Franks midterm

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Franks midterm
2011-02-18 22:18:26

franks quiz questions for midterm review.
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  1. define penumbra
    fuzzy border, a geometric unsharpness around the periphery of the image
  2. the beam of photons, before it reaches the patient is called ________________ radiation
  3. the individual packets of energy contained in the primary beam are called__________
  4. the beam that exits the patient is called______________
    remnant radiation
  5. radiation that is non-diagnostic is called_____________
    scatter radiation
  6. the process by which the nature of the primary beam is altered as it passed through the patient is called _____________
  7. materials that allow x-ray photons to travel through them easily are _______________
  8. materials that are not easily traversed by x-ray photons are ______________
  9. the invisible image recorded on a film that has not been processed is called __________
    latent image
  10. automatic processing of a radiographic image requires approximately ___________ seconds
  11. the radiographer has control of what technical factors?
    mAs, kVp, SID
  12. SID is the distance between _______________
    the source of the x-rays to the IR
  13. the overall blackening of a film is called
  14. the visible differences between densities is called
  15. the distinct representation of an object's true borders is called
    recorded detail
  16. the misrepresentation of an object's true size or shape is called
  17. to produce a mAs of 10 you would use 200 mA at _____________ seconds
  18. to change kVp while maintaining exposure you would
    a. increase kVp by 15% and reduce mAs by half

    b. decrease kVp by 15% and increase mAs by 50%
  19. according to the inverse square law, if distance is doubled, intensity decreases to __________ the original value
  20. _____________ is the chief controlling factor of contrast
  21. high kVp produces an image with a ___________ scale of contrast
  22. define the inverse square law
    the intensity of the beam is inversely proportional to the square of the distance to the source.
  23. a ______________ is a device that is designed to remove scattered photons before they reach the IR
  24. as mAs is increased, density is _______________
  25. ____________ is the chief controlling factor of exposure and density
  26. define attenuation
    the reduction of the number of x-ray photons in the beam, and the subsequent loss of energy, as the beam passes through matter
  27. _______________ directly controls the quality of the x-ray photons produces.
  28. ________________ directly controls the quantity of the x-ray photos produced
  29. ________________ is affected by patient motion.
  30. the ________________ focal spot is used when fine detail is required.
  31. the distance between the object being imaged and the IR is
  32. the most common cause of image unsharpness is _____________
  33. the purpose of beam modification is _____________
    scatter control
  34. scatter is_____________
  35. the fluoroscopic image is a _________________ image
  36. shape distortion may appear as _______________ or _______________
    elongation, foreshortening
  37. the major influences on magnification are __________ and _____________
  38. define the half value layer
    the amount of absorbing material that will reduce the beam intensity to one half of its original value
  39. the ___________ is the medium used to capture the image
  40. when electrons strike the target in the tube about ________% of the interaction results int eh production of x-rays and _________% is converted to heat.
    1%, 99%
  41. the part of the radiographic system that produces the x-rays is the ___________
    x-ray tube
  42. the primary components of the x-ray tube are the ____________ and _____________
    anode and cathode
  43. give an example of a beam limiting device
  44. most x-ray machines are equipped with an automatic collimator known as __________________
    PBL, Positive beam limitation device
  45. free floating, hi/lo, tilting are classifications of x-ray _____________
  46. 90-90 tables can tilt from a _________________ position to a complete _______________ position in either direction.
    horizontal, vertical
  47. a cassette tray is also called a _________ tray
  48. the cathode is the ______________ side of the x-ray tube
  49. the ________________ control the size and shape of the x-ray field
  50. t/f turning on the power to an x-ray machine activates x-ray production
  51. one Kilovolt is equal to ____________
    1000 volts
  52. one milliampere is equal to ____________
    1/1000 of an ampere
  53. t/f most diagnostic radiography is done between 100 and 400 mA
  54. what does the rotor exposure switch do?
    begins the exposure
  55. t/f simultaneous depression of the rotor switch and the exposure switch allows the exposure to be made as soon as the tube is ready
  56. the device that supports the x-ray tube and allows it to move in different directions
    tube stand
  57. the directions that the tube can travel are _______________
    longitudinal, transverse, vertical
  58. t/f x-ray tubes have manual and electric locks
  59. t/f a wall mounted cassette holder includes a bucky mechanism
  60. t/f a wall mounted bucky unit is similar in function to a radiographic table
  61. where is the x-ray tube located in a fluoroscopic unit?
    in the table
  62. in the fluoroscopic unit, the x-ray tube moves with the _____________
    image intensifier
  63. what device allows the radiologist to obtain static images during a fluoroscopic examination?
    spot film device
  64. which piece of equipment is used when radiographic equipment must be taken to the patient?
    mobile equipment
  65. regarding beam limitation, the size of the x-ray beam should always be restricted to the ________ and collimation should be evident on _____________ sides of the image
    region of interest, all 4
  66. according to the NRC regulations the embryo/ fetus dose for an entire pregnancy cannot exceed ________ mSv, _____________ rem, or __________ mrem
    5mSv, .5 rem, 500 mrem
  67. the __________ is the regulatory agency responsible for protecting both the public and occupationally exposed individuals from the effects of ionizing radiation.
  68. when no threshold dose for radiation exists, this effect is known as ____________
  69. _______________ is the deterministic effect of ionizing radiation on the eyes
  70. radiation exposure limits pertinent to the protection of radiation workers are known as __________ limits
  71. the annual effective dose limit for an occupational exposure to ionizing radiation is _____________ rem
  72. the annual effective dose limit for an occupational exposure to ionizing radiation is _______________ mrem
  73. the annual effective dose limit for the general public to ionizing radiation is __________ rem
    .5 rem
  74. what is the dose limit for a 21 year old radiation worker?
    210 mSv
  75. what are the 3 cardinal principals of radiation protection?
    time, distance, and shielding
  76. if the distance between the individual and the source of radiation is double, the exposure to the individual will be reduced by ______________
    a factor of 4
  77. for an individual to reduce exposure by a factor of 25, the distance between the individual and the source should ____________
    by a factor of 5
  78. secondary barriers protect against _____________ and _____________
    scatter and leakage
  79. list 2 protective devices
    glove, apron, thyroid shield, lead glasses
  80. protective aprons and gloves are usually made of lead-impregnated vinyl within the range of ____________ lead equivelancy
  81. for fluoroscopic procedures with a kVp of 100 or more, the protective apron must possess a minimum of ___________ lead equivalency
  82. proper collimation _____________ scatter radiation
  83. using technical factors where _____________ kVp and ____________ mAs are chosen to minimize patient dose
    high kVp, low mAs
  84. the NCRP recommends a minimum total filtration of _______________ for x-ray equipmentoperating above 70 kVp
    2.5 Al/Eq
  85. the use of a grid in a radiographic procedure will result in a ___________ in patient dose
  86. special gonadal shields should be employed any time the gonads are within ______________ cm of the primary beam
  87. the lenses of the eyes will receive the greatest dose during what procedure?
    AP skull
  88. the fetus is most sensitive during __________ post contraception
    8-15 weeks
  89. what does ALARA stand for?
    as low as reasonably achievable
  90. compound filters use_________ or more materials to enhance the absorbing ability of the filter
  91. the the percentage of attenuated photons________ as energy increases even when filtration is increased
  92. when filtration is increased, technical factors must be ________________ to maintain the dame density
  93. total filtration is equal to the sum of _________ and _________ filtration
    inherent and added
  94. does filtration remove a portion of the useful beam?
  95. the __________ portion of a wedge filter is placed over the less dense part of the patient
  96. any filtration that occurs outside the tube and housing is considered__________
    added filtration
  97. __________________ filtration is the filtration found inside the tube design
  98. in diagnostic radiology, filtration is typically added between the ______________ and the ___________
    source and the patient
  99. filtration is the process of eliminating the undesirable _____________ x-ray photons by the insertion of absorbing materials into the primary beam
    low energy
  100. filtration permits the radiographer to ____________ the photon emission spectrum into a more useful beam
    narrow or harden
  101. increased filtration __________ patient dose
  102. in general, low energy x-ray photons are _________ by the patient
  103. name 3 materials considered filters in the x-ray tube
    aluminum, glass, oil
  104. the most common filter material used is __________
  105. all filtration can be expressed in terms of _________
    Al/Eq aluminum equivalency
  106. the collimator is categorized as ____________ filtration
  107. how many half value layers must be added to the primary beam to reduce intensity to less than 20% of its original value?
  108. the problem of unequal subject density is solve by the use of a _________________ filter
  109. reducing agents provide ________ to the silver ions attached to the sensitivity specks
  110. fixing is the process of removing _____________
    undeveloped silver halides
  111. dryer system air dries the _________ and seals the _________
    emulsion, supercoat
  112. the usual storage time for radiographic film is _____________
    5-7 years
  113. the average time to process film in an automatic processor is about ____________
    90 seconds
  114. the pass box is used to pass _____________
    film cassettes
  115. most darkrooms are equipped with a dark red ______________
    filter safelight
  116. darkroom walls should be ________ in color because reflected light is lower in intensity
  117. the recovery system is used to remove ___________ from the _________
    silver, fixer solution
  118. about __________ of the silver is removed from the emulsion after processing
  119. scrap film is a valuable source of ___________ for a radiology department
  120. the primary purpose of radiographic film processing is to _____________
    convert the latent image into the visible image
  121. the most variable and sensitive factor in the production of a radiograph is the __________
    film processor
  122. what are the 4 primary steps of automatic processing?
    developing, fixing, washing, drying
  123. the image becomes visible during ___________
  124. the primary chemical agents in the developer are called ___________
    reducing agents
  125. the primary agents in the fixer are called ___________
    clearing agents
  126. if the fixer is not cleared from the film, it may result in a film that will become _________________
    yellow then brown with age
  127. a stable black metallic silver atom is formed when a positive silver ion obtains an
  128. reducing agents __________ positive silver ions
  129. when unexposed silver halides are reduced by a solution with high concentration, this is called ___________
    chemical fog
  130. if silver halide crystals have more than 3 silver atoms on their sensitivity specks, the crystal will be able to be ____________
  131. the reducing agents used in automatic processors are _______________ and _____________ and are sometimes called _____________
    phenidone, hydroquinone, PQ developer
  132. _____________ quickly reduces silver, enhancing fine detail
  133. ___________ is the reducing agent that works only in areas of light exposure
  134. ____________ is the reducing agent that slowly reduces silver, producing heavy density
  135. when ___________ and ___________ are combined, their reducing ability is greater that the sum of their independent abilities. this phenomenon is known as ______________
    pheidone, hydroquinone, superadditivity
  136. as the developer is in its final stages of oxidation, its color will change to __________
    rusty red
  137. the restrainer added to the developer is ___________
    potassium bromide
  138. the preservative agent added to both the developer and the fixer is ______________
    sodium sulfite
  139. the most common developer solution hardener is _____________
  140. the solvent used in both developing and fixing is ___________
  141. the ______________ is most affected by contamination
  142. a film developed in contaminated developer will exhibit ________________
    low contrast
  143. the most common cause of developer contamination is ____________
  144. the processor lid is propped open when the processor is not in use to prevent ______________
  145. a clearing agent will bond with ___________ silver halides
  146. the most commonly used clearing agents found in fixer solution is ________________
    ammonium thiosulfate
  147. fixer becomes saturated with ___________
    silver ions
  148. developer has an ____________ PH, while the fixer has an ______________ PH.
    alkaline, acidic