Radiation Physics and Protection - Key Concepts

Question 1 What theory relates the ionization produced in a small cavity within an irradiated medium or object to the energy absorbed in that medium as a result of its radiation exposure? Bragg-Gray Question 2 As the intensity of x-ray exposure of the air volume increases, the number of electron-ion pairs produced also increases. Question 3 In the SI system, an energy absorption of 1 J/kg of matter in the irradiated object equals which of the following? 1 Gy Question 4 For x-ray and gamma ray photons with energies up to 3 million electron volts (MeV), which of the following radiation quantities may be defined as the measure of the total electrical charge of one sign, either all pluses or all minuses, per unit mass that these two types of radiation generate in dry air (i.e., nonhumid) at standard temperature and pressure (760 mm Hg or 1 atmosphere at sea level and 22° C)? Exposure Question 5 The whole-body TEDE regulatory limit for exposed personnel is _____________ and ______________ for the general public. 0.05 Sv; 0.001 Sv Question 6 Cataract formation, fibrosis, reduced fertility, and sterility are classified as late tissue reactions of ionizing radiation. Question 7 The total kinetic energy released in a unit mass (kilogram) of air and expressed in metric units of joules per kilogram is air kerma. Question 8 Among physicians, cancer deaths attributed to x-ray exposure were reported as early as 1910. Question 9 Beta particles are actually high-speed electrons. Question 10 0.2 Gy equals 200 mGy. Question 11 Which of the following is essentially the sum total of air kerma over the exposed area of the patient's body surface? Dose area product Question 12 Who discovered x-rays on November 8, 1895? Wilhelm Conrad Roentgen Question 13 Who was the first American radiation worker to die from radiation-induced cancer in October of 1904? Clarence Madison Dally Question 14 What instrument can be calibrated to read air kerma? Standard, or free-air, ionization chamber Question 15 If 400 people receive an average effective dose of 0.25 Sv, what is the collective effective dose? 100 person-Sv Question 16 How is dose area product usually specified? In units of mGy-cm2 Question 17 Which of the following units of measure are not SI units? Roentgens and rads and rems Question 18 Which of the following is the SI unit of electrical current? Ampere Question 19 Which of the following are early tissue reactions of ionizing radiation that were experienced by early radiation workers? 1. 2. 3. 4. 1, Diffuse redness of skin Blood disorders Organ atrophy Intestinal disorders 2, and 4 only Question 20 In therapeutic radiology what SI units are now routinely used to specify absorbed dose? Gray and centigray Question 1 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. 1, and 2 only, 1, and 3 only ,2, and 3 only All of the options Question 2 Which of the following instruments generally has a check source of a weak, long-lived radioisotope located on one side of its external surface to verify its constancy daily? Muller survey meter Question 3 The personnel direct ion storage dosimeter provides an instant read-out of dose information when connected to a computer via a connector such as a (an) universal serial bus (USB). Question 4 An ionization chamber connected to an electrometer is a device that can measure tiny electric currents with high precision and accuracy. Question 5 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. Question 6 Three different filters are incorporated into the detector packet of the optically stimulated luminescence (OSL) dosimeter. These filters are respectively made of 1. aluminum. 2. copper. 3. molybdenum. 4. rhenium tungsten. 5. tin. 1, 2, and 5 only Question 7 Which of the following are advantages of the personnel direct ion storage dosimeter? 1. Instant access to reports 2. No waiting time for mailing dosimeters 3. Lightweight and durable 4. Can be dropped or scratched with little chance of harm to the device 1, 2, and 3 only, 1, 2, and 4 only ,2, 3, and 4 only The correct answer is: All of the options Question 8 Three different filters are incorporated into the detector packet of the optically stimulated luminescence dosimeter. Of what are these filters made? Aluminum, tin, and copper Question 9 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 Question 10 What is the maximum period of time that a thermoluminescent ring dosimeter (TLD) may be worn as a personnel device? 3 months Question 11 Medical physicists use ionization chambers, connected to electrometers to perform the annual standard measurements required by state, federal, and health care accreditation organizations for radiographic and fluoroscopic devices. These annual measurements include 1. x-ray output in Gy or mGy. 2. fluoroscopic radiation entrance rates in mSv/min or R/min. 3. kVp setting accuracy. 4. exposure time exactness. 5. half-value layers, or beam quality. 1, 2, and 3 only, 2, 3, and 5 only, 1, 3, and 4 only All of the options Question 12 Which of the following personnel monitoring devices can be used to provide an immediate exposure readout for a radiation worker? Personnel direct ion storage dosimeter Question 13 Which of the following is not a requirement that radiation survey instruments must meet? They must all be equally sensitive in the detection of all types of ionizing radiation. Question 14 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. Question 15 The effective atomic number (Zeff) of lithium fluoride (LiF) is equal to 8.2. Question 16 When changing employment, what must a radiation worker convey to his/her new employer? Data pertinent to accumulated permanent equivalent dose to be placed on file Question 17 The optically stimulated luminescence (OSL) dosimeter is "read out" by using a (an) laser light at selected frequencies. Question 18 What do optically stimulated luminescence dosimeters, thermoluminescent ring dosimeters, and personnel direct ion storage dosimeters have in common? These devices are all used for personnel monitoring. Question 19 Which of the following devices contains an aluminum oxide detector? Optically stimulated luminescence dosimeter Question 20 Which of the following is a disadvantage of the optically stimulated luminescence dosimeter? Exposure not determinable on the day of occurrence without an in-house reader Question 1 Adenine bonds only with thymine. Question 2 What do the highly organized enzymes in the inner membranes of the mitochondria break down? Carbohydrates, Fats & Proteins All of the options Question 3 During which of the following subphases of mitosis do the centrioles migrate to opposite sides of the cell and begin to regulate the formation of the mitotic spindle? Prophase Question 4 What is any chemical reaction in which atoms lose electrons called? Oxidation Question 5 Antibodies are protein molecules created by specialized cells in the bone marrow called B lymphocytes. Question 6 Which of the following are major tasks of the cytoplasm? 1. Accepts and builds up unrefined materials and assembles from these materials new substances such as carbohydrates, lipids, and proteins. 2. Breaks down organic materials to produce energy. 3. Packages substances for distribution to other areas of the cell or to various sites in the body through the circulation. 4. Eliminates waste products. All of the options Question 7 Which of the following can cause an increase in cellular activity that in turn causes biochemical reactions to occur more rapidly to meet the needs of the cell in stressful situations? Enzymes Question 8 What should the constant core temperature of the human body be? 37° C Question 9 Inorganic materials are compounds that do not contain carbon. Question 10 A nucleotide is formed from a nitrogen-containing organic base, a ______ molecule, and a phosphate molecule. five-carbon sugar Question 11 Lysosomes are sometimes referred to as "suicide bags," because their enzymes break down and digest not only proteins and certain carbohydrates but also will do the same to the cell itself should the lysosome's surrounding membrane rupture. Exposure to radiation may induce such a rupture. When this occurs what will happen to the cell? It is likely to die. Question 12 The much smaller structures that are building blocks of nucleic acids are called nucleotides. Question 13 Fraternal twins may also be referred to as dizygotic twins. Question 14 Cytosine bonds only with guanine. Question 15 In the human body mineral salts are necessary for 1. proper cell function. 2. creation of energy. 3. conduction of impulses along nerves. All of the options Question 16 Which of the following are compounds called purines? Adenine and guanine Question 17 The steps, or rungs, of the DNA ladder-like structure consist of complementary chemicals that are pairs of nitrogenous bases. Question 18 The cell components that contain the centrioles are the centrosomes. Question 19 Which of the following serves as a prototype for messenger RNA (mRNA)? Deoxyribonucleic acid (DNA) Question 20 In general, which of the following can human cells do? 1. Move, grow, react, and protect themselves 2. Repair damage and regulate life processes 3. Reproduce All of the options Question 1 A biologic reaction is produced by 4 Gyt of a test radiation. It takes 16 Gyt of 250-kVp x-rays to produce the same biologic reaction. What is the relative biologic effectiveness (RBE) of the test radiation? 4 Question 2 A periodic blood count is not recommended as a method for monitoring occupational radiation exposure because c. Biologic damage from ionizing radiation cannot be determined from a blood test. Both B and C. Question 3 Based on current data, which of the following would be considered a safe radiation dose for the gonads of both males and females? 0 Gyt Question 4 If bone marrow cells have not been destroyed by exposure to ionizing radiation, they can repopulate after a period of recovery. Question 5 Neutrophils play an essential role in fighting infection. Question 6 OH* + OH* = __________. H2O2 Question 7 One micron (μm) = __________. 10-6 m Question 8 The normal white blood cell count for an adult range from 5000 to 10,000/mm3 of blood. Question 9 The radiation dose required to produce mitotic death is less than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells. Question 10 The radiosensitivity of ova varies considerably throughout the lifetime of the germ cell. Question 11 The term apoptosis is synonymous with programmed cell death. Question 12 When free radicals previously produced by the interaction of radiation with water molecules act on a molecule such as DNA, the damaging action of ionizing radiation is indirect in the sense that the radiation is not the immediate cause of injury to the macromolecule. What is the immediate cause of this damage? The free radicals produced by the interaction of radiation with water molecules Question 13 When LET increases, the chance of a significant biologic response in the radiosensitive DNA macromolecule also increases. Question 14 Which of the following curves illustrates the radiation sensitivity of a particular type of cell? Cell survival curve Question 15 Which of the following gonadal radiation doses may cause permanent sterility in a male human? 5.0 or 6.0 Gyt Question 16 Which of the following groups of cells is least radiosensitive? Adult nerve cells Question 17 Which of the following humans is most radiosensitive? An embryo-fetus during the first trimester of pregnancy Question 18 Which of the following is a category of white blood cell that is essential in fighting infections? Granulocytes Question 19 Which of the following is/are considered low-LET radiation(s)? X-rays and gamma rays Question 20 Which of the following statements is true concerning patients who receive radiation exposure from a routine radiographic procedure such as a chest xray? Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.