在臨床檢查中經常遇到無法配合檢查之患者，多數為老人或孩童。為避免受檢者接受過多之輻射劑量及移動 時所產生之假影，建議由陪檢者進入檢查室，協助患者進行放射相關之檢查，但針對陪檢者所接受之輻射劑量較 少探討。本研究將進行640切電腦斷層檢查陪檢者劑量之量測並評估其風險，研究設計為在距離電腦斷層 (Computed Tomography, CT)約70公分處，分別於高度160公分、140公分和80公分各設置一組光激發光劑量計 (Optically Stimulated Luminescence Dosimeter, OSLD)，依常規頭部檢查條件進行掃描，分別測量陪檢者在有無鉛 防護下所接收之輻射劑量。結果顯示受檢者在無鉛防護於高度160公分、140公分及80公分之等價劑量分別為 0.0066 mSv、0.0248 mSv及0.0448 mSv。在鉛防護中於高度160公分、140公分及80公分之等價劑量分別為0.0066 mSv、0.0232 mSv及0.0448 mSv。本研究顯示陪檢者於有無鉛衣防護之等價劑量，皆遠小於游離輻射防護法之一 般人劑量限值規定。醫事放射師基於合理抑低(As Low As Reasonably Achievable, ALARA)之原則，應給予適當的 輻射防護，將可使陪檢者在陪伴過程中降低不必要的輻射效應風險。

There are many patients who are elderly people or children cannot cooperate during Computer Tomography (CT) scanning in the hospital. To prevent patients from receiving unnecessary radiation doses. Radiologist will allow accompanier into the CT examination room with patients. In this study, we put on one set of optically stimulated luminescence dosimeter (OSLD) that distance of 70 cm from the CT radiation source at the height of 160 cm, 140 cm and 80 cm. And to measure the radiation dose that with or without lead clothing protection after CT head scanning, and calculating the effective dose. The result shows: without lead clothing protection are 160 cm: 0.0066 mSv, 140cm: 0.0248 mSv, 80 cm: 0.0448 mSv, the total effective dose is 0.0762 mSv; And with lead clothing protection are 160cm: 0.0066 mSv, 140cm: 0.0232mSv, 80 cm: 0.0448 mSv, the total effective dose is 0.0746 mSv. The radiologist will give appropriate radiation protection in the spirit of As Low As Reasonably Achievable, (ALARA). Even are without or with lead clothing protection, the effective dose are far less than the radiation protection laws and regulations. Therefore, the accompanier may not have to worry about the impact of radiation anymore.