by vtxsue


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Front Back
Who discovered x-rays
Wilhelm Conrad Roentgen in 1901
What is physics
The science of matter and energy and of interactions between the two
What was the most common cause of death among early radiographers?
Electrocution
Matter
is anything that occupies space: gas, liquid, solid


made up of atoms and molecules
Mass
Quantity of matter
How is weight different from mass?
Weight is the mass of an object in a gravitational field
Is matter and energy interchangeable?
Yes, proven by Einstein's theory of relativity E=mc2
e= energy
m= mass
c= constant (speed of light)
Energy can neither be created nor destroyed, but can be converted from one form to another
Types of energy
  • Potential
  • kinetic
  • chemical
  • electrical
  • thermal
  • nuclear
  • electromagnetic
Natural Sources of Radiation
  • Cosmic
  • Terrestrial
  • Human radionuclides
ALARA
As Low As Reasonably Achievable
Basic radiation protection
  • Time-minimize exposure time
  • Distance-maintain a reasonable distance from the source
  • Shielding-shield persons whenever possible
      Shielding-shield persons whenever possible
Directly proportional
As you increase exposure time, radiation exposure increases
Inversely proportion
As you increase distance from x-ray source, radiation exposure decreases
mAs equates to
  • Quality of beam
  • Controls density
  • Major component of patient dose
kVp
  • Kilovolt peak
  • Energy of the beam
  • Quality of the beam
  • Major component of contrast of the film
  • Has some impact on density of the film
15% Rule
  • This rule states that an increas in kVp by 15% will cause a doubling in exposure (density/mass)
  • This is the same as doubling the mA or doubling the exposure time
Scientific Notation

n 173,562=
1.7 x 105

For numbers larger than zero move the decimal to the left
Scientific Notation

.002578=
2-6 x 10-3

For numbers less than one move the decimal to the right
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