Chapter 2 Flashcards
The ability to do work
Energy
Kinetic energy that passes from one location to another and can have many manifestations
Radiation
Mechanical vibration of materials
Ultrasound
Types of EM radiation
Radio waves
Microwaves
Infared
Visible light
Ultraviolet
Xrays
Gamma Rays
EM waves are characterized by their:
Frequency and
Wavelength
EM radiation can travel through space in the form of a wave but can interact with matter as a particle of energy
Wave-particle duality
EM spectrum is dividied into what 2 parts
Ionizing and nonionizing
What EM radiation is ionizing?
X-rays
Gamma rays
High-energy UV (higher than 10 ev)
What is ionization?
Coversion of atoms to ions
The amount of energy transferred to electrons by ionizing radiation is the basis of the concept of:
Radiation dose
Correlates to the absorbed dose in biological tissue with the type and energy of the radiation to which a human has been subjected
Equivalent dose
Equivalent dose only applies to what type of radiation
Ionizing
What forms of radiation does particulate radiation include?
Alpha particles
Beta particles
Neutons
Protons
Subatomic particles that are ejected from atoms at very high speeds
Particulate radiation
Particulate radiation possesses enough energy to be capable of causing ionizing by:
Direct atomic collision
No ionization occurs when the subatomic particles are:
At rest
Alpha particles are emitted from:
Nuclei of very heavy elements during the process of radioactive decay
What elements are alpha particles emitted from
Uranium and plutonium
How many protons and neutrons in an alpha particle
2 protons
2 neutrons
What is the mass of an alpha particle
4x the mass of a hydrogen atom
Does an alpha particle have a positive or negative charge?
Positive
What is the charge of an Alpha Particle
Twice that of an electron
Alpha particles are _____ penetrating than beta particles
Less
Alpha particles lose energy: quickly or slowly?
Quickly
Alpha particles can be very damaging when absorbed in the _______ tissue
Epitheal
Beta rays are identical to:
High-speed electrons
What is the weight of a beta particle compared to an alpha particle
8000 times lighter
What is the charge of a beta particle
-1
Beta particles are capable of penetrating biological matter to a ___________ depth than alpha particles with far less ionization in their path
Greater
High-speed electrons that are produced in a radiation oncology treatment machines called a:
Linear accelerator
Nonnuclear electrons are used to treat:
Superficial skin lesions in small areas
Nonnuclear electrons are used to deliver radiation boost treatments to breast tumors at tissue depth not exceeding:
5-6 cm
High-speed electrons require what material to absorb them
MM of lead
Multicentimeter thick slabs of wood
For beta rays energies of less than 2 millielectron volts, what should be used for absorption?
1-cm thick block of wood
1-mm thick lead shield
Positvely charged component of an atom
Proton
Protons exceed the mass of an electron by a factor of
2800
Z number is
of protons
Atomic number
Electrically neutral component of an atom
Neutrons
Neutrons have appox. the same mass as a:
Proton
If two atoms have the same number of protons but a different number of neutrons in their nuclei, they are referred to as
Isotopes
If one of these combinations of Z protons and so many neutrons leads to an unstable nucleus, then that combination is referred to as a
Radioisotope
A radiation quantity used for radiation protection purposes when a person receives exposure from various types of ionizing radiation
Equivalent dose
Equivalent dose enables the calculation of the:
Effective dose
The SI unit of EqD is:
Sievert
Takes into account the dose for all types of ionizing radiation to various irradiated organs or tissues in the human body
Effective dose
___________ dose takes into account the chance/risk that each of those body parts will develop a radiation-induced cancer.
Effective
Because ____ dose includes all of the organ weighting factors, it represents the uniform whole-body dose that would give an equivalent biological response or change of cancer
Effective
Produced by ionizing radiation while pentrating body tissues primarily by ejecting electrons from atoms composing the tissues
Biologic damange potential
Types of changes from destructive radiation interactions at the atomic level
Molecular change
Cellular damage
Organic damage
Natural radiation that humans are exposed to
Terrestrial
Cosmic
Internal from radioactive atoms
Types of Terrestrial radiation
Radon
Thoron
Types of Cosmic radiation
Solar
Galactic
Types of manmade radiation
Consumer products containing radioactive material
Air travel
Nuclear fuel
Atmospheric fallout from nuclear weapons testing
Nuclear powerplant accidents
Nuclear powerplant accidents due to natural disasters
Medical radiation exposure results from the use of:
Diagnostic xray machines and pharmaceuticals in medicine
The two largest sources of artificial radiation are
Diagnostic medical imaging (x-ray,CT, IR, fluoro)
Nuclear medicine procedures
Diagnostic xray and nuclear medicine procedures accounted for ___% of the total collective EfD of the US in 2006
48%
The amount of radiation received by a patient from diagnostic xray procedures may be indicated in what terms
ESE (entrance skin exposure; includes skin and glandular dose)
Bone marrow dose
Gonadal dose
What NCRP report reflects usage patterns through 2006?
160
What NCRP report states that medical radiation was estimated to contribute .54mSv to manmade background radiaiton
93
In 2006, the estimated number of medical radiaiton that contributed to manmade background radiation increased by how much?
3.0mSv, more than a factor of 5
In 1980, use of CT resulted in a collective dose of ____ person-sieverts. In 2006, that number increased to _______
3700
440000
Current total annual background radiation due to medical radiation
6.3 mSv per person
Representative entrance and fetal doses for radiographic examinations frequently performed with a:
400 speed image receptor
Radiation that produces positively and negatively charged particles when passing through matter
Ionizing radiation
Effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation
Radiation protection
Sources of radiation
Natural
Manmade/medical
Energy range of x-rays
.4-400 keV
Energy equation for subatomic particles w/mass
KE = 1/2mv^2
Energy equation for subatomic particles without mass and travel at the SOL
E=hv
Lowest energy on the EM spectrum
AM radio
Highest energy on the EM spectrum
Gamma rays
Flow of destructive radiation interactions
Atomic level - molecular change - cellular damage - abnormal cell function
Multicellular damage can cause:
- Mutations
- Cataracts
- Leukemia
How many sV are needed to cause blood changes
.25
How many sV are needed to cause death
6
The highest ESE does comes from what exam
CT head
The highest bone marrow dose comes from what exam
L spine
The highest gonadal dose comes from what exam
CT pelvis