Radiation Protection Unit 1

What is defined as “the transfer of kinetic energy form on location to another?”

radiation

radiation is a form of _____ waves. These waves consist of fluctuating ____ and ____ fields.

electromagnetic, electric, magnetic

Any phenomenon that can be measured in an orderly broad range of values is called a?

spectrum

The full range of frequencies and wavelengths of EM waves is called the?

electromagnetic spectrum

radio waves have ____ wavelengths, ____ frequencies, and ____ energy.

high, low, low

Xrays have ___ wavelengths, ____ frequencies, and ____ energy.

low, high, high

All forms of EM radiation travel at the speed of ____. Which is?

light, 3×10^8 m per sec

Who accidentally discovered X-rays in 1895 leading to the learning of its benefits and destructive power?

whilhelm Conrad roentgen

The discover happened when he was experimenting with cathode rays and ____ materials.

fluorescent

Cases of ____ from X-rays were reported in Europe as early as 1896

somatic damage

When xrays pass thru matter and interact with atoms they are capable of ____ electrons from their orbit. This produces electrically charges particles called ____ The atom and ejected electron form an ____. X-rays are considered ____ radiation.

ejecting, ions, ion pair, ionizing

What is defined as “removal of an orbital electron from an atom resulting in a positively or negatively charged state?

ionization

List the possible consequences of ionization in human cells.

-injury to cell that may manifest as abnormal function or loss of function

-creation of unstable atoms

-production of free electrons

-production of low energy X-ray photons

-creation of highly reactive free molecules capable of producing substances poisonous to the cell (free radicals)

-creation of new biological molecules which are detrimental to the living cell

On the electromagnetic spectrum ___, ___, and ___ are considered ionizing radiation

ultraviolet, xrays, gamma rays

On the electromagnetic spectrum what energy ionizing radiation have?

10 eV

List the fundamental properties of xrays

-xrays are invisible

-xrays have varying degrees of penetration in normal tissue

-although visible light may be focused. with a lens, xrays cat be

-xrays travel in straight lines and at the speed of light until they interact with atoms

-when passing thru matter xrays will produce charged particles by interactions with atoms

-xray beams generally contain a wide range of energies

particulate radiation includes:

-alpha

-beta

-neutrons

-protrons

with particulate radiation, subatomic particles are ejected from the ___ of atoms at ___ speeds.

nucleus, very high

Particle that has two protons and 2 neutrons and is harmless as an external source of radiation but damaging as an internal source

Alpha

---

particles are 8000 times lighter than alpha particles and are capable of penetrating biological matter to a greater depth than alpha particles

beta

Rank radiation form least to most penetrating

alpha, beta, xray, gamma ray, neutron

If xrays enter human tissue they may

-(absorption) interact with atoms of biologic matter and be ____

-interact with atoms of biological matter and be ____

-Pass thru ___ interaction. We call this ___ radiation

absorbed, scattered, exit (image formation)

The reduction in number (or intensity) of primary photons in the xray beam thru absorption and scatter is called:

attenuation

Within the body the ___ a structure attenuates radiation the ___ it will appear on the image and the ___ a structure attenuates radiation the ___ it will appear on the image.

less, darker, more, lighter

What two xray interactions in matter are we most concerned about in diagnostic radiology?

photoelectric absorption and Compton scattering

with photoelectric absorption the photon hits an atoms ___ shell electron and gets completely absorbed.

The photon has lost al of its ___ and ceases to ___.

Since all the photons energy is absorbed the displaces electron becomes a ___.

The photoelectron gets ____ by the body which results in increased ___.

Structures in the body that absorb more xray will appear ___ on an image. Structures that contain air will appear ___ on the image.

inner energy, exist, photoelectron, absorbed, patient dose, lighter, black

during Compton scattering an xray photon interacts with a _______ of an atom.

The photon spends ___ of its kinetic energy to eject the electron from orbit ___ the atom

The photon continues on its way but in a ___ direction and with ___ energy.

Those scattered xrays contribute to ___ dose.

Because of Compton scattered xrays we must wear ___ if we are in th room when xray is ___.

If a scattered xray reaches the imaging receptor by indirect transmission it can add ___ to the image.

loosely bound outer electron, some, ionizing, new, lower, occupational, protective lead shielding, active, radiographic fog

ionizing radiation produces ____ mainly by ___ electros from atoms of tissues.

biologic damage, ejecting

Atomic level damage leads to ___ changes which leads to ___ damage.

molecular, cellular

Excessive cellular damage can cause significant ___ or ____ changes.

genetic, somatic

Somatic effects are categorized as either ___ or ___.

early, late

Genetic effects are effects on ___ due to irradiation of ___ cells

future generations, reproductive

With early tissue reactions as radiation dose ___ the severity of the tissue reactions also ___.

increases, increases

Early tissue reactions have a ____ or a point at which they begin to appear

threshold

Do we normally deal with early tissue reactions within diagnostic radiology?

no

Late tissue reactions are similar to early tissue reactions but may take __ to fully manifest.

Result of ___ developing changes to body tissue.

months, slowly

Stochastic (probablistic) effects are describes as ___ or ___ biological changes from irradiation.

mutational, randomly occurring

With stochastic effects the ____ of occurrence is proportional to the dose of radiation. These effects are ___ of dose

chance, indépendant

Since stochastic effects are considered late ___ effects they may occur months or ___ after radiation exposures.

somatic, years

Stochastic effects include:

cancer, genetic effects, cataracts, atrophy, fibrosis

why are stochastic effects relevant within diagnostic radiology?

any level of dose could cause these effects; there is no safe dose

Assistant to Thomas Edison, _____ was the first American radiation fatality in 1904

clarence madison daly

The amount of radiant energy absorbed by an irradiated object (per unit mass) describes the term:

dose

Absorbed dose refers to the amount of kinetic energy that has been ___ in a material due to its interaction with ionizing material.

Measured in units of ___ more commonly used in units of ___

absorbed, gray (Gy), milligray (mGy)

Equivalent dose is used to predicts actual ___ caused by radiation.

Accounts for the ___ of ionizing radiation absorbed by the body since the degree of ___ interactions vary for different types of radiation.

In diagnostic radiology the radiation absorbed is ___ but exposure to natural background radiation involves ____ radiation.

Measured in units of ___ more commonly ___.

biological harm, type, tissue, xrays, particulate, seiverts (Sv), millisieverts (mSv)

Besides the type of radiation another factor in determine actual biological harm from ionizing radiation is the ___ being irradiated.

organ

Effective dose (EfD) is the best estimate of ___ from radiation in human tissue.

overall harm

EfD is often referred to as the ___ dose.

whole body

EfD considers both the ___ of radiation and the ____ irradiated.

type, part of the body

EfD is measured in

sieverts; millisieverts

Terrestrial radiation is from ___ materials in the crust of the ___.

radioactive, earth

What percentage of natural background radiation exposure comes from the gases radon and thoron?

37%

Radon:

behaves as a ___ floating around in the soil

natural flow of air can draw radon gas into lower levels of ___

Always in the air and can be inhaled into ___

EPA considers radon to be ___ leading cause of lung cancer.

free agent, homes, air, lungs, 2nd

How many cancer deaths are caused by radon every year?

20,000

Average US resident equivalent dose of Radon?

2.0 mSv per year

Cosmic radiation comes from the ___ and beyond the solar system.

sun

The greatest intensity of cosmic radiation on Earth can be found at ___

increased altitudes and on planes

Cosmic radiation consists mostly of ___

high energy protons

Average US resident EqD of cosmic radiation

0.3 mSv per year

When we travel on airplanes we get in closer contact with high energy ___ radiation

cosmic

What occurrences on the sun play a role in increasing cosmic radiation exposure?

sun spots and solar flares

10 hours on a plane during normal sunspot activity is equal to?

1 chest xray

Solar flares can increase dose by

10-100 times

Internal radiation is from ___ in our body from various ___ or inhaled particles in the ari

radionuclides, food

What is a radionuclide

unstable nucleus that emits 1 or more forms of ionizing radiation to become stable

Avergage us resident EqD of internal radiation

0.7 mSv per year

Combined EqD of background radiation

3 mSv per year

Average US resident EqD of nuclear power plants

0.1 mSv per year

Why can’t accurate estimates of EqD from nuclear fallout be made?

actual radiation measurements for this do not exist

Actual radiation dose from fallout is delivered over a ___ at ___ dose rates.

period of years, changing

What nuclear event in history released only 15 curies of radiation into the air?

Three Mile Island

The Chernobyl power plant accident released ___ times more radiation into the air than three mile.

significant

The two largest sources of manmade radiation comes from ___ and ___ which accounts for ___ of the collective EfD of the US population. This increase is due to ___.

diagnostic xray radiation, nuclear medicine exams, 48%, CTs

Average Us resident receives EfD of ___ per year from medical radiation.

3.2 mSv

Total average EfD from manmade and natural background radiation?

6.2 mSv

What is an added benefit of the team approach in healthcare?

increased radiation safety

List the good practices that all rad techs and radiologists should follw

-educated in safe operation of xray producing equipment

-use protective devices whenever possible

-follow established protocols

-select xray machine settings that significantly reduce radiation exposure to patients and themselves

What is defined as effective measures employed by radiation workers to safeguard patients personnel and general public from unnecessary exposure to ionizing radiation?

radiation protection

We fulfill our ongoing responsibility to ensure radiation safety during all exams by following an established _____

radiation protection program

Radiation safety is legally considered a ___ for our profession

standard of practice

What organization governs our code of ethics?

American registry of radiologic technologists (ARRT)

When illness or injury occurs or when a health screening is necessary the patient may elect to assume a relatively ___ risk to obtain essential diagnostic information.

small

A diagnostic study that accurately reveals the prescnce or abscence of a disease is considered to have?

This provides the basis for determining when an imaging exam is ___

diagnostic efficacy, justified

who is directly responsibly for the execution enforcement and maintenance of a radiation safety program?

radiation safety officer