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RadRev 2010 Midterm
Rad Review 2010 Midterm Questions
| Question | Answer |
|---|---|
| Which of the following tissues is considered to be particularly radiosensitive? | Intestinal Mucus Membrane |
| An optically stimulated luminenscence dosimeter contains which of the following detectors? | Aluminum Oxide |
| All diagnostic xrays photons produced in the xray tube have which of the following characteristics? | Ionizing and travel at the speed of light |
| What is the annual dose limit for the lens of the eye? | 150 mSv/year |
| Point lesions occur when there is disruption in? | Single chemical bonds |
| The correct ways to check for cracks in the lead aprons is? | To fluoroscope them once a year |
| The positive electrode of the xray tube is the: | Anode (+) |
| Radiation induced abnormalities to the fetus during the 7th or 8th week of pregnancy is likely to cause which of the following? | Neurologic anomalies |
| The amount of time that xrays are being produced and directed toward a particular wall is referred to as: | Use factor |
| Which of the following is used to describe a fluoroscopic skin dose that exceeds 15 gy? | Sentinel event |
| How will xray photon intensity be affected if the SID is doubled? | Its intensity decreases four times. |
| The dose required to cause erythema in 50% of those exposed is roughly? | 5 Gy |
| The basic cardinal principles of radiation protection are: | Time, distance, and shielding |
| Skin erythema follows a ________ dose response relationship. | Deterministic, Threshold |
| Occupational radiation monitoring is required when it is possible that the individuals annual dose might exceed: | 5 mSv |
| Which of the following contributes most to patient dose? | Photoelectric effect |
| Gray may be described as: | Energy deposited in an absorber |
| Which of the following will produce the most significant increase in patient dose? | Decreased SID |
| The TLD dosimeter, lithium fluoride is most commonly used material due to its atomic number and attenuation of xrays. Which of the following is lithium fluoride similar to? | Soft Tissue |
| During a xray production at the target anode, which of the following interactions yields a photon of a discrete energy? | Characteristic production |
| To monitor radiation dose, pocket dosimeters utilize chambers filled with which of the following? | Air |
| Which of the following factors affect the amplitude of an xray emission spectrum curve? | Tube current, Exposure time and Added filtration |
| Which of the following statements is true about Shadow shielding? | They attach to the collimator box, and positioning is determined by adjusting the shield within the light field. |
| Examples of potential late (Stochastic) effects of ionizing radiation on humans can include? | Leukemia, Genetic defects, and malignant disease |
| In the production of characteristic radiation at the tungsten target, the incident electron: | Ejects an inner shell from the tungsten electron |
| According to the Bohr model, the neutral atom of oxygen (Z=8) will have how many valence electrons? | 6 |
| What is the single most important way to reduce patient exposure? | Restriction of the useful beam |
| When the radiographer selects kVp on the control panel, which device is adjusted? | Autotransformer |
| The unit of measurement used to express occupational exposure is: | Seviert (Sv) |
| A metal added to the cathode filament of the xray tube to increase thermionic emission and extend filament life is: | Thorium |
| Factors that affect xray emission spectrum curve on the x-axis are: | Tube voltage and Target material |
| Which of the following factors will affect both the QUALITY and QUANTITY of the xray beam? | HVL and kV |
| Factors that lead to High energy bremsstrahlung xrays when a filament (projectile) electron interacts with an anode tungsten atom? | Filament electron travels close to nucleus The nuclear electrostatic field creates a strong force of attraction on the passing filament electron, The filament electron arrives at the anode with HIGH kinetic energy Atomic number of tungsten is HIGH |
| All the following statements regarding DUAL xray absorptiometry are true except: | Radiation dose is considerable |
| The effects on radiation on biologic material depend on several factors, if a Quantity of radiation is delivered to a body over a long period of time, the effect: | Will be less than if it were delivered all at one time |
| The focal spot to table distance in mobile fluoro should not | Not be less than 30 cm |
| Gray is the unit of | Absorbed dose |
| Which of the following radiographic factors will affect the xray intensity at the IR? | kVp, SID, beam filtration |
| All of the following devices can be used to reduce patient dose, except: | Grid |
| Which interaction between xray photons and matter results in total absorption of the incident photon? | photoelectric effect |
| Occupational exposure received by the radiographer is mostly from: | Compton scatter |
| Irradiation of water molecules within the body and their resulting breakdown is termed: | Radiolysis |
| Types of secondary radiation is: | Scattered and leakage |
| The purpose of the xray tube housing is to: | Shield radiation workers from leakage radiation Support and protect the xray tube Contain cooling and insulating oil |
| When considering various types of radiation in regards to LET which of the following statements is NOT TRUE: | Beta particles have HIGHER LET than Alpha particles |
| Which is likely to improve image quality and reduce patient dose? | Beam restriction |
| Benefits on a primary beam include: | Increased penetrability and Increased quality |
| Which conditions make tissue more radiosensitive? | Tissue is composed of stem cells Tissue has a HIGH miotic rate Tissue is well oxygenated |
| The dose equivalent limit for a radiographer under the age of 18 is: | 1.0 mSv |
| The target theory applies to | DNA molecules |
| Which of the following are susceptible ways to monitor the radiation exposure of those who are occupationally employeed? | TLD and OSL dosimeter |
| Muscle tissue absorbs more radiation than fat tissue because muscle tissue has which of the following? | Higher tissue density |
| Electrons from the cathode filament that collide with K shell electrons within the Tungsten target yield which of the following? | Characteristic rays with a discrete emission of energy |
| The major function of filtration is to reduce | Patient dose |
| Which of the following cell types has the GREATEST radiosensitivity? | Lymphocytes |
| Any wall that the useful xray beam can be directed toward is called what | Primary barrier |
| The frequency of the xray photon is: | Directly proportional to its energy Inversely proportional to its wavelength |
| All of the following have an effect on patient dose except: | Focal spot size |
| Which of the following is NOT considered a somatic effect of radiation exposure? | Mutation effects in offspring |
| What is the intensity of scattered radiation perpendicular to and 1 m from a patient compared with the useful beam at the patients surface? | 0.1 % |
| Radiation dose of 5 Gy to the ovaries | Cause sterility |
| The average energy of the xray beam is increased by which of the following? | Increased added filtration and Increased Kilovoltage |
| The production of scattered radiation is dependent on which of the following factors: | Muscle mass Bone density Adipose tissue Pathology Fluide accumulation |
| Which is used to account for the difference in tissue sensitivity to ionizing radiation when determining effective dose E? | Tissue weighing factor |
| Reducing the number of repeat images is an important way to decrease the patient exposure and can be accomplished by: | Good patient communication Accurate positioning Using AEC |
| The radiation dose to an individual depends on which of the following? | Type of tissue interaction Quantity of radiation Biologic differences |
| Methods of reducing radiation exposure to patients and or personnel includ: | Beam restriction, shielding and High kVp/Low mAs |
| RBE and LET have what type of relationship? | Directly proportional / Direct relationship |
| Occupational dose limit to hands is | 500 mSv |
| Which is associated with Compton scatter? | High energy incident photon and Outer shell electron |
| Filtration is added to the xray beam to | produce an xray beam with higher average energy |
| As the radiographer increases KVP to compensate for decreased mAs when performing an xray, which accompanying changes would be expected? | Patient dose would decrease and Scatter striking IR would increase |
| A controlled area is defined as | Occupied by people trained in radiation safety Occupied by people who wear radiation monitors Occupancy factor is 1 |
| If a quantity of radiation is delivered to a body in a single dose, its effect: | Will be greater than if it were delivered in a number of doses over a long period of time |
| All of the following are functions to reduce patient dose except: | High ratio grid |
| Late or long term effects of radiation exposure are generally represented by which of the following dose response curves? | Linear nonthreshold |
| What percentage of xray attenuation does a 0.5 mm lead equivalent apron at 100 kVp provide? | 75% |
| Xray photon beam attenuation is influenced by? | Tissue type Subject thickness photon quality |
| Isotopes are atoms that have the same: | Atomic number but different mass number |
| At least how many HVLs are required to reduce the intensity of a beam of monoenergetic photons to less than 10% of its original value | 4 |
| Which of the following interactions between xray photons and matter is most responsible for patient dose? | The photoelectric effect |
| The interaction between ionizing radiation and a cell that is most likely to occur within the human body is termed: | Indirect action |
| Filtration increases beam quality through | Increase attenuation of low energy xrays, Increase HVL |
| The energy of an L characteristic ray is equal to the | difference in energy between the L & M shells |
| Following types of adult tissue is comparatively insensitive to effects of Ionizing radiation? | Nerve tissue and Muscle Tissue |
| Effective dose refers to | Whole body dose |
| Which of the following has been identified as a source of radon exposure? | Indoors (In house) and Smoking cigarettes |
| Which of the following tissues or organs is the most radiosenstive? | Small bowel |
| The dose response curve that appears to be valid for genetic and some somatic effects is the | Linear Nonthreshold |
| Term for electric charge flowing per second is | Current |
| What two rules of electrostatics occur at the focusing cup and function to confine the space charge to a smaller area thus focusing the beam of electrons onto the target anode? | Opposite charges attract while like charges repel Electrostatic force is proportional to the product of the charges and inversely proportional to the square of the distance between them. |
| The source of electrons within the xray tube is via | Thermionic emission |
| Which of the following is most likely to deliver the largest patient dose to the ovaries? | AP lumbar spine, 14x17 IR and 80 kVp |
| Major effects to DNA irradiation include: | Malignant disease Chromosome aberration Cell death |
| Differential absorption of the xray beam is dependent on: | Atomic number of irradiated tissues Beam quality Part density |
| Annual occupational dose to the whole body is | 50 mSv |
| Biological material is least sensitive to irradiation under which of the following? | Anoxic |
| The product of absorbed dose and weighing factor unit is | Seivert (Sv) |
| Which of the following methods is used to focus the electrons on the anode target of the xray tube? | Electrostatic repulsion |
| Long term somatic effects of radiation exposure? | Cataractogenesis and Embryologic effects |
| Which of the following statements regarding dual xray absorptiometry is true? | Low dose procedure Two xray photon energies are used Photon attenuation by bone is calculated |
| Considered the unit of exposure in air? | Air kerma |
| Each time an xray photon scatters, at 1 m from the scattering point, | It intensity decreases 1000 times |
| Which acute radiation syndrome requires the largest exposure before any effects become apparent? | Central nervous system |
| Possible anomalies when a pregnant uterus is exposed at 400 mgy in the third week of pregnancy are: | Skeletal anomaly and Organ anomaly |
| Which personnel radiation monitor will provide an immediately reading? | Pocket dosimeter |
| To eject a Kshell electron from a tungsten atom, the incoming electron must have an energy of at least: | 70 keV |
| Characteristics of xray photons include: | Penetrating effect on ALL matter An Ionizing effect on air |
| Possible responses to irradiation in utero include; | Spontaneous abortion Congenital anomalies Childhood malignancies |
| Hair loss caused by ionizing radiation is termed | Epilation |
| Which type of dose response relationship represents radiation included leukemia and genetic effects? | Linear Nonthreshold |
| Stochastic effects of radiation are those that: | May be described as "All or nothing" effect Are late in effects |
| The automatic exposure device that is located immediately under the xray table is the: | Ionization chamber |
| What is the component of the personnel dosimeters that can help evaluate radiation quality? | Filters |
| The annual dose limit for radiographers include radiation from which of the following? | Occupational exposure |
| The benefits of shadow shielding include: | Useful during surgery due to easier manipulation around sterile field |
| For a given exposure, the amount of scatter radiation produced by a large patient compared to that of a smaller patient is: | More than a smaller patient |
| When electrons in Air are ionized or excited, they only do so after absorption of energy supplied by an xray photon. Measuring the amount of energy, divided by the total mass of the air irradiated yields: | Air kerma |
| Dose area product (DAP) is an expression of | xray exposure in air based on a specific area |
| Which of the following personnel monitoring devices is commonly used in diagnostic radiography and considered to be the most sensitive and accurate? | OSL dosimeter |
| Following methods could be used to reduce radiation exposure and patient dose? | Provide clear patient instructions Apply the 15% rule Use anatomical compression |
| Cummulative occupational effective dose is calculated as follows: ________ x age in years | 10 mSv |
| A free radical is a (n) ______ molecule with a single unpaired electron in the _______ shell. | Uncharged, Outer |
| A dose of 250 mGy to the fetus during the 4th and 5th week of pregnancy is most likely to cause which of the following: | Skeletal anomalies |
| Damage to the DNA double helix latter structure, which results in spurs that form unintended bonds that join the macromolecule into irregular loops is called? | Cross-linking |
| Which of the following CELLS is least radiosensitive? | Myocytes |
| Xrays within the xray beam that do not reach the image receptor during a radiographic exposure of an anatomic part describes which of the following? | Attenuation |
| Neck and thyroid shields should be of an equivalent thickness of: | 0.5 mm Pb |
| Transparent shields used for scoliosis series radiography contain which of the following? | 30% lead |
| Which of the following techniques can reduce scattered radiation to the IR and improve image quality? | Body part compression and Grid usage |
| What is the term used to describe the xray photon interaction with matter and the transference of part of the photons energy to matter? | Scattering |
| Cone cutting or cut off from cylinder or cone extensions for beam restriction is caused by misalignment of the: | Tube, Cone or cylinder and image receptor |
| The primary xray beam consists of | Combination of both bremsstrahlung and characteristic xrays |
| As the xray tube filament ages, it becomes progressively thinner because of evaporation/vaporization. The vaporized tungsten is frequently deposited on the window of the glass envelope. This way | Act as a additional filter Reduce the tube output Result in arcing and tube puncture |
| Somatic effects of radiation refer to effects that are manifested | During the life of the exposed individual |
| Patient dose increases in fluoroscopic | FOV decreases |
| The xray unit of Exposure defines what | Air kerma |
| What are non-dividing differentiated cells? | Neurons and Neuroglia |
| Leakage radiation should not exceed: | 1 mGy/hr at 1 m from the xray tube |
| All of the following radiation exposure responses exhibit a Nonlinear threshold dose response relationship except | Leukemia |
| The annual dose limit for occupationally exposed individuals is valid for | Beta, X rays, and Gamma rays |
| Which groups of exposure factors will deliver the LEAST patient dose? 300 mA, 250 ms, 70 kVp 300 mA, 125 ms, 80 kVp 400 mA, 90 ms, 80 kVp 600 mA, 30 ms, 90 kVp | 600 mA, 30 ms, 90 kVp |
| Ring badges often issued to nuclear med and IVR techs to monitor dose to the hands, are typically which type of dosimeter? | TLD |
| Which of the following influence the average energy of the primary xray beam? | kVp, Filtration and Bremsstrahlung interaction |
| In addition to shielding, which of the following choices will best reduce the patient dose during a radiology exam? | Decreasing mAs, and Increasing collimation |
| The most efficient type of male shielding is called | Shaped contact (contour) |
| Which of the following will most likely result in the greatest increase in patient exposure? | Changing from nongrid technique to 8:1 grid technique |
| The advantages of beam restriction include which of the following? | Less scattered radiation is produced Less biologic material is irradiated |
| Thermoluminescent dosimetry systems use which of the following crystals? | Lithium Fluoride |
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