Handout  

Module:  Radiation physics and biology (revised 1/13 - Dr. V.)
Competency II-3:
Produce diagnostic radiographs utilizing radiation physics and chemistry principles and following the ALARA principle.  
Facilitator:
Varnell                                                                                               
Primary Resources: Dental Radiography Principles & Techniques, 4th ed.: Chapter 2 "Radiation Physics"; Chapter 3 "Radiation Characteristics"; Chapter 4 "Radiation Biology" 
Supplemental Resources:
previous PP & modules
Key Terms:

Anode

Indirect theory

Maximum permissible dose (MAD)

Beam intensity

Insulating oil

Milliampere seconds

Bremstrahlung

Inverse square law

Milliamperage

Cathode

Ionizing radiation

Photon

Coherent scatter

hydroquinone

Primary beam

Compton scatter

sodium carbonate

Quality factor

Contrast

sodium thiosulfate

RAD

Copper stem

acetic acid

Radiation

Coulomb

Tungsten target

Recovery period

Critical organ

Vacuum tube

REM

Cumulative effects

Wavelength

Roentgen

Direct theory

Kilovoltage

Scale of contrast

Film badge

Kilovoltage peak rule

Shell

Film density

Latent period

Sievert

filtration

elon

somatic effects

Focusing cup

sodium sulfite

Thermionic emission

Free radical

potassium bromide

Transformer

Gray

potassium alum  

Half value layer

Impulse  

Learning Objectives

  1. Explain atomic structure in sufficient detail to provide an understanding of x-radiation production,     

  2. Specify the function of each of the primary components of a simplified x-ray unit including, cathode (tungsten filament and molydbenum focusing cup), anode(tungsten target and copper stem),cooling mechanism, vacuum, collimator, filter, step up transformer, step down transformer,

  3. Differentiate between ionizing radiation and other types of radiation,

  4. Explain ways to reduce scatter radiation,

  5. Describe how properties of ionizing radiation are related to its use in dentistry,

  6. Compare and contrast sharpness, resolution and magnification,

  7. Compare exposure measurement, dose measurement and dose equivalent measurement with regards to what is measured and the standard and SI units of measurement,

  8. Describe the effects on magnification with a change in tube to film distance,

  9. Compare the effects of altering the "film to object" distance and  "source to object" distance,

  10. Describe how changes in millamperage, kilovoltage and time changes the quality of radiographic exposures,

  11. Utilize the kilovoltage peak rule to vary exposure time in impulses,

  12. Compare Compton with coherent scatter radiation,

  13. Compare the direct theory to the indirect theory of radiation injury using appropriate key words,

  14. Compare characteristic radiation with Bremstrahlung radiation,

  15. Differentiate between a long and short scale of contrast,  

  16. Explain the inverse square law,

  17. Utilize the inverse square law to calculate exposure times and tube to film distance,  

  18. Explain the physical nature of electromagnetic radiation,

  19. Compare particulate to electromagnetic radiation,

  20. Understand the concept of half-value layer (hvl) in regard to x-ray beam quality,

  21. Determine the chemical components of developer and fixer and their purpose,

Learning Activities:

 

Problem Solving:
Mr. Givens says he does not want radiographs because he is concerned about receiving too much radiation.  How do you respond to Mr, Givens?