建立雙和醫院之電腦斷層診斷參考水平及應用

Establishmentof Local Diagnostic Reference Level in Computed TomographyatTaipei Medical University － Shuang Ho Hospital

顏鳳賢(Feng-Xian Yan)；黃懷恩(Huai-En Huang)；陳啟仁(Chi-Jen Chen)；曾櫻綺(Ying-Chi Tseng)

機構診斷參考水平 ； 電腦斷層掃描 ； 體積電腦斷層劑量指標 ； Local Diagnostic Reference Level (LDRL) ； Computed Tomography (CT) ； Volume Computed Tomography Dose Index (CTDI_(vol))

中華放射線技術學雜誌

39卷3期（2015 / 09 / 01）

137 - 143

繁體中文

近年來電腦斷層掃描的使用人次與日俱增，且單次電腦斷層掃描所接受之輻射劑量比一般X 光檢查要高，然而接受輻射劑量可能會提升機率效應的輻射危險度。為了定期檢視本院兩台電腦斷層掃描儀之劑量的穩定性及長期變化，我們選擇四個臨床常見的檢查項目（成人頭部、成人胸部、成人腹部及骨盆、和成人低劑量胸部），並利用電腦斷層劑量指標（體積電腦斷層劑量指標（Volume Computed Tomography Dose Index, CTDI_(vol)））來建立符合本院特性的機構診斷參考水平（Local Diagnostic Reference Level, LDRL）；此外，我們根據此LDRL 的建立方式進行兩次半年期的劑量檢視。本院所建立之成人頭部、成人胸部、成人腹部及骨盆、和成人低劑量胸部的LDRL 分別為61.0、10.0、11.9、3.20 毫戈雷，而兩次劑量檢視的結果均符合標準，故本研究所提出的建立標準能提供其他醫療院所作參考以協助其建立LDRL，進而促請國家相關單位建立本國之國家診斷參考水平（National Diagnostic Reference Level, NDRL）。

In recent years, computed tomography (CT) plays an important role in medical diagnosis. In the world, number of people receiving CT scans is rapidly increasing. However, a worrying thing is that the radiation dose of single CT scan is much higher than those of other radiation examinations such as plain radiography. When receiving more radiation doses, the probability of the risk of stochastic effects may be increased. To effectively and regularly review the long-term changes in the radiation dose of the two CT scanners in our hospital, we developed a hospital-based survey method to setup the local diagnostic reference level (LDRL). In this study, we selected four clinically common CT examinations (i.e., brain, chest, abdomen and pelvis, and low dose chest) and used the volume computed tomography dose index (CTDI_(vol)) to measure the LDRL. In addition, we applied this method to semi-annually examine the CTDI_(vol) values of these four CT examinations. The LDRL of the brain, chest, abdomen and pelvis, and low-dose chest were 61.0, 10.0, 11.9, and 3.20 mGy, respectively. In twice semi-annual surveys, all CTDI_(vol) values were consistent with the LDRL. Therefore, this hospital-based survey method could provide an established procedure and standard for other medical institutions. In the future, it may promote our relevant authority organization to establish the national diagnostic reference levels (NDRL) of CT scans in Taiwan.