Radiation Protection Ch 13 Part 1 and 2 Flashcards Preview

Radiography Spring 2016 > Radiation Protection Ch 13 Part 1 and 2 > Flashcards

Flashcards in Radiation Protection Ch 13 Part 1 and 2 Deck (64):

designed to limit exposure to reasonable levels of risk comparable with risk from other common sources

dose limit


expresses the relationship between distance and intensity (quantity) of radiation and governs the dose received

inverse square law


prevents direct or unscattered radiation from reaching from reaching personnel or members of the general public on the other side of the barrier

primary protective barrier


typical installation of primary protective barrier

consist if 1/16" (1.6mm)lead that extends 7ft (2.1m) upward from the floor of the x-ray room when the x-ray tube is 5-7ft from wall in question


where are primary protective barrier located

undeflected line of travel of the x-ray beam


consist of radiation that has been deflected from the primary. Leakage from the tube housing and scatter make it up.

secondary radiation


protects against secondary radiation (leakage and scatter))

secondary protective border


classification of the secondary protective barrier

any wall or barrier that is never struck by the primary beam is classified as a secondary protective border


typical installation of the secondary protective barrier

should overlap the primary protective barrier by 1/2" and consist of 1/32" lead


secondary protective barrier: must extend 7ft upward from the floor and permanently secured to it. X-ray should scatter a minimum of 2 times before reaching any area behind it.

control booth barrier


what is the annual occupational dose?

EfD=50mSv or 5 rem whole body


what the lifetime effective dose recommendations is

should not exceed 10xs the occupationally exposed persons age in years


what is the annual effective dose limit allowed for nonoccupationally exposed individuals frequent exposure?

1 mSv (0.1 rem)


what is the annual effective dose limit allowed for nonoccupationally exposed individuals for infrequent exposure?

5 mSV (0.5 rem)


know the 9 dose-reduction methods and techniques

1. Avoiding repeat examinations
2. the pt is a source of scattered radiation
3. scattered radiation occupational hazard
4.filtration of the x-ray beam
5. protective apparel
6. technical exposure factors
7. use of high speed image receptor systems
8. retakes in digital imaging
9. correct processing of radiographic images


know the process that make the patient become a source of scatter radiation

Compton interaction process


at what angle and distance should a technologist stand, because the intensity of the scatter is approximately 1/1000 of the primary beam?

90 degree angle at a distance of 1m (3.3 ft)


what poses the greatest occupational hazard in radiology

scatter radiation


what s the first step in a pregnancy policy that makes the facility recognize the pregnancy

voluntary declaration of pregnancy


know what the pregnant worker does after receiving radiation safety counseling

must read and sign a form acknowledging they received the counseling and understands the ways to implement appropriate measure to ensure the safety


know what maternity protective apparel must consist of

maternity aprons consist of 0.5 mm lead over their entire length and width and have an extra 1mm lead equivalent protective panel that runs transversely across the width of the apron for added protection


if regular wraparounds are worn by a pregnant worker how much lead equivalency must be in them

0.5 mm lead equivalent


know the 3 basic principles of radiation protection

time, shielding, distance


know what the amount of radiation received is directly proportional to

length of time for which the individual is exposed to radiation


under the cardinal principle of time, when is the only time a radiographer should be present in a fluoroscopic exam

only when needed to perform relevant patient care and to fulfill respective duties associated with the procedure


what is the most effective means of protection from ionizing radiation



be able to state the inverse square law

"the intensity of radiation is inversely proportional to the square of the distance from the source."


know when the principle of shielding should be used

when it is NOT possible to use the cardinal principles of time and/or distance to minimize occupational radiation exposure


what are the most common materials used for structural protective barriers

lead and concrete


know what accessory protective devices are made of

lead impregnated vinyl


know what makes up secondary radiation

leakage from the tube housing and scatter


know how many times a typical x-ray will scatter before reaching any area behind a control booth barrier

minimum of 2 times


know the lead equivalent that a lead glass window must have

1.5 mm lead equivalent


know how the exposure cord plays a role in protecting the radiographer

it must be short enough so that the exposure switch can be operated from only behind the control booth barrier


know how modular x-ray barriers are made

must be shatter resistant, can extend 7ft (2.1 m) upward from the floor and is available in lead equivalency from 0.3 to 2mm


know what clear lead plastic protective barriers lead equivalent is typically

0.5 mm


radiation that emerges directly from x-ray tube collimator and moves without deflection

primary radiation


whenever a diagnostic x-ray beam passes through matter

scattered radiation


radiation generated in x-ray tube that does not exit from the collimator opening but rather penetrates through the protective tube housing and sides of collimator

leakage radiation


the quantity that best describes the weekly radiation use of a diagnostic x-ray unit
-radiation output weighted time that the unit is actually delivering radiation during the week



used to modify the shielding requirement for a particular barrier by taking into account the fraction of the work week during which the space beyond the barrier is occupied

occupancy factor


a region adjacent to a wall of any x-ray room and is used only be occupationally exposed personnel

control area


a nearby hall or corridor that is frequented by the general public

uncontrolled area


in protective shielding devices what material other than aluminum and lead can be used



when should protective lead aprons and leaded gloves be used

when radiographer cannot remain behind a protective lead barrier during an exposure and lead gloves when the radiographers hands will be ear the x-ray beam


what is the minimum lead equivalent that can be used in a protective apron

0.25 mm


know what the most commonly used equivalency throughout the department is?



lead equivalency of lead aprons

0.5 mm - 1 mm


lead equivalency of thyroid shields

0.5 mm


lead equivalency of protective eye wear

0.35 mm


lead equivalency of lead aprons during fluoro

0.5 mm


lead equivalency of protective spot film curtain

0.25 mm minimum


lead equivalency of bucky slot shielding device

0.25 mm at least


know where you should stand during fluoro procedure to protect yourself from scatter

stand as far away as practical from the patient, only move closer when assistance is required. Stand behind the radiologist and or behind the control booth until needed.


if you are in a fluoro room but not required to assist with the patient where should you stand

as far away as possible behind control booth


know the methods and devices included in dose-reduction techniques

-adequate beam collimation
-gonad shielding
-control of technical exposures
-high speed IR systems
-correct imaging processing
-adequate structural shielding
-appropriate source to skin distance
-using a cumulative timing device
-correct tube housing


know what the bucky slot shielding device does

automatically cover the bucky slot opening on the side of the x-ray table during standard fluoro exams when the bucky tray is positioned at the foot end of the table


how long does the exposure cord have to be

long enough to permit the radiographer to stand 6ft (2M( from the tube, patient, and beam


where does a radiographer need to stand during mobile radiography

6 ft (2m) from tube, patient, beam


what happens to dose when magnification is used

adds additional radiation


when restraining a patient know where a radiographer should never stand

never stand in the primary beam


when you cannot use mechanical restraint device know what should be done (or used) to restrain patient?

nonoccupationally exposed person should hold the patient


what is workload essentially

the radiation output weighted time that the unit is actually delivering radiation during the week


know what must be posted in any area where radiation and radioactive material is present as part if a radiation safety program

caution signs