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Midterm Review
Chapter 3
23
Health Care
Undergraduate 3
03/21/2015

Additional Health Care Flashcards

 


 

Cards

Term
what does kVp control
Definition
quality or penetrating power, contrast
Term
what does mAs control
Definition
quantity, density
Term
when x-rays enter human tissue they either:
Definition
interact with the atoms or pass through without interaction
Term
what are the benefits of low patient dose
Definition
reduced scatter and reduced occupational dose
Term
what is the target made of and why
Definition
tungsten because of high melting points and high atomic number
Term
what filtration of the x-ray beam is used
Definition
inherent and added (2.5 mm aluminum)
Term
what does filtration do
Definition
removes low energy x-rays decreasing patient dose
Term
what is the energy of the average photon
Definition
about 1/3rd the energy of the most energetic photon
Term
direct transmission
Definition
primary photons traverse the patient without interacting (forms the image)
Term
indirect transmission
Definition
when primary photons undergo compton and coherent interactions causing them to be scattered or deflected
Term
how to reduce scatter
Definition
air gaps and grids
Term
what are primary photons
Definition
exit or image-formation or small angle
Term
attenuated photons
Definition
scattered or absorbed, do not reach the IR
Term
is it possible to predict photons interaction with matter
Definition
no, it is random
Term
what 2 interactions with matter are important to diagnostic radiology
Definition
compton and photoelectric
Term
compton scatter
Definition
lower atomic number, higher energy photon which comes from a higher kVp
Term
photoelectric effect
Definition
higher atomic number, lower energy, lower kVp
Term
more attenuation=
Definition
less density ex)bones
Term
positive contrast
Definition
barium, iodine 56
Term
negative contrast
Definition
air
Term
pair production
Definition
happens at 1 million electron volts, interacts with nucleus, results in 2 new particles
Term
photodisintegration
Definition
10 MeV, radiation therapy
Term
what three things influence attenuation
Definition
atomic number, mass density, part thickness
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