Intro To Radiography Basic Radiation (outline)

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86 terms

Energy

the ability to do work

Law of Conservation of energy

energy can be converted from one form to another but can be neither created nor destroyed

Kinetic Energy

the energy of motion

Potential Energy

energy stored due to an object's position or arrangement

Chemical Energy

energy from chemical reactions

Electrical Energy

result of an electron or electronic charge passing through an electric potential

Thermal Energy

result of atomic or molecular motion

Nuclear Energy

result of energy contained in the nucleus of an atom

Radioactive Energy

energy emitting from the nucleus

Electromagnetic Energy

an electric and magnetic disturbance traveling through space at the speed of light

Matter

Anything that takes up space and has mass.

Weight

a measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe

E=mc(2)

Einstein's equation proposing that energy has mass; E is energy, m is mass, and c is the speed of light

Radiation

the transfer of energy by waves moving through space

Irradiation

referring to matter that intercepts radiation and absorbs part or all of it; exposed

Ionizing radiation

radiation that can dislodge electrons from atoms to form ions

Man Made Radiation

medical xrays, nuclear medicine, consumer products and nuclear power are examples of what type of radiation

Naturally Occuring Radiation

-cosmic rays
-terrestrial radiation (rocks, buildings)
-inside human body
-radon in the air

300 mrem

how much radiation you are exposed to being alive per year

5 rem

Limit of rems allowed each year

Equator at Sea Level

where is the best place to live because vanhalen belts and atmosphere belts are protecting you

Somatic

pertaining to the body

Stochastic

cancer and genetic defects are examples of what

Nonstochastic

Describes biologic radiation effects that are predictable and their intensity is does-dependent. These effects occur only after a certain threshold amount of exposure has been received

Genetic

Pertains to transmitted hereditary characteristics because of radiation

ALARA

As Low As Reasonably Achievable

LET-Linear Energy Transfer

____ is a measure of the rate at which energy is transferred from ionizing radiation to soft tissue.

LD 50/30

Lethal dose for 50% of the population over 30 days

LD 50/60

the amount of radiation necessary to kill 50% of a population within 60 days

Discovery of X-ray

November 8, 1895 Wilhelm Conrad Roentgen

Radiography

Production of captured shadow images on photographic film through the action of ionizing radiation passing through the body from an external source

Fluoroscopy

procedure for viewing the interior of the body using x-rays and projecting the image onto a television screen

Potential Difference

difference in electric potential (voltage) between two points

Kilovolt

a unit of measurement equal to 1000 volts

Current

The movement of electric charge; the flow of electrons through an electric circuit.

Electricity

energy made available by the flow of electric charge through a conductor

Milliampere

1/1000 of an ampere

Exposure time

is directly proportional to the number of electrons crossing the tube and is therefore directly proportional to the number of x-rays created

Roentgen unit

c/kg
measures exposed based on ionization of air
Unit of measurement used for radiation dosage

1 Roentgen unit

2.08X10(9th) ion pairs/cm(3) equal what
2.58X10(-4) C/kg (81 unit)

mR

10(-3)R=?

Rad

radiation absorbed dose

1 Rad

10 mGy=?

1 Gray

100 rad=?

Rem

this equals Rad X QF=DE (dose equivalent)

1 Seivert (Sv)

100 rem=?

DE

This = absorbed dose X qualifying factor

Rem

Radiation equivalent man
biological absorbed dose and how damaging

1

QF for x-ray, gamma ray. and beta radiation

5

QF for thermal nertrons

20

QF for alpha particles

5

QF for slow neutrons

10

QF for medium neurtrons

20

QF for fast neutrons

Curie

a unit of radioactivity equal to the amount of a radioactive isotope that decays at the rate of 37,000,000,000 disintegrations per second

Electron Volt

A unit for expressing the kinetic energy of subatomic particles; the energy acquired by an electron when it is accelerated by a potential difference of 1 volt; equals 1.6 x 10⁻¹² erg or 23.1 kilocalories/mole (abbreviation: eV).

Unstable element

when the number of neutrons greatly out numbers the number of protons that means what?

Alpha particle

a positively charged atom that is released in the disintegration of radioactive elements and that consists of two protons and two neutrons

Beta particle

a proton or neutron that spontaneously changes itself and a new particle is created

Identity

If a particle loses a proton it changes its what

Atomic mass

If a particle loses a neutron it changes its what

Gamma

come from the nucleus of unstable atom

x-rays

produced within electron clouds

Exposure rate X time

Time exposure=?
reduce time to make low as possible

Distance

make as much of this between you and the rays as possible
(inverse square law)

Shielding/protective barriers

you do this to patients and ourselves to protect us

Primary barrier

lead in walls and under table in the central beam

Secondary barrier

helps to prevent scatter and leakage of radiation, lead doors, glass

Fixed or movable barriers

any lead that moves

Benefit over weighs risk

benefit of image should always out weigh risk of exposure

2.5 mm Al equivalent

this is what cuts down the amount of photons to parts of the body

Skin Distance

at least 15 inches between tube and skin

NCRP (national council of radiological protection)

they come up with the radiation limits for occupational dose limits, and non occupational limits

5 rem (50 mSv)

NCRP Stochastic effect (annual) for occupational is what

15 rem (150 mSv)

NCRP Nonstochastic effect for lens of eye for occupational is what

50 rem (500 mSv)

NCRP Nonstochastic effect for all other body parts other than the lens for occupational is what

1(x age in years) rem or 10(x age in years) mSv

Lifetime cumulative exposure

.5 rem for 9 months of year

pregnant worker limited by embryo/fetus dose limits

.5 rem (5.0 mSv)

NCRP Effective dose limit for infrequent exposure for nonoccupational public exposure for a year

.1 rem (1 mSv)

NCRP Effective dose limit for frequent exposure for nonoccupational public exposure for a year

1.5 rem 15 mSv

NCRP Effective dose limit for eye exposure for nonoccupational public exposure for a year

5 rem (50 mSv)

NCRP Effective dose limit for skin and extremity exposure for nonoccupational public exposure for a year

.1 rem (1.0 mSv)

NCRP Effective dose limit for trainees under 18 for nonoccupational public exposure for a year

.5 rem (5 mSv)

NCRP dose for embryo for nonoccupational for total dose

.05 rem (.5 mSv)

NCRP dose for embryo for nonoccupational for 1 month

.001 rem (.01 mSv)

NCRP dose for negligible for nonoccupational

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