Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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As the beam passes through a body, there is a shift in energy distribution so
that a large fraction of the remaining photons have a higher energy. This spectral shift is
called:
a. | spectroscopy | c. | attenuation | b. | transmission | d. | beam hardening |
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2.
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More photons reaching the detectors will result in lower quantum noise in the
images, but the radiation exposure to the patient will _______
a. | improve | c. | increase | b. | decrease | d. | remain
stationary |
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3.
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Within the X-ray tube is a cathode that has a very small ______, which is
several millimeters in length.
a. | anode | c. | filament | b. | electrical potential | d. | vacuum |
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4.
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Higher energy X-ray photons are needed to penetrate which of the
following?
a. | a,b,c only | d. | all of the above | b. | shoulder bones | e. | vertebrae bones | c. | hip
bones | f. | skull |
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5.
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Characteristic X-rays are produced following the ionization of an atom that
leaves an inner shell, typically the _____, with an electron valancy.
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6.
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For a typical Whole Body PET/CT study, the average kVp is set between:
a. | 60-120 kVp | c. | 80-110 kVp | b. | 80-140 kVp | d. | 100-150 kVp |
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7.
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The purpose that an anode rotates many of thousands of times per minute is to
a. | cool the cathode | d. | a and c | b. | all of the above | e. | prevent the beam from burning the
anode | c. | dissipate heat |
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Matching
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Match the advantages and disadvantages of using a higher kVp on a
patient. a. | Advantage | b. | Disadvantage |
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8.
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Greater penetration through the body
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9.
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Higher doses to patient
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10.
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Reduces differences in tissue densities
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11.
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Decrease in quantum noise
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12.
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Reduction in beam hardening artifacts
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True/False
Indicate whether the
statement is true or false.
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13.
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“Bremsstrauhlung” radiation is a German word meaning
“braking” radiation.
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14.
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A general rule is that an increase of approximately 15% in kVp is roughly
equivalent to doubling the mAs.
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15.
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Within the x-ray tube, there are two different types of reactions that produce
Bremsstrauhlung radiation and Characteristic X-rays.
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16.
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An increase in the high voltage applied to the X-ray tube will result in a
corresponding increase in the maximum energy of the X-rays that are produced.
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17.
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The closer the distance between the electron and the nucleus, the greater the
deceleration of the electron and the higher the X-ray energy emitted.
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18.
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The energy loss is released as electromagnetic radiation (gamma rays) with a
specific or characteristic energy determined by the energy difference between the two shells.
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19.
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The outer shell electron that drops in to fill in the inner shell vacancy must
lose energy.
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20.
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Higher energy X-rays are attenuated more by the body.
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21.
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The X-ray tube is a glass shell envelope that contains a high vacuum so that
accelerated electrons from the internal electrodes may move with ease.
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