Ch 1 Essential Concepts of Radiologic Science Flashcards
matter:
anything that occupies space and has mass, the material substance that physical objects are composed of
all matter is composed of fundamental building blocks:
atoms
mass:
the quantity of matter contained in any physical object (weight)
mass is measured in:
kilograms (kg)
energy:
the ability to do work
potential energy:
the ability to do work by virtue of position
kinetic energy:
energy of motion
chemical energy:
energy released by a chemical reaction
electrical energy:
represents the work that can be done when an electron moves through an electric potential difference (voltage)
thermal energy (heat):
the energy of motion at the molecular level
nuclear energy:
the energy contained within the nucleus of an atom
electromagnetic energy:
type of energy used in x-rays, includes radio waves, microwaves, and ultraviolet, infrared, and visible light
radiation:
the transfer of energy
matter that intercepts radiation and absorbs part or all is said to be:
exposed or irradiated
ionization:
the removal of an electron from an atom
the only forms of electromagnetic radiation with sufficient energy to ionize are:
x-rays, gamma rays, and ultraviolet light
particle-type ionizing radiation are:
alpha and beta particles
natural environmental radiation has an annual dose of:
3mSv
man-made environmental radiation has an annual dose of:
3.2mSv
natural environmental radiation comes from:
cosmic rays, terrestrial radiation, internally deposited radionuclides, and radon
the largest source of natural environmental radiation is:
radon, radon emits alpha particles which are not penetrating and only contributes a radiation dose to the lungs
the largest source of man-made environmental radiation is:
diagnostic x-rays
x-rays were discovered:
on November 8, 1895 by Roentgen at the Wurzburg University in Germany using a Crookes tube
by exposing two glass x-ray plates with the emulsion surfaces together:
exposure time was halves and the image was considerably enhanced
fluoroscopy was developed:
in 1898 by Thomas Edison
Radiology emerged as a medical specialty because of:
the Snook transformer and the Coolidge x-ray tube
the first x-ray fatality in the US occurred in:
1904
in early years radiation injuries included:
skin damage, loss of hair, anemia and leukemia
filters are used for:
inserted into the x-ray tube housing so low energy rays are absorbed before they reach the patient
collimation is used for:
restriction of the primary beam and spares the adjacent tissues from unnecessary radiation exposure
intensifying screens are used for:
reducing the exposure of the patient to x-rays by more than 95%
physics:
the study of interactions of matter and energy is all their diverse forms
the base quantities include:
mass, length, and time
the secondary quantities include:
energy, power, work, momentum, force, velocity, and acceleration; they are derived from a combination of the base quantities
the special quantities include:
exposure, dose, effective dose, and radioactivity; they support measurements
the second (s) is based on:
the vibration of atoms of cesium
every measurement has two parts:
a MAGNITUDE and a UNIT
mechanics:
deals with objects at rest (statics) and objects in motion (dynamics)
the motion of an object can be described by two words:
velocity and acceleration
velocity is:
(speed) a measure of how fast something is moving or the rate of change of its position with time
acceleration is:
the rate of change of velocity with time, how quickly or slowly the velocity is changing
if the velocity is constant, the acceleration is:
zero
the fundament laws of motion were created by:
Isaac Newton
Newton’s first law- Inertia:
A body will remain at rest or will continue to move with constant velocity in a straight line unless acted on by an external force.
Newton’s second law - Force:
The force that acts on an object is equal to the mass of the object multiplied by the acceleration produced.
Newton’s third law - Action/Reaction:
For every action there is an equal and opposite reaction.
Inertia is:
the property of matter that acts to resist a change in it state of motion
the total momentum before any interaction is equal to:
the total momentum after the interaction
the British unit of power is he:
horsepower (hp)
1 hp =
746 W
1,000 W =
1 kilowatt (kW)
the law of conservation of energy states that:
energy may be transformed from one form to another, but it cannot be created or destroyed
two forms of mechanical energy used in radiology are:
kinetic energy and potential energy
heat is:
the kinetic energy of the random motion of molecules
the unit of heat is:
the calorie
calorie is defined as:
the heat necessary to raise the temperature of 1 g of water by 1°C
heat is transferred by:
conduction, convention, and radiation
conduction is:
the transfer of heat through a material or by touching
molecular motion from a high-temperature object that touches a lower-temperature object:
equalizes the temperature of both
convection is:
the mechanical transfer of “hot” molecules in a gas or liquid form from one place to another
thermal radiation is:
the transfer of heat by the emission of infrared radiation
an x-ray tube cools primarily by:
radiation
MRI with a superconducting magnet requires:
extremely cold liquids called cryogens (liquid nitrogen and liquid helium)
air kerma:
the kinetic energy transferred from protons to electrons during ionization and excitation
SI unit for air karma is:
mGy (absorbed)
a becquerel is:
a unit of quantity of radioactivity material, the quantity in which a nucleus disintegrates every second
Crooke’s or Coolidge? gas tube, partial-vacuum
Crooke’s
Crooke’s or Coolidge? hot cathode tube, vacuum
Coolidge
