homework review Flashcards
Cosmic radiation occurs in which two forms?
solar and galactic
Diagnostic efficacy includes….
- determining if an imaging procedure is justified.
- producing optimal quality images with the least radiation exposure to the patient.
- adhering to radiation safety guidelines.
- revealing the presence or absence of disease in a patient.
Of the two sources of ionizing radiation listed below, which source remains fairly constant from year to year?
Natural, human-made
natural
terrestrial radiation includes long-lived radioactive elements such as ______________ that are present in variable quantities in the _____ of the Earth
uranium-238, radium-226, and thorium-232, crust
The term as low as reasonable achievable (ALARA) is synonymous with the term
optimization for radiation protection (ORP)
What is the most common unit of measure of equivalent dose?
millisievert
Which of the following are forms of electromagnetic radiation?
1. Microwaves
2. Visible light
3. X-rays
4. Gamma rays
5. Ultraviolet radiation
all of the options
Which of the following is a method of explaining radiation to the public?
a. BERT
b. ALARA
c. NEXT
d. ORP
BERT
ALARA is important because radiation-induced cancer (does/does not) appear to have a fixed threshold, that is, a dose level below which a person would have no chance of developing this disease.
does not
true/false: after TMI-2, many 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.
false
Compton scattering is synonymous with
incoherent scattering
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
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 holds the electron in its orbit
Particles associated with electromagnetic radiation that have neither mass nor electric charge and travel at the speed of light are
x-ray pohtons
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
What are the by-products of photoelectric absorption?
photoelectron, characteristic photon
What particle is considered to be a form of antimatter?
positron
What results in all-directional scatter?
compton interactions
The x-ray photon energy required to initiate pair production is
1.022 MeV
Which of the following is not a type of interaction between x-radiation and biologic matter?
a. Photoelectric absorption
b. Bremsstrahlung
c. Compton scattering
d. Pair production
Bremsstrahlung
An ionization chamber connected to an electrometer is a device that can measure
tiny electric currents with high precision and accuracy.
Because of the OSL dosimeter’s sensitivity down to as low as 10 µSv for x-ray and gamma ray photons in the energy range 5 keV to 40 MeV, it is an excellent and practical monitoring device for
employees working in low-radiation environments and for pregnant workers.
Beta particles are actually
high speed electrons
How is the readout for a personnel direct ion storage dosimeter obtained?
Through a physical connecting device such as a universal serial bus (USB) or via wireless connection
In therapeutic radiology what SI units are now routinely used to specify absorbed dose?
Gray and centigray
Some of the advantages of the optically stimulated luminescence (OSL) dosimeter are
1. can be used for up to 1 year.
2. lightweight, durable, and easy to carry.
3. integrated, self-contained, preloaded packet.
all of the above
The whole-body TEDE regulatory limit for exposed personnel is _____________ and ______________ for the general public.
0.05 Sv, 0.001 Sv
Whenever the letter “M” appears under the current monitoring period or in the cumulative columns of a personnel monitoring report, it signifies that a (an)
equivalent dose below the minimum measurable radiation quantity was recorded during that time.
effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation defines
radiation protection
the amount of ionization produced in the air when ionizing radiation is present is known as
exposure
the degree to which the diagnostic study accurately reveals the presence or absence of disease in the patient while adhering to radiation safety guidelines defines what?
diagnostic efficacy
a millisievert (mSv) is equal to
1/1000 of a sievert
an effect radiation safety program requires a firm commitment to radiation safety by
a. imaging facilities
b. radiation workers
c. patients
1 and 2 only
the amount of radiation actually received by a patient from a diagnostic x-ray procedure may be indicated in terms such as:
a. entrance skin exposure (ESE), which includes skin and glandular dose
b. bone marrow dose
c. gonadal dose
all of the above
Why are the long-term effects, such as an increased incidence of cancer in the exposed population living near Japan’s Fukushima Daiichi Nuclear Plant, unable to be accurately determined?
it was extremely difficult to measure the amounts of radiation people received
According to the most recent available data from 2016, what is the radiation dose from natural background radiation attributed to exposure from radon and thoron?
2.3 mSv
An equivalent dose as low as 250 mSv delivered to the whole body may cause which of the following within a few days?
A substantial decrease within a few days in the number of lymphocytes or white blood cells that are the body’s primary defense against disease.
How is actual radiation dose to the global population from atmospheric fallout from nuclear weapons testing received?
It is not received all at once but instead is delivered over a period of years at changing dose rates.
As of 2016, which of the following is the total average annual radiation equivalent dose from medical, human-made, and natural radiation?
5.5 mSv per year
The Russian liquidators who worked during 1986 and 1987 at the Chernobyl power complex demonstrated a statistically significant rise in the number of:
leukemia cases
Which of the following is recognized as the main adverse health effect from the 1986 Chernobyl nuclear power accident?
Increase in the incidence of thyroid cancer in children and adolescents
The concept of tissue weighting factor (WT) is used to do what?
Account for the risk to the entire organism brought on by irradiation of individual tissues and organs
To convert the number of gray into milligray, the number of gray must be:
multiplied by 1000
What is the SI radiation unit coulomb per kilogram used to specify?
radiation exposure in the air only
What radiation quantity accounts for some biologic tissues being more sensitive to radiation damage than other tissues?
effective dose
If 100 people received an average effective dose of 0.35 Sv, what is the collective effective dose?
35 person-sieverts
How is the SI unit for dose area product (DAP) usually specified?
mGy-cm^2
When laser light is incident on the sensing material in an OSL dosimeter, the material:
Becomes luminescent in proportion to the amount of radiation exposure received
What chemical compound functions as the sensing material in a thermoluminescent ring dosimeter?
lithium fluoride
Which of the following requirements should radiation survey instruments fulfill?
- Instruments must be reliable so that radiation exposure or exposure rate in a given area can be accurately assessed.
- Instruments must be durable enough to withstand normal use.
- Instruments should interact with ionizing radiation similar to the way in which human tissue reacts.
all of the options
What instrument is used to calibrate radiographic and fluoroscopic x-ray equipment?
Ionization chamber with electrometer
For x-ray and gamma ray photons with energies from 5 keV to greater than 40 MeV, the _______ gives an accurate reading as low as 10 µSv (1 mrem).
OSL
What instrument should be used to locate a lost radioactive source or detect low-level radioactive contamination?
GM survey meter
Which of the following instruments should be used in an x-ray installation to measure the fluoroscopic scatter radiation exposure rate?
cutie pie
