MI 120 Introduction to Radiation Protection

Chapter 1

What is Radiation?

the transfer of energy from one location to another

What is the Energetic form of radiation called?

X-ray

What were x-ray’s found to produce when passing through normal matter?

(+) ans (-) electrically charged particles

What are altered atoms or molecules called that make up electrically charged particles?

Ions

What are X-rays classfiied as?

Ionizing radiation

What are the fundamental properties of X-rays?

• Classified as ionizing radiation

• Invisible

• Can have varying degrees of penetration in normal tissue depending on energy

• Travel in straight lines at the speed of light until they interact with atoms

• Have a wide range of energies within the xray beam; typically heterogenous, not monoenergetic

What may cause injury in normal biologic tissues?

Production of ions during ionizing radiation and the ejected electrons

What is it called when living tissue can be damaged by exposure to ionizing radiation?

Biological effects

How do we minimize x-ray exposures?

• Proper techniques — appropriate kVP/mAs, technique books, proper measuring of body part

• Procedural factors — Immobliziations, proper image receptor, positioning around patient’s limitations

• Human determinants — pathological conditions, body habits, movement

What is the meaning of ‘unnecessary exposure’?

Exposure that does not benefit a person in terms of diagnostic information and enhancing the quality of study

What is the good voluntary risk in imaging?

• Screening purposes: mammogram

• Injury

• Illness

What is Diagnostic Efficacy?

Provides the basis for the justification of procedure, the degree to which a study reveals the presence or absence of a disease while following radiation safety guidelines

As a technologist, what do we take responsibility for?

• Welfare of patients

• Quality patient care

• Quality images

What are the multiple responsibilities of technologists?

• Keep radiation level at lowest level

  • Techniques — use smallest amount of exposure to produce a good, diagnostic image

  • ALARA

  • Minimize repeats — optimal image the 1st time

    • Repeats cause increased exposures to patient and technologist

  • Proper shielding

    • Reduces exposures

  • Be aware of rules of your department — follow protocols

  • Be educated in safe operations

What are the responsibilities of the Radiologist/Physician?

• Consulting

• Do not order unnecessary exams

• Radiologists utilize same safe practices as the technologist when performing studies

What are the responsibilities of the employer?

• Implement and maintain a radiation safety program

• Supply the necessary resources

• Written policy describing ALARA and the commitment of managing it

• Exposure audit

What is ALARA?

Keep radiation “as low as reasonably achievable” for patients and personnel

What does ORP stand for?

Optimization for radiation protection

True or False: Radiation induced cancers do not have a threshold (linear, non-threshold)/

True, they do not have a threshold

What are the 3 cardinal rules of radiation protection?

Time, Distance, Shielding

What is the Alliance for Radiation Safety in Pediatric Imaging?

Partnership with overall purpose to reduce dose to pediatrics, raise awareness among non radiology users

What is the Image Gently Campaign?

In 2008, alliance initiated this compain, dissemination of pediatric CT dose reduction. most recent is “pause and pulse” in fluoroscopy

What is BASICS?

Beam, Artifacts, Structures, Indicators, Collimation, Support; Digital Radiology Image Analysis Tool

What does the B in BASICS stand for?

Beam

• Was the x-ray beam centered appropriately to the patient or part for the projection?

• Was the tube-detector aligned or angled correctly?

What does the A in BASICS stand for?

Artifacts

• Are there removal objects in the imaging field?

• Are positioning aids, equipment, or markers obscuring pertinent anatomy?

What does the S in BASICS stand for?

Structures

• Are all necessary anatomical structures included?

• Was the patient or part orientation correct?

• Is there unacceptable patient or part rotation?

• Is there evidence of patient motion?

• Was the correct distance used?

What does the I in BASICS stand for?

Indicators

• Is the Deviation Index (exposure indicators) in the appropriate ate range?

• Is there excessive quantum mottle/noise present?

• Were the selected technical factors (kVp, mAs) based on measured part thickness

• Do you need to adjust your technique or approach for the next similar patient?

What does the C in BASICS stand for?

Collimation

• Was pre-exposure collimation appropriate?

• Was digital/electronic post collimation avoided?

What does the second S in BASICS stand for?

Support

• Did you appropriately coach the child and educate the parent to facilitate a successful imaging exam?

• Were breathing instructions explained and appropriately utilized?

Who formed Joint Task Force on Adult Radiation protection about large increase in general public to ionizing radiation?

2009, ACR and RSNA

What are the 4 pillars of patient education?

1. Explain procedure and what cooperation is needed to complete the study

2. Explain what, if anything, needs to be done as a follow up to the exam

3. Make your patient feel like an active participant in their health care

4. Answer questions about the potential risks of the radiation to reduce fears and anxiety

What does BERT stand for?

Background Equivalent Radiation Time

What is BERT?

Compares amount of radiation received during a specific procedure to the amount of natural background radiation over a certain period of time, can be referenced to explain exposure levels to patients, helps educate and reduces anxiety

What are extra points about BERT?

• Does not imply radiation risk; is means for comparison

• Emphasizes to patient that radiation is an innate part of the environment

• Provides a more comprehendible answer to patient

• BERT is not a radiation quantity, it is a method

What is Radiographic Dose Documentation?

Dictating dose exposures and/or fluoro time into radiology reports

What is the definition of Radiation?

The emission of energy in the form of electromagnetic waves or as moving subatomic particles passing through space from one location to another

What are the types of Radiation?

1. Mechanical vibration - causes sound (ultrasound)

2. Electromagnetic wave-radio, microwaves, visible light, x-rays

What is the Electromagnetic Spectrum?

The full range of frequencies and wavelengths of electromagnetic waves

What are the 2 parts of the Electromagnetic Spectrum?

Ionizing and Nonionizing

What is Ionizing radiation?

• X-rays

• Gamma rays

• UV > 10 eV

• High energy + frequency, short wavelength transfers energy that can remove an electro from atom it is attached to

• Foundation of x-rays and human tissue interactions

• Valuable to produce images

What is Non-Ionizing radiation?

• UV < 10 eV

• Visible light

• Infrared rays

• Microwaves

• Radiowaves

• Lower energy, lower frequency, longer wavelength

What are the 2 sources of radiation?

• Natural (background)

• Human-made (man-made, artificial)

What percentage of background/natural radiation is there?

50%

Why has natural radiation always been a part of the environment?

Due to planets geology and relative location to sun and solar system

What is approximate dose found in background/natural radiation?

3.1 mSv

What are the 3 components of Natural Radiation?

• Terrestrial

• Cosmic

• Internal

What is Terrestrial Radiation?

From radioactive material in the crust of the earth

What do the levels of Terrestrial Radiation depend on?

Composition of the soil or rocks, such as Uranium, Radium, Thorium

What is Radon/Thoron?

• 2.3 mSv of natural radiation

• Free agent floating around in soil

• Most significant contributor to Terrestrial Radiation

What is the highest contributor of natural background radiation?

Radon

What are some features of Radon?

• Colorless, odorless, radioactive gas that is always present in some degree in the air

• Higher levels in soil that contains granite, shale, phosphate and pitchblende

• Enters building through cracks or holes in the framework

• Present in building material like bricks, concrete, and gypsum wallboard

• Usually higher in the cooler months

Why does Radon have the potential to cause serious health hazards?

High concentrations, emits alpha radiation

What is the 2nd leading cause of lung cancer, per EPA?

Radon

What is Cosmic Radiation?

Nuclear interactions caused by the sun (solar) and beyond solar system (galactic)

Where do the greatest and lowest intensities of Cosmic Radiation occur?

• Greatest intensity occurs at high altitudes

• Lowest intensity occurs at sea level

What is Internal Radiation?

Part of the human metabolism, radioactive atoms that make up small percentage of the body tissue

• Ingested, inhaled; various foods, particles of air, dust

How does internal radiation exist within the body?

Small quanities: Potassium-40, Carbon-14, Hydrogen-3, and Strontium-90

What other products contribute to Human-made (artificial) Radiation?

• Consumer products: Early TVs, airport surveillance, ionizing smoke detectors, timepieces with luminous dials, video display terminals, shoe fitting fluoroscopes, dentures

• Air travel

• Nuclear fuel for generation power

• Atmospheric fallout from weapon testing

• Nuclear power plant accidents

  • Three Mile Island Unit 2 (TMI1) 1979

  • Chernobyl 1986

    • Naub effect is thyroid cancer of children and adolescents

    • Increase seen in breast cancer

  • Fukushima 2011

• Medical radiation

  • Diagnostic machines

  • Radiopharmaceuticals/radioisotopes

Which of the following is not a source of background radiation?

Radioisotopes used in Nuclear Medicine

What term is a synonym of ALARA?

ORP