ROENTNOLOGY LAB

• 1895: Discovery of Xrays - Wilhelm Conrad Roentgen
• 1896: First dental radiographs
• 1901: Golden Age of Radiology
• 1904: Bisecting Angle Technique - Dr. W.A. Price
• 1913: First machine-made film packets - Eastman Kodak Company
• 1920: First dental x-ray machine
• 1923: First papers on dangers - William Herbert Rollins
• 1925 - First dental radiograph textbook - Howard Raper
• 1925 - Bitewing Technique - Howard Raper
• 1947: Paralleling Technique - F. Gordon Fitzgerald
• Types of x-ray machines: Fixed & Mobile
• Main parts:

  • Control Panel
  • Extension Arm
  • Tube Head
• The primary components of an x-ray machine are the:

  • X-ray tube
  • Power supply
• X-ray Tube

  • Is composed of a cathode and anode situated within an evacuated glass envelope or tube
  • For the x-ray tube to function, a power supply is necessary to heat the cathode filament to generate electrons and establish a high-voltage potential between the anode and cathode to accelerate the electrons toward the anode.
• Cathode

  Consists of:

  • (1) a filament which is the source of electrons within the x-ray tube
  • (2) a focusing cup, which is a negatively charged concave reflector made of molybdenum
• Anode

  • Consists of a tungsten target embedded in a copper stem.
• Power Supply

  Primary functions are to:

  • (1) provide a low-voltage current to heat the x-ray tube filament
  • (2) generate a high potential difference between the anode and cathode.
• Filament and electron cloud - These are part of the cathode, where the filament heats up, emitting electrons that form an electron cloud.
• Focal spot on tungsten target - The focal spot is the area on the anode (typically made of tungsten) where the electrons from the cathode strike to produce X-rays.
• Glass envelope - It's the protective housing around the anode and cathode, containing the vacuum.
• Vacuum - Essential for the X-ray tube to prevent air molecules from interfering with electron movement.
• Copper stem - A part used for cooling purposes to dissipate heat generated during X-ray production.
• Anode - It's the positive electrode in the X-ray tube where the electrons from the cathode strike, generating X-rays.
• Useful X-ray beam - The X-rays produced and emitted through the tube window that are utilized for imaging purposes.
• Tube window - The area of the X-ray tube where the X-rays exit to irradiate the patient and produce the image.
• Cathode - The negative electrode that emits electrons when heated by the filament, starting the X-ray production process.
• Electronic focusing cup - Helps in directing and focusing the emitted electrons towards the anode for X-ray production.
• Label:

  A) Filament and electron cloud

  B) focal spot on tungsten target

  C) glass envelope

  D) vacuum

  E) copper stem

  F) anode

  G) useful xray beam

  H) tube window

  I) cathode

  J) electronic focusing cup