【作者】 刘海宽； 高佚名； 顾乃谷； 黄卫琴； 王凤仙； 王力； 吴锦海；

【Author】 LIU Hai-kuan,GAO Yi-ming,GU Nai-gu,HUANG Wei-qin, WANG Feng-xian,WANG Li,WU Jin-hai

【机构】 复旦大学放射医学研究所；

【摘要】 探讨CT扫描所致红骨髓剂量计算方法,以及不同能量的CT进行不同部位的扫描所致红骨髓剂量,为CT受检者的防护提供剂量依据。方法借助MCNPX蒙特卡罗模拟软件和RPI体素人体模型,采用质量吸收系数法(MEAC),分别模拟计算能量为80kV、100kV、120kV和140kV的CT装置,对人体模型分别进行胸部、腹部和躯干CT扫描所致的红骨髓剂量(mGy/100mAs)。在其他扫描条件相同的情况下,CT扫描选取的射束能量越大红骨髓剂量就越大,各扫描部位140kV的计算结果约是80kV计算结果的2倍;相同的射束能量下,不同扫描部位所致红骨髓剂量略有不同,但相差在10%以内。结论在其他条件相同的情况下,CT扫描所致红骨髓剂量主要取决于扫描管电压和总有效mAs;在总有效mAs相同的情况下,扫描部位对红骨髓剂量的影响较小。更多还原

【Abstract】 To evaluate the methods of calculating red bone marrow dose from CT scan,simulating red bone marrow doses from different CT scan protocols using different energy can provide the basic dose data for patient radiation protection. Method:Monte Carlo software MCNPX and RPI voxel phantom were used for the simulation,by mass absorption coefficient(MEAC)method,energy including 80kV,100kV,120kV and 140kV of the CT device were simulated,and different CT protocols such as chest scan,abdomen scan and body scan were taken into consideration when simulating the red bone marrow dose(mGy/100mAs).Results:Under the same other conditions,the larger beam energy caused larger red bone marrow dose,the results of 140kV was two times larger than that of 80kV for the same protocol;while under the same beam energy,the difference among different protocol was less than 10%.Conclusion;Under the same conditions,the red bone marrow dose from CT scan depends on beam energy(tube voltage)and total effective mAs;if the total effective mAs was constant,the influence of scan protocol to red bone marrow dose was not much.更多还原