ICRP103号建议书所致常规CT扫描有效剂量变化的研究

目的：对比采用ICRP60和ICRP103器官组织权重因子计算64排螺旋CT头胸腹扫描及冠脉成像所致患者有效剂量的变化。方法：采用在ART仿真人体辐照体模（fluke biomedical）躯干部分布放热释光剂量计的方法获得器官剂量,再将器官剂量按照不同版本ICRP器官权重因子加权求和获得有效剂量,同时计算有效剂量转换系数。结果：ICRP103给出的器官组织权重因子的变化带来了CT检查中有效剂量的变化,头部（29.74%）,胸部（20.97%）,腹部（-11.88%）及冠脉成像（29.94%）。基于ICRP60（103）,头胸腹扫描中有效剂量对DLP的转换系数分别为0.0025（0.0032）、0.0191（0.0230）及0.0166（0.0146）mSv/（mGy·cm）。结论：不同版本ICRP给出的器官组织权重因子对CT检查所致患者有效剂量产生的影响是基于不同的扫描部位的;新版本在强调某些器官对计算有效剂量重要性的同时,也削弱了另外一些器官的作用。

Variations of Effective Dose for Head, Thoracic, Abdomen and Coronary CT Examinations According to New ICRP Publication

Objective To find the influence on effective dose for head,thoracic,abdomen and coronary CT examinations according to new ICRP publications.Methods Effective dose was calculated using the sum of organ doses,which were measured with an ART phantom,weighted by tissue weighting factor provided by different ICRP publication.Sex-specific effective doses were also compared according to different ICRP publications.The ratio of effective dose to dose length product defined as conversion factor was also observed in this study.Results The change of the weighting factor for different ICRP publication led to noticeable variations in the effective dose for head（29.74%）thoracic（20.97%）abdomen （-11.88%）and coronary （29.94%）CT examinations.The effective conversion factors of DLP were 0.002 5,0.019 1 and 0.016 6 according to ICRP 60 and 0.003 2,0.023 1 and 0.014 6 according to ICRP 103 for head,thoracic and abdomen respectively.Conclusion The revision of the tissue weighting factors result in significant variation of effective dose calculation on CT examinations.These variations depend on the scan area of patient＇s body.