Radiation Injury
TRUE OR FALSE?
All ionizing radiation are harmful and produce biological changes in living tissues.
TRUE: there is no such thing as "safe" x-rays.
Radiation effects can be classified as either?
Roentgen (R)
Radiation absorbed dose (rad)
Roentgen Equivalent in Man (rem)
What are Traditional Units?
Humans are exposed to daily radiation from BOTH ________&_________
Natural Background Radiation & Synthetic/Artificial Human-Made Radiation
Time that elapses between exposure to ionizing radiation and the appearance of observable clinical signs?
What is Latent Period?
What are the TWO specific mechanisms of radiation injury are possible?
(1) Ionization
(2) Free radical formation
Effects that are seen within minutes, days, or weeks are associated with LARGE amounts of radiation absorbed in a SHORT time.
Examples include nausea, vomiting, diarrhea, hair loss, and hemorrhage.
What is Short-Term effects?
Coulomb/ kilogram (C/kg)
Gray (Gy)
Sievert (Sv)
What are SI Units?
_________ Radiation sources include radon, cosmic, terrestrial, and internal.
What is Natural Background?
What is Period of Injury?
What is the process called when an X-ray strikes patient tissues during imaging, leading to the formation of a positive atom and a dislodged negative electron through the photoelectric effect or Compton scatter?
What is Ionization?
Effects that appear after years, decades, or generations; associated with SMALL amounts of radiation absorbed REPEATEDLY over long period of time.
Examples, are induction of cancer, birth abnormalities, and genetic defects.
What is Long-Term effects?
measurement of ionization in air produced by x-rays
What is Exposure?
______ Radiation includes medical procedures, consumer products, nuclear medicine, industrial and occupational.
What is Artificial Human-Made?
Considered as LAST EVENT, not all cellular radiation injuries are permanent; cellular damage is followed by repair.
What is Recovery Period?
When an X-ray photon interacts with water, a key component of living cells, and causes cell damage, what process occurs that leads to the creation of hydrogen and hydroxyl?
What is Free Radical Formation?
Biologic effects of radiation can be classified as?
What is Somatic & Genetic?
amount of energy absorbed by tissue
What is Dose?
The likelihood of adverse effects or death resulting from exposure to a hazard.
What is Risk?
This effect is that repeated radiation exposure to tissues & organs can lead to health problems. (i.e. cancer, cataracts, birth defects)
What is Cumulative effects?
Is an uncharged (Neutral) atom or molecule that exists with a single, unpaired electron in its outermost shell. It is highly reactive and unstable.
What is a free radical?
All cells in the body EXCEPT reproductive cells
Seen in the person who has been irradiated.
NOT transmitted in Future Generations.
What is Somatic Effect?
measurement is used to compare the biological effects of different kinds of radiation
What is Dose Equivalent?
TRUE OR FALSE?
The potential risk of dental imaging including fatal cancer in an individual is approximately 6 in 1 million.
FALSE
Correct Answer: 3 in 1 million
Small lymphocyte, bone marrow, reproductive cells, intestinal mucosa, skin, lens of eye, oral mucosa falls under which category?
Radiosensitive Organs
what is the term used to describe the theory that suggests cell damage occurs when ionizing radiation directly hits critical areas or targets within the cell, such as DNA?
What is the Direct Theory?
ONLY reproductive cells (ova & sperm)
NOT seen in irradiated person
Passed to future generations.
Radiation-induced mutations affect offspring.
Genetic Damage CANNOT be repaired.
What is Genetic Effects?
the Traditional Unit for measuring x-ray exposure in are is termed:
What is Roentgen?
Which Critical Organs are at risk?
Thyroid Gland
Bone Marrow
Skin
Eyes
Muscle, Nerve, Mature Bone, Salivary Gland, Thyroid Gland, Kidney, Liver falls under which category?
Radioresistant Organs
How is cellular damage caused according to the theory that involves absorption of x-ray photons by water molecules within the cell, leading to the formation of free radicals and cause the formation of toxins?
What is Indirect Theory?
Cells that divide frequently or undergo many divisions over time are more sensitive to radiation.
What is Miotic Activity?
The unit for measuring the absorption of x-rays is termed:
What is Radiation Absorbed Dose (rad)?
Digital Sensor
Small Lymphocyte.
Cells that are IMMATURE or not highly specialized are more sensitive to radiation.
What is Cell Differentiation?
Unit of electrical charge; the quantity of electrical charge transferred by 1 ampere in 1 second.
What is Coulomb (C)?
What is the estimated dose necessary to produce cancer in the thyroid gland?
6000mrad (0.06 Gy)
Which is the GREATEST source of exposure to Background Radiation in the US?
When it comes to radiation effects, this type occurs as a direct function of absorbed dose, does not have a threshold, and affects chromosomes causing genetic mutations?
Examples include: Leukemia & cancer tumors
What is Stochastic Effects?
What is Cell Metabolism?
TRUE OR FALSE?
Small quantities of radiation are used in Dental Imaging Procedures
True
"milli" - 1/1000
"micro" - 1/1,000,000
Approximately 3.1 mSv
This type of radiation effect have a threshold, and is characterized by cell damage or cell death, which can lead to observable functional impairment of tissues or organs (i.e. skin erythema, hair loss, cataracts, fetal death, etc.) What are these effects known as?
What is Nonstochastic effects?
An organ that, if damaged, diminished the quality of an individual's life is termed:
What is "Critical Organs?"
What do 2 millisieverts (mSv) convert to Sievert (Sv)?
2mSv = 0.002Sv
In the United States, medical radiation exposure contributes to almost half of the yearly TOTAL exposure. On average, how much radiation does the average person receive in a year?
6.2 mSv
(3.1 mSv from natural resource + 3.1 mSv from human-made resources = 6.2 mSv total)