Department of Imaging, Nagoya Kyoritsu Hospital, Nagoya, Aichi, Japan.
Department of Radiological Technology, Faculty of Health Sciences, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
J Appl Clin Med Phys. 2023 Feb;24(2):e13884. doi: 10.1002/acm2.13884. Epub 2022 Dec 22.
Numerous medical conditions are associated with pregnancy in women, including pulmonary thromboembolism, which can be fatal. An effective treatment of this condition is the positioning of an inferior vena cava filter (IVC-F) under the guidance of X-ray imaging. However, this procedure involves the risk of high radiation exposure to pregnant women and fetuses. Moreover, there are no published reports comparing the values of fetal dose, received during IVC-F placement in pregnant women, determined using dose calculation software and actual measurements. To address this issue, we compared the fetal radiation dose and entrance surface dose (ESD) for pregnant women for gestation periods of 6 and 9 months based on software calculations and actual measurements. The ESD and fetal doses were estimated for a pregnant woman for gestation periods of 6 and 9 months during IVC-F placement. For actual measurements, one pregnant model phantom was constructed using an anthropomorphic phantom, and two custom-made different-sized abdomen phantoms were used to simulate pregnancy. The custom-made abdomen phantoms were constructed using polyurethane. For software calculations, the software utilized a set of anatomically realistic pregnant patient phantoms. The ESD estimated using the software was consistent with the measured ESD, but the fetal dose estimations were more complicated due to fetal positioning. During fetal dose evaluation using software calculations, the user must carefully consider how much of the fetal length is in the irradiation field to prevent underestimation or overestimation. Despite the errors, the software can assist the user in identifying the magnitude of the dose approaching critical limits.
许多医学病症与女性妊娠相关，包括肺血栓栓塞症，该病可能危及生命。该病的有效治疗方法是在 X 射线成像的引导下放置下腔静脉滤器（IVC-F）。然而，该程序会使孕妇和胎儿面临高辐射暴露的风险。此外，目前尚无比较 IVC-F 放置过程中孕妇胎儿剂量值的报告，这些剂量值是通过剂量计算软件和实际测量得出的。为了解决这个问题，我们比较了软件计算和实际测量的 6 个月和 9 个月妊娠期孕妇的胎儿辐射剂量和入口表面剂量（ESD）。我们在放置 IVC-F 时，对 6 个月和 9 个月妊娠期孕妇的 ESD 和胎儿剂量进行了估计。对于实际测量，我们使用人体模型模型构建了一个孕妇模型幻影，并用两个定制的不同大小的腹部幻影模拟了妊娠。定制的腹部幻影是使用聚氨酯构建的。对于软件计算，我们使用了一组解剖逼真的孕妇患者幻影。软件估算的 ESD 与实测 ESD 一致，但由于胎儿定位，胎儿剂量估算更为复杂。在使用软件计算胎儿剂量评估时，用户必须仔细考虑胎儿长度有多少在照射场中，以防止低估或高估。尽管存在误差，但软件可以帮助用户识别接近临界极限的剂量大小。
