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57 Cards in this Set
- Front
- Back
the principle parts of an xray imaging system designed to provide a large number of electrons with high kinetic energy focused towards a small spot on the anode
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operating console, high voltage generator, xray tube
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energy of motion
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kinetic energy
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if electrons have the same mass, how do you increase electrons kinetic energy
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raising kVp
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as election kinetic energy is increased, both the intensity (____) and the energy (____) of the xray beam are increased
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quantity, quality
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at 100 mA , _____ electrons travel from the cathode to the anode of the xray tube every second
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6x10 to the 17th
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keV
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kiloelectron volt
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at 70 kVp, each electron arrives at the target with a maximum kinetic energy of
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70 keV
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the distance between the filament and xray tube target is only ___cm
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one
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electrons traveling from cathode to anode constitute the xray tube current and are sometimes called
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projectile electrons
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what happens when projectile electrons hit the heavy metal atoms of the xray tube target
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they transfer their kinetic energy to the target atoms
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these interactions result in the conversion of electron kinetic energy in _____ energy (heat) and electromagnetic energy in the form of ______ (also heat) and xrays
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thermal, infrared radiation
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most of the kinetic energy of projectile electrons is converted into
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heat
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projectile electrons do not have enough energy to ionize these outer shell electrons, there they simply
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excite, or raise to a higher energy level
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outer shell electrons immediately drop back to their normal state and emit
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infrared radiation
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how much of the projectile's kinetic energy is converted into heat
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99%
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approximately how much of the projectiles electrons kinetic energy is used for the production of x radiation
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1%
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the production of heat in the anode increases directly with increasing
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xray tube current
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at 60 kVp only ____ of electron kinetic energy is converted to xrays
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.5%
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at 100 kVp approximately ___ is converted to xray
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1%
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at 20 MV ____ is converted to xray
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70%
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if a projectile electron interacts with an inner shell election of the target rather than with am outer shell electron, this is a
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characteristic xray
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emitted when an outer shell electron fills an inner shell void
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characteristic xray
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the transition of an orbital election from an outer shell to an inner shell is accompanied by the emission of
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xray
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electrons in outer shell have to give up energy to get to a lower this is an example of what type of energy
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inherent energy
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how can you calculate the energy given up from each shell
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by its binding energy
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when a K shell electron is ionized it can be filled with an electron from any of the outer shells, these xrays are called
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K xrays
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projectile electrons pass by the nucleus, it is slowed down and changes it's course, leaving it with less kinetic energy in a different direction, the loss of kinetic energy reappears as
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xrays
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produced when a projectile electron is slowed by the nuclear field of a target atoms nucleus
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Bremsstrahlung xray
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what does Bremsstrahlung mean
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slowed down radiation
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can be considered radiation that results from the breaking of projectile electrons by the nucleus
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Bremsstrahlung xray
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in the diagnostic range most xrays are
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Bremsstrahlung xrays
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what does a discrete spectrum only contain
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specific values
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a continuous spectrum contains
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all possible values
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what xrays are the only characteristic xrays of tungsten with sufficient energy to be of value in diagnostic radiology
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K xrays
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what xrays have a range of energies and form a continuous emission spectrum
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Bremsstrahlung
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t or f is the shape of the bremsstrahlung xray spectrum is the same for all xray imaging systems
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true
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the maximum energy (keV) of a bremsstrahlung xray is numerically equal to the ___ operation
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kVp
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xray energy is inversely proportional to it's wavelength. As xray wavelength increases, xray energy ____
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decreases
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the farther to the right a spectrum is the higher the effective energy or ___ of the xray beam
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quality
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the larger the area under the curve the higher is the xray intensity or ___
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quantity
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if one changes the current from 200 to 400 mA while all other conditions remain constant, twice as many electrons will flow from the cathode to the anode and the mAs will be
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doubled
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in other words the xray emission spectrum will be changed in ___ but not ___
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amplitude, shape
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when kVp is increased the relative distribution of emitted xray energy shifts to the ____ to a higher average xray energy
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right
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a change in kVp affects both the ____ and the ____of the xray emission spectrum
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amplitude, position
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adding filtration to the useful beam reduces xray beam ___ while increasing the average _____
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intensity, energy
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the result of added filtration is an increase in the average ____ of the xray beam with an accompanying reduction in xray _____
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energy, quantity
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adding filtration is sometimes called _____ the xray beam because of the relative increase in average energy
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hardening
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what spectrum is not affected, nor the maximum energy of xray emission when filtration is added
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characteristic
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the atomic number of the target affects both the number (____) and the effective energy (____) of xray
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quantity, quality
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as the atomic number of the target material increases the efficiency of the production of bremsstrahlung radiation ____, and high energy xrays ___ in number to a greater extent than low energy xrays
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increase, increase
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increasing rather atomic number enhances the efficiency of xray production and the energy of ____ and ______ xrays
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characteristic, bremsstrahlung
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a high voltage ripple is
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bad
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an increase in current (mAs) results in
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an increase in quantity, no change in quality
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an increase in voltage (kVp) results in
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an increase in quantity and quality
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an increase in added filtration results in
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a decrease in quantity and an increase in quality
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an increase in target atomic number (Z) results in
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an increase in quantity and quality
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an increase in voltage ripple results in
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a decrease in quantity and quality
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