IMAGE RECEPTORS

1
IMAGE RECEPTORS
2
Follow the Sequence- Film System

• Tube
• Patient
• (bucky) or non-bucky
• Cassette
• INTENSIFYING SCREEN
• FILM

3
Follow the Sequence- Filmless (CR) System

• Tube
• Patient
• (bucky) or non-bucky
• Cassette
• IMAGING PLATE
• DIGITIZER OR READER
• MONITOR

4
Follow the Sequence- Filmless (DR) System

• Tube
• Patient
• (bucky) or non-bucky
• DIGITAL RECEPTOR
• MONITOR

5
INTENSIFYING SCREEN

• PG 171
• When using intensifying screens in cassette the
  exposure to the film is 90 -99 FROM LIGHT
• Anatomy of a screen
• Protective layer
• Phosphor or active layer
• Reflecting or absorbing layer
• base

6
PHOSPHORS

• SPECTRAL EMISSION
• RARE EARTH
• HIGH ABSORPTION HIGH CONVERSION EFFICIENCY
• FASTER SPEED

7
PHOSPHOR THICKNESS, SIZE

• Impacts screen speed and detail
• Faster screen less detail less mAs
• Slower screen more detail more mAs
• Old screen speed/new screen speed
• Reflecting layers increase screen speed
• Light absorbing layer or light absorbing
  dyesdecrease speed but increase recorded detail
• Table 7-2
• Quantum Mottle
• Screen Maintenance

8
Follow the Sequence- Filmless (CR) System

• Tube
• Patient
• (bucky) or non-bucky
• Cassette
• IMAGING PLATE
• DIGITIZER OR READER
• MONITOR

9
CR cassette

• Protective layer
• Photostimulable phosphor
• Reflective layer
• Base
• Backing

10
Barium Fluorohalide crystals coated with europium

• Phosphor releases some visible light
• The x-ray energy is absorbed (trapped)
• Latent image
• Sensitive to a wide range of energies
• Erase plate if not used in 48 hours
• Process within an hour of exposure
• Increase mAs as CR is equivalent to 200 screen
  speed vs 400 screen speed used in film
  systemswhy?

11
Follow the Sequence- Filmless (DR) System

• Tube
• Patient
• (bucky) or non-bucky
• DIGITAL RECEPTOR
• MONITOR

12
DIRECT CAPTURE DETECTOR

• CCD (CHARGE COUPLED DEVICE)
• Radiation interacts with the detector (within the
  table, upright chest unit or on a extremity unit)
• X-rays are either converted to light that reacts
  to a layer of amorphous silver electric charge
• Or
• X-rays are interact directly with layer of
  amorphous silver electric charge