PR 2 - Designing for Rad Protection

What is the purpose for protective tube housing in diagnostic testing?

reduce leakage radiation

In diagnostic testing, leakage radiation must not measure more than.....

1 mGya/hr at 1 meter from protective housing

In diagnostic testing, what does the control panel positively indicate?

conditions of exposure

What can you see on the control panel?

mAs and kVp

During exposure when the beam is energized, you notice_________during exposure.

audible sound and visual signal

A tape measure and laser are two ways to measure....

SID (source to image distance)

The tape measurer or laser must be accurate within ___ percent of the SID?

2%

What is another name for the xray beam or light beam?

collimation

What must coincide within 2% of SID?

x-ray beam / collimation

PBL stands for.....

positive beam limitation

T or F: Positive Beam Limitation (PBL) is currently mandatory in diagnostic testing?

false

A PBL must be accurate to within ___% of the SID.

2%

What is it called when the center of image receptor and the x-ray beam are aligned?

beam alignment

What is true about filtration in diagnostic testing?

all-purpose rooms must have at least 2.5mm Al equivalent

What decreases exposure of the patient in diagnostic testing?

filtration

What is the required filtration equivalence when the kVp is set above 70?

2.5mm Al equivalence

1.5mm Al equivalence is used when the tube uses what kVp, regarding filtration?

kVp between 50 and 70

What is the required filtration equivalence when the kVp is set below 50?

0.5mm Al equivalence

How do we measure filtration for diagnostic testing?

HVL - half value layer

How many micro-meters of Molybdenum (Mo) is used for filtration in Mammography?

30

How many micro-meters of Rhodium (Rh) is used for filtration in Mammography?

60

Repeated exposures at a given technique must provide consistent intensity.

Reproducibility

Referring to reproducibility the difference in intensity during reproducibility should only change within........

5% or less

what is the formula linearity

mA x s (time)

what does linearity mean

different combinations but the same amount of intensity

Linearity must not deviate more than____ in diagnostic testing?

10%

How is intensity expressed in linearity?

mGya/mAs

how long/short is the cord for the exposure switch in the imaging department?

as short as possible

A 6 foot long cord is used with what kind of machine?

portable / mobile machine

When using a portable xray machine the cord must be at least 6 feet, ____cm, or _____meters long.

180cm / 2m

What does SSD mean?

source to skin distance

SSD for fluoroscopy must be_____cm for stationary or in room examinations

no less than 38 cm

SSD for a portable (C-arm) fluoroscopy must be_______cm for a portable examinations.

no less than 30 cm

In fluoroscopy, the dose is ______ when the tube is closer to the patient's skin

higher

In fluoroscopy, the dose is lower when the tube is moved ______ from the patient's skin

further

PPB means....

primary protective barrier

The image intensifier is part of the PPB and must be _______ equivalent

2mm PB equivalent

In fluoroscopy, the _____ and _____ must be connected and able to move together

Image Intensifier and tube

When the image intensifier is in park, xrays_______

cannot be produced

Filtration in fluoroscopy must be at least________equivalent

2.5mm Al

Anything that is between the _____ and the _____counts as part of the 2.5mm Al equivalent for fluoroscopy filtration

xray tube and patient

Filtration in fluoroscopy is measured by______

HVL

When collimating in fluoroscopy, what should you be able to see on the image monitor?

an unexposed (dark) visible border

What type of switch is an exposure switch?

dead-man type

When your foot in not touching the exposure (dead-man) switch, xrays ______ be produced

cant

In fluoroscopy, what is the opening on the table where the IR is placed?

bucky slot cover

All area that the IR does not occupy is considered to be_______

open space

The bucky slot cover is covered in Pb during fluoroscopy exams so that the _____ and _____ are protected

radiologist and technologist

The bucky slot cover must be at least _________ in fluoroscopy

0.25 Pb equivalent

The protective curtain must be _______ equivalent and reduces exposure to the _____

0.25 Pb; technologist

What indicates how long the fluoro has been on or energized for?

cumulative timer

In what intervals does the timer go off for?

5 minutes

The timer produces audible sound and ______ exposure

interrupts

The x-ray beam intensity at the tabletop during fluoroscopy must not exceed _____mGya/minute for each mA at _______kVp

20; 80

The x-ray beam intensity at tabletop with NO High-Level Control should not exceed__________/minute

100 mGya/minute

The x-ray beam intensity at tabletop WITH High-Level Control should not exceed__________/minute

200 mGya/minute

T of F: There is no limit on xray intensity when the image is recorded?

true