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):
1

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

dose limit

2

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

inverse square law

3

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

4

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

5

where are primary protective barrier located

undeflected line of travel of the x-ray beam

6

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

secondary radiation

7

protects against secondary radiation (leakage and scatter))

secondary protective border

8

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

9

typical installation of the secondary protective barrier

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

10

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

11

what is the annual occupational dose?

EfD=50mSv or 5 rem whole body

12

what the lifetime effective dose recommendations is

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

13

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

1 mSv (0.1 rem)

14

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

5 mSV (0.5 rem)

15

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

16

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

Compton interaction process

17

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)

18

what poses the greatest occupational hazard in radiology

scatter radiation

19

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

voluntary declaration of pregnancy

20

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

21

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

22

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

0.5 mm lead equivalent

23

know the 3 basic principles of radiation protection

time, shielding, distance

24

know what the amount of radiation received is directly proportional to

length of time for which the individual is exposed to radiation

25

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

26

what is the most effective means of protection from ionizing radiation

distance

27

be able to state the inverse square law

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

28

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

29

what are the most common materials used for structural protective barriers

lead and concrete

30

know what accessory protective devices are made of

lead impregnated vinyl

31

know what makes up secondary radiation

leakage from the tube housing and scatter

32

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

minimum of 2 times

33

know the lead equivalent that a lead glass window must have

1.5 mm lead equivalent

34

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

35

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

36

know what clear lead plastic protective barriers lead equivalent is typically

0.5 mm

37

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

primary radiation

38

whenever a diagnostic x-ray beam passes through matter

scattered radiation

39

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

40

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

workload

41

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

42

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

control area

43

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

uncontrolled area

44

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

tin

45

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

46

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

0.25 mm

47

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

0.5mm

48

lead equivalency of lead aprons

0.5 mm - 1 mm

49

lead equivalency of thyroid shields

0.5 mm

50

lead equivalency of protective eye wear

0.35 mm

51

lead equivalency of lead aprons during fluoro

0.5 mm

52

lead equivalency of protective spot film curtain

0.25 mm minimum

53

lead equivalency of bucky slot shielding device

0.25 mm at least

54

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.

55

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

56

know the methods and devices included in dose-reduction techniques

-adequate beam collimation
-filtration
-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

57

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

58

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

59

where does a radiographer need to stand during mobile radiography

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

60

what happens to dose when magnification is used

adds additional radiation

61

when restraining a patient know where a radiographer should never stand

never stand in the primary beam

62

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

nonoccupationally exposed person should hold the patient

63

what is workload essentially

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

64

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

caution signs