不同全脊椎X光攝影技術之有效劑量評估

Effective Dose Evaluation in Different Full Spine Radiographic Techniques

洪清瑞(Ching-Ruei Hung) ； 林妤穎(Yu-Ying Lin) ； 黃怡璇(Yi-Shuan Hwang) ； 廖大富(Ta-Fu Liao)

《中華放射線技術學雜誌》 41卷3期 (2017/09) Pp. 139-144

摘要

罹患脊椎側彎的患者需要長時間的定期追蹤檢查，最經常使用的診斷設備為全脊椎X 光攝影。不同於電腦斷層或者特殊X 光檢查，全脊椎X 光攝影之輻射劑量評估較少進行研究。隨著科技進步，本院有三種方式可進行全脊椎攝影檢查，本次研究目的為使用10 歲類人形假體與熱發光劑量計（TLD）進行三種全脊椎X 光技術攝影之劑量評估。本研究使用兩部X 光系統共三種攝影技術：Fujifilm CR 搭配Toshiba X 光機（簡稱Fujifilm CR）與Shimadzu DR 自動拼接技術（簡稱Shimadzu DR)，病患可在後者系統以仰躺或站立方式攝影。先利用10 歲類人形假體進行曝露條件最佳化，TLD 進行一連串篩選與校正後，將TLD 包埋置於10 歲類人形假體內進行各攝影技術最佳化條件之曝露，讀取各器官平均劑量與計算其等價劑量，再使用ICRP 103 號建議之組織加權因數，計算有效劑量。結果顯示Shimadzu DR 攝影技術有效劑量皆大於Fujifilm CR 者。新式全脊椎X光攝影技術增加放射師之工作效率，然而Shimadzu DR 為影像拼接且多曝露照野之重疊，使得病患接受輻射劑量上升，進行曝露長軸設定時需更加謹慎。

關鍵字

全脊椎X光攝影 ； 小兒 ； 劑量 ； 熱發光劑量計

並列摘要

Patient with scoliosis should have scheduled examinations for a long time period. Full spine radiography is the common used imaging modality. Unlike computed tomography or interventional radiology, radiation dose from full spine radiograph is seldom discussed. With the medical technology development, there are three different techniques for full spine radiography. The purpose of this study is the effective dose evaluation of three full spine radiographic techniques by using adolescent phantom and thermoluminescence dosimeter (TLD). Study was performed by two radiographic systems, three full spine radiographic techniques: Fujifilm computed radiography (CR) with Toshiba system (Fujifilm CR) and auto-stitching technique provided by Shimadzu combined with standing or supine imaging methods (Shimadzu DR). With the adolescent phantom, peak kilovoltage and milliamp seconds was optimized for different full spine radiograph techniques. TLD were selected and calibrated. TLD were put into the specific organs of the phantom and exposed to the optimized parameters. Average organ dose was obtained by TLD readout. The quality factor of photon beam is 1, equivalent dose is obtained. Afterwards effective dose was calculated according to ICRP 103. Effective dose with Shimadzu DR technique was higher then Fujifilm CR. Newer technique for full spine radiograph enhances radiology technologist's working efficiency. However, absorbed dose increased due to the multiple exposures for image stitching. Thus, the manual setup for exposure range should be very careful.

並列關鍵字

Full spine radiograph ； Adolescent ； Dose ； TLD