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58 Cards in this Set
- Front
- Back
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At the anode of the xray tube, the energy of electrons may be change into what type of energy?
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Heat and Xray
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When electrons are decelerated in the the process of xray production, their energy is converted to
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heat and xray
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the term that refers to the quantity of electrons moving from the cathode to the anode in the xray tube is ...
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Millamperage
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An xray bean in which all the photon have the same energy is said to be ....
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homogeneous and monenergetic
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The total quanity of electricity which flowed through a circuit during an exposure is measured by ...
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mAs
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The number of xrays produced in the beam is ...... proportional to the number of electrons striking the anode
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Directly
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Radiation is emitted when an outer shell electron fills the orbit of a vacant inner shell. This type of radiation is described as what?
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Characteristic
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The release of electrons by manipulatin of current, producing extreme temperatures on the filament is known as?
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Thermionic emission
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In most xray tubes, there are two filaments to ...
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provide two focal spots
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Increasing the temperature of the xray tube filaments increases the
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mA
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The heel effect occurs because of ...
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the xray absorption at the anode
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Tungsten is the choice material for xray anodes because of its ..
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high atomic number
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Which of the following components of a diagnostic xray tube is on the positive side ofthe tube? Cathode, filament, focusing cup, stator
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the Stator
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What is defined as the production of xray photons by the electrostatic attraction between the incident electron and the nucleus of the tungsten atom
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bremsstrahlung interaction
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What is the source of radiation within the tube?
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Anode (created, focal spot is the actual place of production of radiation (anode side)
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An increase in the kilovoltage applied to the tube results in .... wavelenths
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Shorter
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What device is turned by a rotor?
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Anode
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During an exposure most of the .... energy of the projectile electons is converted to ...
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Kinetic, heat
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Electron interactions at the inner shell of the target produce ... radiation
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characteristic
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Most of the xrays produced at the target are
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bremsstrahlung
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Characteristic xrays are produced by
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released binding energy
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Bremsstrahlung xrays are produced by
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slowing electrons
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Approximately what percent of the energy of the projectile electons is converted to xrays at the target?
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One percent
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Increasing the kVp will do which of the following? decrease tube current, increases the speed of electrons, increase beam quality
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increases the speed of electrons & increase beam quality
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The number of lead strips per inch in a grid is a measure of ...
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grid frequency
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What determines visibility of detail in a radiograph
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density and contrast
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Low energy radiation will result in what scale of contrast?
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Short scale
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Why is contrast needed on a radiographic image?
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makes detail visable
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What is the effect of scatter radiation on the radiograph?
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produces fog
is detrimental to visibility it destroys contrast |
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What is a method of limiting the production of scatter radiation?
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Restricting the beam
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If all factors remained the same, increasing the SID would have what effect on the density of the radiograph?
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less density
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Radiographic Density refers to...
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the amount of overall blackening on a radiograph or a particular part of the radiograph
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which factor is most often manipulated if a radiograph must be repeated becuase it is too light or too dark?
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mAs
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What is the effect on the xray when exposure time is longer?
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the number of photons emitted by the xray tube is larger
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A higher kVp usually has what effect on scatter?
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Increases the amount of scatter radiation produced.
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For maintaining the original desnity, mA and exposure time combinations are...
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inversely proportional
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Radiographic distortion can be seaprated into two categories.. What are they?
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Size and shape
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what will minimize the amount of distortion that is recorded on the finished radiograph?
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Long SID and Short OID
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What is used to determine grid ratio?
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The height of the lead strips divided by the space between the lead strips.
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What will produce a decrease in contrast without changing density?
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increasing kVp and decreasing mAs (15% rule and density maintenance)
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Which primary radiographic exposure factors are controlled by geometric factors such as distance?
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Recorded Detail
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Which conditions contribute to increased recorded detail?
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Small effective focal spot size, long SID, Short OID
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What will produce visible changes in radiographic contrast?
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Primary Beam field size and Grid Ratio
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What physical interactions between radiation and matter most assists in producing long scale contrast?
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Compton Effect = Fog
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What can minimize magnification?
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Decreased OID
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What factors affect radiographic image density?
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Distance
Grids Anatomic Part size |
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What interaction between xrays and matter most assists in producing high contrast?
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Photoelectric
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What factor will cause loss of recorded detail?
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Subject motion
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The undesirable absorption of image-forming xrays by a grid is called...
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Grid cutoff
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What is the simplest type of grid?
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Parallel grid
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If radiographic grids are used and technique is compensated, patient exposure ...
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increases with increasing grid ratio
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What is an indesirable characteristic of parallel rids compared to focus grids?
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More grid cutoff
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What is the result of replacing an 8:1 grid with a 12:1 grid?
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Higher contrast
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... is the loss of some of the energy from the xray beam as it passes through the tissue being imaged.
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Attenuation
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..... is the term to descrive what happens when the xray phon travel through the part completel.
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Penetration
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Density if a ..... property of the radiographic image.
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Photographic
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Contrast is a .... property of the radiographic image.
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Photographic
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What is the minimum change in the radiographic density.
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30%
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