scientific principles Flashcards
what does kV stand for
Energy of X-Rays emerging from X-Ray tube(kV)
What does kVp stand for ?
Maximum energy of X-Rays from X-Ray tube
Higher kV =
higher penetration
how do we measure kV?
joules per Coulomb
what does kv stand for ?
kilo volatge
What does mA stand for ?
Milli amps
define current
Number of X-Rays emerging from X-Ray tube
what is current measured in ?
mA
Higher mA higher number of photons=
Higher intensity
what does mAs stand for ?
Milli Amp Seconds
def mAs
Product of mA and length of time X-Rays are produced
how can we change mAs ?
Vary mA or time to get different mAs
Not enough mAs =
Not enough photons
Lack of photon density and contrast as a result of low mAs can result in ?
Low “photon density”
what can not enough kV result in ?
-not enough energy to penetrate:
-Tissue Density
-Tissue Thickness
what is another result of low kV ?
Very “black and white” images
what can high mAs result in ?
Too many photons
high “photon density”
if to many photons hit the image receptor what can occur
loss of visible anatomy
Reduced contrast
def di
di value is a feedback system which tells you whether or not the exposure you are giving is optimal
what can too high kv result in
High energy and so can penetrate too much
High energy and so can penetrate too much (high kV) why is this bad ?
Loss of visible anatomy
Low contrast
Image appears “grey”
list the properties of an x-ray tube ?
Deceleration of fast moving electrons
Radiation protection and primary beam
Electrical protection
Dissipation of heat
elections go from ca… to a…. in x-ray tube ?
cathode and anode.
