X-ray Radiography: Principles and Characteristics

X-ray in Radiography

Definition and Principle

• X-ray is a type of electromagnetic radiation with high energy and a short wavelength (0.01-10 nm)
• Produced when high-energy electrons are suddenly stopped or decelerated, resulting in the emission of X-ray photons
• X-rays interact with matter, causing ionization and absorption, which is exploited in radiography to produce images

Characteristics

• High penetrating power, allowing X-rays to pass through soft tissues and capture images of internal structures
• Different tissues have varying X-ray absorption rates, which affects the image produced:
  • Bone and metal: high absorption, appear white or light gray on the image
  • Soft tissues: low absorption, appear gray or dark gray on the image
  • Air: very low absorption, appear black on the image

X-ray Production

• X-ray tubes are used to produce X-rays:
  • Consist of a cathode (filament) and an anode (target) in a vacuum tube
  • When a high voltage is applied, the cathode emits electrons, which are accelerated towards the anode, producing X-rays

X-ray Detectors

• Digital detectors or film are used to capture X-ray images:
  • Digital detectors convert X-rays into electrical signals, which are then processed into a digital image
  • Film is sensitive to X-rays, producing a latent image that is developed into a visible image

Applications

• Medical imaging: diagnostic and therapeutic applications, such as chest X-rays, bone fracture diagnosis, and cancer treatment
• Industrial inspection: non-destructive testing of materials and welds
• Security screening: airport security and border control

Safety Considerations

• X-rays are ionizing radiation, posing a risk to human health and safety
• Operators must follow safety protocols, including wearing protective clothing and limiting exposure time and dose

X-ray in Radiography

Definition and Principle

• X-ray is a type of electromagnetic radiation with high energy and a short wavelength of 0.01-10 nm.
• Produced when high-energy electrons are suddenly stopped or decelerated, resulting in the emission of X-ray photons.
• X-rays interact with matter, causing ionization and absorption, which is exploited in radiography to produce images.

Characteristics

Interaction with Matter

• X-rays have high penetrating power, allowing them to pass through soft tissues and capture images of internal structures.
• Different tissues have varying X-ray absorption rates, which affects the image produced:
  • Bone and metal: high absorption, appear white or light gray on the image.
  • Soft tissues: low absorption, appear gray or dark gray on the image.
  • Air: very low absorption, appear black on the image.

X-ray Production

X-ray Tubes

• X-ray tubes are used to produce X-rays:
  • Consist of a cathode (filament) and an anode (target) in a vacuum tube.
  • When a high voltage is applied, the cathode emits electrons, which are accelerated towards the anode, producing X-rays.

X-ray Detectors

Digital Detectors and Film

• Digital detectors convert X-rays into electrical signals, which are then processed into a digital image.
• Film is sensitive to X-rays, producing a latent image that is developed into a visible image.

Applications

Medical Imaging and Beyond

• Medical imaging: diagnostic and therapeutic applications, such as chest X-rays, bone fracture diagnosis, and cancer treatment.
• Industrial inspection: non-destructive testing of materials and welds.
• Security screening: airport security and border control.

Safety Considerations

Radiation Risks

• X-rays are ionizing radiation, posing a risk to human health and safety.
• Operators must follow safety protocols, including wearing protective clothing and limiting exposure time and dose.

Learn about the definition and principles of X-ray radiation, its characteristics, and how it's used in radiography to produce images.