微劑量X 光系統(micro dose system, EOS)為新型全身X 光檢測系統，採用站立姿勢進行X 光攝影。可應用於 脊椎側彎、骨頭受損或變形等疾病。其原理為使用狹縫X 光射束進行雙向同步攝影，並將影像組成三維立體影像 呈現，使輻射劑量遠低於一般X 光攝影檢查。文獻顯示與電腦斷層及數位X 光比較，分別可降低約95%及50% 之輻射劑量。本研究將比較微劑量X 光系統與數位放射攝影系統，以建立本院臨床全身攝影各器官輻射劑量之參 數。本研究使用光刺激發光劑量計及擬人假體進行輻射劑量測量及評估。結果顯示使用數位X 光機照射全脊椎正 面時，儀器輸出劑量面積約為微劑量X 光機的5 倍(EOS 為37.78 μGy．m2，DR 為188.58 μGy．m2)，而正面及 側面同時受檢時，劑量約為10 倍(EOS 為54.74 μGy．m2，DR 中為587.63 μGy．m2)，此研究結果將可提供臨床 使用之參考。

The EOS micro-dose X-ray is a new body X-ray detection system using standing position for X-ray photography. It can be applied to scoliosis, bone damage or deformation and other diseases. The principle is to use slit X-ray beam for bidirectional synchronous photography, and the image is composed of 3D stereo image rendering, so that the radiation dose is much lower than the general X-ray photographic examination. The study shows that compared with computed tomography and digital X-ray machines, the radiation doses of about 95% and 50% can be reduced respectively. This study will compare the micro-dose X-ray system and digital radiography system in order to establish the parameters of the radiation doses of the organs of clinical body radiography. In this study, radiation dose measurement and evaluation using optically stimulated luminous dosimeter and phantom. The results were showed that the output dose area product (DAP) of the instrument is irradiated with the Direct radiography (DR) in the frontal spine is high than micro-dose X Ray machine (EOS) five times ( EOS was 37.78 μGy．m2, DR was 188.58 μGy．m2), while both the frontal and lateral doses were about ten times the same (EOS was 54.74 μGy．m2, DR was 587.63 μGy．m2).The results of this study will provide a reference for clinical use.