Radiation Protection Unit 1 Exam
Acute symptoms from an Uranium bomb?
-Blood disorders -Cerebral Edema -Death
Who was the first fatality due to x-ray exposure and when?
-Clarance Dally -1904
Processes of Interactions
-Coherent Scattering -Photoelectric Absorption -Compton Scattering -Pair Production
Which TWO consist of the remant beam (image forming)?
-Compton -Direct transmission
What are some examples of ionizing radiation?
-X-rays -Gamma rays -High energy UV
What is the average amount of Radon we receive a year?
About 2.0 mSv
The transference of energy FROM an x-ray beam TO the atoms of matter:
Absorption
Transference of energy to the atoms of the body?
Absorption
ALARA
Acronym for as low as reasonably achievable
What are some examples of particulate radiation?
Alpha and Beta
What occurs during Brem's radiation production?
An electron approaching a positive nuclear charge changes direction and loses energy
When the ______ in the body tissue increases there are more photoelectric interactions
Atomic number
The reduction in the intensity of an x-ray beam as it passes through material is termed:
Attenuation
Radiation protection
Effective measures employed by radiation workers to safegaurd patient, personnel from unnecessary exposure
SV
SI unit measure for EqD
Characteristic Radiation
-10% of primary beam -Occurs when electron interacts with inner shell tungsten atom
Absorption
-A total loss of radiation energy -If there is transference of electromagnetic energy to the atoms of the material
What are some examples of Cosmic radiation?
-Alpha particles -Atomic nuclei -Mesons -Gamma Rays -High energy electrons
Compton Scattering
-Also known as incoherent, inelastic, or modified scattering -Is responsible for most of the scattered radiation produced during radiologic
Chernobyl
-April 26, 1986 -Near Kiev in Ukraine in the former USSR -World's worst nuclear power accident -Thyroid Cancer, Leukemia
What are the 3 possible fates for an x-ray photon?
-Attenuation -Absorption -Scatter
What is BERT?
-Background -Equivalent -Radiation -Time
What are some examples of changes when radiation interacts at the atomic level?
-Blood changes -Erythema -Temporary Sterility -Death
Examples of Man-made radiation?
-Consumer products -Air travel ( airplane is man made) -Nuclear fuel for power -Nuclear Fallout from weapons testing -Nuclear power plant accidents
Amount of energy absorbed per unit mass is referred to as what?
-Dose (D) -Gray
Characteristics of X-rays
-Electromagnetic waves -Short wavelengths -Ionizing
What are the basic radiaiton quantities?
-Exposure (X) -Air kerma -Absorbed dose (D) -Equivalent dose (EqD) -Effective dose (EfD)
For Staff
-In-service education on radiation safety topics -Facts-to-remember sheets -Emails highlighting most important topics
As X-ray energy increases...
-Increased direct transmission -Increased Compton
Phase 1 for Patients
-Informational posters placed -Brochures describing imaging procedures: simple terms -Basic information on website designed for patient education -Wallet size card for radiation exposure to be recorded and tracked
Significance of X Ray absorption and 2 outcomes of interactions
-Interact with atoms of biologic material -Pass through without interactions
How does Altitude affect dosage?
-Living at high elevations above sea level, there is less atmosphere to absorb cosmic rays -Eg: Colorado
What are some examples of Non ionizing radiation?
-Low energy UV -Visible light -Infrared -Radiowaves
Three Mile Island, Unit 2 Accident (TMI-2)
-MOST SERIOUS US commercial nuclear plant operating history -Nuclear power plant near Harrisburg, Pennsylvania -March 28, 1979 was a meltdown -Small amount of I- 131
Photoelectric Effect
-Most important mode of interaction -X-ray photon and inner shell electron -Results in patient dose -Responsible for "contrast"
Fukishima Nuclear Plant Crisis
-No fatalities linked to radiaiton due to the accident -The accident is expected to be around 130-640 people in the years and decades ahead
Compton Effect
-Occupational dose -"Fog" on image -Contributes to density
Phase 2 - in order to accommodate technologic enhancements
-Operational / capital budget e.g. acquiring CT dose reduction technology -Utilization of tools for recording and reporting dose -Providing notification for excessive radiation dose
Direct transmission
-Primary x-ray photons that transverse the object without interacting -These photons reach the radiographic image receptor
What are some things that increase cosmic radiation dose?
-Prolonged space flights -Living in Denver -Climbing mountains -Airline personnel....
kVp
-QUALITY -Penetrating power, affects quantity in the beam
How does radon cause lung cancer?
-Radon daughter particles are electrically charged and can stick to floors and lungs! -Alpha particles released. -Slow and large but... -Breaks lung tissue
ALARA Examples for Patients:
-Reduce the beam on time -Use as much SSD as possible -Shield
ALARA Examples for Personnel:
-Reduce time in room -Increase distance from source -Wear shield
Which would increase in probability with an increase in kVp?
-Scatter -Small angle scatter -Backscatter -Direct transmission
Coherent/Classical Scatter
-Sometimes called Elastic or unmodified scattering -A relatively simple process that actually results in no loss of energy as x-rays scatter
What conditions are necessary for X-ray beam production?
-Source of electrons -Potential difference -Deceleration of electrons
Types of natural background radiation?
-Terrestrial -Cosmic -Internal
What happens when radiation safety principles are correctly applied?
-The energy deposited in living tissue by the radiation can be limited -Reduces the potential for adverse biologic effects
For Non Radiologist Physicians
-Through discussions, create increased awareness of radiation dose for specific procedures -Establish goals for lowering radiation dose for patients, assisting personnel and self. -Radiographers informing physicians when they have reached specific dose: fluoroscopist decide to continue or stop procedure
What are the 3 Cardinal rules?
-Time -Distance -Shielding
Dose from other man made radiation
.1 mSv
How much Cosmic radiation do we get per year?
.3 mSv per year
For a typical diagnostic x-ray unit, the energy of the average photon in the x-ray beam is about ______ the energy of the most energetic photon.
1/3
How does Air Travel affect dosage?
10 hours on an aircraft during a normal sunspot activity is equal to one chest x ray
Leakage radiation must not exceed how much?
100 mR/hour
What is the total amount of inherent filtration?
2.5 mm AL
Radium atomic number
226
Thorium atomic number
232
Uranium atomic number
238
EPA considers radon to be what?
2nd leading cause of lung cancer
Dose of natural radiation
3.0 mSv
Dose from medical imaging
3.2 mSv
How much radiation is received from Medical Radiation?
3.2 mSv
If an exposure of 90 kVp was used, what would the average photon energy be?
30 keV
EPA suggests no more than how much of air??
4 picocuries/liter
Total Average Effective Dose
6.3 mSv
Scatter
A change in direction of travel that may also involve a partial loss of radiation energy as the beam passes through the object in its path.
EgD
A radiation quantity that is used for radiation protection purposes when different types of radiation is received.
What are some examples of Internal radiation?
Bananas and table salt
What is somatic damage?
Biologic damage to the body of the exposed individual caused by exposure to ionizing radiation
Genetic Damage
Biologic effects of ionizing radiation on generations unborn
An interaction between x-rays and matter would NOT be:
Brems
What occurs when ELECTRONS interact with an inner shell tungsten atom?
Characteristic
What is Radon?
Colorless, Odorless, Heavy radioactive gas
Radiographers are most concerned about exposure due to the _____ effect?
Compton
Alpha Particle
Contains 2 protons and 2 neutrons/ extremely ionizing
Biologic Effects
Damage to living tissue of humans exposed to radiaiton
As x-ray energy increases the photoelectric effect will
Decrease
Diagnostic Efficacy
Degree to which the diagnostic study accuracy reveals the presence or absence of disease.
The passage of x-ray photons without interaction is called?
Direct transmission
The process of x-ray photons passing through an object without interaction is called:
Direct transmission
Non Ionizing Radiation
Does not have sufficient kinetic energy to eject electrons from the atom
What is the unit of measurement for Energy?
EV
Examples of natural background radiation?
Earth and Cosmic rays
Dose limitation 1991-Present
Effective Dose
Dose limitation 1977-1991
Effective Dose Equivalent
What is radiation protection?
Effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation.
Electromagnetic wave
Electric and magnetic fields that fluctuate rapidly as they travel through space
Radiation
Energy that passes from one location to another
What is the responsibility of the Radiation Safety Officer?
Execution, enforcement and maintenance of records and maintaining ALARA
Direct transmission and small angle scatter photons comprise:
Exit radiation
Small angle scatter results in:
Fog
Organic Damage
Genetic or somatic changes in a living organism caused by excessive cellular damage from exposure to radiation
What is the purpose of the Toshiba Dose Tracking system?
Gives clinicians the flexibility to track X-ray skin dose exposure in real time during interventional procedures.
Pair Production
Happens in PET Scanning
What is the unit of measurement for Frequency?
Hertz (cycles per second)
What is Cosmic radiation?
High energy protons from nuclear interactions that take place in the sun and stars
Differential absorption is _____ with lower kVp.
Increased
Introduction of contrast medial will result _______ photoelectric absorptions
Increased
The probability of the occurrence of photoelectric absorption ______ as the atomic number of the irradiatied material _____.
Increases, Increases
Cellular Damage
Injury on the cellular level caused by sufficient exposure to ionizing radiation on the molecular level
How are frequency and wavelength related?
Inversely proportional
X-rays cause biological damage to tissue by a process known as:
Ionization
Why is ionizing radiation damaging?
It ejects electrons from atoms in tissue
Why do we use Tungsten Rhenium in the Anode?
It has a high atomic number and high melting point
What is the purpose of the Cathode?
It is the source for electrons
What is the purpose of the Anode?
It is the target for electrons
What is Radiation?
Kinetic energy that passes from one location to another and can have many manifestations
Long term symptoms from an Uranium bomb?
Leukemia
Terrestrial Radiation
Long lived elements such as Uranium, Radium, and Thorium
Terrestrial Radiation
Long lived radioactive elements present in variable quantities in the Earth's crust
Photoelectric interactions will occur more often with ______ kVp.
Low
Examples of man-made radiation?
Mainly X-rays
Dose limitation 1950-1977
Maximum Permissible Dose
What is the unit of measurement for Wavelength?
Meters
BERT
Method for comparing the amount of radiation received compared with natural background radiation received over a given period
What happens when radiation interacts at the atomic level?
Molecular change
As tissue atomic number increases...
More Photoelectric effect
Internal Radiation
Natural internal radionuclides within the body deposited in the body through natural processes such as ingestion of foods or inhaled particles in the air.
ALARA is synomymous with what?
ORP (Optimization for Radiation Protection)
Bremstrahlung radiation
Occurs when electrons undergo deceleration by interaction within the nuclei of the target atoms
Which interaction is responsible for radiographic contrast?
Photoelectric
Which interactions of radiation with tissue results in the complete absorption of the x-ray photon?
Photoelectric effect
Which of the following interactions between x-ray and matter result in the highest patient exposure?
Photoelectric effect
Between 80 and 100 kVp, only 10% of the primary beam is composed of:
Photoelectric photons
The x-ray beam is described as being _______ in nature.
Polyenergetic
Before interacting with matter, an incoming photon may be referred to as _______.
Primary beam
Brems is one interaction that makes up the ________.
Primary beam
Before interacting with matter, an incoming x-ray photon may be referred to as which?
Primary photon
Ionizing Radiaiton
Produces positively and negatively charged particles when passing through matter
mAs
Product of electron tube current ( mA) and amount of time in seconds
Fallout
Radiation produced as a consequence of nuclear weapons testing and chemical explosions in nuclear power plants
EFD
Radiation quantity that takes into account the dose of all types of radiation to tissues and the various types of radiation
EqD
Radiation quantity used for radiation purposes when a person receives exposure from various types of radiation
What is Natural Background Radiation?
Radiation received from natural environmental sources
What is Ionizing radiation?
Radiation that produces positively and negatively charged particles (ions)
Cosmic Rays
Rays extraterrestrial origin that result from nuclear interactions in the sun and stars
What is Erythema?
Reddening of the skin due to x-ray exposure
Electromagnetic Spectrum
The full range of frequencies and wavelengths of electromagnetic waves
What does exit radiation strike?
The image receptor
Atomic Number
The number of protons contained within the nucleus of an atom
What justifies the use of ionizing radiation to produce a radiographic image?
The potential benefit outweighs the risk
Risk can be defined as:
The probability of injury, ailment, or death resulting from an activity.
Attenuation
The reduction in the number of primary photons in the x-ray beam through
Dose limitation 1930-1950
Tolerance Dose
Exposure (X) is defined as:
Total electrical charge per unit mass that x-ray and gamma ray photons with energies up to 3 million electron volts generate in DRY AIR
Rem
Traditional unit of measure for EqD
What is the anode composed of?
Tungsten Rhenium
Dose limitation 1900-1930
Unit of Skin Erythema Dose
What is used as a source of power production in Nuclear Fuel?
Uranium
The highest energy level of photons in the X-ray beam is represented by what?
kVp
When ______ is increased the patient receives a lower radiation dose, but image quality may be compromised
kVp
What is MOST of the concern for contributing to patient exposure?
mAs