Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
238 Midterm
238 midterm stack
| Question | Answer |
|---|---|
| Effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation defines: | radiation protection |
| Medical radiation procedures account for | The largest dose of ionizing radiation received by human beings |
| Al equivalent dose as low as 0.25 Sv (25 rem) delivered to the whole body may cause __________within a few days? | a decrease in the number of lymphocytes in the circulating blood |
| Which of the following increases radiation exposure for both the patient and the radiographer? | Repeated radiographic exposures as a result of technical error or carelessness |
| A patient may elect to assume the risk of exposure to ionizing radiation to obtain essential diagnostic medical information when:A)Illness occurs, B) inJUry occurs C) a specific imaging procedure for health screening purposes is prudent | all of the above |
| Occupational and non occupational doses will remain well below maximum allowable levels when | Radiographers and radiologists keep exposure as low as reasonably achievable. |
| Which commonly used building materials contain(s) radon? | a.Bricks c.Concrete b.Gypsum wallboard |
| What do airport surveillance systems; ionization type smoke detectors; older, luminous dial timepieces; nuclear power plants; and false teeth made of porcelain have in common? | They are all sources of manmade radiation. |
| Repetition of a radiographic exposure because of poor patient positioning results in | An increase in total radiation exposure to the patient and the radiographer |
| From which of the following sources do human beings receive the largest dose of ionizing radiation? | Medical radiation procedures |
| Which of the following is the total average annual effective dose from manmade and natural radiation? | 3.6 mSv (360 mrem) per year |
| Any radiation exposure that does not benefit a person in terms of diagnostic information obtained or that does not enhance the quality of a radiologic examination is called | Unnecessary radiation |
| Which of the following is a naturally occurring process by which instability of the nucleus is relieved through various types of nuclear spontaneous emissions? | Radioactive decay |
| During the__________, an atomic cloud was created by a 37 kiloton testing device that was exploded from a balloon at tht Nevada test site on June 24, the atomic cloud, which contained manmade ionizing radiation, ascended approximately 43,000 feet. | Priscilla Test |
| An effective radiation safety program requires commitment to radiation safety by:1. facilities providing imaging services 2. radiation workers 3. patients | 1 and 2 only |
| Effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation. | radiation protection |
| The degree to which the diagnostic study accurately reveals the presence or absence of disease in a patient. | diagnostic efficacy |
| Traditional unit of measure for the EqD. | rem |
| Damage to living tissue of animals and human beings exposed to radiation. | biological effects |
| Biologic effects of ionizing radiation or other agents on generations yet unborn. | genetic damage |
| Electric and magnetic fields that fluctuate rapidly as they travel through space, including radio waves, microwaves, visible light, and x-rays. | electromagnetic wave |
| Genetic or somatic changes in a living organism (e.g., mutation,cataracts, and leukemia) caused by excessive cellular damage fromexposure to ionizing radiation. | organic damage |
| Radiation quantity used for radiation protection purposes when a person receives exposure from various types of ionizing radiation. Used to numerically specify the differences in biologic harm that are produced by different types of radiation. | EqD equivelent dose |
| Radiation quantity that takes into account the dose of all types of ionizing radiation to irradiated organs or tissues in the human body. and chance of each of those body parts for developing a radiation-induced cancer or the risk for genetic damage). | EfD effective dose |
| SI unit of measure for the EqD. | rem |
| Method for comparing the amount of radiation received from a radiologic procedure with natural background radiation received over a given period. | BERT |
| Produces positively and negatively charged particles (ions) when passing through matter. | ionizing radiation |
| The full range of frequencies and wavelengths of electromagnetic waves. | electromagnetic spectrum |
| Energy that passes from one location to another. | radiation |
| Injury on the cellular level caused by sufficient exposure to ionizing radiation at the molecular level. | cellular damage |
| Acronym for as low as reasonably achievable. | ALARA |
| Rays of extraterrestrial origin that result from nuclear interactions that have taken place in the sun and other stars. | cosmic rays |
| Long-lived radioactive elements present in variable quantities in the earth's crust; they emit densely ionizing radiations. | terrestrial radiation |
| Contains two protons and two neutrons. | alpha particle |
| Natural sources of ionizing radiation that become increased because of accidental or deliberate human actions, such as mining. | enhanced natural sources |
| Identical to high-speed electrons, except they are emitted from the nuclei of radioactive atoms instead of originating in atomic shells. | beta particle |
| The number of protons contained within the nucleus of an atom. | atomic number, Z number |
| Positively charged components of an atom. | protons |
| Radiation produced as a consequence of nuclear weapons testing and chemical explosions in nuclear power plants. | fallout |
| An unstable nucleus that emits one or more forms of ionizing radiation to achieve greater stability. | radionuclide |
| According to NCRP Report No. 160, which reflects usage patterns through 2006, radon and thoron account for what percent of natural background radiation exposure? | 37% |
| As of 1987, manmade radiation contributed what amount of mSv (mrem) to the annual exposure of the U.S. population? | 0.65 (65) |
| When are human beings in closer contact with extraterrestrial radiation? | A flight on a commercial airplane |
| As of 1987, medical radiation exposure from the use of diagnostic x-ray machines and radiopharmaceuti¬cals collectively accounted for approximately what amount of the average annual- individual effective dose of ionizing radiation? | 0.54 mSv (54 mrem) |
| Which is a radiation quantity used for radiation protection purposes that attempts to numerically specify the differences in biologic harm that is produced by different types of radiation? | equivalent dose |
| This project launched in the Republic of Belarus in 1996, in the aftermath of the Chemobyl nuclear accident, to empower local citi¬zens in making their own decisions regarding recon¬struction of their overall quality of life; this project was known as the | ETHOS Project |
| Any radiation exposure that does not benefit a person in terms of diagnostic information obtained for the clinical management of medical needs or that does not enhance the quality of a radiologic examination is called: | Unnecessary radiation |
| The amount of radiation a patient receives may be indicated in terms of:1. Entrance skin exposure2. Bone marrow dose3. Gonadal dose | all of the above |
| When an imaging procedure is justified in terms of medical necessity, diagnostic efficacy is achieved when optimal-quality images, revealing the presence or absence of disease, are obtained with: | Minimal radiation exposure |
| Ultraviolet radiation below 10 e V, visible light, infra¬red rays, microwaves, and radio waves are consid¬ered to be nonionizing because they: | Do not have sufficient kinetic energy to eject electrons from atoms |
| Which of the following is a naturally occurring pro¬cess by which instability of the nucleus is relieved' through / various types of nuclear spontaneous emissions? | Radioactive decay |
| Effective radiation protection measures take intoconsideration: | 1. Both human and environmental physical determinants 2. Technical elements 3. Procedural factors |
| Radioactive elements in the earth's crust and in the human body may be classified as | Natural sources of ionizing radiation |
| The most effective tool(s) for diagnosing breast can¬cer continue to be: | Mammography |
| The millisievert (mSv), a subunit of the sievert, is equal to: | 1/1000 of a sievert |
| Repetition of a radiographic exposure because of poor patient positioning results in | an increase in total radiation exposure to the patient and radiographer |
| l. X-rays are carriers of _______electro¬ magnetic energy. | manmade |
| 2. As _______interact with the atoms of the target, x-ray_______emerge from the target with a broad range of energies and leave the x-ray tube through a glass window. | electrons, photons |
| 3: The energy of the electrons inside the x-ray tube is expressed in terms of the_______applied across the tube. | electrical voltage |
| 4. In clinical situations, d:attered Rhotons reach the image receptor and_______image quality. | degrade |
| 5. In a diagnostic x-ray beam, the ultimate destination of photons is the_______receptor. | image |
| 6. In the process of_______scatter¬ing, because the wavelengths of both incident and scattered waves are the same, no net energy has been absorbed by the atom. | coherent |
| 7. Compton scatter may be directed _______ as small-angle scatter, _______ as backscatter, and to the side as sidescatter. | forward, backward |
| 8______ scattering and _______absorption in tissue are equally probable at about 35 ke V. | compton, photoelectric |
| A inner-shell e is removed in a photoelectric interaction, causing an in-shell vacancy, the NRG liberated when the vacancy is filled can, instead of emerging as fluorescent rad, be transferred to another e of the atom, ejecting it, the ejected e is called | Auger |
| 10. Biologic damage may result from the _______of x-ray energy. | absorbtion |
| 11. A diagnostic x-ray beam is produced when a stream of high-speed _______bombard a_______-charged target in a highlyevacuated glass tube. | electrons, positively |
| 12. Although all photons in a diagnostic x-ray beam do not have the same _______ ,the most energetic photons in the beam an have no more_______than the electrons that bombard the target | energy, energy |
| 13. For a typical diagnostic x-ray unit, the energy of the average photon in the x-ray beam is about _______the energy of the most energetic photon. | one third |
| 14. The _______of radiation scatter in various directions is a major factor m the plannmg of protection for medical imaging personnel during a radiologic examination. | intensity |
| 15._______and_______scattering play essentially no role in radiography | rayleigh and thompson |
| 16. The less a given structure attenuates radiation, the_______its radiographic image will be,and vice versa. | darker |
| 17. Use of a positive contrast medium leads to an_______ in absorbed dose in the body structures that contain the medium. | increase |
| 18. A positron is classified as a form of _______ | antimatter |
| The ___________effectis the basis of radiographic imaging, whereas the___________effect is its bane. | photoelectric, compton |
| ___________ scattering is most likely to occur at below l0keV | coherent (classical, elastic, unmodified) |
| When ___________ is increased, the patient receives a lower radiation dose, but image quality may be compromised. | kVp |
| In diagnostic xray Range(23 to 150kVp), when kVp is decreased, the number of photoelectric interactions___________ and the number of Compton interactions___________ ; however, the patient absorbs more energy, and therefore the patient dose ___________ | increases, decreases, increases |
| Variations in the x-ray ___________ properties of various body structures make radiographic imaging of human anatomy possible. | absorption |
| A Compton-scattered electron is also known as a secondary, or__________ , electron. | recoil |
| An incoming x-ray photon has ___________ energy. | kinetic |
| 1. Name Five types of interactions between x-radiation and matter | (1) coherent (classical, elastic, or unmodified) scat¬tering(2) Compton (incoherent, inelastic, or modified) scatter¬ing(3) photoelectric absorption(4) pair production(5) photodisintegration |
| 2. How is a Tech responsible for a dose the patient receives? | Radiographers should use appropri¬ate techniques that can minimize the dose to the patient and pro¬duce optimal-quality images; as well as, use shielding and collumation where appropriate. |
| 3. What is responsible for producing diagnostically useful images? | Varied attenuation of photons by various body structures makes it possible to produce useful images where different anatomic structures identified. |
| 4. How can you reduce fog produced by small angle scatter? | Reducing the amount of tissue irradiated by use of collimation reduces the amount of fog produced by small-angle scatter. |
| 5. How is the energy of the electrons inside a xray tube expressed? | in terms of the electrical voltage applied across the tube. in thousands of volts, or kilovolts (kV). Because the voltage across the tube fluctuates, it usually is expressed in kilovolt peak (kVp). |
| 6. What is The minimum energy required to produce an electron-positron pair | 1.022 MeV. |
| 7. What does Positive contrast media consist of | solutions containing elements having a higher atomic number than surrounding tissue (e.g., bar¬ium or iodine based) that are either ingested or injected into the tissues or structures to be visualized. |
| 8. Name Three unstable nuclei used in positron emission tomography (PET) scanning | fluorine-18 (18F), carbon-II (1IC), and nitrogen-13 (13N). |
| 9. What type of energy does A photoelectron have? | kinetic energy equal to the energy of the inci¬dent photon less the binding energy of the electron shell. |
| 10. What does Scattered radiation do to an image? | may contribute to degradation of the radio graphic image by creating an additional, unwanted density, radiographic fog. |
| 11. The two methods most often used to limit the effects of indirectly transmitted x-ray photons are | air gaps and radiographic grids. |
| 12. During the process of coherent scattering, why is no net energy absorbed by the atom with widh the incident xray interacts? | because the wave¬ lengths of both incident and scattered waves are the same, no net energy is absorbed by the atom. |
| 13. What is Mass density and how is it measured? | the quantity of matter per unit volume. It generally is specified in units of kilograms per cubic meter (kg/m3) or grams per cubic centimeter (g/cc). |
| 14. What is Radiographic contrast? | the difference in density level between the radiographic images of objects in an image. |
| 15. What modality uses Annihilation radiation | used in PET. |
| 1. When a technical exposure factor of 1O0kVp is selected, which of the following occurs? | The energy of the average photon in the x-ray beam is about 33keV. |
| 2. The passage of x-ray photons through a patient with¬out interaction is called: | Direct transmission |
| 3. In which of the following x-ray interactions with matter is the energy of the incident photon completely absorbed? | Photoelectric |
| 4. What is the result of coherent scattering? | Usually just a small angle change in the direction of the incident photon |
| 5. A technical exposure factor of 1O0kVp means that the electrons bombarding the anode ofthe x-ray tube have a maximum energy of: | 1O0,000eV, or 1O0keV |
| 6. A Compton-scattered electron: | Is absorbed within a few microns ofthe site of the original Compton interaction |
| 7. Most scattered radiation produced during radiographic procedures is the direct result of which of the following? | Compton interactions |
| 8. A reduction in the number of primary photons in the x-ray beam through absorption and scatter as the beam passes through the patient in its path defines: | Attenuation |
| 9. Before interacting with matter, an incoming x-ray photon may be referred to as which of the following? | Primary photon |
| 10. Within the energy range of diagnostic radiology that includes mammography (23 to 150kVp), when kVp is decreased, the patient dose: | Increases |
| 11. Which of the following statements best describes mass density? | it is measured in grams per cubic centimeter |
| 12. Of the following interactions between x-radiation and matter, which does not occur in the range of diagnostic radiology?1. Photoelectric absorption 2. Pair production 3. Photodisintegration | 2 and 3 only |
| 13. For a diagnostic radiologic examination, the selec¬tion of technical exposure factors using an optimal kVp and mAs combination: | Produces an x-ray image of acceptable quality while minimizing patient dose |
| 14. The quality, or penetrating power, of an x-ray beam is controlled by: | kVp |
| 15. Small-angle scatter: | Degrades the appearance of a completed radio¬graphic image by blurring the sharp outlines of dense objects |
| 16. Within the energy range of diagnostic radiology, as absorption of electromagnetic energy in biologic tissue increases, the potential for biologic damage: | Increases |
| 17. Which of the following terms are synonymous? 1. Coherent scattering 2. Classical scattering 3. Unmodified scattering. | 1, 2, and 3 |
| 18. Noninteracting and small-angle scattered photons compnse: | Exit, or image formation, radiation |
| 19. Direct transmission means that x-ray photons: | Pass through biologic tissue without interaction |
| 20. Which of the following has the same mass and magnitude of charge as a negatron? | Positron |
| 21. Which of the following interactions between x-radiation and matter does not occur within the range of diagnostic radiology? | Pair production |
| 22. kVp controls: | Quality, or penetrating power, of the photons in the x-ray beam |
| 23. Primary radiation is synonymous with: | Direct radiation |
| 24. Which of the following are radiographic Image receptors?1. Radiographic grid 2. Digital radiography receptor 3. Phosphor plate 4. Radiographic film | . 2, 3, and 4 only |
| 25. The process most responsible for the contrast between bone and soft tissue in a diagnostic radio¬graphic image is: | Photoelectric absorption |
| 1. Although the radiographer and other diagnostic imaging personnel are allowed to absorb more radia¬tion than the general public, the ________ received must be minimized whenever possible. | equivalent dose |
| 2. ________radiation poses the greatest occupational hazard in diagnostic radiology. | Scattered |
| 3. Correct radiographic film processing techniques lead to a________in the num¬ber of repeat examinations required, with a resultant in exposure to the radiographer. | decrease, reduction |
| 4. After receiving radiation safety counseling, a pregnant rad tech must read and sign a form acknowledging that she has received counseling and understands the ways to implement appropriate measures to ensure the ________of the embryo¬-fetus. | safety |
| 5. If a declared-pregnant radiographer is reassigned to a lower-radiation exposure risk area, other unknowing potentially pregnant radiographers can be subject to ________risk. | increased |
| 6.________the length of time spent in a room where x-radiation is produced reduces occupational exposure. | Shortening |
| 7. The most effective means of protection from ionizingradiation is________ | distance |
| 8. Structural barriers such as walls and doors in an x-ray room provide radiation________for both imaging department personnel and the general public. | |
| 9. Accessory protective shielding includes-________, ________,and________made of lead- impregnated vinyl. | |
| 10. No one should touch the tube________ or________cables while a radiographic exposure IS In progress. | housing, high-tension |
| When high-speed IR systems are used, smaller radiographic exposure (less milliamperage) is required, which results in fewer x-ray photons being available to produce_______. Because of this reduction in _____ ___personnel exposure is decreased. | Compton scatter, Compton scatter |
| 12. It is imperative that the EqD to the embryo-fetus from occupational exposure of the mother not exceed the NCRP-recommended monthly EqD limit of________mSv (________rem) or a limit of ________mSv (________ rem) during the entire pregnancy. | 0.5, 0.05, 5, 0.5 |
| Maternity aprons consist of________lead equivalent over their entire length and width and also have an extra________lead equivalent pJotective panel that runs transversely across the width of the apron to provide added safety for the embryo-fetus. | 0.5mm, lmm |
| Shortening the length of________in a room where x-rad is produced, standing at the greatest________possible from an energized x-ray beam, and using a rad absorbent________material between the rad worker and the source, all reduce occupational exposure. | time, distance, shielding |
| When the distance is doubled, the radiation at the new location spans an area________times larger than the original area. However, because the same amount of radiation covers this larger area, the intensity decreases by a factor of________ | four, four |
| 16. Primary protective barriers are located________to the undeflected line of travel of the x -ray beam. | perpendicular |
| If the peak energy of the x-ray beam is 130kVp, the primary protective barrier in a typical installation consists of________lead and extends_____feet (____ m) upward from the floor of the x-ray room when the x-ray tube is 5 to 7 ft from the wall. | 1/16 inch, 7, 2.1 |
| 18. In a typical diagnostic x-ray installation, the second¬ary barrier consists of________lead. | 2inch |
| 19. During fluoroscopy and x-ray special procedures, a neck and thyroid shield can guard the thyroid area of occupationally exposed people. It should be________lead equivalent. | 0.5mm |
| 20. To ensure protection from________radiation emanating from the patient during a fluo¬roscopic examination, the radiographer should stand as far from the________as is practical and should move closer to the patient only when ________is required. | scattered, patient, assistance |
| 21. Protective lead gloves of at least________lead equivalent should be worn whenever the hands must be placed near the fluoroscopic field. | 0.25mm |
| 22. For better visualization of small body parts, C-arm fluoroscopes have the capability to ________the Image. | magnify |
| 23. A________protective apron is recom¬mended to protect personnel who must move around the x-ray room during a fluoroscopic examination. | wraparound |
| The tech should attempt to stand at________( ____ degrees) to the x-ray beamscattering object (the patient) line; this is the place where the _______amount of scattered radiation is received. | right angles, 90, least |
| 25. In________imaging, because the image contrast and overall brightness can be manipulated after image acquisition, the need for almost all retakes resulting from improper technique selection is eliminated. | routine |
| 1. Because the workforce in radiation-related jobs is small compared with the population as a whole, the amount of radiation received by this workforce can be larger than the amount received by the general public without altering the: | Genetically significant dose (GSD |
| 2. Which of the following is a tenet of the ALARA concept? | The radiographer's exposure should be kept as low as reasonably achievable. |
| 3. A facility that employs a pregnant rad tech should give them a additional monitor to be worn at waist level during all radiation procedures. The purpose of this additional monitor is to ensure that the monthly EqD to the embryo-fetus does not exceed: | 0.5 mSv (0.05 rem) |
| 4. Which of the following are radiation sources that can be generated in a diagnostic x-ray room?1. Primary radiation 2. Scatter radiation 3. Leakage radiation | 1, 2, and 3 |
| 5. During C-arm fluoroscopy, the exposure rate caused by scatter near the entrance surface of the patient (the x-ray tube side) the expo¬sure rate caused by scatter near the exit surface of the patient (the image intensifier side). | Exceeds |
| 6. which dose reduction features should be in working order?1. low-dose fluoroscopy mode& pulsed beam mode 2. Collimation, beam filtration, removable grids, variable | 1,2, and 3 |
| 7. In diagnostic radiology, which of the following radi¬ation sources poses the greatest occupational hazard for the radiographer? | Scattered radiation |
| 8. Which of the following methods and devices reduce(s) the radiographer's exposure during a fluo¬roscopic examination?1. Adequate x-ray beam collimation 2. Control of technical exposure factors 3. Use of a remote control fluoroscopic system | 1, 2, and3 |
| 9. If the peak energy of the diagnostic x-ray beam is 130kVp, the primary protective barrier generally should consist of at least and extend upward from the floor of the x-ray room when the tube is 5 to 7 feet from the wall in question. | 1/16-inch lead, 7 feet |
| 10. Which of the following radiation sources is the con¬trol booth barrier not intended to intercept in a diag¬nostic x-ray room?1. Leakage radiation 2. Primary radiation 3. Scattered radiation | 2 only |
| 11. Protective shielding for an uncontrolled area (e.g., a hall or corridor frequented by the general public) must ensure that the maximal EqD for that area is no greater than____per week. | 20 microsieverts (2 mrem) |
| 12 T/F Radiographers and non occupationally exposed individuals should never stand in the useful beam to restrain a patient during a radiographic procedure. | true |
| 13. Of the devices listed below, which eliminates non¬useful low-energy photons from the primary beam? 1. Collimator light source 2. Electronic sensors 3. Aluminum filtration | 3 only |
| 14. Which of the following is the most effective means of protection from ionizing radiation normally available to the radiographer? | Placing as much distance as possible between oneself and the source of radiation |
| 15. The lead glass window of the control booth barrier in a stationary (fixed) radiographic installation typi¬cally consists of which of the following? | 1.5 mm lead equivalent |
| 16. The beam direction factor is also known as the: | Use factor |
| 17. If the intensity of the x-ray is inversely proportional to the square of the distance from the source, how does the intensity of the x -ray beam change when the distance from the source of radiation and a measure¬ment point is quadrupled? | It decreases by a factor of 16 at the new distance |
| 18. Leakage radiation and scatter radiation are forms of: | Secondary radiation |
| 19. Diagnostic x-ray installations must be equipped with: | Radiation-absorbent barriers. |
| 20. What are the main principles used to minimize occupational radiation exposure? | 1. Time 2. Distance 3. Shielding |
| 21. Pregnant radiographers can wear an additional moni¬toring device at waist level to ensure that the monthly EqD does not exceed: | 0.5 mSv (0.05 rem) |
| 22. During fluoroscopy, which of the following will pro¬vide radiation protection for the radiographer and the radiologist?1. Adequate collimation of the x-ray beam 2. Use of high-speed image receptor systems 3. Use of a cumulative timing device | 1,2, and 3 |
| 23. Floors of radiation rooms except dental installa¬tions, doors, walls, and ceilings of radiation rooms exposed routinely to the primary beam are given a use factor of: | 1 |
| 24. If a radiographer stands 1 m from an x-ray tube and is subjected to an exposure rate of 4 mR/h, what will the exposure rate be if the same radiographer moves to a position 2m from the x-ray tube? | 1 mR/h |
| 25. If a radiographer moves closer to a source of radia¬tion, the radiation exposure to the radiographer: | Increases significantly |
| in keeping with the ALARA concept, most health care facilities issue personnel might receive about _____of the annual occupation EfD limit in any 1 month, or approximately 0.5mSv or 50mrem | 1% |
| a simple detection system of a radiation survey instrument will do what | indicates only the presence or absence of radiation |
| diagnostic imaging personnel should wear a personnel dosimeter during routine operations in an imaging facility because the device provides | indication of working conditions and individual working habits |
| what do the image densities cast by the filters in a film badge permit? | estimation of the energy of the radiation reaching the badge |
| what personnel dosimeter allows a radiation worker to determine occupational exposure received as soon as a specific radiologic procedure is completed? | pocket dosimeter |
| What instrument should be used in a laboratory to detect alpha and beta radiation and small amounts of other types of low-level radioactive contamination? | proportional counter |
| What device is used to measure the visible light emitted bt the sensing material contained in the TLD after exposure to ionizing radiation and heating? | personnel monitoring report |
| When the negatively and positively charged electrodes in the pocket ionization chamber are exposed to ionizing radiation, what does the mechanism do? | it discharges in direct proportion to the amount of radiation to which has been exposed |
| What is a densitometer is used to measure? | optical density |
| What do radiation survey instruments measure? | total qty of electrical charge resulting from ionization of the gas and rate at which an electrical charge is produced |
| What do ionization chamber-type survey meters, proportional counters, and GM detectors have in common? | all contain a gas-filled chamber |
| Which radiation monitor is most commonly used for monitoring occupational exposure in diagnostic imaging? | OSL |
| What are some disadvantages of using a TLD as a personnel monitoring device? | it can only be read once because the read out process destroys the stored information, it is necessary to use calibrated dosimeters with TLD’s, the initial cost is higher than that for a film badge |
| Before a pocket dosimeter is used to record radiation exposure, the quartz fiber indicator of the transparent reading scale should indicate a reading of ? | zero |
| The OSL dosimeter uses what kind of detector? | Al2O3 |
| A pocket ionization chamber resembles? | an ordinary fountain pen |
| Where should the control badge sent from monitoring companies with each batch of dosimeters badges be kept? | in a radiation-free area |
| Dosimeter badge readings that exceed a trigger level set by the health care facility are investigated to? | ascertain the cause of the reading |
| What does the TLD readout process do to the information stored in TLD? | destroys it |
| An ionization chamber-type survey meter is also referred to as a? | Cutie pie |
| The increased sensitivity of the OSL dosimeter makes it ideal for monitoring employees working in low-radiation environments and for? | monitoring of pregnant workers |
| The RSO in a health care facility receives and reviews personnel monitoring reports to? | assess compliance with ALARA guidelines |
| Wearing a personnel dosimeter in a consistent location is the responsibility of the? | individual wearing the device |
| On termination of employment a radiographer should receive a copy of? | occupational exposure report |
| What two devices are used for personnel monitoring? | OSL and TLD |
| When the 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 functions as the sensing material in a thermoluminescent dosimeter? | lithium fluoride |
| During routine radiographic procedures when a protective apron is not being worn the primary personnel dosimeter should be attached to the clothing on the front of the body at? | collar level to approximate the maximum radiation dose to the thyroid and the head and neck |
| What are the requirements radiation survey instruments should fill? | reliable to accurately record exposure or exposure rate, durable to withstand normal use, interact with ionizing radiation in a manner similar to the way in which human tissue interacts |
| During diagnostic imaging procedures how should the radiation dose to the abdomen of a pregnant tech be monitored during gestation? | obtained from a second radiation monitor worn at abdominal level |
| When hands of a radiation worker are near the primary beam, the equivalent dose to the hands may be determined through the use of? | TLD ring badge worn on the hand |
| 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 5KeV to excess Mev what dosimeter gives and accurate reading as low as 1mrem? | OSL |
| What instrument should be used to locate a lost radioactive source or detect low-level radioactive contamination? | GM detector |
| What instrument should be used in an x-ray installation to assess fluoroscopic scatter radiation exposure rate? | ionization chamber with electrometer |
| 1. The beam should be collimated so that it is what? | No larger that the IR |
| 2. Both alignment, length, and width dimensions of the light beam must be within: | 2% of the SID |
| 3. What is the function of a filter in diagnostic radiology? | To decrease the x-radiation dose to the pt’s skin and superficial tissue |
| 4. HVL may be defined as the thickness of a designated absorber required to do what? | Decrease the intensity of the primary beam by 50% of its initial value |
| 5. Because of the increased sensitivity to scatter of the photostimulable phosphor in CR imaging plate, which is true? | A radiographic grid may be used more frequently during CR imaging |
| 6. To minimize skin exposure to electrons produced by photon interaction with the collimator, how far below the collimator should the pt’s skin surface be? | Atleast 15 cm below |
| 7. Which of the following aluminum equivalents for total permanent filtration meets the minimum requirement for mobile diagnostic and flouro equipment? | 2.5 mm aluminum equivalent |
| 8. The trough or bilateral wedge filter which is used in some dedicated chest x-ray units is an example of which of the following? | Compensating filter |
| 9. To decrease pt exposure during flouro, the flouroscopist can: | limit the size of the field to include only area of interest and employ the practice of pulsed flouro to reduce length of exposure |
| 10. Protective tube housing must be constructed so that leakage radiation measured at a distance of 1 m from the x-ray source does not exceed______ when the tube is operated at its highest voltage at the highest current that allows continuous operation. | 100 mR/hr (2.58 x 10^-5 C/kg per hour) |
| 1. To meet radiation safety features, radiographic equipment must have: | correctly functioning control panel, protective tube housing, radiographic examination table designed to reduce pt radiation dose |
| 2. There are various types of digital radiography image receptors. Some use a scintillator such as amorphous silicon, to: | Convert x-ray energy into visible light |
| 3. The luminance of the collimator light source must be: | Adequate to permit the localizing light beam to outline the margins of the radiographic beam adequately on the pts anatomy |
| 4. Which of the following results in an increase in the pt dose? | Use of a radiographic grid |
| 5. The pt dose decreases and the life of the flouro tube increases with which of the following? | Intermittent, or pulsed, flouro |
| 6. When fluoroscopic field size is limited to include only the area of clinical interest by adequately collimating the x-ray beam, pt area or integral dose: | decreases substantially |
| 7. Digital radiography eliminates the need for almost all retakes resulting from improper technique selection because the image: | Contrast and overall brightness can be manipulated after image acquistion |
| 8. Computed radiography involve: | Use of conventional radiographic equipment, selection and use of standard technical exposure factors, and traditional pt positioning performed by a radiographer |
| 9. Which of the following is the most versatile for defining the size and shape of the radiographic beam? | Light-localizing variable-aperture rectangular collimator |
| 10. The use of digital radiographic systems offers a number of advantages over both CR and conventional film-screen systems. Some of these include: | immediate imaging results and lower dose |
| 11. In CR imaging, when a grid is required to radiograph anatomy sections over 10 cm in thickness or for techniques that exceed 70 kVP, pt dose received is: | Significantly higher than is delivered with film-screen imaging because the mAs required is significantly higher |
| 12. Flouro equipment equipped with high-level control(HCL) may permit a skin entrance exposure rate as great as which of the following? | 20 R/min |
| 13. To protect the pts skin form exposure to electrons produced by photon interaction with the collimator, the skin surface should at least_____ below the collimator. | 15 cm |
| 14. To reduce pt entrance dose during C-arm flouro procedures, the patient-image intensifier distance should be: | As short as possible |
| 15. Which of the following may reduce pt exposure to off-focus radiation? | placing the first pair pf shutters in the collimator as close as possible to the x-ray tube window |
| 16. Which of the following is an effective technique for reducing pt dose when a digital flouro system is used? | Using the last-image-hold feature |
| 17. Compared with pts who undergo cineflouro procedures that use lower frame rates, pts who undergo more rapid dynamic function studies (eg heart catherterization) receive: | Higher radiation doses |
| 18. HLCF is an operating mode for state-of-the-art flouro equipment in which exposure rates are: | Substantially higher than those normally allowed in routine flouro procedures |
| 19. Monitoring and documentation of procedural flouro time is essential to good practice. The responsibility for monitoring and documentation generally belongs to: | the radiographer assisting with the procedure |
| 20. HVL is expressed in: | Milimeters of aluminum |
| 21. Dose reduction and uniform imaging of the body parts tat vary considerably in thickness or tissue composition may be accomplished by use of: | Compensating filters constructed of aluminum, lead-acrylic, or other suitable material |
| 22. Resolution of a digital image is sharper when pixels are: | Smaller |
| 23. For certain radiographic examinations the use of asymmetric fil emulsion and intensifying screen combinations result in a recorded image with: | Greater uniformity and a decrease in pt exposure |
| 24. Compared with the resolution of an optimal quality image produced on radiographic film, the resolution of a digital image is: | actually somewhat less |
| 25. Some of the reasons for high exposures during interventional procedures include: | the flouro tube being used for longperiods of time in continuous and not pulsed mode, failure to use the protective curtain or shields on the image intensifier as a means of protection, and extensive use of cine as a recording medium |
| 1. A pt may elect to assume the relatively small risk of exposure to ionizing radiation to obtain essential diagnostic medical information when: | illness occurs, injury occurs, or a specific imaging procedure for health screening purposes is prudent |
| 2. Effective measures employed by radiation workers to safeguard pts, personnel, and the general public from unnecessary exposure to ionizing radiation defines: | radiation protection |
| 3. Which of the following is a method that can be used to answer pt questions about the amount of radiation received from a radiographic procedure? | BERT |
| 4. The term optimization for radiation protection (ORP) is synonomous with the term: | As low as reasonably achievable (ALARA) |
| 5. Which of the following are natural sources of ionizing radiation? | Radioactive elements in the crust of the earth and in the human body |
| 6. An equivalent dose as low as 0.25 SV (25 rem) delivered to the whole body may cause which of the following within a few days? | A decrease in the number of lymphocytes in the circulation blood |
| 7. The degree to which the diagnostic study accurately reveals the presence or absence of disease in the pt defines which of the following terms? | Diagnostic efficacy |
| 8. Which of the following was the total average annual effective dose from manmade and natural radiation as of 1987? | 3.6 mSv (360 mrem) per year |
| 9. An effective radiation safety program requires a firm commitment to radiation safety by: | facilities providing imaging services and radiation workers |
| 10. 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 |
| 2. What contributes significantly to the exposure of the radiographer? | Compton-scattered photons |
| 3. What defines attenuation? | Absorption and scatter |
| 4. In the radiographic kV range, what structures will undergo the most photoelectric absorption? | Compact bone |
| 5. In which x-ray interaction with matter is the energy of the incident photon partially absorbed? | Compton |
| 6. When a high atomic | solution is either injested or injected into human tissue or a structure to visualize it during an imaging procedure, what occurs? |
| 7. What characteristics primarily differentiate the probability of occurrence of the various interactions of x-radiation with human tissue? | Energy of the incoming photon |
| 8. What influences attenuation? | Effective atomic |
| 9. A decrease in contrast of the image by adding an additional, unwanted density (fog) results from what interaction between x-radiation and matter? | Compton scattering |
| 10. The interactions of x-ray photons with any atoms of biologic matter are: | Random in nature, and therefore the effects of such interactions cannot be predicted with certainty |
| 1. As a consequence of their anatomic location, the female reproductive organs receive__________exposure during a given radiographic procedure involving the pelvic region than do male reproductive organs. | 3 times more |
| 2. In fluoroscopy, how is the amount of radiation that a patient receives usually estimated? | By measuring the radiation exposure rate at table top and multiplying this by fluoro time |
| 3. Direct patient shielding is not typically used in: | CT |
| 4. In which projection will a young female patient receive a significantly lower dose to her breast tissue during a chest x-ray? | PA |
| 5. How should the radiographer protect a woman who is 3 months pregnant and is suspected of having a c-spine injury from a MVA? | Select smallest exp factors to produce a diagnostically useful image, adequately collimate to only the area of interest, shield the patients lower abdomen and pelvis |
| 6. Pediatric patients require special consideration and appropriate radiation protection because they are more vulnerable to: | Both the late somatic effects and genetic effects of radiation |
| 7. Why is a PA projection used for a juvenile scoliosis examination? | Lower entrance exposure dose to the anterior body surface, thereby significantly reducing the dose to the breast |
| 8. Federal regulations set forth for screening mammography facilities state that the mean dose to the glandular tissue for a 4.5cm compressed breast using a screen-film mammography system should not exceed what? | 3 mGy (300 rad) per view |
| 9. Duplicate of | 25 in workbook |
| 10. If 500 people were inhabiting the earth and each person received an Eqd of .005Sv (.5 rem) gonadal radiation, the gross genetic effect would be__________ the effect if 50 inhabitants received .05Sv (5 rem) of gonadal radiation. | Identical to |
| 1. Effective communication between the radiographer and the patient depends on what? | Verbal/nonverbal messages are congruent, so they are understood as intended; procedure is explained in simple terms, clear and concise instructions are given; patient can ask questions which are answered truthfully w/in ethical limits |
| 2. Interslice scatter during a CT scanning procedure results in: | Increase in patient dose |
| 3. Because no localizing light field exists and the field of view is usually moving during a fluoroscopic study: | A shadow shield is not suitable for use |
| 4. What results in an increase in patient dose? | Use of the lowest possible kVp with the highest possible mAs for each exam |
| 5. Duplicate of | 2 in book |
| 6. If a cross-table c-spine was taken with an 8:1 ratio grid & appropriate exp factors, then another radiograph is taken using an air gap technique and exp factors comparable to those used with the 8:1 ratio grid, the patient dose is: | About the same |
| 7. The skin and gonads of the patient receive a "double-dose" of x-radiation: | Whenever a repeat radiograph occurs as a consequence of human or mechanical error |
| 8. The benefits of a repat analysis program include: | |
| 9. The exposure of the fetus to radiation arising from diagnostic procedures: | Would rarely be cause, by itself, for terminating a pregnancy |
| 10. When an person of childbearing age undergoes a diagnostic procedure, gonadal shielding should be used to protect the reproductive organs from exposure: | When the reproductive organs are or w/in 5cm of the beam; unless shielding will compromise the diagnostic value of the exam |
| 11. What device is most often used to assess skin doses? | Thermoluminescent dosimeters |
| 12. The Image Gently campaign advocates lowering patient dose by: | Child-sizing the kV and mA; scanning only the indicated area; removing multiphase scans from pediatric protocols |
| 13. In computed tomography, which factors affect patient dose? | Changes in noise level; pixel size; slice thickness |
| 14. If 75% of the acive bone marrow were in the useful beam during a procedure, and were to receive an average absorbed dose of .4mGy (40mrad), what would the mean marrow dose be? | .3mGy (30mrad) |
| 15. The actual dose delivered during a computed tomography scanning procedure depends on the: | Type of scanner being used; radiation technical exp factors selected |
| 16. Digital mammography units with the ability to enhance contrast w/image gray level manipulation offers improvement for: | Patients with dense breasts |
| 17. To ensure a diagnostic image w/minimal patient dose, the technique chosen must ensure: | Adequate radiographic density; an adequate amount of contrast between adjacent tissue densities; sufficient penetration of the area of interest |
| 18. If a radiographic procedure will cause pain, discomfort, or any strange sensations, the patient: | Must be informed before the procedure begins, but the radiographer shouldn't overempasize this aspect of the exam |
| 19. The product of x-ray electron tube current & the amount of time in seconds during which the x-ray beam is activated results in: | mAs |
| 20. Negelecting to use standardized technique charts when AEC isn't used necessitates estimating the technical exp factors, which may result in: | Poor-quality images; repeat exams; unnecessary exp for the patient |
| 21. Duplicate of | 3 in book |
| 22. From a radiation protection point of view, the goal of CT imaging should be to obtain the best possible image while delivering: | An acceptable level of ionizing radiation to the patient |
| 23. CT scanning is considered a relatively high-radiation exposure diagnostic procedure because of increasing use of: | Multislice spiral CT scanners using small slice thickness |
| 24. If a pregnant patient is inadvertently irradiated, which medical professional should determine fetal dose? | Radiologic physicist |
| 25. What radiographic procedures are considered unnecessary? | Chest x-ray exam as part of a preemployment physical; chest x-ray exam for mass screening for TB; whole body multislice spiral CT scanning |
Created by:
StudyGroup