Båth Magnus, Svalkvist Angelica, von Wrangel Alexa, Rismyhr-Olsson Heidi, Cederblad Ake
Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden.
Radiat Prot Dosimetry. 2010 Apr-May;139(1-3):153-8. doi: 10.1093/rpd/ncq092. Epub 2010 Mar 16.
Chest tomosynthesis, which refers to the principle of collecting low-dose projections of the chest at different angles and using these projections to reconstruct section images of the chest, is an imaging technique recently introduced to health care. The main purpose of the present work was to determine the average effective dose to patients from clinical use of chest tomosynthesis. Exposure data for two chest radiography laboratories with tomosynthesis option (Definium 8000 with VolumeRAD option, GE Healthcare, Chalfont St. Giles, UK) were registered for 20 patients with a weight between 60 and 80 kg (average weight of 70.2 kg). The recorded data were used in the Monte Carlo program PCXMC 2.0 (STUK-Radiation and Nuclear Safety Authority, Helsinki, Finland) to determine the average effective dose for each projection. The effective dose for the chest tomosynthesis examination, including a scout view and the tomosynthesis acquisition, was finally obtained by adding the effective doses from all projections. Using the weighting factors given in ICRP 103, the average effective dose for the examination was found to be 0.13 mSv, whereas the average effective dose for the conventional two-view chest radiography examination was 0.05 mSv. A conversion factor of 0.26 mSv Gy(-1) cm(-2) was found suitable for determining the effective dose from a VolumeRAD chest tomosynthesis examination from the total registered kerma-area product. In conclusion, the effective dose to a standard-sized patient (170 cm/70 kg) from a VolumeRAD chest tomosynthesis examination is ~2 % of an average chest CT and only two to three times the effective dose from the conventional two-view chest radiography examination.
胸部断层合成是一种最近引入医疗保健领域的成像技术，它是指在不同角度采集胸部低剂量投影并利用这些投影重建胸部断层图像的原理。本研究的主要目的是确定胸部断层合成临床应用对患者的平均有效剂量。对两家具备断层合成选项（配备VolumeRAD选项的Definium 8000，通用电气医疗集团，英国查尔方特圣贾尔斯）的胸部X光摄影实验室的20名体重在60至80千克（平均体重70.2千克）的患者的曝光数据进行了记录。记录的数据用于蒙特卡罗程序PCXMC 2.0（芬兰赫尔辛基国家辐射与核安全管理局）来确定每个投影的平均有效剂量。最终通过将所有投影的有效剂量相加得到包括定位视图和断层合成采集在内的胸部断层合成检查的有效剂量。利用国际辐射防护委员会第103号出版物给出的权重因子，发现该检查的平均有效剂量为0.13毫希沃特，而传统的双视图胸部X光摄影检查的平均有效剂量为0.05毫希沃特。发现一个0.26毫希沃特·戈瑞⁻¹·厘米⁻²的转换因子适用于根据总记录的比释动能面积乘积确定VolumeRAD胸部断层合成检查的有效剂量。总之，对于标准体型患者（身高170厘米/体重70千克），VolumeRAD胸部断层合成检查的有效剂量约为平均胸部CT有效剂量的2%，仅为传统双视图胸部X光摄影检查有效剂量的两到三倍。
