WEEK 1 Flashcards
It is the study of the effects of ionizing radiation on
biologic tissue.
Radiobiology
The energy emitted and transferred through space
than can either be in a form of waves or particles is
called
Radiation
It is an energy in transit from one location to another.
Radiation
It is transfer of energy.
Radiation
What are the 2
classifications of
radiation according to its
ionizing ability?
Ionizing radiation
Non-ionizing radiation
Radiation with enough energy so that during an
interaction with an atom, it can remove tightly bound
electrons from the orbit of an atom, causing the atom
to become charged or ionized.
Ionizing radiation
Carried by any of several types of particles
(particulate) and rays (electromagnetic radiation) given
off by radioactive material, X-ray machines, and
nuclear reactions.
Ionizing radiation
It has the potential to cause harmful
effects due to the way it interacts with
atoms in living matter.
Ionizing radiation
It has the potential to cause harmful
effects due to the way it interacts with
atoms in living matter.
Ionizing radiation
Radiation that has enough energy to move around
atoms in a molecule or cause them to vibrate, but not
enough to remove electrons, is referred to as
“non-
ionizing radiation.
they do not have sufficient kinetic energy to eject
electrons from the atom
Non ionizing radiation
does not cause the production of charged particles
Non ionizing radiation
Extremely low-frequency radiation has very long
wave lengths and frequencies in the range of 100
Hertz or less.
Non ionizing radiation
the
electromagnetic spectrum
Radiowaves
Microwave
Infrared
Visible light
Ultraviolet
Xray
Gamma
It is the range of wavelengths or
frequencies over which electromagnetic
radiation extends.
Electromagnetic spectrum
travel in a wave-like pattern
Electromagnetic radiation
the only difference between the various types of
electromagnetic radiation is the ____ found in the photoms
Amount of energy
electromagnetic radiation travels in a straight line at
the
speed loght pr 3x10^8 m/s
Pure energy with no mass and is like vibrating or
pulsating waves of electrical and magnetic energy.
Electromagnetic energy
Produced by a vibrating electric charge and as such,
they consist of both an electric and a magnetic
component.
Electromagnetic radiation
Acts like a stream of small “packets” of energy called
photons.
Electromagnetic radiation
small “packets” of energy
Photons
Wavelength and Photon Energy =
Inversely proportional
Wavelength and Frequency=
Inversely proportional
has the shortest wavelength but has the
highest energy.
Gamma ray
As wavelength gets shorter, frequency ___ .
increases
radiations that are classified as ionizing radiations:
Xrays
Gamma rays
High energy ultraviolet radiation (energy higher than 10eV)
Illustration of the electromagnetic spectrum.
X- and γ-rays have: the same nature as visible light,
radiant heat, and radio waves; however,
They have shorter wavelengths and,
consequently, a larger photon energy.
As a result,
x- and γ-rays can break chemical
bonds and produce biologic effects.
Types of ionizing radiation
Electromagnetic radiation
Particulate radiation
often called photons
Electromagnetic radiation
often called photons
Electromagnetic radiation
the only difference between them is their origin.
Xrays and gamma rays High
produced outside the nucleus in the
electron shells.
Xray
emitted from the nucleus of a
radioisotope and are usually associated with alpha or
beta emission.
Gamma rays
emitted from the nucleus of a
radioisotope and are usually associated with alpha or
beta emission.
Gamma rays
a stream of atomic or subatomic particles that
may be charged positively (alpha particles) or
negatively (beta particles) or not at all (neutrons)
Particulate radiation
atomic or subatomic particles (electrons,
protons, etc.) which carry energy in the form of
kinetic energy or mass in motion
Particulate radiation
Involves tiny fast-moving particles that have both
energy and mass
Particulate radiation
Involves tiny fast-moving particles that have both
energy and mass
Particulate radiation
primarily produced by
disintegration of an unstable atom.
Particulate radiation
Also known as corpuscular radiation
Particulate radiation
symbolized by the Greek letter α
Alpha particle
Aplpha particle also called
alpha ray or alpha radiation
emitted from nuclei of very heavy elements such as
uranium and plutonium during the process of
radioactive decay.
Alpha particle
consisting of two protons and two neutrons.
Alpha particle
Atomic mass of alpha
Atomic number of alpha
4
2
They are simply helium nuclei
Alpha particle
Less penetrating. They lose energy quickly as they travel a short distance in biologic matter. They are considered
virtually harmless as an external source of radiation.
Alpha particle
Have no applications in diagnostic radiology.
Alpha particles
The positive charge of alpha particle is useful in
Nuclear medicine
may be used to treat cancer,
Radium 226
Beta means
High speed
Identical to an electron except for its origin.
Beta particle
Emitted from the nuclei of radioactive material, while electrons exist in orbital shells around the nucleus.
Beta particle
High velocity electrons with an electrical charge of -1
Beta particle
more penetrating than an alpha particle but less penetrating than a gamma ray or an x-ray.
Beta particle
Penetrate through several millimeters of body tissue
Beta particle
encountered in nuclear medicine applications.
Beta particle
Neuron have a mass of approximately
1 amu and no charge
Neutrons are the only one that can make objects
radioactive, through the process called
Neutron activation
Because of their exceptional ability to penetrate other
materials, neutrons can travel great distances in air
and require very thick hydrogen-containing materials
(such as concrete or water) to block them.
Neutron
Neutron produced in
Nuclear reactors and cyclotrons
produces and controls the release of energy from splitting the atoms of certain elements.
Nuclear reactor
In a nuclear power reactor, the energy
released is used as heat to make steam
to generate
Electricity
the antiparticle or the antimatter
counterpart of the electron.
Positron or antielectron
The positron has an electric charge of ____ and has the same mass as an
+1e
electron
When a low-energy positron collides with a low-energy electron, ____occurs, resulting in the production of
annihilation
two or more gammaray photons.
What are the 2 sources of human exposure to
radiation?
Natural or Background Radiation
Man-made (artificial)
from radioactive materials in the crust of the earth.
Terrestrial radiation
The major isotopes of concern for terrestrial radiation are
Uranium
decay products of uranium; thorium, radium and radon
have always been a part of the human environment since the formation of the universe.
- IR from environmental sources
Natural or Background Radiation
also found throughout nature such as in
soil, water, and vegetation.
Radioactive material
Natural or Background Radiation:
Terrestrial radiation
Cosmic radiation
Internal Radiation from Radioactive atoms (radionuclides)
from the sun (solar) and beyond the solar
system (galactic)
Cosmic radiation
also known as radionuclides that make up a small percentage of the body’s tissue.
Internal Radiation from Radioactive atoms
Ionizing radiation created by humans for various uses
Man-made (artificial)
Sources of artificial ionizing radiation include the following:
A. Air travel
B. Nuclear fuel for generation of power
C. Consumer products containing radioactive material
D. Atmospheric fallout from nuclear weapons testing
E. Nuclear power plant accidents
Consumer products containing radioactive material
1920 - 1970 shoe fitting fluoroscopes
Germany in the 1940s, Doramad
Radithor
were used in shoe
stores so that customers could see how well a pair of shoes fit before purchase.
shoe fitting fluoroscopes
In Germany in the 1940s, a radioactive “biologically effective toothpaste” The ionising radiation originating
from this toothpaste, according to the advertisement, was supposed to massage the gums and refresh the whole mouth.
Doramad
Radioactive water, containing radium This was supposed to ease all kinds of diseases, including rheumatism, headaches, neuralgia, and constipation.
Radithor
who
died 1932, because he had drunk twelve bottles of radiumwater every day,
hoping to relieve the pain after an arm injury.
American golfer Eben Byers
Man-made (artificial)
Diagnostoc radiology
Dental radiology
Cardiovascular radiology
Nuclear medicine
Radiation oncology
-takes place when the radioactive
source is located outside the body.
- less dangerous.
External radiation exposure
occurs when the source of
ionizing is radiation is located inside
the organism, usually because of
ingestion or inhalation of radioactive
substances.
Internal radiation exposure
- Making Observations
- Exploring
- Validating
To be certain that the transmitted message has been correctly received, it is necessary to
obtain
Feedback
If the patient understands the message, he or she will respond in the manner anticipated. If
the patient does not respond correctly, it is the radiographer’s responsibility to restate the
message in the manner that is understood.
Feedback
