Radiation Safety COPY Flashcards
The bucky slot cover of a fluroscopic unit must provide a minimum lead equalvelant absorption equal to what mm of lead?
0.25 mm
What is the minimum lead equivalent thickness that must be present within aprons worn during fluroscopic procedures?
0.5 mm
What is the term applied to radiation injuries that are limited to an exposed individual and the area of exposure only?
local somatic injuries
What exam category is the single greatest form of acute radiation exposure a patient will receive within a diagnostic radiology department?
upper gastrointestinal exam, lumbar spine series, scoliosis series, skull series?
upper gastrointestinal exam
A dose of radiation to a patients long bones results in a 70% loss of operation of the ematopoietic system making the patient susceptable to developing infections. This is an example of what type of radiation induced injury?
general somatic effect
What factor is the missing from the following list that is useful in determine the degree of radiosensitivity of cels to exposrue to ionizing radiation? List: degree of specificity, maturity, and …
mitotic activity
At what period during a cell’s life cycle will the cell be at its highest point of radiosensitivity?
mitosis
What are the effects between a radiation dose delivered in a single dose versuls delivered in incremental doses spread out over a series of exposures?
in a single dose, effects are worse, versus spread out over a series
During which trimester is the developing fetus considered to be at its greates perios of radioresistance?
the third
Which of the following emissions released during radioactive decay, produces the greates amount of radiolysis per mm of irrdiated material?
alpha emission
The correct term for a picture element is what?
pixel
When glass is present in a wall of a radiographic room that has the potential to be struck with the primary x-rya beam, what is the minimum requirement of radiation shielding for the glass?
1/16” of lead equivalent shielding
What is the term for “the unit of absorbed dose”?
Rad
Which response region of an ionization chamber instrument would be used to accurately calibrate the output of a radiographic unit?
ionization chamber region
What units are radiation film badge reports for dianostic radiographers stated in?
millirem
What is the active component of a thermoluminescent radiaion monitoring
lithium fluoride
What source of acute radiation exposrue listed below provides the greates risk to humans?
diagnostic
When time is used as a means of radation protection, what should operatators do?
limit the length of time for any one exposure
reduce frequency of exposure events
An atom containing three protons and three neutrons in its nucleus has
an atomic number of three
What does” the rate of energy deposited per unit tracklength through an abosorber” define?
linear energy transfer
Sterility to a male patient due to excessive radation exposure to the gonads is an example of what type of radiation effect?
somatic local
What is the maximum exposre rate at the surface of the table top for a conventional fluoroscopic unit?
10 R / minute
What feature is essential component of modern fixed radiographic equipment, designed to minimize unnecessary radiation exposure to patients?
positive beam limiation
The effectiveness of low LET sources of radiation in producing some predetermined effect within a cell population will be enhanced under what conditions?
aerobic
When a minimum amount of radiation is required to produce some predetermined response within a test popluation of cells, the dose response relationship is termed what relationship?
threshold
A comparison of photon energies would demonstrate that scattered photons resulting from a “Compton” interaction are ______ the energy of the incident x-ray photon.
lower than
What are examples of a stochastic evenT?
random
any amount of radiation could cause an effect
no threshold for damage
What are examples of a non stochastic event?
not random
need specific amount of radiation to cause an effect
does have a threshold
As LET increases a cell’s survival and recovery increases or decreases?
decreases
What is fractionation?
equal doses of radiation that are delivered with time interval separations.
Offers a cell the greates ability to survive and recover from radiation exposure
What is protraction?
radiation dose that is delivered continously but at a lower dose rate
What is the target theory?
radiation interaction with cells, atoms and molecules is a random act.
If the master molecule of a cell is destroyed, the cell will die
What is interphase death of a cell?
cell dies without attempting to divide (apoptosis)
What is mitotic death of a cell?
cell goes through 1 or more mitotic phases then dies.
What is mitotic delay?
mitiotic activity resumes after a short delay, can be caused by as little as 1 rad
What is reproductive failure in a cell?
cell does not die during radiation exposure, but loses the ability to procreate (100-1000 rads)
What are somatic effects?
limited to exposed population short term: occur relativly soon after exposure nausea, vomiting, red skin long term: cancer, leukemia, cataracts, life span shortening
What is an acute exposure to radiation?
large dose delivered over a short time
What is chronic exposure?
radiation delivered in small increments over a long period of time
based on whole body exposure
What is carcinogenesis?
long term somatic effect of radiation
What dose range can cause permanent sterility
500-600 rads
What is the 10 day rule?
radiation should be limited to a period of time 10 days following the onset of mensturation
What areas of the body are high risk examinations for radiation exposure?
abd, pelvis, sacrum, cocyx, lumbar spine and hips
True or False:
mature male sperm are morphologicaly resistant to radiation
true
Why are children especially sensitive to radiation exposure?
pediatric cells reproduce more frequently, more radiosensitive
longer life expectancy, long term somatic effects time to develop
smaller size-larger percentage of their body exposed
What are the systematic responses to acute radiation syndrome for the CNS?
cardiovasular syndrome
exposure >5000 rads
death occurs within hours or days
What are the systematic responses to acute radiation syndrome for the hemopoetic syndrome?
bone marrow syndrome most radiosensitive system in the body exposure between 100-1000 rads (whole body) blood disorders, and blood clotting death occurs between 3-6 weeks
what are the systematic responses to acute radiation syndrome for the skin/
erythmia, and desquamation
on set of results as much as 10 days
severity of effects with increasing dose
What are the systematic responses to acute radiation syndrome for the gastrointestinal syndrome?
doses between 600- 1000 rads
nausea vomiting and fatigue
death occurs approx 1 week
What is the GSD (genetic significan dose)?
the dose that is delivered to every member of a popluaiotn would be expected to yield the same total genetic injury as the actual doses recieved by the various individuals
approx 20 mrem
the effect of large doses of radiaiton to few individuals is greatly diluted by the total population and results in small genetic impact
What is the lead equivalant of the lead apron and what percentage does it attenuate?
0.5mm Pb
88% attenuation at 75 kVp
0.25mm Pb
66% attentuation at 75 kVp
