Exam 1 - Radiation safety

in a left lateral view, what side of the patient is facing the imaging receptor

left

in an oblique view, how many degrees is the patient rotated

45

thickness of a patient has a large impact on image quality. A more thick patient will create more _____ of the photons and thus produce decreased image quality

scatter

increasing body DENSITY requires additional x-rays or an increase in (mAs or kVp?) this will lead to increased exposure time and can introduce motion artifact

mAs

increase body THICKNESS requires increased beam energy or (mAs or kVp?) which creates more scatter

kVp

what would you adjust if you encounter these:

increased density = increase ____

increased thickness = increase ____

mAs

kVp

what is a way to move tissue away from the area of interest when taking an x-ray. This decreases tissue density and scatter

move the patient recumbent onto a table

does kvp or mas control contrast

kvp

What are the 2 ways in which ionizing radiation can affect DNA

Directly

Indirectly - via OH radicals

when DNA is affected by ionizing radiation, it has 3 fates. What are these?

apoptosis, autophagy, DNA repair

TQ!

What does the Law of Bergonie and Tribondeau state

radiosensitivity....

decreases with cell maturity

decreases with tissue age

increases with metabolic rate

increases with proliferation rates

based on the Law of Bergonie and Tribondeau, what age range is more sensitive to ionizing radiation

children

what are some highly sensitive areas of the body in regards to ionizing radiation

lymphoid tissue, bone marrow, gonads

what are some low sensitivity areas of the body in regards to ionizing radiation

muscle, nerves, mature bone

t/f

exposure to low-levels of radiation does not cause immediate health effects, but it can cause a small increase in the risk of cancer over a lifetime

true

what are the Deterministic Effects of radiation

number of people exposed to the same dose of radiation and 1% of them have symptoms...this represents the threshold of the dose

Stochastic Effects is associated with what

cancer

does stochastic effects contain a threshold dose

no

what are the units of measurment for radioactivity

becquerel (Bq - int)

Curie (Ci - US)

what is radioactivity

amount of ionizing radiation released by a material

what is exposure

amount of radiation traveling through the AIR

what are the units for exposure

coulomb/kg (C/kg - int)

roentgen (R - US)

what is absorbed dose

amount of radiation absorbed by an object or patient

what is the unit for absorbed dose

gray (Gy - int)

rad (US)

what is effective dose

amount of radiation absorbed by the person and adjusted for the type of radiation received and the effect on particular organs

what is the unit for effective dose

sievert (Sv - int)

rem (US)

what is the 10 day rule

confine imaging of the abdomen or pelvis to the 10-day interval following the onset of menstruation

what is the guiding principle in radiation exposure

As Low As Reasonably Achievable

ALARA