
Reset Password Free Sign Up


Remove Ads
incorrect cards (0)
correct cards (0)
remaining cards (0)

Pass complete!

Correct box contains:
Time elapsed:
restart all cards


  Normal Size     Small Size show me how

RADT 355- Unit 1

Radiobiology review of chapters 1-3 major concepts

Degree to which the diagnostic study accurately reveals the presence or absence of a disease in the patient Diagnostic Efficacy
What is another term that means the same as the ALARA principle? ORP= Optimization for radiation protection. Keeping the radiation exposure and consequent dose as low as reasonably achievable
How can a radiographer improve understanding and reduce fear/anxiety for the patient? Use BERT. Background equivalent radiation time.
BERT compares the amount of radiation received with _______. a natural background radiation received over a specific period of time. Days, weeks, months, etc.
Amount of energy transferred by ionizing radiation Radiation dose
_______ has both a beneficial and a destructive potential. Ionizing radiation
T or F. Ionizing radiation produces electrically charged particles that can cause biologic damage on molecular, cellular, and organic levels in humans. True
The two types of radiation dose are? Equivalent dose and effective dose
Information obtained from the exam benefit patient care, increase lifespan, have no affect, or decrease lifespan Risk- Benefit Continuum
Equivalent dose (EqD) is measured in, Effective dose (EfD) is measured in, EqD measured in Sievert (Sv), EfD measured in REM
What three radiation disasters did we gain understanding from? Three mile island, Chernobyl, Japan
For the average population, what is the total annual background radiation? 6.25 millisievert
What scale ranks the severity of radiation incidents? International Nuclear and Radiological Event Scale (INES)
A radiation quantity used for radiation protection purposes when a person receives exposure from various types of ionizing radiation Equivalent dose (EqD)
Takes into account the dose for all types of ionizing radiation to irradiated organs or tissues in the body. Effective dose (EfD)
A patient receives a chest x-ray. Using BERT, how many days of natural background radiation is the single chest x-ray equivalent to? 10 days
A patient has a UGI exam done. Using BERT, how many years of natural background radiation is the single UGI exam equivalent to? 1.5 years
What are three characteristics of the electromagnetic spectrum? Wavelength, energy and frequency
X-rays possess high energy, high frequency and ____ wavelength Short
What are the four types of radiation? Primary, scatter, leakage, remnant (exit) radiation
Direct and indirect transmission of x-ray photons Attenuation
How can a radiogapher limit indirect transmission of photons? Grids and air-gap technique
T or F. Some absorption must occur to form a diagnostic x-ray image. True
What is the best way to reduce scatter radiation? The use of collimators
Produces an Auger electron as a secondary process from photoelectric absorption. An inner electron is removed from an atom in a photoelectric interaction, causing an inner shell vacancy, causing an emission of an auger electron. Auger effect
Occurs at energies above 10 mEv Photo disintegration
Interactions with matter that are not in diagnostic energy range Pair production and photo disintegration
Bending of photon path. Degrades appearance of a completed radiographic image by blurring the sharp outlines of dense structures. Small-angle scatter
Also known as classic, elastic, unmodified scattering. Interacts with entire atom and is never ionized. Coherent scattering
Net effect of coherent scattering. The process of which the photon energy is absorbed and then reradiated in a different direction with no change in wavelength. Rayleigh scattering
Another kind of coherent scattering. Occurs when a low-energy photon interacts with one or more free electrons. Thompson scattering
What happens to patient dose when kVp increases? Patient dose decreases
Type of energy an x-ray photon possesses? Kinetic
This type of effect is called a radiationless effect. It is more prevalent in materials with a higher atomic number. It does not produce radiation therefore it has no effect on patient dose. Auger effect
Of the four types of radiation, which is most useful? Primary Beam
Photons with middle energy are more likely to interact with? Orbital electrons
Photons with the lowest amount of energy are more likely to interact with? Whole atom
The less a given structure attenuates the _____ its radiographic density will be. Greater
What factors influence attenuation? Mass density, thickness of body part, atomic number, and energy range
An increase in photoelectric absorption will predominately occur with Increased atomic number, decreased energy of x-ray photon, increased mass density, thicker structures
If two structures have the same density and atomic number but one is twice as thick as the other, which structure absorbs twice as many photons? Thicker structure
What is the function of filtration in diagnostic x-ray beam? Hardens the beam by removing low energy photons. Decreases patient dose.
What year was the first radiation fatality? Who was it? Clarence Daly in 1904
Received quantity of radiation that causes diffuse redness over an area of skin. Varied for each person-not precise Skin Erythema Dose
A dose that occupational workers could be exposed to without having any harmful acute affect Tolerance Dose
A dose that is below which an individual has a chance to sustain specific biological damage Threshold Dose
T or F. Neither tolerance dose nor threshold dose are currently being used for the purposes of radiation safety True
Acute or early effects. Appear within minutes, hours, days or weeks. Short-term somatic effects
What are some long-term somatic effects? Cancer, embryologic effects, formation of cataracts
Biologic effects of ionizing radiation on generations yet unborn Genetic effects (Heritable Effects)
What are some acute somatic effects? Nausea, fatigue, diffuse redness of skin, fever, loss of hair, intestinal disorders, shedding of the outer layer of skin
The unit that measures radiation intensity Roentgen (R) or Gray (Gy)
Radiation absorbed dose. Responsible for patient dose. RAD or Gray(Gy)
Radiation equivalent man. Responsible for occupational dose. REM or Sievert(Sy)
The unit of quantity of radioactive materials Curie (Ci) or Bequerel (Bq)
This quantity, describes radiation exposure of a population or group from low doses of different sources of ionizing radiation. Collective effective dose (ColEfD)
What two systems can radiation units be expressed in? International System (SI) or the traditional system
How is the conversion of the roentgen to coulombs per kilogram accomplished? Multiplying the number of roentgens by 2.58 x (10) to the negative fourth power
Amount of energy transferred on average by radiation to an object Linear energy transfer (LET)
The higher the LET the more biological damage and the higher ______ factor. Quality
What is the unit of collective effective dose? Person-sievert
The weighting factor that takes into account the relative risk associated with irradiation of different body tissues Tissue weighting factor
If absorbed dose is stated in rad, how can gray can be determined? Dividing by 100
In the International System, what is the exposure unit measured in? Coulombs per kilogram (C/kg)
How do you convert GRAY to RADS? Multiply number of Grays by 100
Created by: kjschapker on 2012-01-20
