Ch. 1-4 Book Review Questions
How does radon affect epithelial tissue of the lungs in humans?
After Radon is inhaled, the radioactive gases and decay products produce daughter radioactive isotopes that give off alpha radiation that injures lung tissue, risk of lung cancer.
When inhaled, how is Radon more dangerous than Thoron?
After Radon is inhaled, the radioactive gases and decay products produce daughter radioactive isotopes that give off alpha radiation that injures lung tissue, risk of lung cancer.
What level of radon does the EPA recommend to stay below?
Less than 4pCi/L
What are the effects of ionizing radiation?
May cause injury or damage to biological tissue.
How many homes does EPA estimate goes over the 4pCi/L amount?
1 in 15 homes
What instrument can be calibrated to read air karma?
A standard or free-air Ionization chamber
What is a solar flare?
A tremendous explosion of the surface of the sun.
The radiation weighting factor for alpha particle is 20, and tissue weighting factor for the lungs is 0.12. If the lungs receive an absorbed dose of 0.2Gy, from alpha particles, what is the effective dose in sievert? A. 0.48Sv B.4.8Sv C.48.0Sv D.480.0Sv
A. 0.48Sv
A decrease in contrast of the image by adding an unwanted additional exposure (radiographic fog) results from which of the following interactions between x-radiation & matter? 1. Compton scattering 2. Pair production 3. Photoelectric absorption A. 1 only B. 2 only C. 3 only D. 1, 2 & 3
A. 1 only
Optimization for radiation protection (ORP) is synonymous with the term: A. As low as reasonably achievable (ALARA) B. Background equivalent radiation time (BERT) C. Effective dose (Efd) D. Diagnostic efficacy (DE)
A. ALARA
Which of the following define attenuation? A. Absorption and scatter B. Absorption only C. Scatter only D. Weakened only
A. Absorption and scatter
The concept of tissue weighting factor (Wt) is used to which of the following? A. Account for the risk to entire organism brought on by irradiation of individual tissues and organs B. Eliminate the need for determining effective dose C. Measure absorbed dose from all different types of ionizing radiations D. Modify the radiation weighting factor for different types of ionizing radiation
A. Account for the risk to entire organism brought on by irradiation of individual tissues and organs
In which of the following x-ray interactions with matter is the energy of the incident photon partially absorbed? A. Compton B. Photoelectric C. Coherent D. Pair Production
A. Compton on encountering the electron, the incoming x-ray photon surrenders a portion of its kinetic energy. photoelectric absorbs all kinetic energy, coherent doesn't have enough energy and pair production requires too much energy.
Which of the following characteristics primarily differentiates the probability of occurrence of the various interactions of x-radiation with human tissue? A. Energy of the incoming photon B. Direction of the incident photon C. X-ray beam intensity D. Exposure time
A. Energy of the incoming photon
Which of the following processes is the foundation of the interaction of x-rays with human tissue? A.Ionization B.Linear acceleration C. Particle emission D. Radioactive decay
A. Ionization
How can a flight on a typical commercial airliner result in radiation exposure for a passenger?
Airliners being in high elevation comes closer contact with the high energy cosmic radiation. Sunspots are increased electromagnetic field activity that are responsible for ejecting particulate radiation and contribute to an increase to radiation dose to passenger and airline crew.
What type of radiation is used in Positron emission tomography (PET)?
Annihilation Radiation
The Russian liquidators who worked during 1986 and 1987 at the Chernobyl power complex demonstrated a statistically significant rise in the number of : 1. Breast cancer cases 2. Leukemia cases 3. Prostate cancer cases A. 1 only B. 2 only C. 3 only D. 1,2 &3
B. 2 only
If 100 people received an average effective dose of 0.35Sv, what is the collective effective dose? A. 17.5 person-sieverts B. 35 person-sieverts C. 70 person-sieverts D. 285 person-sieverts
B. 35 person-sieverts (ColEfD) is # of people x average effective dose= person-sieverts
A radiation weighting factor (WR) has been stablished for each of the following ionizing radiations: x-rays (WR=1) fast neutrons(WR=20) alpha particles (WR=20) What is the total equivalent dose in sieverts fo a person who has received the following: 0.2Gy of x-rays, 0.07Gy of fast neutrons and 0.3Gy of alpha? A. 9.4Sv B. 7.6Sv C. 4.3Sv D. 1.9Sv
B. 7.6Sv
An equivalent dose as low as 250mSv delivered to the whole body may cause which of the following in a few days? A. An increase in number of lymphocytes in the circulating blood B. A substantial decrease within a few days in the number of lymphocytes or WBC that are the body's primary defense against disease C. A drop immediately to zero in the lymphocyte count D. A large increase in the number of platelets
B. A substantial decrease within a few days in the number of lymphocytes or WBC that are the body's primary defense against disease
Which of the following is a method that can be used to answer patient's questions about the amount of radiation received from a radiographic procedure? A. ALARA Concept B. BERT C. BRET D. EPA
B. BERT
In the radiographic kilovoltage range, which of the following structures undergoes the most photoelectric absorption? A. air cavities B. Compact bone C. Fat D. Soft tissue
B. Compact bone appears most white on the radiographic image
If a child receives a dose of radiation in a CT scan where adult protocols are used, the child, because of being smaller in size, will receive a: A. Lethal dose of radiation B. Higher effective dose than would an adult, but the image produced will be of acceptable quality C. Lower effective dose that would an adult, and the image produced will be of acceptable quality D. Severe radiation burns
B. Higher effective dose than would an adult, bu the image produced will be of acceptable quality
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? A. After the tsunami, winds carried all the radiation back out to sea B. It was extremely difficult to measure the amounts of radiation people received. C. Radiation from the crippled reactors was negligible D. Radiation levels exceeded the reading scales on the instruments used to measure population exposure
B. It was extremely difficult to measure the amounts of radiation people received.
Exit, or image-formation, radiation is composed of which of the following? A. Primary photons and wide-angle Compton scattered photons B. Non-interacting and small-angle scattered photons C. Very low energy photons D. Auger electrons
B. Non-interacting and small-angle scattered photons
When a high atomic number solution is either ingested or injected into human tissue or a structure to visualize it during an imaging procedure, which of the following occurs? A. Photoelectric interaction becomes greatly decreased, resulting in an increase in the absorbed dose in the body tissues or structures that contain the contrast medium. B. Photoelectric interaction becomes significantly enhanced, leading to an increase in the absorbed dose in the body tissues or structures that contain the contrast medium. C. Photoelectric interaction becomes greatly decreased, resulting in a decrease in absorbed dose in the body tissues or structures that contain contrast medium D. Photoelectric interaction becomes significantly enhanced, leading to a decrease in the absorbed dose in the body tissues or structures that contain the contrast medium.
B. Photoelectric interaction becomes significantly enhanced, leading to an increase in the absorbed dose in the body tissues or structures that contain the contrast medium. increases due to the high atomic number of barium, this will increase the photoelectric interaction but also increase PT dose, the body tissue is absorbing more.
Which of the following are natural sources of ionizing radiation? A. Medical x-radiation and cosmic radiation B. Radioactive elements in the crust of the earth and in the human body C. Radioactive elements in the human body and a diagnostic x-ray machine D. Radioactive fallout and environs of atomic energy plants
B. Radioactive elements in the crust of the earth and in the human body
Which of the following was used as the first measure of exposure for ionizing radiation? A. Air kerma B. Skin erythema C. Sievert D. Roentgen
B. Skin erythema
What were the black spots in digital images seen in some hospitals attributed to from the Fukushima Daiichi nuclear plant disaster?
Black spots were attributed to radioactive particulate fallout from the accident.
How can BERT method be used to help eliminate a PT's fears about medical radiation exposure?
By comparing the medical radiation exposure in terms of what a pt is normally exposed to natural background of radiation in specific periods.
Why should the ALARA philosophy be established and maintained as a main part of every health care facility's radiation safety program?
By doing so these actions will reduce doses to PTs and personnel.
The millisievert (mS) is equal to: A. 1/10 of a sievert B. 1/100 of a sievert C. 1/1000 of a sievert D. 1/10,000 of a sievert
C. 1/1000 of a sievert
According to the most recent available data, what percentage of natural background radiation exposure comes from Radon and Thoron? A. 10 B. 29 C. 37 D.48
C. 37%
Which of the following contributes significantly to the exposure of the radiographer? A. Positrons B. Electrons C. Compton scattered photons D. Compton scatted electrons
C. Compton scattered photons the photons from the PT can expose personnel whoa re present in the room to scattered radiation.
How is actual radiation dose to the global population from the atmospheric fallout from nuclear weapons testing received? A. It is received all at once within a short period of tine after such a test B. It is received in large quantities within a period of 2 years after such a test C. It is not received all at once but instead is delivered over a period of years at changing dose rates D. No fallout from such testing is ever received.
C. It is not received all at once but instead is delivered over a period of years at changing dose rates
Which of the following unit of collective effective dose (ColEfD)? A. Coulombs per kilogram-sievert B. Gray-sievert C. Person-sievert D. Rad-sievert
C. Person-sievert
Effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation define: A. Diagnostic Efficacy B. Optimization C. Radiation Protection D. Reference Values
C. Radiation Protection
What is the SI radiation unit coulomb per kilogram used for? A. Equivalent dose B. Absorbed dose in biologic tissue C. Radiation exposure in air only D. Speed at which x-ray photons travel
C. Radiation exposure in air only
The interactions of x-ray photons with any atoms of biologic matter are: A. Able to be preplanned to selective atoms to limit radiation exposure to those atoms B. Important only in therapeutic radiology C. Random, so the effects of such interactions cannot be predicted with certainty D. Unimportant in diagnostic radiology, thus making radiation protection unnecessary
C. Random, so the effects of such interactions cannot be predicted with certainty
Monitoring and reporting of PT dose for CT and IT procedures can lead to: A. An invasion of PT privacy B. An increase in PT radiation dose C. A reduction in PT radiation dose D. Elimination of the need for imaging equipment radiation safety features
C. a reduction in PT radiation dose
How is the SI unit for dose area product (DAP) usually specified? A. Coulomb B. Erg-sec C.mGy-cm^2 D.Sievert
C.mGy-cm^2
Define the term effective atomic number (Zeff)
Composite Z valley weight for a material that is composed of multiple chemical elements
What interactions between x-radiation and matter occur within diagnostic radiology range?
Compton scattering and photoelectric absorption. -Compton scattering are responsible for most of scattering, directed forward as small angle scatter, rear as back scatter, the various directions of scatter is a major factor in medical imaging exposure, major factor for protection for medical imaging. -Photoelectric absorption is the most important mode of interaction between x-rad. and atoms of PT body. This interaction is responsible for PT dose and contrast in image.
What are the consequences of ionization in the human cell?
Creates an unstable atom Produce of free electrons produce low energy photons creates free radicals, produces poisonous substances in the cell creation of new biological molecules detrimental to the living cell injury to cell, manifests to abnormal or loss of function
An effective radiation safety program requires a firm commitment to radiation safety by: 1. Facilities providing imaging services 2. Radiation workers 3. Patients A. 1 & 2 only B. 1 & 3 only C. 2 &3 only D. 1,2 & 3
D. 1, 2 & 3
The amount of radiation actually received by a patient from a diagnostic X-ray procedure may be indicated in terms such as: 1. Entrance skin exposure (ESE) 2. Bone Marrow dose 3. Gonadal dose A. 1 &2 B. 1 &3 C. 2&3 D. 1,2 &3
D. 1, 2 & 3
Which of the following influences attenuation? 1. Effective atomic number of the absorber 2. Mass density 3. Thickness of the absorber A. 1 &2 only B. 1&3 only C. 2 &3 only D. 1, 2 & 3
D. 1, 2 & 3 attenuation occurs because of absorption and scattering. the higher the atomic number the more it will absorbed it will increase interaction, thicker the absorbent the more it will absorb and density too.
PT may elect to assume a relatively small statistical risk of exposure to ionizing radiation to obtain essential diagnostic medical info when: 1. illness occurs 2. injury occurs 3. a specific imaging procedures for health screening purposes is prudent A, 1 &2 only B. 1 &3 only C. 2 &3 only D. 1,2 & 3
D. 1,2 & 3
Which of the following is the total average annual radiation equivalent dose from manmade and natural radiation? A. 1.8mSv per year B. 3.0mSv per year C. 3.2mSv per year D. 6.3mSv per year
D. 6.3mSv per year
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 which term: A. Radiation protection B. Radiographic pathology C. Effective diagnostic D. Diagnostic efficacy
D. Diagnostic efficacy
Which of the following radiation quantities accounts for some biologic tissues being more sensitive to radiation damage than other tissues? A. Absorbed dose B. Exposure C. Equivalent dose D. Effective dose
D. Effective dose
The amount of ionization produced in the air when ionizing radiation is present known as: A. Absorbed dose B. Effective dose C. Efficacy D. Exposure
D. Exposure
Which of the following is recognized as the main adverse health effect from the 1986 Chernobyl nuclear power accident? A. Increase in the incidence of leukemia in adults B. Increase in the incidence of leukemia in children C. Increase in the incidence of thyroid cancer in adults D. Increase in the incidence of thyroid cancer in children and adolescents
D. Increase in the incidence of thyroid cancer in children and adolescents
To convert the number of gray into milligram. the number of gray must be: A. Divided by 100 B. Divided by 1,000 C. Multiplied by 100 D. Multiplied by 1,000
D. Multiplied by 1,000 ex 0.010Gy x 1,000=10mGy
Why do human bones appear lighter in completed diagnostic imaging?
Densities and atomic numbers have an affect on absorption, the more dense the tissue the more it will appear as white, from the photoelectric absorption. Compact bones have effective atomic number and greater mass density.
Explain the use of the radiation quantity "equivalent dose" (EqD)?
Equivalent dose provides an overall dose value that includes the different degrees of tissue interaction that could be caused by different types of radiation. Used in diagnostic radiology by absorption of x-rays, but exposure to radioisotopes in the environment, or radioactive materials released from nuclear plants.
When a person receives exposure from various types of ionizing radiation, what radiation quantity and what SI unit should be used?
Equivalent dose, use Sievert (mSv)
What radiation quantities are currently in use, and what SI units are used to relate these quantities?
Exposure of ionization of air SI unit C/kg Coulombs per kilogram Air Kerma uses quantity (J/kg) joules per kilogram and SI unit Gy Absorbed dose amt of energy per unit mass absorbed by irradiated object. SI unit Gy Equivalent dose average absorbed dose in a tissue or organ and specific type of radiation Sievert is the SI unit Effective dose the type of radiation and sensitivity of organ, or organ system SI unit sievert
What is the goal of the Alliance for Radiation Safety in Pediatric Imaging?
First goal to raise awareness among non radiology users, then raise awareness of need for dose reduction protocols by promoting pedi scan protocols for both radiology and non radiology users of CT.
What is Image Wisely & Image Gently Campaign?
IWC- lower the amt of radiation used medically, by eliminating unnecessary procedures. IGC- reducing CT dose radiation in pediatrics.
Why should diagnostic imaging personnel be familiar with standardized radiation quantities and units?
Ionization radiation can cause harmful effects it is important to be able to control PT and personnel exposure in a consistent and uniform manner.
Why is it necessary for radiographers to have a basic understanding of the processes of interaction between radiation and matter?
It is necessary for radiographers to have a basic understanding to optimally select the technical factors kVp (quality, determines the level of energy of photons) and mAs (quantity of electrons and amount of time X-ray tube is activated)
What form of energy is radiation?
Kinetic energy, and comes in many different forms.
What premise is BERT based?
Natural radiation that PTs are exposed to from earth, cosmic and natural radioactivity in their own bodies.
When, where and how did Wilhelm Conrad Roentgen discover x-rays?
November 8th, 1895 Laboratory at the University of Wurzburg in Bavaria Passed electricity through Crookes tube, experimenting with cathode rays, discovered fluorescence effect from compound of barium, platinum & cyanide.
What are 4 examples of radioactive nuclides that exist in small quantities in the human body?
Potassium-40 (40^K) Carbon-14 (14^C) Hydrogen-3 (3^H) Strontium-90 (90^Sr)
What factors determine the amount of x-ray energy absorbed by human anatomic structure?
Radiation Weighting factors (WR) adjust value of the absorbed dose of different capacities from various energies of ionizing radiation. (EqD) Tissue Weighting factors(WT) reflects different values based on sensitivity of specific organs and organ systems that are being irritated.(EfD)
What is attentuation?
Reduction in primary photons from x-ray beam, by either absorption & scatter.
How is an x-ray beam produced?
Stream of very energetic electrons strike a positively charged target in an evacuated glass tube.
Why is a team approach of significant value in patient care?
Teamwork reduces the rate of medical errors. Team approach will include various participants assume responsibility for their areas of expertise, & importance of communication throughout the team is emphasized.
When a high-energy photon collides with the nucleus of an atom during the process if photo disintegration, how much of the photon's energy is directly absorbed by the nucleus?
The high-energy photon collides with the nucleus of an atom, which directly absorbs all the photon's energy.
Explain the function of permanent inherent filtration in a diagnostic X-ray tube.
The inherent filtration the glass window and aluminum help increase the quality of the primary beam. The glass window removes some of the low energy photons that are not useful, the aluminum filter hardens the beam by removing low-energy components that would increase pt dose.
What is the benefit of using the International System of Units of measurement for ionizing radiation?
The system makes possible the interchange of units among all branches of science throughout the world.
Why are tungsten and rhenium used in the target of the X-ray tube?
They both have high melting points, to create electrons the filaments must be heated to 2200 degrees Celsius so must withstand high heat, and they both have atomic numbers (74 & 75) higher the atomic number, the more electrons to interact with and create photons.
How were radiation does limits calculated and established?
They were calculated and established to ensure that the overall risk from radiation exposure acquired on the Jon did not exceed risks encountered in "safe" occupations. Which is 1 in 10,000 chance per year, revised in 1991 with adding weighting factors.
How is centigray converted to gray?
This is done just by dividing the number of centigray by 100. 10cGy / 100 =0.1Gy
What has The WHO estimated the lifetime risk for development of some cancers to be in the areas where the most exposure occurred from the natural disaster Fukushimas nuclear plant disaster in 2011?
WHO estimated that the lifetime risk for development of some cancers may be somewhat higher "above baseline rates in certain age and sex groups that were in areas with the highest estimated doses"
When are PTs more likely to suppress any radiation phobia & be willing to assume a small chance of possible biologic damage?
When the medical benefit outweighs the risk of radiation. i.e getting a mammogram to see if there is cancerous tissue/tumors and accepting the risk of the radiation exposure.
What are enhanced natural sources of radiation?
accidental (nuclear plant explosions, accidents from natural disasters) or deliberate human actions such as mining radioactive elements.
What types of medical problems did early radiation workers develop as a consequence of their occupational exposure?
acute biologic damage, increase of cancer deaths, radio dermatitis & blood disorders (aplastic anemia, bone marrow failure & abnormal overproduction of WBC)
What consumer products contain radioactive materials?
airport surveillance system electron microscope ionization-type smoker detector alarms industrial static eliminators
What is a threshold dose?
alternatively this tolerance exposure level could be regarded as threshold dose, dose of lower radiation than which an individual has a negligible chance of sustaining specific biologic damage.
When is medical radiation exposure considered unnecessary?
any radiation exposure that does not benefit a person for diagnostic information from image or medical needs
In 1991 the International' Commission on Radiological Protection (ICRP) revised tissue weighting factors, what data was this revision based?
based on data from the recent epidemiological studies of the atomic bomb survivors, adopted the effective dose (Efd) combines type of radiation and sensitivity of tissues exposed to radiation.
What is small-angle scatter?
bending of the path of image formation radiation, essentially the same energy as the incoming, or incident photons. Degrades the image by blurring the sharp outlines of dense structures.
Somatic Damage
biologic damage to the body of the exposed individual caused by exposure to ionizing radiation may include cataracts, mutations and leukemia
How do electromagnetic and particulate radiations differ?
electromagnetic radiation has frequency and wavelengths, has high frequency can transfer energy to remove orbital atoms, causing ionization. Particulate radiation are subatomic particles are ejected from the nucleus at high speeds, if have sufficient kinetic energy can cause ionization by direct atomic collision.
How can RT use ALARA concept in their performance or daily responsibilities?
incorporating the 3 cardinal rules: Time, Distance & Shield reduce x-ray beam on time, use as much distance as possible (SID), always shield PT. For occupational : spend least amt of time in room w/ exposure keep greatest distance from energized beam use radiation absorbent shielding material between source (lead lined walls/glass)
How will a PT benefit from monitoring & reporting radiation dose?
keeping dose reports will help create data to use toward dose requirements in all modalities in radiology.
Air Kerma
kinetic energy released per unit mass of air, mass will replace exposure
In medical radiation science industry, how is Risk defined?
possibility of inducing adverse biologic effects: injury to the skin, induction of cancer or genetic defect after irradiation.
ionizing radiation
radiation that produces positively and negatively charged particles (ions) passing through matter.
E=mc^2 , what does c represent
speed of light