minimizing exposure to personnel Flashcards
what is the radiation dose threshold to be declared a radiation worker
1/20th of the whole body dose limit (20 mSv)
when a protective apron is worn, the personal dosimeter must be worn (over/under) the apron
under
why do radiation workers have a higher eqD than the public
the workforce is small
can be higher without reaching the GSD
what is GSD
genetically significant dose
what 2 types of damage can occur from radiation
somatic damage
genetic (hereditary) damage
what are the 3 biggest principles of radiation protection
distance, time, shielding
what is the most effective means of protection from ionizing radiation
distance
mobile x-ray unit cords must be ___ from the tube
3 metres, or 9 feet
where (during mobile) should the radiographer attempt to stand
at a right angle to the beam-scattering object line
at a 90 degree angle and 1m distance, the scattered x-ray is at ___ of the original intensity of the primary beam
1/1000
how can time be used to reduce exposure to personnel
rotational scheduling of personnel
what procedures can increase risk of radiographer exposure (5)
general fluoro
interventions with high-level-control fluoro (HLCF)
mobile exams
general rad procedures
c-arm fluoro
when is shielding used to reduce dose
when not possible to reduce time and distance
what 2 technical exposure factors can be used to protect personnel
inc avg beam energy (more forward scatter, less side)
lower mAs (fewer photons)
what regulation is in place in relation to the control booth entrance
photons must scatter TWICE before the entrance
what property of the control booth is regulated for safety
the cord must be short enough that the operator must be in the booth
controlled areas may be occupied ONLY by whom
the occupationally exposed
what is the radiation dose limit for uncontrolled areas
1mSv/yr
direct radiatio exposure of personnel by the primary beam…
must NEVER be allowed
should operators hold patients?
no!
are pregnant women permitted to assist in holding a patient
NO NEVER
where should you aim to point the beam whenever possible
unoccupied areas r primary barriers
what is the rule about the primary beam and secondary barriers
never expose a secondary barriers with the primary beam
the control booth is a (primary/secondary/tertiary) barrier
secondary
what must be marked on protective materials
must be permanently and clearly marked
how often must protective equipment be tested
on a yearly basis
what must you not do with aprons during storage
fold them
scatter is more intense on which side of the patient
the side closer to the source
which position is better for personnel
2, under the table
on which side of the table should personnel stand when doing lateral exposures
on the II side
what is the required lead equivalency of an apron for 100 kV or less
0.25mm
what is the required lead equivalency of an apron for 100 kV or less, 150 k|V or more
0.35mm
what is the required lead equivalency of an apron for 150 kV or more
0.5mm
what Pb equivalency must protective gloves have
0.25mm Pb eq
throughout entire glove
protective gonadal shielding for pts:
MUST have ____PB eq
SHOULD have ___ Pb eq
must have 0.25 mm
should have 0.5 mm
full wrap protective gowns must have;
___ Pb eq in front panels
___ Pb eq in back panels
0.50 mm in front
0.25 mm in back
for interventional procedures, thyroid shields of ___ Pb eq are recommended
0.50 mm Pb eq
what is recommended if the procedure could approach the annual exposure limit of ___ to the eye?
150 mSv
lead glasses
the exposure rate from scatter at the (ent/exit) of pt exceeds that if at the (ent/exit)
at entrance exceeds that of at the exit
which lead glasses style is an appropriate choice, with monitors at 45deg from the field
classic
which lead glasses style is an appropriate choice, with monitors at 90deg from the field
sport wrap
what is the minimum lead eq for a fluoro spot film protective curtain/sliding panel
0.25mm lead eq
