Standardized assessment of new electromagnetic field generators in an interventional radiology setting
Standardized assessment of new electromagnetic field generators in an interventional radiology setting
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DOI：
10.1118/1.4712222
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发表时间：
2012-06-01
期刊：
影响因子：
3.8
通讯作者：
Meinzer, H. -P.
中科院分区：
文献类型：
--
作者：
Maier-Hein, L.;Franz, A. M.;Meinzer, H. -P.
目的：与计算机辅助干预（CAI）中的电磁（EM）跟踪相关的两个主要挑战是（1）补偿由场发生器（FG）或跟踪传感器附近的金属影响引起的系统距离误差，以及（2）FG的优化设置，以最大限度地提高感兴趣区域的跟踪精度。最近，针对成熟的Aurora跟踪系统[北方数字公司（Northern Digital，Inc.）(NDI)，加拿大滑铁卢]：台式50-70 FG，一种带有内置屏蔽的平面发射器，用于补偿治疗台产生的金属变形，以及原型紧凑型FG 7-10，一种设计用于连接到移动的成像设备的移动的发生器。本文的目的是在介入放射学setting.Methods：一个标准化的评估协议，它使用一个精确加工的基板来测量位置和方向的相对误差，评估这些新的FG的准确性和精密度，适用于两个新的FG以及完善的标准Aurora（R）Planar FG。实验在两种不同的环境中进行：参考实验室环境和计算机断层扫描（CT）扫描室。在每个设置中，该协议被应用到三个不同的姿势的测量板内的跟踪体积的三个FGs.Results：这两个新的FGs提供了更高的精度和准确性在各自的测量体积以及更高的鲁棒性相对于CT扫描仪相比，建立FG。考虑到网格上所有可能的5 cm距离，与实验室环境中的误差（0.8 mm）相比，临床环境中Planar FG的误差（4.4 mm）增加了5.94倍。相比之下，两种新的FG的平均值均低于1 mm，误差仅增加了2.94倍（参考：0.3 mm; CT：0.9 mm）和1.04（均为0.5 mm）。结论：由于其高精度和鲁棒性，桌面FG和紧凑型FG可以消除某些CT引导介入中对EM场失真补偿的需要。(C)2012年美国医学物理学家协会。[http：//dx.doi.org/10.1118/1.4712222]
Purpose: Two of the main challenges associated with electromagnetic (EM) tracking in computer-assisted interventions (CAIs) are (1) the compensation of systematic distance errors arising from the influence of metal near the field generator (FG) or the tracked sensor and (2) the optimized setup of the FG to maximize tracking accuracy in the area of interest. Recently, two new FGs addressing these issues were proposed for the well-established Aurora (R) tracking system [Northern Digital, Inc. (NDI), Waterloo, Canada]: the Tabletop 50-70 FG, a planar transmitter with a built-in shield that compensates for metal distortions emanating from treatment tables, and the prototypical Compact FG 7-10, a mobile generator designed to be attached to mobile imaging devices. The purpose of this paper was to assess the accuracy and precision of these new FGs in an interventional radiology setting.Methods: A standardized assessment protocol, which uses a precisely machined base plate to measure relative error in position and orientation, was applied to the two new FGs as well as to the well-established standard Aurora (R) Planar FG. The experiments were performed in two different settings: a reference laboratory environment and a computed tomography (CT) scanning room. In each setting, the protocol was applied to three different poses of the measurement plate within the tracking volume of the three FGs.Results: The two new FGs provided higher precision and accuracy within their respective measurement volumes as well as higher robustness with respect to the CT scanner compared to the established FG. Considering all possible 5 cm distances on the grid, the error of the Planar FG was increased by a factor of 5.94 in the clinical environment (4.4 mm) in comparison to the error in the laboratory environment (0.8 mm). In contrast, the mean values for the two new FGs were all below 1 mm with an increase in the error by factors of only 2.94 (Reference: 0.3 mm; CT: 0.9 mm) and 1.04 (both: 0.5 mm) in the case of the Tabletop FG and the Compact FG, respectively.Conclusions: Due to their high accuracy and robustness, the Tabletop FG and the Compact FG could eliminate the need for compensation of EM field distortions in certain CT-guided interventions. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org/10.1118/1.4712222]