RAD 254 Chapt. 26 Digtal Imaging

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RAD 254 Chapt. 26Digtal Imaging

• Many types/names for the
• Digital imaging to come

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Thought

• A tight beam close collimation adequate
  penetration!

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Types

• CR Barium fluorohalide PSP
• SPR (scan projection RAD)Nal scintillator/photodi
  ode
• Indirect DR Csl, GdOS scintillator
• Indirect DR Csl/Charge coupled device
• Direct DR a-Se, Thin-film transistor

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ESs Clever approach(capture element, coupling
element, collection element

• Capture element how the x-rays are captured
  (PSPs, CsI, gado, etc.)
• Coupling element transferring the x-ray
  signal to the collection element
• Collection element devices to either collect
  light photons or electrons

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Scan Projection Radiography

• As in CT, uses a fan beam (collimated by
  pre-pt. collimators) Post pt. remnant beam is
  collimated by to a fan for the detector array
  Neither the tube or detector MOVE!
• SPR is NOT too successful, but is re-emerging for
  another breath

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Charge Coupled Devices

• CCDs are SMALL, thus GREAT for digital imaging
• Have HIGH sensitivity to radiation and WIDE
  dynamic range (dim to bright lite)
• STRAIGHT C D curve

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Types of CCDs

• Cesium Iodide/CCD
• Cesium Iodide/ Amorphous Silicon
• Amorphous Selenium