Rad Bio Exam 1 Ch 1 to 3

Acute melting of the uranium dioxide fuel of a nuclear reactor core requires how great a temperature?

Greater than 5000° F

When exposed to high radon levels in the home, which of the following groups of people have the highest risk of developing lung cancer?

Smokers

Cosmic radiation occurs in which two forms?

Solar and galactic

Compton scattering is synonymous with:

incoherent scattering.

The probability of occurrence of photoelectric absorption _________ as the energy of the incident photon decreases and the atomic number of the irradiated atoms _________.

increases markedly, increases

X-rays are a form of which of the following kinds of radiation?

ionizing

The FDA presently considers the risk of radiation exposure to the U.S. population from consumer products to be:

negligible

When spread over the inhabitants of the United States, fallout from nuclear weapons tests and other environmental sources along with other human-made radiations contributes:

only a small portion of 0.1 mSv to the equivalent dose of each person.

The amount of energy transferred to electrons by ionizing radiation is the basis of the concept of:

radiation dose

The ALARA principle provides a method for comparing the amount of radiation used in various health care facilities in a particular area for specific imaging procedures. This information may be helpful to many:

regulatory agencies

Electromagnetic radiation can travels or propogates through space in the form of a wave but can also interact with matter as a particle of energy called a photon. This dual nature is referred to as:

wave-particle duality

Which of the following radiation quantities is intended to be the best overall measure of the biologic effects of ionizing radiation?

effective dose

Which of the following provides the basis for determining whether an imaging procedure or practice is justified?

efficacy

If two anatomic structures have the same density and atomic number but one is twice as thick as the other, the thicker structure will absorb

twice as many x-ray photons

What is the term for the number of x-rays emitted per inner-shell vacancy during the process of photoelectric absorption?

Fluorescent yield

Which of the following are by-products of photoelectric absorption?

Photoelectron and characteristic photon

In a hospital setting, which of the following professionals is expressly charged by the hospital administration to be directly responsible for the execution, enforcement, and maintenance of the ALARA program?

Radiation Safety Officer

The first decay product of radium is:

Radon

Which of the following is NOT another term for coherent scattering? Characteristic Classical Elastic Unmodified

characteristic

What is the half-life of radon-220?

54.5 seconds

What is the effective atomic number of compact bone?

13.8

A flight on a typical commercial airliner results in an equivalent dose rate of:

0.005 to 0.01 mSv/hr

Which of the following statements below is true? 1. It appears that no safe dose level exists for radiation-induced malignant disease. 2.The ALARA method establishes a dose level for radiation-induced malignancy. 3. The BERT method establishes a dose level for radiation-induced malignancy. 4. The NEXT program and reference values establish a dose level for radiation-induced malignancy.

1

Why is a question about the amount of radiation a patient will receive during a specific x-ray procedure difficult to answer? 1. Because the received dose is measured in a number of different units 2. Because scientific units for radiation dose are not comprehensible by the patient 3. Because the patient should not receive any information about radiation dose

1 and 2

Which of the following sources of radiation is human-made?1. Atmospheric fallout from nuclear weapons testing 2. Cosmic radiation from the sun and beyond the solar system 3. Nuclear power plant accidents as a consequence of natural disasters

1 and 3

Diagnostic efficacy includes: 1. imaging procedure or practice justified by the referring physician. 2. minimal radiation exposure used. 3. optimal image(s) produced. 4. presence or absence of disease revealed.

1, 2, 3, and 4

Some ways of providing education for non-radiologist physicians who perform fluoroscopic procedures can include: 1. creating increased awareness of radiation dose for specific procedures through discussion. 2. establishing goals for lowering radiation dose for patients, assisting personnel, and themselves. 3. radiographers helping physicians performing fluoroscopic procedures by informing them that they have reached a specific dose, thereby giving fluoroscopists the opportunity to decide to continue or stop a procedure.

1, 2, and 3

Through which of the following routes can radon enter houses? 1. Crawl spaces under living areas 2. Floor drains and sump pumps 3. Porous cement block foundations

1, 2, and 3

Effective protective measures take into consideration: 1. both human and environmental physical determinants. 2. technical elements. 3. procedural factors.

1,2,3

The advantages of the BERT method are: 1. it does not imply radiation risk; it is simply a means for comparison. 2. it emphasizes that radiation is an innate part of our environment. 3. the answer given in terms of BERT is easy for the patient to comprehend.

1,2,3

Which of the following are required by The Joint Commission for CT? 1. Annual education of staff in dose reduction techniques. 2. Minimum qualififcations for medical physicists. 3. Documentation of CT radiation doses. 4. Management of CT protocols to minimize radiation doses.

1,2,3, and 4

The millisievert (mSv) is equal to:

1/1000 of a sievert.

Since the density of air is approximately ______ than that of soft tissue, a given volume of air will interact with far fewer x-ray photons than adjacent regions of soft tissue, thereby permitting more radiation to reach the image receptor.

1000 times smaller

What is the latent period for most radiation-induced cancers?

15 years or more

Both occupational and nonoccupational dose limits may be stated in: 1. coulombs per kilogram. 2. grays. 3. Sieverts.

3

What is the total average annual radiation equivalent dose for estimated levels of radiation exposure for humans?

6.3 mSv

Which of the following interactions results in the conversion of matter into energy?

Annihilation reaction

Which of the following is a method of explaining radiation to the public?

BERT

Why should the selection of technical exposure factors for all medical imaging procedures always follow ALARA?

Because radiation-induced cancer does not appear to have a dose level below which individuals would have no chance of developing this disease.

Which of the following is not a type of interaction between x-radiation and biologic matter?

Bremsstrahlung

Which two interactions between x-radiation and matter may result in the production of small-angle scatter?

Coherent scattering and Compton scattering

Which of the following results in all-directional scatter?

Compton

What unit is used to measure radiation exposure in the metric International System of Units?

Coulomb per kilogram

Which of the following statements concerning the 1979 nuclear reactor accident at TMI-2 is NOT true?

Excess cancer deaths have been predicted to occur in the 2 million people living within 50 miles of the plant at the time of the accident.

Terrestrial radiation includes which of the following sources?

Long-lived radioactive elements such as uranium-238, radium-226, and thorium-232 that are present in variable quantities in the crust of the earth

What is the most common unit of measure of equivalent dose?

Millisievert

Which of the following interactions between x-ray photons and matter involves a matter-antimatter annihilation reaction?

Pair production

The radiographer must answer patient questions about the potential risk of radiation exposure:

honestly and in understandable terms.

In photoelectric absorption to dislodge an inner-shell electron from its atomic orbit, the incoming x-ray photon must be able to transfer a quantity of energy:

as large as or larger than the amount of energy that binds the electron in its orbit.

Coherent scattering is most likely to occur ____________ even though some of this scattering occurs throughout the diagnostic range and may result in small amounts of radiographic fog.

below 10 keV

Radiographic density is

defined as the degree of overall blackening on a completed radiograph.

When natural sources of ionizing radiation become increased because of accidental or deliberate human actions such as mining, they are referred to as:

enhanced natural sources

Typically, people are more willing to accept a risk if they perceive that the potential benefit to be obtained is:

greater than the risk involved.

In the electromagnetic spectrum, higher frequencies are associated with:

shorter wavelengths and higher energies