本研究利用標準擬人形假體(Anthropomorphic phantom, Rando) 模擬病患進行頭部電腦斷層檢查(Computed tomography，簡稱CT)，並以熱發光劑量計 (Thermoluminescent Dosimeter，簡稱TLD)佈點於假體內各器官，評估對病患實施頭部電腦斷層掃描時，受檢病患所接受到的各器官等價劑量，並根據這些器官劑量結果與國際放射防護委員會(International Commission on Radiological Protection，簡稱 ICRP)所建議之器官組織加權因數，評估出全身之有效劑量，進一步利用ICRP-60 報告所建議之輻射致死癌風險係數評估出受測病患之輻射誘發致死癌風險(5 % Sv-1)。本論文之研究結果顯示，在實施單次頭部電腦斷層檢查時，腦部與眼球所接受之器官等價劑量分別為57.14 ± 2.90 mSv 及56.46 ± 3.06 mSv 為最高，全身有效劑量以ICRP-60 號及ICRP-103 號報告之組織加權因數評估分別為1.38 mSv 與1.79 mSv；考慮輻射誘發致死癌風險後所評估之輻射致癌風險則分別為6.88×10-3 %及8.96×10-3 %。此外，在特殊情形下頭部掃描病患之家屬或醫院工作人員須在檢查室內協助病患進行頭部CT 掃描，本研究針對這些協助者可能站立的位置之空間劑量亦進行評估。

This research used an anthropomorphic phantom, Rando, to simulate the patient did the head Computed tomography, CT, scan. TLD-100 chips were put inside the radiation sensitive organs recommended by ICRP in the
phantom to measure the organ equivalent doses. The organ equivalent doses were all estimated by means of the TLD measurements. The effective dose of the patient taking head CT scan can be calculated by means of the measured organ equivalent doses and the tissue weighting factor recommend by ICRP report. According to the fatal cancer risk coefficient of 5×10-2 Sv-1 for general population recommend by ICRP 60 report, the health risk of induced secondary cancer risk for a patient has a head CT scan were assessed. In The results of this study, brain and lens received the highest equivalent doses of 57.14 ± 2.90 mSv and 56.46 ± 3.06 mSv, respectively for a patient was performed the single head CT scan. Effective doses estimated from the method of ICRP 60 and 103 reports were 1.38 mSvand 1.79 mSv, respectively. And the induced cancer risks were 6.88×10-3 % (ICRP-60) and 8.96×10-3 % (ICRP-103) after a patient was performed the single head CT scan. Besides, in some special cases, the patient’s family or workers in the hospital had to stay in the CT scan room to help the patient finished the scans. In these cases, the doses received by the helpers were considered and also estimated in this study by means of the measurements of spatial doses in ths CT scan room.