basic radiation protection

Radiation has been present since

Life began

Uranium decays into

Radon, a radioactive gas made by natural decay

Its found in bricks or drywall

Sources of ionizing radiation

Natural and man-made

Natural sources of radiation exposure

Cosmic rays

Terrestrial radiation

Internal radionuclides (potassium 40)

Man-made sources of radiation

Medical

Industrial

Consumer products

Nuclear power

Radon is a

Heavy radioactive gas thats colorless and orderless

And always present in air

Radon emits

Alpha particles

And is highly ionizing

Radon can be blocked by

Paper but would wreak havoc if inhaled

Ionizing radiation

Any type of radiation thats can remove an electron from an atom it interacts with

ionizing radiation is a type of

EMR electromagnetic energy

Ex) x-rays

Particulate radiation is not

A type of EMR

Examples of particulate radiation

Alpha particles

Beta particles

Neutrons

Protons

Examples of EMR

Gamma rays

X- rays

The only difference between x rays and gamma rays

X rays are man made

Properties of x ray

Invisible

Electrically neutral (ions are not)

No mass

Travel at speed of light

Cant be optically focused

Form polyenergetic or heterogeneous beams

Travel in straight lines

Can make some stuff glow

Primary radiation

Beam of photons before it reaches the patient

Remnant radiation

Beam thats able to exit the patient

Frequent injuries from exposure

Skin damage erythema

Alopecia

Anemia (low red blow count)

NCRP (national council on radiation protection and measurements)

Establishes radiation limits

Goal is to Minimize harm

ICRP international council of radiation protection

made ALARA

Radiation exposure must have a benefit and limits for radiation exposure cannot be exceeded

Tissue sensitivity

Higher tissue weighting factor, higher sensitivity

Ex) gonads .20 → most sensitive

Shield when

• when practical

• Gonads lie within or close to x ray field

• Clinical objective is not compromised - not shielding needed anatomy

• Patient has reasonable reproductive potential

Cardinal principles

1. Time

2. Distance

3. Shielding

Ten commandments of radiation protection

1. Cardinal rules

2. dont get too familiar

3. Never stand in the primary beam

4. Always wear protection when not behind a protective barriers

5. Always wear a dosimeter

6. Never hold a patient

7. Person holding patient should always wear apron

8. Use gonadal shields

9. Avoid pelvis and lower abdomen of pregnant people

10. Always collimate to smallest field size appropriate

Practices to reduce patient dose

• use high kVp/low mAs

• Use fast screens

• Position patient to avoid gonadal exposure (PA instead of AP)

• Use lead shielding

Basic rad protection

Cardinal principles

Filtration

Collimation

Intensifying screens

Protective barriers

Protective apparel

Gonadal shielding

Gonad shielding is required when the gonads lie within ___ of the primary x ray

5cm

Collimation reduces

Scatter and secondary radiation

Patient radiation

Primary protective barrier

Protects against primary beam

Lead or concrete

Behind wall bucky or under x ray table

Secondary protective barrier

Protects against scatter radiation

Thinner

Window of x ray room

Speed of light

3×10^8