week 2 Shielding Flashcards

1
Q

Aprons are made from

A

vinyl w/lead inside

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2
Q

minimum amount of lead in an apron is

A

.25mm

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3
Q

Fluoro is to check for what

A

lead cracks

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4
Q

shield gonads if they are w/in _ of the primary beam

A

4-5cm

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5
Q

what are the 3 types of shields

A

flat contact-lead blockers
shaped contact-cup shaped for males
shadow shields-in the path of the beam and cast a shadow over the part to be protected

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6
Q

what controls the size and shape of the x-ray field coming out of the tube (coning)

A

collimator

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7
Q

collimator controls the movement of the _ that block a portion of the x-ray beam

A

lead shutters

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8
Q

collimator can be either

A

manual and automatic

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9
Q

automatic is the

A

PBL

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10
Q

what is PBL

A

positive beam limitation-detects the size of the image receptor

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11
Q

what cuts down on patient dose and increases film quality by preventing fog

A

PBL

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12
Q

filtration is the use of attenuating material made of _ between the x-ray tube and the patient

A

aluminum

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13
Q

grids are made of

A

lead strips in between spacing material

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14
Q

where are grids placed

A

between the patient and the image receptor

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15
Q

why are grids used

A

to remove as may scattered photons exiting the patient before it reaches the film and creates fog on the cassette

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16
Q

reducing scatter creates an image with

A

better contrast

17
Q

why does grids not help the patient dose

A

due to increased lead in the grid we have to use a higher technique to get through it. Grids create a higher ESE

18
Q

THe higher the grid ratio (more lead strips)

A

the less scatter on the film but also less density

19
Q

Radiation protection uses what concept

A

ALARA

20
Q

what is a regulator agency that collects and distributes info regarding radiation awareness and safe practice to the public

A

NCRP

21
Q

Radiation protection uses what law

A

inverse square law

22
Q

personnel monitoring determines

A

estimated occupational exposure

23
Q

what are the most common personnel monitoring

A

OSL
film badge
TLD
pocket dosimeter

24
Q

rad. techs use what type of personnel monitor

A

OSL

25
Q

how long do you wear the OSL

A

2 months at the collar

26
Q

OSL are unaffected by

A

heat, moisture, and pressure

27
Q

ionization in the air

A

Roentgen (C/kg) (R)

28
Q

amount of energy absorbed in any medium

A

Rad (gray) (GY)

29
Q

sV- dose equivalence, biologic response

(1rad x1=1rem) quality factor for x-ray is 1

A

Rem (sievert)

30
Q

rate of activity or at which rate a radionuclide decays. . Nuke med or rad therapy

A

curie (becquerel) (Ci) (Bq)

31
Q

who and when discovered cells are most radiosensitive during active division and when they are primitive in structure and function

A

Bergonie and Tribondeau

1906

32
Q

what cells are most radiosensitive during active division

A

basil kin cells, crypt cells of the small intestine and gem cells

33
Q

least sensitive are the

A

nerve cells
muscle cells and
brain cells

34
Q

when you use proper positioning, immobilization, higher kV, lower mAs, high filtration, collimation, and shielding

A

ESE decreases