IMAGE RECEPTORS

Follow the Sequence- Film System Tube Tube Patient Patient (bucky) or non-bucky (bucky) or non-bucky Cassette Cassette INTENSIFYING SCREEN INTENSIFYING SCREEN FILM FILM

Follow the Sequence- Filmless (CR) System Tube Tube Patient Patient (bucky) or non-bucky (bucky) or non-bucky Cassette Cassette IMAGING PLATE IMAGING PLATE DIGITIZER OR READER DIGITIZER OR READER MONITOR MONITOR

Follow the Sequence- Filmless (DR) System Tube Tube Patient Patient (bucky) or non-bucky (bucky) or non-bucky DIGITAL RECEPTOR DIGITAL RECEPTOR MONITOR MONITOR

INTENSIFYING SCREEN PG 179 PG 179 When using intensifying screens in cassette the exposure to the film is 90% -99% FROM LIGHT When using intensifying screens in cassette the exposure to the film is 90% -99% FROM LIGHT Anatomy of a screen Anatomy of a screen Protective layer Protective layer Phosphor or active layer Phosphor or active layer Reflecting or absorbing layer Reflecting or absorbing layer base base

PHOSPHORS SPECTRAL EMISSION SPECTRAL EMISSION RARE EARTH RARE EARTH HIGH ABSORPTION +HIGH CONVERSION EFFICIENCY= HIGH ABSORPTION +HIGH CONVERSION EFFICIENCY= FASTER SPEED FASTER SPEED

PHOSPHOR THICKNESS, SIZE Impacts screen speed and detail Impacts screen speed and detail Faster screen =less detail = less mAs Faster screen =less detail = less mAs Slower screen = more detail =more mAs Slower screen = more detail =more mAs Old screen speed/new screen speed Old screen speed/new screen speed Reflecting layers = increase screen speed Reflecting layers = increase screen speed Light absorbing layer or light absorbing dyes=decrease speed but increase recorded detail Light absorbing layer or light absorbing dyes=decrease speed but increase recorded detail Table 7-9 Table 7-9 Quantum Mottle Quantum Mottle Screen Maintenance Screen Maintenance

Follow the Sequence- Filmless (CR) System Tube Tube Patient Patient (bucky) or non-bucky (bucky) or non-bucky Cassette Cassette IMAGING PLATE IMAGING PLATE DIGITIZER OR READER DIGITIZER OR READER MONITOR MONITOR

CR cassette Protective layer Protective layer Photostimulable phosphor Photostimulable phosphor Reflective layer Reflective layer Base Base Backing Backing

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

Follow the Sequence- Filmless (DR) System Tube Tube Patient Patient (bucky) or non-bucky (bucky) or non-bucky DIGITAL RECEPTOR DIGITAL RECEPTOR MONITOR MONITOR

DIRECT CAPTURE DETECTOR TFT –Thin film transistors –flat panel consists of detectors and TFT’s TFT –Thin film transistors –flat panel consists of detectors and TFT’s Radiation interacts with the detector (within the table, upright chest unit or on a extremity unit) 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 chargeCCD (CHARGE COUPLED DEVICE) X-rays are either converted to light that reacts to a layer of amorphous silver = electric chargeCCD (CHARGE COUPLED DEVICE)Or X-rays are interact directly with layer of amorphous silver = electric charge X-rays are interact directly with layer of amorphous silver = electric charge