牙科放射線學 (1) 陳玉昆副教授 : 高雄醫學大學 口腔病理科 ~2755 Dental Radiographic Facility 牙科放射線設備與設施

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

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

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

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

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

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

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

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

操作步驟 鉛玻璃 X- 光使用中 警告標誌 關 門關 門 鉛片

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

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

鉛 片鉛 片底 片底 片 背面 黑 紙 塑膠封套 上 下 顛 倒上 下 顛 倒 Film orientation 正面 鉛 片鉛 片 底 片底 片 塑膠封套 黑 紙黑 紙 背面 Film orientation Left Posterior 正面

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

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

Intensifying Screen Cross over 底 片底 片 Cross-section Phosphor layer Calcium tungstate (CaWO 4 ) Rare earth phosphors (gadolinium, lanthanum) Non-rare earth phosphorus (yttrium) Protective coating Reflective layer (Titanium dioxide) Screen support layer (polyester/ plastic) 螢 光螢 光 CaWO 4 System (Blue light) Absorb low energy photons Absorb high energy photons No cross-over – better resolution Ultraviolet system Photoelastic effect

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

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

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

Cephalometric radiography 2 m True cephalometric lateral skull

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

Image detectors (Digital) Laser scanner Intraoral Extraoral Direct Indirect

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

顯 影 液顯 影 液 成 分成 分功 用功 用 ( 高溫作用 ) ( 低溫作用 ) Softens

成 分成 分功 用功 用 定 影 液定 影 液 (hyposulfite)

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

自 動 洗 片 機自 動 洗 片 機 底 片底 片 Rollers 底 片底 片 顯 影顯 影 底 片底 片 定 影定 影 底 片底 片

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