Week 1: Image Process and X-ray Principles

Question 1

Roentgens List of X-ray Properties

Answer 1

1. highly penetrating and invisible rays, form of electromagnetic radiation
2. electrically neutral, not affected by electric of magnetic fields
3. can be a wide variety of energies and wavelengths
4. release small amounts of heat as they pass through matter
5. travel in straight lines
6. travel at the speed of light in a vacuum
7. can ionize matter
8. cause fluorescence (emission of light)
9. cannot be focused by lens
10. affect photographic film
11. produce chemical and biological changes in matter through ionization
12. produce secondary and scatter radiation

Question 2

Excitation

Answer 2

X-rays transfer energy to an atom. Electrons remain with the atom but x-rays can move an electron to a higher energy level within the atom. Electrons will drop back to original level naturally to maintain atom stability

Question 3

Binding Energy

Answer 3

The amount of energy required to remove an electron from the atom. Electrons closer to the nucleus have higher binding energy. Increased number of protons and electrons = increased binding energy.

Question 4

Ionization

Answer 4

Occurs within an atom when an electron is removed from the atom (or added). -ray energy must be more than the binding energy of the material for ionization to occur. X-rays can ionize atoms within the body and disrupt the metabolic relationships.

Question 5

Non-ionizing Radiation (Excitation only)

Answer 5

• heat
• infrared, UV and visible light
• microwaves
• radar
• radio waves
• TV transmission

Question 6

Ionizing Radiation (Ionization and Excitation)

Answer 6

• alpha and beta particles
• gamma rays
• neutron radiation
• x-rays
• some wavelengths of UV light