Radiobiology COPY Flashcards
What does ALARA stand for?
as low as reasonably achievable
True or False: Collimate to the smallest field size of the desired anatomy
True
True or False: Radiography should not be used in place of physical examination
True
When is full body shielding mainly used? Partial shielding?
Full Body shielding: Extremity radiography
Partial shielding: cervical and thoracic radiography
Do you perform P-A or A-P views with pediatric patients?
P-A
What is radiosensitivity of cells is dependent on their rate of maturation or differentiation and metabolism?
1906 law of Bergonie and Tribondeau?
What does Linear Energy Transfer measure?
the rate which energy is transferred from ionizing
radiation to soft tissues
What happens to LET when the ability of ionizing radiation to produce a biological response increases?
LET increases
What is the Oxygen effect?
Tissues are more sensitive under an oxygenated state
True or False: Humans are more radiosensitive before birth.
True
What are some agents that enhance radiosensitivity?
- halogenated pyrimidines
- vitamin K
- methotrexate
What is radiolysis of water?
When H2O is irradiated and separates into free radicals
What is the Direct effect?
What is the Indirect effect?
- X-rays directly hit a DNA molecule
- X-rays hit an H2O molecule releasing an ion radical that will hit a DNA molecule indirectly
True or False: Linear Dose response is directly proportional to radiation dose and are non-threshold type
True
True or False: deterministic effect leads to cell killing
True
What is the Stochastic effect expressed by?
cancerogenesis, mutations and hereditary changes
What fetal development period is most vulnerable to radiation effects?
organogenesis 3-7 weeks
What does Rad measure?
how much energy is absorbed per unit mass
True or False: Dose versus cell recovery time are inversely related
True
What does 1 Grey equal?
100 Rads
What is Roentgen? Rad? Rem?
Roentgen: measures amount of gamma or X-rays in air
Rad: measures absorbed energy from radiation
Rem: measures biological damage from radiation
What does 1 Sv (Sievert) equal?
100 Rem
what is it called when animals receive low radiation dose express better survival ability
hormesis
