Basic Of Radiation Quiz 1 Flashcards
EMR IN ORDER
Most ENERGETIC to LEAST
1) XRays/Gamma rays
2)Ultraviolet
3)Visible light
4)Infrared
5)Microwaves
6)Radio wave
What is Radiation?
Transfer or energy
Energy that is emitted and transferred through space
What is Exposed (irradiated)?
Matter that intercepts radiation and absorbs all or some of it
(Does not necessarily mean harm or injury)
What is ionizing radiation or ionization?
Removal of an electron from an atom
What are forms of EMR that can ionize matter?
X-rays
Gamma rays
High energy UV (UVC)
UV-C light is too…
short to go past our ozone layer
What are two main categories of ionizing radiation?
Natural Environment and Man-made
Types of Natural Radiation
-Cosmic radiation
-Terrestrial Radiation
-Internally Deposited Radionuclides
What is cosmic radiation?
EMR emitted from the sun and stars
-The intensity increases with altitude and latitude when closer to equator
What is terrestrial radiation?
Its radiation that comes from the earth
-Has deposits of Uranium, Thorium, and other radionuclides
What is the largest source of natural radiation?
Radon
What is internally deposited radionuclides?
they are radionuclides that are incorporated into the body through ingestion, inhalation, injection, implants.
What is the main source of internally deposited radionuclides?
Potassium 40 which is found in food, water, and soil
How is radon produced?
Gas produced by natural decay of uranium
Types of man-made radiation
-X rays
-Nuclear power generators
-Exit signs
-Smoke detectors
When was the discovery of x-rays?
November 8, 1895
Who was the person who discovered xrays?
Wilhelm Rontgen
Examples of reports of early radiation
-Skin damage
-Loss of hair
-Anemia
Later effects
Blood disorders
What is a filter or filtration?
A device that removes low energy x ray photons that have no diagnostic value and don’t contribute to image quality
What is collimation/collimator?
Its a radiation safety device underneath the xray tube where the radiation is being directed
Types of shielding
Protective apparel
Gonadal Shields
Protective barriers
They are made with lead material
What does ALARA stand for?
As Low As Reasonably Achievable
What’s the purpose of ALARA?
Its a radiation safety principle
-to reduce radiation dose
-release radioactive material by using reasonable methods
What are the cardinal principles of radiation protection
Minimize time
Maximize shield
Maximize distance
What are iso exposure lines?
Represents positions of equal radiation exposure in a fluoroscopy room at waist height
What is a OSL dosimeters?
Optically Stimulated Luminescence
They are monitors for accumulated dose for radiation
Ways to reduce unnecessary patient dose
-Unnecessary examinations
-If they had pervious x rays for the body part
-Emergency room CT
-Mass screening for Tuberculosis
What is the severity of the potential response of an unborn baby to radiation?
Time and dose
Pregnancy
what happens in 2-10 weeks ?
Most sensitive to radiation exposure
Major organogenesis
What happens in the 2-3 trimesters?
Can have a response to malignant disease during childhood
How can you reduce the chances of exposing a pregnant patient?
-Elective booking (Patient’s choice)
-Patient Questionary
-Posting
What is today’s average patient radiation dose?
3.2 mSv
Why is today’s average patient radiation dose 3.2 mSv?
Public demand
Using to much CT
Physican ownership
What are ways to reduce occupational radiation exposure?
Minimize xray beam on time (Fluoroscopy)
Maximize distance and shielding
Where does the 95% of occupational exposure comes from?
Mobile and fluoroscopy
What is KERMA?
Kinetic Energy Released per Unit of Mass of Air
What does KERMA measure?
The radiation intensity in the air
What is KERMA’s SI unit?
mGya or Gya
What is Roentgen?
KERMA
What does absorbed dose measure?
the calculation of dose in a living tissue.
How much was absorbed in the skin?
What is the SI unite for Absorbed dose (RAD)
mGyt or Gyt
What is absorbed dose?
Radiation Absorbed Dose (RAD)
What is Sievert?
Radiation Equivalent Man (REM or mREM)
What is the SI unite for Sievert?
SV
What does sievert measure?
The biological damage in the human body
-Quantity of radiation received
What is Becquerel?
The unit of the quantity of radioactive material not the radiation emitted
-Nothing to do w/ xrays
What is Becquerel unit?
Bq or Curie
What is the current level of human radiation exposure for natural?
3 mSv
What is the current level of human radiation exposure for medical imaging?
3.2 mSv
What is the current level for human radiation exposure for Man made?
0.1 mSv
What is the total estimate of human radiation exposure?
6.3 mSv
Going from rems to mrem you are going to…
Multiply by 1,000
Going from mrem to rems you are going to…
Divide by 1,000
Going from rems to Sv you are going to…
Multiply by .01
Going from Sv to rems you are going to…
Divide by .01
