牙科放射線學 (1)

1. 牙科放射線學(1) Dental Radiographic Facility 牙科放射線設備與設施 陳玉昆副教授: 高雄醫學大學 口腔病理科 07-3121101~2755 yukkwa@kmu.edu.tw

2. Dental Radiographic Facility X-ray generating equipment X-ray machine Image receptors Radiographic film/detector Processing facilities Dark room, machine Components of X-ray machine

3. Length Material Shape Parallel X-ray beam Not recommended Correct focus Correct focus Parallel X-ray beam Parallel X-ray beam at most 7.6cm in diameter (tube head) Correct focus Parallel X-ray beam Short cone Long cone

4. Cooling (99% heat) Cooling (tube head) e - e - e - e - Thickness of aluminium filter (absorblow level x-ray) =70kVp -- at least 1.5cm >70kVp -- more than 2.5cm 直徑-2mm 長度-1cm Absorb of unwanted x-ray from all other directions 60 - 90 kVp Molydenum cup (focal device) Tungsten filament 真空 Copper Target 3 - 5V (Tungsten) Anode (+) Cathode (-) Window (lead glass) Tungsten (鎢) 熔點:3410℃ Higher kVp – faster electron produced X-ray release in all directions Higher (5-20) mA – more electron produced Effective X-ray beam (1%)

5. DC current (+) Voltage Time AC current X-ray production X-ray production Constant-potential rectification Time Single phase, full wave rectification DC current X-ray production DC current 3 phase, full wave rectification X-ray production DC current Half wave rectification

6. Sharp image 20 degree Blurred image e e - e - e - e - Penumbra effect Anode (+) Cathode (-) Target Actual focal spot Focal spot 10mm X-ray beam Apparent focal spot X-ray beam 4mm

7. Exchangeable cathode Target Lateral view Anode (+) e e e e e e e e e e e e e e e e Focal spot Front view X-ray Machine > 90kVp Rotatory Target Cathode 1 Anode (+) X-ray beam Cathode (-) X-ray beam Stronger X-ray beam Cathode 2 X-ray beam

8. Arm X-ray tube X-ray tube Tube head Extraoral/ intraoral film Extraoral film Conventional Arm X-ray tube X-ray tube Tube head Extraoral film Conventional/ digital Intraoral film

9. kV mA Control Panel 固定 kVP 調整 時間 Upper anterior Lower molar Upper premolar Lower premolar Upper molar Lower anterior Control Panel X-ray tube Extraoral film Conventional Intraoral film Arm X-ray tube Tube head

10. 關 門 警告標誌 X-光使用中 操作步驟 鉛玻璃 鉛片

11. Dental Radiographic Facility X-ray generating equipment X-ray machine Image receptors Radiographic film/detector Processing facilities Dark room, machine Double film Direct-action, non-screen, wrapped/packet film Periapical film (2#) (31x41mm) Front (smooth surface) dot Front (white color) dot Back Occlusal film (57x76mm) largest intraoral film (pebbled surface) Back Back Front Periapical film (0#) (22x35mm) Intraoral film dot Bitewing film

12. Placed towards X-ray beam Placed towards occlusal surface of tooth 鉛 片 底 片 Dot Film orientation 黑 紙 塑膠封套 塑膠封套 底 片 鉛 片 0.007吋 0.2mm 黑 紙 從此處拉開封套 紋路 黑 紙 黑 紙 底 片 鉛 片 塑膠封套 Protective layer Film emulsion (silver halide) Adhesive layer Film base cellulose (flexible) Protective layer Film emulsion (silver halide) Adhesive layer

13. Film orientation Film orientation 塑膠封套 黑 紙 正面 背面 底 片 鉛 片 Left Posterior 上 下 顛 倒 鉛 片 底 片 背面 正面 黑 紙 塑膠封套

14. 粒子 最大 感光 最快 Detail 最差 粒子 最小 感光 最慢 Detail 最好 0.007吋 cellulose (flexible) Speed of Film 大 小

15. Panoramic Cassette Front Intensifying Screen Back Back Cephalometric Panoramic Cassette Back Intensifying Screen Front Front Front Intensifying Screen Cross- Section Back Intensifying Screen Unexposed film Indirect-action, screen film Extraoral Film

16. Cross-section Protective coating Phosphor layer Calcium tungstate (CaWO4) Rare earth phosphors (gadolinium, lanthanum) Non-rare earth phosphorus (yttrium) Reflective layer (Titanium dioxide) Screen support layer (polyester/ plastic) Ultraviolet system No cross-over – better resolution Intensifying Screen Photoelastic effect Absorb low energy photons 螢 光 Cross over 底 片 Absorb high energy photons CaWO4 System (Blue light)

17. Cassette carrier orbits around the front of the face Shifting centers Start Finish Shifting centers Continuous mode The film also starts to move The entire film has been exposed Split mode R L

18. Orbit before patient Orbit Cassette carrier X-ray source cassette Orbit behind patient Cassette carrier Cassette with film inside

19. 3D focal trough Control panel X-ray source F-H plane Anterior Bite block

20. True cephalometric lateral skull 2 m Cephalometric radiography

21. CR Cephalometric postero- anterior of the jaws (PA jaws)

23. Intraoral Indirect Direct Laser scanner Extraoral Image detectors (Digital)

24. Dental Radiographic Facility X-ray generating equipment X-ray machine Image receptors radiographic film/detector Processing facilities Dark room, machine 洗 片 槽 觀片箱 安全紅燈 (25W) 定影液 清水 顯影液 水槽 1.2m 洗 片 槽 觀片箱 水槽 門

25. 顯 影 液 成 分 功 用 (低溫作用) (高溫作用) Softens

26. 定 影 液 成 分 功 用 (hyposulfite)

27. Green silver halide emulsion Non-exposed film Green sensitized silver halide emulsion Green non-sensitized silver halide emulsion Developer Black metallic silver Green silver halide Wash Fixer Black metallic silver White/Transparent Wash + Dry Final black + white image (無曝光) (有曝光)

28. 自 動 洗 片 機 底 片 底 片 顯 影 Rollers 底 片 定 影 底 片

29. 清水 顯影 定影 5 min later 溫度 Power Drive Rollers Off 開 闢 Roller film transporter Developer component Fixer component Water component Drying chamber Film lead slot Film slot Processor housing Replenisher pump Replenisher solution 自 動 洗 片 機 溫度越高— 洗片時間 越短

30. The End