Chapter 1: Introduction to Radiation Protection Flashcards
What are x-rays?
a form of ionizing radiation
- removal of an electron
the production of ionizing radiation causes what
may cause injury in normal biological tiissue
is a radiation that produces positively and negatively charged particles (ions) when passing through matter
ionizing radiation
the transfer of energy from one location to another
radiation
when where x-rays discovered
November 8, 1895
What are some concepts of radiation
it can be beneficial or destructive
a form of biological damage
radiation
What does the acronym ALARA stand for
as low as reasonably achievable
creation of unstable atoms is
ionization
what are some consequences of ionization in human cells
- creating of unstable atoms
- production of free electrons
- production of low-energy, x-ray photons
- creation of highly reactive free molecules capable of producing substances poisonous to the cell
- creation of a new biological molecules detrimental to the living cell
- injury to the cell that may manifest itself as a abnormal function or loss of function
why is production of free electrons bad
most damaging
injury to the cell can be what
- cell survival
- complete cell death
- abnormal function
What are some characteristics of x-rays
- x-rays are invisible
- x-rays have no mass
- x-rays are neutral
- x-rays can’t be focused or refracted
- x-rays travel at the speed of light and in straight lines
- x-rays form a polyenergetic or heterogeneous beam
Team concept in medical field
-team approach to patient care
- team includes many allied health professionals
- communication is very important
How to control radiant energy
- use knowledge of radiation- induced hazards that have been gained over many years
- employ effective methods to eliminate those hazards
- control radiation produced from an x-ray tube and ensure safety during all medical radiation procedures
- limiting the energy deposited in living tissue by radiation can reduce the potential for adverse effects
What is the goal of radiation protection
protect persons from both short term and long term effects of radiation
what are some short term effects of radiation
hair loss, redness, nausea, vomiting, headache, fatigue
means to yourself
somatic
what are some long term effects of radiation
cancer, cardiovascular disease
future generations
genetic
what is an ongoing responsibility of diagnostic imaging professionals
to ensure radiation safety during all medical radiation procedures
how can diagnostic imaging professionals keep this obligation
is fulfilled by adhering to an established radiation protection program
what are effective measures employed by radiation workers
effective measures employed by radiation workers to safeguard patients, personnel, and the general public from unnecessary exposure to ionizing radiation
what are some kind of unnecessary radiation
- any radiation exposure that does not benefit a person in terms of diagnostic information obtained for the clinical management of medical needs
- any radiation exposure that does not enhance the quality of study
the less dose they have
the less damage they get
amount of radiation produced in air when ionizing radiation is present
exposure
what’s in the air
exposure
the amount of energy that is deposited in a material per unit mass of the material
absorbed dose
what do you measure exposure in air with
coulomb per kilogram (C/kg) <=(si unit) or milliroentgen (mR)
what do you measure absorbed dose with
measure in milligram / milligray (mGy)
what’s deposited in the patient
absorbed dose
a quantity that is a measure of general harm in humans.
effective dose
what’s the measurement of effective dose
measured in millisievert (mSv)
what involves effective dose
- type of radiation
- organ system affected
- amount of absorbed dose
- best method
measures the type of radiation and dose received
equivalent dose
general harm to the human body
effective dose
some tissue are more
sensitive
Need to safeguard against adverse biological effects of ionizing radiation
damage to living tissue of animals and humans exposed to radiation
justification and responsibility for imaging procedures
patient can elect to assume the relatively small risk of exposure to ionizing radiation
What are the achievement of diagnostic efficacy
- imaging procedure or practice justified by referring physician
- minimal radiation exposure
- optimal image desired
4 process of absence of disease revealed - diagnostic efficacy
the degree to which the diagnostic study accurately reveals the presence of absence of disease in the patient
diagnostic efficacy
What’s the acronym for ALARA
acronym for as low as reasonably achievable
another word for ALARA
optimization for radiation protection (ORP)
intention behind these concepts of radiologic practice is to keep radiation exposure and consequent dose to the lowest possible level
ALARA principle
The three basic principles of radiation protection
- time
- distance
-shielding
time, distance, and shielding are considered what
Cardinal Rules of Radiation Protection
What is the radiation worker’s responsibility
- Be aware of rules governing the workplace.
- Perform duties consistent with ALARA.
The Cardinal Rules of radiation protection can be applied to
- Patient
- Radiographer
What are the Employers’ Responsibilities
- It is the responsibility of the employer to provide the necessary resources and appropriate environment in which to execute an ALARA program.
- A written policy statement describing this program and identifying the commitment of management to keeping all radiation exposure ALARA must be available to all employees in the workplace
- how radiation exposure in the workplace may be lowered, management should perform periodic exposure audits.
Radiation Worker’s Responsibility
- always function with full awareness of rules governing the work situation
- perform their occupational practices in a manner consistent with the ALARA principle
What can educating patient do
- educating about imaging services helps to ensure the highest quality of service
- Use appropriate and effective communication
- Answer questions about the potential risk of radiation exposure honestly
- Inform patients of what needs to be done, if anything, as a follow-up to their examination
The probability of injury, ailment, or death resulting from an activity
Risk in general term
the possibility of inducing adverse biologic effects, such as injury to the skin or induction of cancer or a genetic defect after irradiation.
Risk ( in the medical industry) with reference to the radiation sciences
A method that can be used to improve understanding and reduce fear and anxiety for the patient.
Background Equivalent Radiation Time (BERT)
Compares the amount of radiation received with natural background radiation received over a given period of time
Background Equivalent Radiation Time (BERT)
on an annual US population exposure of natural background per year
3 mSv millisieverts per year.
What are the Advantages of the BERT Method When It Is Used Appropriately
- BERT does not imply radiation risk; it is simply a means for comparison.
- BERT emphasizes that radiation is an innate part of our environment.
- The answer given in terms of BERT is easy for the patient to comprehend.
Who are more sensitive to radiation
Children are significantly more radiation sensitive than are adults
What have studies have shown regarding radiation exposure to children
Studies have shown that the more radiation exposure a child receives the more likely for them to develop cancer later in life
was founded in 2007. It is a partnership of medical societies whose overall common purpose is to reduce the radiation dose for pediatric patients
Alliance for Radiation Safety in Pediatric Imaging
What is Alliance for Radiation Safety in Pediatric Imaging primary goal
raise awareness among nonradiology users (e.g., emergency room physicians, referring physicians, orthopedists, neurosurgeons, etc.) of potentially high radiation exposure from computed tomography.
Started by Alliance for Radiation Safety in Pediatric Imaging
Image Gently Campaign.
dissemination of information on pediatric CT dose reduction among the various medical specialties that refer patients for CT examinations or even operate their own CT scanners.
Image Gently Campaign
delivers the message that CT scanning saves children’s lives but that patient dose should be lowered by “child sizing” the kV and mA settings, by scanning only the indicated area
- Created to address concerns about the increase of public exposure to ionizing radiation from medical imaging
Image Wisely Campaign
Monitoring and Reporting Radiation Dose
- Trend toward more rigorous reporting of patient dose in radiology
- CT and interventional procedures are more cognizant of patient dose recording.
- Required in some states
project in place to provide data on the measurement of radiation of x-ray machines
NEXT ( Nationwide Evaluation of X-ray Trends) Program and Reference Values
These levels may then be used to allow individual institutions to determine where they stand with regard to standard practices at the majority of institutions.
NEXT Program and Reference Values
When patient dose is predicted to or has actually substantially exceeded normal dose levels, what happens
the staff radiologist is notified.
may be called upon to estimate patient doses such as effective dose, peak skin dose, or fetal dose
medical physicist
Protects against leakage radiation and electric shock
Tube housing
Contains the filament and focusing cup
- has a negative charge
cathode
serves to expel the electrons from the circuit and focus them in a beam on the focal spot
cathode
made of thoriated tungsten
- high melting point
- Responsible for producing thermionic emission
-Source of electrons for x-ray production
- Determines the size of the focal spot
Filament
- made of nickel/ molybdenum
- keeps the electron cloud and space charge
- negative charge
- concentrates the electron beam towards the focal spot of the anode
focusing cup
Electrons cloud near filament.
Space Charge
Area of anode struck by electrons from cathode.
Target
The process of boiling off electrons and produces a cloud of electrons by heating the filament
Thermionic Emission
Occurs when no more electrons can be boiled off the filament
Space charge effect
Three components of anode.
Anode, stator and rotor
Is the primary thermal conductor of the tube
Anode
Two types of anodes
Rotating and stationary
What is the anode made up of
Tungsten rhenium alloys
Purpose of rotating anode
Promote greater heat dissipation
Absorption of X-rays produces in the tube by the anode, causes uneven distribution of X-ray intensity between the cathode and anode, more intensity on cathode side (fat cat)
Anode heel effect
Atomic number of tungsten rhenium alloy
74
Spreads heat over a greater area of the anode and allows the effective focal spot to be smaller than the actual focal spot
line focus principle
Is made of molybdenum and connects the anode to the rotor
Stem
What is the X-ray efficiency
1% X-ray , 99% heat
The only thing located outside of the envelope that consists of copper windings
Stator
Made of a copper cylinder in the step of the X-ray tube and is support by the high strength ball bearings
Rotor
- Spread the heat produced over the entire anode circle, rather than one spot
- Promote greater heat dissipation of the anode overall
rotating anode
how much mSv does Dental, intraoral have
and how many BERT
0.06 mSv
- 1 week
how much mSV from a chest radiograph
and how many BERT
0.08 mSv
- 10 days
how much mSv from a cervical spine
and how many BERT
0.1 mSv
- 2 weeks
how much mSv from a thoracic spine
and how many BERT
1.5 mSv
- 6 months
how much mSv from a lumbar spine \
and BERT
3.0 mSv
- 1 year
how much mSv for Upper GI series
and BERT
4.5 mSv
- 1.5 years
how much mSv for a Lower GI series
and BERT
6.0 mSv
- 2 years
how much mSv for skull
and BERT
0.07 mSv
- 11 days
how much mSv for hip
and BERT
0.3 mSv
- 7 weeks
how much mSv for abdomen
and BERT
0.7 mSv
- 4 months
how much mSv for a pelvis
and BERT
0.7 mSv
- 4 months
how much mSv for limbs and joints except hips
and BERT
<0.01 mSv
- <1.5 days
how much mSv for CT brain
and BERT
2.0 mSv
- 1 year
how much mSv for CT chest
and BERT
8.0 mSv
- 3.6 years
how much mSv for CT abdomen/pelvis
and BERT
10.0 mSv
- 4.5 years
