Extra Review Flashcards
Which populations were used as sources of data on the incidence of radiation-induced cancer?
- Atomic bomb survivors
- Medically exposed patients
- Occupational exposed personnel
- Populations who received high natural background exposure
What are the limitations on epidemiologic studies?
- Failure to control experimental groups
- Insufficient observation periods
- Using improper control groups
- Deficient or Incorrect health records
Which of the following describes radiation damage that increases the probability of causing a late effect but will not increase the severity of the effect?
Stochastic
What’s the dose response relationship for Radiation-induced leukemia
linear-nonthreshold dose relationship
What’s the dose response relationship for Skin cancer
threshold
What’s the dose response relationship for Thyroid cancer
linear nonthreshold
What’s the dose response relationship for Osteosarcoma
linear-quadratic
What’s the dose response relationship for lung cancer
linear-nonthreshold
The function of a filter is to remove what from the x-ray beam?
Long wavelength radiation
To within what percent of the SID must the collimator light and actual irradiated area be accurate?
2%
The greatest beam limitation is accomplished when the cone/cylinder is _____, and the diameter opening is _____.
longer ; smaller
How much total filtration is required when using over 70 kVp?
2.5 mm of aluminum equivalent
The number of repeat radiographs can be reduced by
eliminating voluntary patient motion using immobilization devices
Using CR, it is estimated that overexposures of up to _____, and underexposures up to _____ are recoverable, thus eliminating the need for retakes.
500% ; 80%
An effective way of reducing patient dose is through
Accurate and effective positioning
Causes of repeat radiographs include the following:
- Dirty screens
- Incorrectly loaded cassettes
- Light leaks
- Chemical fog
- Processor artifacts
How tall must primary protective barriers be?
7 ft.
Leakage radiation from the x-ray tube housing shall not exceed _____ mR/hr at a distance of 1 meter from the tube.
100
Lead aprons worn during a mobile exam must have a lead equivalency of at least _____ mm.
0.5
The cardinal rules of radiation protection include:
- Time
- Distance
- Shielding
When wearing a lead apron, a pregnant radiographer is required to wear their fetal dosimeter
at the waist level on the inside of the apron
Factors which determine protective barrier thickness include:
- Time of occupancy
- Workload
- Use
Applying the inverse square law, if we double our distance from the source, the intensity at our new distance is _____ as much as the original intensity
1/4
The lethal dose required to kill 50% of the population in 30 days is the definition of
LD 50/30
The acute radiation syndrome includes the following:
- Bone marrow syndrome
- Gastrointestinal (GI)
- Central nervous system (CNS) syndrome
For the acute radiation syndrome, in the 100-1,000 R range, death is mostly the result of damage to the _____ system
hemopoietic (development of blood cells)
In the _____ stage, the person experiences nausea, vomiting, and diarrhea.
prodromal
In the _____ stage, the person appears to be symptom-free
latent
In the _____ stage, the person becomes noticeably ill and shows signs and symptoms of the specific syndrome reflecting the organ system which is damaged.
manifest
define chromatid aberration
- Occurs after DNA synthesis
- During the S-phase, a chromosome duplicates itself, creating sister chromatids
define chromosomal aberration
- Occurs before DNA synthesis
- Both daughter cells inherit a damaged chromatid
what are the 2 types of damage in chromosomal aberration?
- single break damage
- double break damage
define single-break damage
- Chromosome arm is broken off
- Deletion - arm does not reattach itself
- Inversion - inverts and reattaches itself
- Duplication - attaches itself to a different chromosome