Radiograph equipment Flashcards
which type of anode allows for the use of higher mA and kVp settings without concern for anode damage?
rotating anodes
how often should x-ray machines be tested for quality assurance?
every 2 years
mA
milliamperage
kV
kilovoltage
s or mAs
time
what does the mA setting do?
it’s used to control the quality of electrons that will be produced and released from the filament
when an adjustment is made to the mA, the density of the finished radiograph is affected
what is the density of the radiograph like when using a higher mA setting?
increased density and degree of blackness
what is the density of the radiograph like when using a lower mA setting?
the density is lightened and the film is less black
what does kV refer to?
the energy of the electrons when they reach the anode
what does the kV setting do?
controls the acceleration of electrons and their striking energy or quality of the x-ray beam
higher kVp=
more penetrating power that the x-ray beam will have
what kVp setting is needed for thicker tissues?
increased kVp is needed to penetrate the tissue and reach the cassette
contrast
shades of gray that are produced on the finished radiograph
greater number of shades of gray present, the higher the quality of the image will be
what are higher kVp and lower mA settings used for?
soft tissue
what are lower kVp and higher mA settings used for?
extremities where sharper differences are needed with fewer shades of gray
time
duration that controls the quantity of electrons released
what settings are used to reduce risk of blur due to patient movement?
higher mA and lowest time possible
how do you work the pedal when taking an x-ray?
push it half-way down to initiate pre-exposure switch and begin exciting the electrons while the anode starts to rotate
once the machine has enough excited electrons and the anode is at the correct speed the x-ray light will illuminate
as the foot pedal is fully depressed the electrons are released from the cathode, striking the anode and are directed down toward the patient and the cassette
what are cassettes used for in radiographs?
the blank film is placed inside of it to protect it from light exposure
can be plastic, light metal, or graphite
what are the criteria a cassette has to fit to be used for radiographs?
sturdy under patient’s weight, weather resistant, inflexible, have secure properly functioning latches, have a radiolucent front cover, contain lead foil backing to absorb and decrease scatter radiation, contain a washable outer covering, ensure good intensifying screen contact
what is inside the cassette?
intensifying screens that are white with a smooth shiny surface and made from tiny crystals that fluoresce once exposed
helps increase the contrast of an image
what are the different intensifying screen speeds?
fast, regular, medium, par, and detailed
what does the grid do?
decreases scatter radiation while increasing contrast
using a grid requires more time since the grid absorbs some of the primary x-ray beam
what is the grid made of?
thin linear strips of alternating radiodense (lead) and radiolucent material (plastic, aluminum, fiber)
