Personnel Protection

What is the principal source of radiation for Occupation workers?

patient is principal course of scatter radiation

What is the annual dose limit for Occupational exposure?

annual dose limit : 5 rem/year (50mSv/year)

What two places is the most scatter radiation exposure?

Fluoroscopic procedures and Portables

What is leakage radiation?

radiation emitted from xray tube housing

At what rate should leakage not exceed?

100mR/hr @ 1 meter

NCRP guidelines to Reduce Exposure to Personnel (Rad Equip.) : Control Panel

must somehow indicate xray tube energized (visible light indicator)

What type is a X-ray exposure switch?

Dead Man type

What are 8 ways to reduce dose per NCRP Guidelines?

1. II protective barrier from primary beam

2. Exposure Switch

3. Under table tube

4. Cumulative Timer

5. Lead Protective Curtain

6. Normal Fluoroscopy

7. Lead Apron

8. Lead Gloves

What does the II serve as ?

Protective barrier from primary beam (2mm Pb)

Under table tube bucky slot pb?

.25mm Pb to attenuate scatter radiation

What is cumulative timer?

audible, visible 5 min timer

Lead Protection curtain Pb?

.25 mm Pb to reduce scatter to operator

Normal Fluoro rate?

10R/min

Lead Apron Pb?

.5mm Pb minimum

Lead Gloves Pb?

.25mm Pb

High Level Control Boost mA

significantly higher tube current (10 to 40 mA)

Where is high-level control boost used?

used with angiography and cardiac studies

What should sound if the exposure is going on too long?

Cumulative timer

How do you active High-Level Control (boost)?

Special activation required (key and interlock)

What is inverse square law?

length of exposure time in directly proportional to patient and occupational exposure

What are primary protective barriers?

Barriers that attenuation materials used to reduce radiation exposure

What does Primary Protective barriers protect from?

protectsd from useful beam

What are examples of Primary Protective Barriers?

walls, floors, ceilings

What is often used in Primary Protective Barrier?

lead bonded to sheet rock or wood paneling

Primary Protective Barrier: what can be used in place of lead?

Concrete, concrete clock or brick can be used

How high must Primary Protective Barrier be?

msut be at least 7 feet high

What is the rule of thumb for Primary Protective Barrier?

4in of masonry = 1/16 of lead

What does a secondary barriers do?

A barrier to attenuate leakage and scatter radiation

What is the size of secondary barriers ?

Less thick than primary barriers (1/32in)

What material is secondary barriers?

Lead not required, usually gypsum board, glass or lead acrylic

What dos secondary barrier protect?

X-ray control area is protected with secondary barrier material

Protective Barrier Thickness depends on what?

Depends on distance (distance adjacent to occupied area, not inside of walls of x-ray room)

Where are controlled areas ?

Limits are based on proportionate weekly exposure (radiology personnel and radiology)