Radiology and Radiography Basics

Radiation

• Radiation is a form of energy carried by waves or particles.
• X-radiation is a high-energy radiation produced by the collision of electrons with a metal target in an x-ray tube.
• X-rays are beams of energy with the ability to penetrate substances and create image shadows on receptors like film or digital sensors.

Radiology and Radiography

• Radiology is the study and use of radiation in medicine.
• Radiography is the art and science of creating radiographs using x-rays.
• A radiograph is an image produced by exposing a receptor to ionizing radiation.
• Dental radiography is the creation of radiographs of teeth and related structures.
• A dental radiographer is the person who positions, exposes, and processes dental x-ray image receptors.

Types of Radiation

• Primary radiation is the penetrating x-ray beam directly from the x-ray tube.
• Secondary radiation is less penetrating radiation created when primary radiation interacts with matter (soft tissues, bones, teeth).
• Scatter radiation is a type of secondary radiation that is deflected from its original path. Scatter radiation is detrimental to both the patient and the radiographer.

Radiation Injury

• Stochastic effects are proportional to the dose of radiation received.
• Nonstochastic effects have a threshold dose and increase in severity with higher doses.

Determining Factors for Radiation Injury

• Total dose: The quantity of radiation received; higher doses result in more damage.
• Dose rate: The rate at which radiation is absorbed; higher rates lead to more damage.
• Amount of tissue irradiated: The area exposed to radiation; total body irradiation causes more systemic effects than localized exposure.
• Cell sensitivity: Rapidly dividing cells and young cells are more susceptible to radiation damage.
• Age: Children are more sensitive to radiation than adults.
• Mitotic activity: Cells that frequently divide are more sensitive to radiation.
• Cell differentiation: Immature or unspecialized cells are more sensitive.
• Cell metabolism: Cells with a higher metabolism are more sensitive to radiation.

Radiation

• A form of energy carried by waves or a stream of particles
• X-radiation is produced by the collision of electrons with a metal target in an x-ray tube
• X-rays are high-energy radiation that can penetrate substances and create image shadows on receptors
• Radiology is the study of radiation used in medicine, including therapeutic uses of x-rays, radioactive substances, and other forms of radiant energy
• Radiograph is an image produced on a receptor by exposure to ionizing radiation, depicting a two-dimensional representation of a three-dimensional object.
• Dental radiograph is a photographic image of teeth and related structures produced on a receptor by x-ray exposure
• Radiography is the art and science of making radiographs using x-ray exposure
• Dental radiography involves producing radiographs of teeth and adjacent structures
• A dental radiographer positions, exposes, and processes dental x-ray image receptors
• Image receptor is a recording medium, such as:
  • X-ray film
  • Phosphor plate
  • Digital sensor
• Primary radiation is the penetrating x-ray beam produced at the anode and exiting the tubehead, often referred to as the primary beam or useful beam
• Secondary radiation is produced when the primary beam interacts with matter, including soft tissues, bones, and teeth.
• Secondary radiation is less penetrating than primary radiation
• Scatter radiation is a form of secondary radiation resulting from an x-ray being deflected from its path by interaction with matter.
  • It is deflected in all directions by the patient’s tissues
  • It travels to all parts of the patient’s body and dental operatory
  • It is detrimental to both the patient and the radiographer

Radiation Injury

• Stochastic effects are directly proportional to dose, meaning the higher the dose, the higher the chance of the effect
• Nonstochastic effects have a threshold, meaning the effect only occurs above a certain dose. The severity increases with increased absorbed dose
• Determining Factors for Radiation Injury:
  • Total dose: Quantity of radiation received, with higher doses causing more damage.
  • Dose rate: Rate of radiation exposure and absorption; Higher rates cause more damage as rapid delivery doesn't allow for cellular repair.
  • Amount of tissue irradiated: Areas of the body exposed, with total-body irradiation causing more adverse systemic effects than localized exposure.
  • Cell sensitivity: More damage occurs in rapidly dividing and young cells.
  • Age: Children are more susceptible to radiation damage.
  • Mitotic activity: Cells that divide frequently or undergo many divisions are more sensitive to radiation.
  • Cell differentiation: Immature or less specialized cells are more sensitive to radiation.
  • Cell metabolism: Cells with higher metabolism are more sensitive to radiation.

Explore the fundamentals of radiation, radiology, and radiography through this quiz. Understand the types of radiation, the process of creating radiographs, and the role of dental radiographers in the medical field. Test your knowledge on the applications of X-rays in medicine.