影像醫學技術隨著X光機技術提升造福許多病患，許多無法任意移動的急重症或隔離中的患者，需使用移動型X光機執行放射醫學檢查。由於加護病房缺乏輻射防護屏蔽，易造成現場醫師及護理人員恐慌。本研究使用光激發光劑量計(Optical stimulated luminescence dosimeter, OSLD)在加護病房內進行環境空間劑量評估。OSLD分別佈點在模擬受照病患之擬人型假體病人周圍，離地面70公分高度的加護病房內外兩側牆壁、兩相鄰病房間的護理工作站、鉛屏蔽前面及鉛屏蔽後面30、60、90公分各放置三個OSLD。移動型X光機照射條件採用一般成人胸部X光條件，固定管電壓(85 kVp)、管電流及照射時間(6.3 mAs)，主射束方向連續照射三次後，再將檢查床轉90度垂直鉛屏蔽方向，執行相同的照射條件，並評估射源方向改變造成病房外產生較高的輻射累積劑量分布之影響。研究結果顯示，檢查床方向垂直鉛屏蔽會造成兩相鄰病房間護理工作站的周圍產生較高散射輻射劑量為2.67 μSv。鉛屏蔽後面輻射劑量與背景輻射相近。本研究成果可提供加護病房醫療人員了解移動型X光機執行放射醫學檢查空間劑量分布，以建立輻射屏蔽安全距離達到輻射安全的工作環境。

The precision medical environment has gradually taken shape. Imaging medicine technology has aslo benefited many patients with the improvement of X-ray machine technology. Many critically ill or isolated patients who cannot be moved at will need to use mobile X-ray machines to perform radiology examinations. Because the design of the general ward and intensive care unit lack radiation protection shields. So it cause panic among doctors and nursing staff. This study of OSLD was used to evaluate the dose of patients and environment in ICU. Three OSLDs were placed on the back of the anthropomorphic prosthesis, on both sides of the intensive care unit at 70 cm above the ground, the octagonal window sill of the nursing workstation, and 30 / 60 / 90 cm behind the lead shield. The fixed tube voltage (85 kVp), tube current and exposure time (6.3 mAs) were used for the mobile X-ray machine. After three times of continuous exposure in the main beam direction, the table was rotated 90 degrees perpendicular to the lead shielding direction, and then exposed for three times under the same conditions (85 kVp × 6.3 mAs). The results show that the vertical lead shielding in the direction of examination table will cause high scattered radiation dose around the octagonal window sill of nursing workstation. The radiation dose of lead shielding is similar to that of background radiation. The results of study could provide medical staff in ICU to understand the spatial dose distribution of radiation medical examination performed by mobile X-ray machine, so as to establish radiation shielding safety distance and achieve radiation safety working environment. Provide medical radiologists and other medical staff with a clear understanding of the as low as reasonably achievable (ALARA) dose distribution. Find a feasible radiation safety shielding distance to achieve a radiation safety protection working environment.