rules of protection & pregnancy

cardinal rules of radiation protection (3)

time, distance, shielding

what is the dose rate to the patient directly related to?

the time of the exposure

what is the operator exposure to scattered radiation directly proportional to?

patient exposure

distance

the farther the person is from the x-ray source, the less radiation dose per unit time is received

what will most shielding devices attenuate to?

scatter radiation

primary protective barrier

barrier used to attenuate the useful/primary beam

what is the thickness and height of the primary protective barrier?

1/16” of lead or equivalent and 6.6ft in height from the floor

secondary protective barrier

barrier used to attenuate scatter radiation

what is the thickness and height of the secondary protective barrier?

1/32” of lead or equivalent and should extend from the primary barrier to the ceiling with at least ½ overlap

the operator station at the control shall be behind a protective barrier in:

a separate room, a protective booth, or behind a shield that will protect you from primary and secondary radiation

patient observation and communication

provisions shall be made for the operator to observe and communicate with the pt without leaving the shielded position at the control panel

3 assumptions based on biological risks

• there is always a small potential for adverse biological effects to occur following exposure to x-radiation

• there is no threshold for such effects

• such effects are directly proportional to absorbed radiation dose

28-day rule

the examination may proceed if the patient states she is not pregnant and has had a period within the last 28 days

which 2 questions should be asked of all females of child-bearing age?

possibility of pregnancy and last known menstrual period

what happens if a patient is pregnant?

referring physician should be notified and exam is limited or postponed

when should x-rays take place for pregnant women?

during the last trimester or life and death circumstances

TRUE or FALSE: malformation/termination of pregnancy will rarely be the cause of a radiologic procedure by itself

TRUE

fetus dose limit

0.05 rem (50 mrem) in any month, 0.5 rem (500 mrem) for the entire gestation period