computed radiography and digital radiography

DIGITAL PROJECTION RADIOGRAPHY COMPUTED RADIOGRAPHY DIGITAL PROJECTION RADIOGRAPHY DEPENDS ON COMPUTER TECHNOLOGY TO PRODUCE DIGITAL RADIOGRAPHIC IMAGE DIGITAL PROJECTION RADIOGRAPHY COMPUTED RADIOGRAPHY (CR) DIGITAL RADIOGRAPHY (DR) DIGITAL RADIOGRAPHY vs COMPUTED RADIOGRAPHY X-RAYS DR DETECTORS ADC 11011101 X-RAYS CR CR PLATE SCANNER ADC 11011101 COMPUTED RADIOGRAPHY (CR): USES PHOTOSTIMULABLE PLATE (IMAGE PLATE) INSTEAD OF FILM, AS THE IMAGE RECEPTOR CR USES CASSETTE THAT LOOKS VERY SIMILAR TO CONVENTIONAL RADIOGRAPHIC CASSETTE CR PLATE !!!!! DOES NOT USE SCREENS OR FILM ( CONVENTIONAL FILM) CR PLATE INDIRECT CONVERSION CHARGE COUPLED DEVICE DETECTORS ► USE CCD ARRAYS TO RECORD THE VISIBLE LIGHT EMITTED BY A SCINTILLATION CRYSTAL THAT HAS ABSORBED THE ENERGY AN OPTICAL COUPLING SYSTEM DEMAGNIFIES THIS LIGHT AND SENDS IT TO THE CCD ARRAY OPTICAL COUPLING CCD DIRECT TECHNIQUE ► DIRECT CONVERSION FLAT PANEL DETECTORS DIRECT CONVERSION FLAT PANEL DETECTORS ► USE AN AMORPHOUS SELENIUM COATED THIN FILM TRANSISTOR ARRAY THAT DIRECTLY CONVERTS X-RAY ENERGY INTO ELECTRICAL SIGNAL REMNANT X-RAYS ARE ABSORBED IN THE SELENIUM WHERE THEY FORM ELECTRONHOLES CAPACITORS COLLECT THE CHARGE ADVANTAGE: NO LIGHT DIVERGENCE READY - The 17"x17" amorphous selenium-based sensor is electrically sensitized and readied for exposure EXPOSE - Incident X-ray photons are converted into electron-hole pairs A transverse electric field separates the electrons and holes and creates a charge image precisely corresponding to the X-ray image READOUT - The microplasma line scanner sweeps across the sensor in less than seconds causing readout of the charge image and sensor reset                                                                                 DR vs CR COMPARISON DR SYSTEM ADVANTAGE ► ► ► ► ► IMMEDIATE REDOUT CASSETTE FREE OPERATION GOOD FOR HIGH VOLUME RADIOGRAPHY CAN BE USED FOR MAMMOGRAPHY DETECTORS CAN BE RE-EXPOSED IMMEDIATELY DISADVANTAGE ► ► ► MORE EXPENSIVE CAN NOT BE USED IN PORTABLE RADIOGRAPHY?????? NOT COMPATIBLE WITH EXISTING TABLES PORTABLE???? PORTABLE CT???!! MONITORS IN DR ► 1K ► 2K ► 4K ► 1,000 X 1,000 PIXELS ► 2,000 X 2,000 PIXELS ► 4,000 X 4,000 PIXELS 4K MONITORS USED IN MAMMOGRAPHY AND CHEST RADIOGRAPHY DR TERMS TO KNOW ► ► ► ► ► ► PIXEL VOXEL SPATIAL RESOLUTION DYNAMIC RANGE CONTRAST RESOLUTION IMAGE NOISE PIXEL   VOXEL                                                                                                                   The formation .. .DIGITAL PROJECTION RADIOGRAPHY DEPENDS ON COMPUTER TECHNOLOGY TO PRODUCE DIGITAL RADIOGRAPHIC IMAGE DIGITAL PROJECTION RADIOGRAPHY COMPUTED RADIOGRAPHY (CR) DIGITAL RADIOGRAPHY (DR) DIGITAL RADIOGRAPHY. .. DIGITAL RADIOGRAPHY (DR) DIGITAL RADIOGRAPHY vs COMPUTED RADIOGRAPHY X-RAYS DR DETECTORS ADC 11011101 X-RAYS CR CR PLATE SCANNER ADC 11011101 COMPUTED RADIOGRAPHY (CR): USES PHOTOSTIMULABLE PLATE... europium is raised to an excited state and upon luminescence it is returned to its ground Eu2+ state This mechanism holds for both spontaneous luminescence and photostimulated luminescence The