Radiology I- Radiologic Physics, Radiation Protection & Biology Flashcards
According to the law of Bergonie and Tribondeau, living tissues with high radio sensitivity include:
- cells with high metabolic activity
- tissues with high growth rate
T/F the most critical time for irradiation of a fetus is during the first two weeks of gestation
TRUE
T/F in a linear, non-threshold dose-response relationship, any dose, regarding of its size, is expected to produce a response.
TRUE
T/F The radiolysis of water results in the formation of free radicals but not ions.
FALSE
T/F It is not necessary to return the control film badge at the end of each month when returning the personnel film badges to the radiation dosimetry company.
FALSE
Protective barrier thickness is determined by the:
- distance between the radiation source and the barrier
- number of examinations performed per week (workload)
- penetrability of the x-ray beam
- time of occupancy of the area
a free radical
is highly active
T/F primary protective barriers are mainly used to shield areas from scatter and leakage radiation
FALSE
When water is irradiated, it dissociates into other molecular products. this action is known as:
radiolysis
an example of primary radiation is
the useful beam
T/F human cells aren’t capable of recovering from radiation damage.
FALSE
ways to reduce unnecessary pt dose include:
- eliminate repeat exams
- position glands out of the primary beam
T/F compared to using an appropriate kVp technique and appropriate film-screen combination, lowering kVp and selecting a slower speed film-screen combination will increase the pt’s dose.
TRUE
T/F as the proliferation rate for cells and the growth rate for tissues decrease, the radio sensitivity decreases also.
TRUE
T/F lead aprons and gloves should be folded and placed flat on a shelf.
FALSE
the unit of dose equivalent or occupational exposure that is used to express the quantity of radiation received by a radiation worker is known as the:
rem
the most radiosensitive macromolecule is
DNA
precautions to take before or during radiography on a pregnant pt include:
- document
- collimate
- shield
- high kVp technique
cardinal principles of radiation protection include:
- minimize time
- maximize distance
- maximize shielding
fetal congenital abnormalities will most likely occur if the fetus is irradiated during the:
3-8 wks
T/F radiation-induced malignancy and genetic effects are late effects of low-dose radiation over long periods of time
TRUE
T/F secondary barriers are used to shield against the useful beam
FALSE
scatter radiation is increased by:
- increasing the field size
- thicker body parts
a material used as a primary barrier is
concrete
reduction of unnecessary pt dose can be achieved by:
collimating the area in question
a cardinal principal of radiation protection is to minimize:
time
a measure of the rate at which energy is transferred from ionizing radiation to soft tissue is known as:
linear energy transfer
an early effect of radiation on humans is:
skin erythema
of the following, the cell type that has the highest radio sensitivity is the:
lymphocyte
T/F a free radical is a charged molecule containing a single unpaired electron in the valence or outermost shell
FALSE
T/F a film badge (or, personnel monitor) is properly worn at chest level
TRUE
T/F The 3 principal observable effects resulting from irradiation of DNA include cell death, malignant disease, and genetic damage.
TRUE
T/F free radicals cause damage by the direct effect of radiation.
FALSE
the principle observable effects resulting from irradiation of DNA include:
- cell death
- malignant disease
- genetic damage
T/F the delayed or late effects of radiation can follow low doses delivered over a long time period.
TRUE
T/F biologic tissue is more sensitive to radiation when irradiated in the oxygenated (aerobic) state.
TRUE
T/F a measure of the rate at which energy is transferred from ionizing radiation to soft tissue is known as linear energy transfer
TRUE
T/F a podiatric assistant should be used to hold an infant during an x-ray procedure, not the parent
FALSE
T/F when the level of metabolic activity is low, radio sensitivity is high
FALSE
T/F research has shown, on avg, that a full-time radiographer’s life-span is shortened by 4 years.
FALSE
the following dose-response relationship has been adopted as the model for establishing radiation protection guidance:
linear non-threshold
T/F major effects of macromolecule irradiation include main-chain scission, cross-linking, and point lesions.
TRUE
the unit of radiation measurement that is used to describe the radiation quantity or dose absorbed by the pt is known as the:
rad (gray)
T/F a free radical can join with a similar molecule and form hydrogen peroxide which is poisonous to the cell
TRUE
If an undetected pregnant pt is irradiated, the:
fetal dose should be estimated
T/F lead-lined barriers are required for secondary protective barriers.
FALSE
the least radiosensitive macromolecule of the following is:
protein
T/F the dose-response relationship for radiation-induced cataracts is apparently threshold, non-linear
FALSE
a cell type that exhibits high radio sensitivity to ionizing radiation is:
lymphocyte
of the following, the organ or tissue that has the highest radio sensitivity is:
gonad
T/F the principle action of radiation on humans is by the direct effect.
FASLE
T/F ALARA stands for as large as reasonable achievable.
FALSE
T/F a pregnant radiographer should wear an additional personal monitoring device under her apron at waist level.
TRUE
if an infant needs to be held still during a radiographic study, it should be done by the
guardian or parent
barriers are used to shield against:
- the useful beam
- leakage radiation
- scatter radiation
T/F MPD (max permissible dose) is defined as the max dose of radiation expected to produced significant radiation effects.
FALSE
T/F the age of a biologic structure affects its radiosensitivity
TRUE
The pregnant radiographer should:
have her previous radiation exposure history reviewed
T/F the late effect of radiation is defined as follows: the radiation response occurs within minutes or days after radiation exposure.
FALSE
T/F the law of Bergonie and Tribondeau states the following: tissues that are younger, have a high level of metabolic activity, and have a high growth rate are more radiosensitive.
TRUE
according to the Law of Bergonie and Tribondeau:
radio sensitivity increases with increasing tissue growth rate
the effects of proper collimation are:
- reduce pt dose
- improve image contrast
T/F the damage caused by free radicals as they transfer their energy to a target molecule occurs by the direct effect of radiation.
FALSE
T/F if the initial ionizing event occurs on the molecule that is irradiated, the effect is said to be indirect
FALSE
regarding radiation-protection design for x-ray equipment:
the output radiation intensity should be constant from one exposure to the next
T/F one factor that barrier thickness depends on is the distance bw the radiation source and the barrier
TRUE
T/F an infant should be held still during the exposure b the radiographer, not the parent or guardian.
FALSE
T/F a cardinal principle of radiation protection is to maintain a large distance bw the body part and the film
TRUE
T/F a cardinal principle of radiation protection is to keep the time of radiation exposure long
FALSE
T/F radiation dose-response relationships are used to design therapeutic treatment routines for pts with cancer and to provide info on the effects of low-dose irradiation.
TRUE
T/F the linear, non-threshold dose-response relationship states that a specific irradiation dose is necessary to produced a response in tissue .
FALSE
the biologic effectiveness of radiation energy absorbed is measured by the:
rem
protective barrier thickness is determined by the:
all of the above answers are correct
T/F generally speaking, the older tissues and organs are, the less radiosensitive they are:
TRUE
T/F fetal exposure of radiation drink the first week of pregnancy will most likely result in skeletal deformities.
FALSE
an uncharged molecule containing a single unpaired electron in the outermost shell is known as a(n):
free radical
according to the law of Bergonie and Tribondeau, living tissues with high radiosenstivity include:
- cells with high metabolic activity
- tissues with high growth rate
T/F the film badge control monitor should be kept in the radiography procedure room
FALSE
T/F free radicals are formed by the radiolysis of water
TRUE
most states recommend that the film badge be worn at the level of the:
collar
consider the following 2 characteristics: 1) any radiation dose, regardless of its size, is expected to produce a response; and 2) the response to radiation is directly proportional to the dose. This is known as the:
linear non threshold relationship
a disadvantage of the film badge is its:
sensitivity
T/F film badges are inexpensive and reasonably accurate. However, they are sensitive to heat and humidity.
TRUE
T/F the required thickness of a lead apron is 0.25 mm
TRUE