1. 1 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. RADT 1303 Principles of Radiographic Exposure I Class one of a two part physics, exposure, radiographic technique series This semester we learn the basics, next semester we learn the details

2. 2 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. 2 Chapter 1 Radiation and Its Discovery

3. 3 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. Objectives  Describe the events surrounding the discovery of x-rays.  Describe the dual nature of x-ray energy.  State the characteristics of electromagnetic radiation.  List the properties of x-rays.

4. 4 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. Discovery of X-rays  X-rays were discovered on November 8, 1895, by Dr. Wilhelm Conrad Roentgen.  Accidental discovery  First radiograph of Mrs. Roentgen's hand  Roentgen received the first Nobel Prize presented for physics in 1901.  Public viewed discovery as a novelty  Radiographic imaging and therapy important to the medical sciences

5. 5 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. X-rays as Energy  A form of electromagnetic radiation  Behave both like waves and like particles  Move in waves that have wavelength and frequency  Wavelength and frequency are inversely related  X-rays also behave like particles and move as photons

6. 6 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. Properties of X-rays  X-rays are invisible.  X-rays are electrically neutral.  X-rays have no mass.  X-rays travel at the speed of light in a vacuum.  X-rays cannot be optically focused.  X-rays form a polyenergetic or heterogeneous beam.  X-rays can be produced in a range of energies.  X-rays travel in straight lines.

7. 7 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. Properties of X-rays (cont.)  X-rays can cause some substances to fluoresce.  X-rays cause chemical changes to occur in radiographic and photographic film.  X-rays can penetrate the human body.  X-rays can be absorbed or scattered by tissues in the human body.  X-rays can produce secondary radiation.  X-rays can cause chemical and biologic damage to living tissue.

8. 8 Copyright © 2013, 2009, 2004, 2000 by Mosby, an imprint of Elsevier Inc. Standard Radiographic Room