoms:
nausea, vomiting, diarrhea, anemia, leukopenia, hemorrhage, fever, infection, & shock

Front 26

Long Term Effects or late effects

Back 26

of radiation may result from small doses of radiation received over a number of years or latent period

Ex: local tissue effects, chromosomal changes, cataracts, life span shortening

Front 27

Somatic Effects

Back 27

refers to effects of radiation on the body being irradiated

appear w/in minuters, hrs, days or weeks after initial radiation exposure to the
ex. hematopoietic sysndrome, gastrointestinal sysndrome & CNS

Front 28

Late somatic effects

Back 28

those that appear after a period of months or years after initial exposure. May resuld from an intiail high dose of radiation taht caused early acute symptoms, and ultimately repair and recovery or chronic low level doses of radiation recd over long time period. ex: carcinogenesis

Front 29

4 Major Areas to reduce radiation exposure for patient?

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1. patient preparation
2. primary-beam limitation
3. gonadal shielding
4. technical factors

Front 30

ALARA

Back 30

As low as resoanably achievable

Front 31

Occupational Personnel
1.Effective Absorbed dose equivalent limit
2. Lens of eye
3. all other organ, systems, tissue

Back 31

Annual Dose Equivalent

1. 50 mSv (5 rem)
2. 150 mSv (15 rem)
3. 500 mSv (50 rem)

Front 32

Non-Occupational(General public)

1. Continuous or frequent exposure
2. infrequent exposure
3. lens eye,skin,&extremities

Back 32

Annul Dose Equivalent

1. 1 mSv (0.1 rem)
2. 5 mSv (0.5 rem)
3. 50 mSv (5 rem)

Front 33

Education & training exposures

1. Effect absorbed dose equivalent limit

2. Lens eye, skin&extremities

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Annual Dose Equivalent

1. 1 mSv (0.1 rem)
2. 50 mSv (5 rem)

Front 34

Embryo-Fetus Exposures

1. Total dose equivalent limit to term

2. Dose equivalent limit in a month

Back 34

Annual Dose Equivalent

1. 5 mSv (0.5 rem)
2. 0.5 mSv (.05 rem)

Front 35

3 Cardinal Principle of Ratiation Protection

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TDS

T=Time
D=Distance
S=Shielding

Front 36

Protective Apparel

Back 36

Lead apron - 0.5 mm lead
gloves .25 mm lead

Front 37

Various cells - in order of diminishing sensitivity

Back 37

1. Lymphocytes or WBC
2. Erythrocytes or RBC,granulocytes
3. Epithelial cells
4. Endothelial cells
5. Connective tissue cells
6. bone cells
7. muscle cells
8. nerve cells
9. brain cells

Front 38

Most frequently occurring radiation-induces cancers include in descending order of susceptibility

Back 38

1. female breast
2. thyroid gland (especially in women & young children)
3. hemopoetic tissue
4. lungs
5. gastrointestinal tract
6. bones