CHAPTER 1 Flashcards
Complex building blocks of matter
Atoms & Molecules
Anything that occupies space and has mass
Matter
Primary distinguishing characteristics of matter
Mass
-Described by its energy equivalence
-measured in kg
Mass
-The force exerted on a body under the influence of gravity
-measured in pounds
Weight
A kg is equal to?
1000 grams
Kilo stands for?
1000
SI unit of energy
Joules
Ability to do work, by virtue of position
Potential energy
Energy released by a chemical reaction
Chemical energy
Represents the work that can be done when an electron moves through an electric potential difference
Electrical Energy
-Energy in motion at the molecular level
-kinetic energy of molecules & is closely related to temperature
Thermal energy
-least familiar form of energy
-type of energy used in xray imaging
-does not include sound or diagnostic ultrasound
Electromagnetic Energy
Electromagnetic energy includes: ?
Radiowaves, microwaves, ultraviolet, infrared light & visible light
Radiation
-transfer of energy
-energy emitted and transferred through space
Form of electromagnetic energy, radiated by the sun and is electromagnetic radiation
Visible light
Matter that intercepts radiation and absorbs part or all of it
Irradiated
Type of radiation that causes sunburn
Ultraviolet light
-special type of radiation that includes xray
-any type of radiation that is capable of removing an orbital electron from the atom with which it interacts
Ionizing radiation
The orbital electron & the atom from which it was separated are called?
Ion pair
Electromagnetic radiation with sufficient energy to ionize
Xrays, Gamma Rays, Ultraviolet light
Particle type ionizing radiation
Alpha and Beta Particles
Sometimes called rays
Natural environmental radiation results in an annual dose of?
3 mSv
Man-made radiation results in how many dose annually?
3.2 mSv
It is used to express radiation exposure of populations and radiation risk in those populations.
-unit of effective dose
-msv
Natural environmental radiation consists of four components:
cosmic rays, terrestrial radiation, inter- nally deposited radionuclides, and radon.
are particulate and electromagnetic radiation emitted by the sun and stars.
Cosmic rays
results from deposits of uranium, thorium, and other radionuclides in the Earth.
Terrestrial radiation
-is a radioactive gas that is produced by the natural radioactive decay of uranium, which is present in trace quantities in the Earth. All Earth-based materials, such as concrete, bricks, and gypsum wall- board, contain this
-The largest source of natural environmental radiation
Radon
emits alpha particles, which are not penetrating, and therefore contributes a radiation dose only to the lung.
Radon
constitute the largest man-made source of ionizing radiation (3.2 mSv/yr)
Diagnostic xrays
The currently accepted approximate annual dose resulting from medical applications of ionizing radia- tion is
3.2 mSv
uses film or a solid-state image receptor and usually an x-ray tube mounted from the ceiling on a track that allows the tube to be moved in any direc- tion.
Radiography
is usually conducted with an x-ray tube located under the examination table. The radiologist is provided with moving images on a television monitor or flat panel display.
Fluoroscopy
uses a rotating x-ray source and detector array. A volume of data is acquired so that fixed images can be reconstructed in any anatomical plane—coronal, sagittal, transverse, or oblique.
Computed tomography
X-ray voltages are measured in
Kilovolt peak/ KVP
X-ray currents are measured in
MilliAmpere
Michael Pupin
Demonstrated the use of intensifying screen on 1896
Charles Leonard
Double emulsion film on 1904
Thomas Edison
Fluoroscopy, 1898
Clarence Dally
1st xray fatality, 1904
William Rollins
Collimation & Filtration
HC Snook
Interruptless transformer, 1907
William D. Collidge
Hot cathode xray tube, 1913
Gustav Bucky
Glitterblende, 1913
H Potter
Moving grid, 1915
Potter Bucky Grid
1921
Magnetic resonance imaging (MRI) became an accepted modality in the
1980
Metal filters, usually aluminum or copper, are inserted into the x-ray tube housing so that low-energy x-rays are absorbed before they reach the patient. These x-rays have little diagnostic value.
Filtration
-restricts the useful x-ray beam to that part of the body to be imaged and thereby spares adjacent tissue from unnecessary radiation exposure.
-also reduces scatter radiation and thus improves image contrast.
Collimation
is based on the vibration of atoms of cesium.
Seconds
is a segment of physics that deals with objects at rest (statics) and objects in motion (dynamics).
Mechanics
some- times called speed, is a measure of how fast something is moving or, more precisely, the rate of change of its position with time.
Velocity
The rate of change of velocity with time
Acceleration
is a force on a body caused by the pull of gravity on it.
Weight
-the product of mass and velocity.
-represented by p
Momentum
-the rate of doing work.
-quotient of work by time
Power
the product (multiplication) of force and distance.
Work
British unit of power is the
Horse power/hp
-the kinetic energy of the random motion of molecules.
-form of energy that is very important to radio- logic technologists.
Heat
unit of heat
Calorie
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.
Conduction
the mechanical transfer of “hot” molecules in a gas or liquid from one place to another.
Convection
is the transfer of heat by the emission of infrared radiation.
Thermal Radiation
The three scales that have been developed to measure temperature are
Celsius (°C), Fahrenheit (°F), and Kelvin (K)
Magnetic resonance imaging with a superconducting magnet requires extremely cold liquids called
Cryogens
two cryogens that are used.
Liquid nitrogen, which boils at 77 K, and liquid helium, which boils at 4 K,
-the unit of radiation exposure.
-the kinetic energy transferred from photons to electrons during ionization and excitation.
Air Kerma
is the radiation energy absorbed per unit mass
Absorbed Dose (Gyt)
used to express the quantity of radiation received by radiation workers and populations.
Effective Dose, Sievert (Sv).
is the unit of quantity of radioactive material, not the radiation emitted by that material.
Radioactivity, Becquerel (Bq).
A substitute for the glass plate in xray
Cellulose nitrate
