Lecture Notes: Understanding X-rays and Electromagnetic Radiation

Overview of Electromagnetic Radiation

• Definition: Light as a form of electromagnetic radiation.
• Types: Visible light and invisible forms (ultraviolet, infrared, x-rays).

X-rays

• Wavelengths: X-rays have very short wavelengths.
• Penetration: Unlike visible light, x-rays can pass through most tissues.
• Interaction with Bones:
  • Bones contain calcium, a dense material.
  • Calcium in bones can stop some x-rays, creating a 'shadow'.

Comparing Flashlight Shadows and X-ray 'Shadows'

• Hand casting shadow using a flashlight as an analogy.
• X-rays directed at the body produce similar 'shadows' on the opposite side.
• X-ray shadows can be registered on film or digital sensors.

Usefulness of X-ray Images

• 2D Images: X-rays provide two-dimensional images of internal structures.
• Bone Visibility: Bones are clearly visible; soft tissues appear shadowy.
• Applications: Displaying fractures in bones and revealing body structures.