The Virtual Population (ViP) phantoms have been used in many dosimetry studies, yet, to date, anatomical phantom uncertainty in radiofrequency (RF) research has largely been neglected. The objective of this study is to gain insight, for the first time, regarding the uncertainty in RF-induced fields during magnetic resonance imaging associated with tissue assignment and segmentation quality and consistency in anatomical phantoms by evaluating the differences between two generations of ViP phantoms, ViP1.x and ViP3.0. The RF-induced 10g-average electric (E-) fields, tangential E-fields distribution along active implantable medical devices (AIMD) routings, and estimated AIMD heating were compared for five phantoms that are part of both ViP1.x and ViP3.0. The results demonstrated that differences exceeded 3 dB (-29%, +41%) for local quantities and 1 dB (±12% for field, ±25% for power) for integrated and volume-averaged quantities (e.g., estimated AIMD-heating and 10 g-average E-fields), while the variation across different ViP phantoms of the same generation can exceed 10 dB (-68% and +217% for field, -90% and +900% for power). In conclusion, the anatomical phantom uncertainty associated with tissue assignment and segmentation quality/consistency is larger than previously assumed, i.e., 0.6 dB or ±15% (k = 1) for AIMD heating. Further, multiple phantoms based on different volunteers covering the target population are required for quantitative analysis of dosimetric endpoints, e.g., AIMD heating, which depend on patient anatomy. Phantoms with the highest fidelity in tissue assignment and segmentation should be used, as these ensure the lowest uncertainty and possible underestimation of exposure. To verify that the uncertainty decreases monotonically with improved phantom quality, the evaluation of differences between phantom generations should be repeated for any improvement in segmentation. Bioelectromagnetics. 2019;40:458-471. © 2019 Bioelectromagnetics Society.

中文翻译：

---

MRI暴露下金属植入物RF安全性评估的解剖模型不确定性。

虚拟剂量（ViP）体模已在许多剂量测定研究中使用，但迄今为止，射频（RF）研究中的解剖体模不确定性已被大大忽略。这项研究的目的是通过评估两代ViP体模之间的差异，首次获得有关磁共振成像过程中与组织分配，解剖体模的分割质量和一致性相关的RF感应场的不确定性的信息， ViP1.x和ViP3.0。比较了作为ViP1.x和ViP3.0一部分的五个模型的RF感应10g平均电场（E-），沿有源可植入医疗设备（AIMD）路线的切向电场分布以及估计的AIMD发热。 。结果表明，差异超过3 dB（-29％，本地数量为+ 41％，积分和体积平均数量（例如，估计的AIMD加热和10 g平均电场）为1 dB（磁场为±12％，功率为±25％），同一代的不同ViP幻像之间的跨度可能会超过10 dB（场的-68％和+ 217％，功率的-90％和+ 900％）。总之，与组织分配和分割质量/一致性相关的解剖模型幻像不确定性大于先前假定的值，即AIMD加热时为0.6 dB或±15％（k = 1）。此外，需要对基于目标人群的不同志愿者的多个体模进行剂量学终点（例如AIMD加热）的定量分析，这取决于患者的解剖结构。应当使用在组织分配和分割方面保真度最高的幻影，因为这样可以确保将不确定性降到最低，并可能低估暴露量。为了验证不确定性随着改进的幻像质量而单调减少，对于任何分割方面的改进，都应重复评估幻象世代之间的差异。生物电磁学。2019; 40：458-471。©2019生物电磁学会。