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9 Cards in this Set
- Front
- Back
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History of Digital Imaging
Design & Development |
-1972 computed tomography (CT) & advances in digital sensors
-1st sensors designed w/ CCD chip layered w/ phosphor screen, latter sensors developed were direct exposure -requires sesnsor (detector), analog to digital convert (A/D converter), computer or CPU, monitor, printer -additionally modem or other (cable, T1, DSL) connection for Teleradiology -photons strike detector->A/D converter converts elect charge to digital format (PSP) -# assign to each V output ranging from 0-256 (256 shades of gray) |
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Basic Digital System Components
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-X-Ray source
-Sensor or detector (CCD< CMOS, & storage Phosphur) -Computer, CPU -Modem -Printer |
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Sensors:
1. CCD 2. PSP 3. CMOS-APS |
1. silicon chip w/ embedded electric circuit (charged coupled device)
2. plastic plate coat w/ photostimuable phosphor layer (Photostimuable Storage Phosphor) 3. silicon chip w/ ADC for each column of pixels (Complementary Metal Oxide Semiconductor-Active Pixel Sensor) |
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Digital Imaging: Clinical Application
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-anywhere film would be used
-endodontics -intraoperative implant imaging -teleradiology -integration into electronic recorder |
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Pixel
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-matrix element of digital array which IDs a gray level at that point:
0 = black 255 = white |
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Advantages of Digital
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-enhancement & analysis: may increase diagnostic validity of xrays of non-optimal density
-no-processing problems (darkroom, processor & chemcals -envrionmentally friendly) -less exposure errors -allows for quantitative evaluation -lower absorbed dose (20-90% compared to D-speed film) -time saver -quanitfy image: measure length & angles -implant planning |
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Disadvantages of Digital
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-high cost
-inflex cassette for CCD and CMOS sensor: may not have proper placement in intraoral location -spatial resolution (not as good as film) -printed copy not as good as screen (resolution lost when printed) -not standardized -learning curve for staff |
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Teleradiography
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-transmission of digital image to remote sites major driving force in evoluation of digital
-remote consultation, insurance approval |
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Digital Image Software
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-zoom
-contrast/brightness -psuedocolor -rotation -annotation -filters -3D -analysis (line, angle) -manipulating implant -video inversion |
