UNIT 1: ch. 2 Radiation Types, Sources and Doses Received

describe non ionizing radiation

(low-energy ultraviolet radiation, visible light, infrared rays, microwaves, and radio waves) does not have sufficient kinetic energy to eject electrons from atoms.

describe ionizing radiation

(x-rays, gamma rays, and high-energy ultraviolet radiation [energy higher than 10 electronvolts]) can transfer sufficient energy to some orbital electrons to remove them from the atoms to which they were attached.

what is the purpose of the term dose?

-Attempts to put into numerical value the harmful effect of the biologic harm produced by different types of radiation -Enables the calculation of the effective dose (EfD) -

what are manmade sources of radiation? (look at summary in ch. 2)

-Consumer products containing radioactive material -Air travel -Nuclear fuel for generation of power -Atmospheric fallout from nuclear weapons testing -Nuclear power plant accidents (TMI-2 and Chernobyl) -Nuclear power plant accidents as a consequence of natural disasters (Fukushima Daiichi)

the amount of radiation received by a patient from diagnostic x-ray procedures may be indicated in terms of?

-Entrance skin exposure (ESE), which includes skin and glandular dose -Bone marrow dose -Gonadal dose -In a pregnant women, fetal dose also may be estimated.

The amount of radiation received by a patient from diagnostic x-ray procedures may be indicated in terms of what? (tables 2-5 and 2-6)

-Entrance skin exposure (ESE), which includes skin and glandular dose -Bone marrow dose -Gonadal dose -In pregnant women, fetal dose also may be estimated.

what are alpha particles made up of?(potential test question)

2 protons and 2 neutrons

In 2006 that number had increased to blank mSv, an increase of more than a factor of blank.

3.0 msv; 5

what is Radons half life?

3.825 days

Medical use now makes up how much of total background radiation.

48 percent

describe beta particles

8000 times lighter than alpha particles and have only one unit of electrical charge (-1) as compared with the alpha's two units of electrical charge (+2).

what is dose?

A radiation quantity used for radiation protection purposes when a person receives exposure from various types of ionizing radiation"

which of the particles (alpha or beta) are less penetrating?

Alpha particles are less penetrating than beta particles (fast electrons).

what is a neutron?

Are the electrically neutral components of an atom Have approximately the same mass as a proton

what makes patient dose variable?

Because of the large variety of radiologic equipment and differences in imaging procedures and in individual radiologist and radiographer technical skills, the patient dose for each examination varies according to the facility providing imaging services.

what are protons? (potential test question)

Positively charged components of an atom Have a relatively small mass that, however, exceeds the mass of an electron by a factor of 2800

how does biologic damage occur?

Produced by ionizing radiation while penetrating body tissues primarily by ejecting electrons from atoms composing the tissues

what radiation is part of the electromagnetic wave?( test question)

Radio waves Microwaves Infrared Visible light Ultraviolet X-rays Gamma rays

what are the four types of electromagnetic waves?(potential test question)

Radio-waves Micro-waves Visible light X-rays

EPA has deemed this as the 2nd leading cause of lung cancer in USA? 1st?

Radon; Smoking

how do subatomic particles cause ionization?

They possess sufficient kinetic energy to be capable of causing ionization by direct atomic collision

what can stop an alpha particle?

a piece of paper

If one of these combinations of Z protons and so many neutrons leads to an unstable nucleus, then that combination is called?

a radioisotope

what can humans control? why?

artificial sources to protect the general population from further biologic damage

the subatomic particles are ejected from atoms how?

at very high speeds

Number of protons in the nucleus of an atom constitutes its what( potential test question)

atomic number (z number )

Identical to high-speed electrons except for their origin

beta particles

what radiation contributes to life time dose?

both sources

if emitted from a radioisotope deposited in the body (such as the lungs) alpha particles can what

can be absorbed in the relatively radiosensitive epithelial tissue and are very damaging to that tissue. (i.e. RADON gas)

To reduce the possibility of occurrence of genetic damage in future generations, the increase in frequency of radiation exposure in medicine must be

counterbalanced by limiting the amount of patient exposure in individual imaging procedures.

-With electromagnetic waves: blank and blank fluctuate rapidly as they travel through space. (potential test question)

electric and magnetic fields

The full range of frequencies and wavelengths of electromagnetic waves

electromagnetic spectrum

how are both occupational and nonoccipational dose limits expressed? (test question)

expressed as EfD and may be stated in Sievert (Sv).

The number of medical procedures involving ionizing radiation has blank dramatically since the 1980s, when the previous NCRP Report was published.

increased

If two atoms have the same number of protons but a different number of neutrons in their nuclei, they are referred to as ?

isotopes

what type of energy is radiation energy?

kinetic

High-Speed Electrons that are Not Beta Radiation Produced in a radiation oncology treatment machine called a what

linear accelerator

what falls under nonionizing radiation?

lower energy ultraviolet radiation, visible light, infrared rays, microwaves and radiowaves

results from the use of diagnostic x-ray machines and radiopharmaceuticals in medicine.

medical radiation exposure

what are the sources of radiation?

natural and manmade

do all types of radiation produce damage?

no

what is radiation?

refers to kinetic energy that passes from one location to another and can have many manifestations. This means that many types of radiation exist

what can alpha particles be described as? (potential test question)

simply as helium nuclei (i.e., helium atoms minus their electrons)

what risk is considered in the case of reproductive organs?

the risk of genetic damage is considered.

Because EfD includes all of the organ weighting factors, it represents?

the uniform whole-body dose that would give an equivalent biologic response or chance of cancer.

describe how alpha particles are virtually harmless

they lose energy quickly as they travel a short distance into biologic matter like superficial layers of the skin.

what falls under the category of ionizing radiation?

x-rays, gamma rays, high energy ultraviolet radiation (higher than 10 electronvolts)

Increases in Medical Radiation Exposure since the 1980s to the U.S. Population resulted from what?

-Resulted from increased use of imaging modalities such as CT and cardiac nuclear medicine examinations -Ionizing radiation exposure of the population of the United States

In NCRP Report No. 93, medical radiation was estimated to contribute blank mSv to manmade background radiation.

0.54mSv

what happens if alpha particles are interalized?

As an internal source of radiation, they can be very damaging.

has tremendous medical benefit in the diagnosis of disease and trauma, and that risk-to-benefit ratio is still very small when these examinations are ordered for appropriate reasons.

CT

what are positives about ionization?(potential test question)

Conversion of atoms to ions Makes tissues valuable for creating images

what are the two largest sources of artificial radiation?

Diagnostic medical x-ray (which includes computed tomography [CT] scanning, interventional fluoroscopy, and conventional radiography or fluoroscopy) nuclear medicine procedures

what are alpha particles?(potential test question)

Emitted from nuclei of very heavy elements such as uranium and plutonium during the process of radioactive decay

correlates the absorbed dose in biologic tissue, applies only to ionizing types of radiation. (potential test question)

Equivalent dose (EqD

what is particulate radiation?

Form of radiation that includes alpha particles, beta particles, neutrons, and protons.

what are negatives of ionization?(potential test question)

Has the undesirable result of potentially producing some damage in the biologic material

describe the mass of an alpha particle (potential test question)

Have a large mass (approximately 4 times the mass of a hydrogen atom) and a positive charge twice that of an electron

what radiation can we not control?

Humans are unable to control natural background radiation

what is the result of destructive radiation at the atomic level?

Molecular change Cellular damage Organic damage (see Table 2-2 in textbook)

who does reports on medical radiation?

NCRP (national council on radiation protection and measurements)

ionization does NOT occur when?

No ionization occurs when the subatomic particles are at rest.

what does EfD (effective dose) take into account?

Takes into account the dose for all types of ionizing radiation (e.g., alpha, beta, gamma, x-ray) to various irradiated organs or tissues in the human body (e.g., skin, gonadal tissue, thyroid). -Take into effect the different body parts.

what are examples of natural radiation? (test question)

Terrestrial radiation (e.g., radon, thoron) Cosmic radiation (solar and galactic) Internal radiation from radioactive atoms (also called radionuclides)

what is the SI unit of equivalent dose?

The SI unit of EqD is the Sievert (Sv).

what is kinetic?

The ability to do work—that is, to move an object against resistance

what are beta particles capable of penetrating?

Therefore, they are capable of penetrating biologic matter to a greater depth than alpha particles.

what are the high speed electrons that are not beta radiation used to do?

To treat superficial skin lesions in small areas To deliver radiation boost treatments to breast tumors at tissue depths typically not exceeding 5 to 6 cm.

what is the main reason for the increase in usage of CT? (table 2-4)

With the advent of multislice spiral CT, the utility of this imaging modality in areas such as emergency medicine has increased dramatically. In 1980, use of CT resulted in a collective dose of 3700 person-sieverts. In 2006, that number rose to 440,000 person-sieverts according to NCRP Report 160.

how can radon gas enter your house? (potential test question)

can percolate up through soil and enter a home through holes or cracks in its framework, crawl spaces under the living areas, floor drains, sump pumps, and porous cement block foundations. Spaces behind brick veneer on top of block foundation. pores and cracks in concrete block foundation.open top of block foundation walls. floor to wall joints. cracks in concrete floor.exposed soil as in basement sump. weeping drain tile draining into open sump.mortar joints.loose-fitting pipe wall penetration.well water from some wells., building materials such as stone

what is manmade radiation?

created by humans for specific purposes

what can the electromag. spectrum be divided into?

ionizing radiation and nonionizing radiation

what does "dual nature of electromagnetic radiation ( wave particle duality)" mean? (potential test question)

is radiation that can travel as a wave and interact with matter

The amount of energy transferred to electrons by ionizing radiation is the basis of the concept of (potential test question)

radiation dose

describe natural radiation

radiation that is always present in the environment

the electromagnetic spectrum can be divided into how many parts?

two

what is the mechanical vibration of materials? ( test question )

ultrasound