Radiation Safety Flashcards
Bremsstrahlung x-rays
makes up most of primary beam, electron bounces off nucleus
somatic effects
stochastic (random probability)
carcinogesis
epilation
occurs in the individual exposed
most sensitive blood cell?
lymphocytes
x-rays are produced when?
fast moving electrons are rapidly decelerating
which stage are humans most sensitive to radiation?
embryonic
genetic effects
happens in future generations, in ovum
characteristic x-rays
electron knocks another electron, outer shell fills the hole
gestational dose limit
monthly 0.5 mSv
Total 5.0 mSv
filtration for x-ray tubes
2.5mm Al Eq required for all tubes operating above 70 kVp
two sources of radiation
natural (sun, elements)
man made (x-ray)
principles of exposure reduction
time
distance
shielding
what level does an x-ray photon interact with living tissue?
atomic
law of Bergonie and Tribondeau
the radio sensitivity of a cell is directly proportional to reproductive rate and is inversely proportional to its degree of differentiation
ionization
whenever an atom gains or loses an electron
most radio-resistant cells
neurons
muscle cells
RBCs
two processes involved in x-ray production
Bremsstrahlung
Characteristic
dose limit for general public
5 mSv / yr
where does the radiographer get their dose?
the patient/scatter
inverse square law
(I1/I2) = (D22 / D12)
occupational dose limit + formula
50 mSv
10mSv x age
direct hit
x-ray photon hits the DNA molecule and knocks the bases
cells degree of specialization
cells know exactly what their job is, less radio sensitive
indirect hit
x-ray photon and water molecule, majority of the time (95%)
Pb equivalencies
thyroid shield = 0.5mm Pb eq
fluoro/C-arm = 0.5mm Pb eq
Gloves = 0.25mm Pb eq
Glasses = 0.35mm Pb eq
