超声引导高强度聚焦超声相控阵系统焦平面定位精度的评价
Summary
本研究描述了一种评估超声引导高强度聚焦超声相控阵系统焦平面定位精度的方案。
Abstract
在现有的体外超声引导的 hifu (usghifu) 系统中, 相控阵被越来越多地用作高强度聚焦超声 (hifu) 传感器。此类系统中的 hifu 传感器通常呈球形, 中央孔安装在美国成像探头上, 可以旋转。处理平面上的图像可以通过在探头旋转过程中获得的图像序列进行重建。因此, 可以在重建图像上制定处理方案。为了评价这种系统的焦平面上的瞄准精度, 描述了一种使用牛肌肉和标记嵌入幻影的方法的协议。在幻象中, 正方形树脂模型角部的四个实心球作为重建图像的参考标记。目标应移动, 以便其中心和正方形模型的中心能够根据其在重建图像中的相对位置重合。厚度约为30毫米的猪肌肉被放置在幻影上方, 以模拟临床环境中的光束路径。超声后, 扫描幻影中的治疗平面, 并从扫描图像中提取相关病变的边界。通过测量目标中心和病变中心之间的距离, 以及三个导数参数, 可以评估目标精度。该方法不仅可以评估由多个焦点组成的目标的瞄准精度, 而不是在 usghfu 相控阵系统的临床相关光束路径中的单个焦点, 而且还可用于临床前评估或定期维护配备相控阵或自聚焦 hifu 传感器的 usghifu 系统。
Introduction
相控阵越来越多地在 hifu 系统中设计和装备1、2、3、4、5、6、7。在 usghifu 相控阵系统中, 美国成像探头通常安装在球面 hifu 传感器1,2,8的中心孔中。该探头可在三维空间9中旋转, 用于目标定位和图像重建。对于 hifu 治疗的安全性和有效性, 需要精确的定位。然而, 大多数评估目标精度的研究都是为磁共振导向的 hifu 系统或配置了自聚焦 hifu 传感器10,11的usghifu 系统进行的,12,13,14,15,16. 下文所述方法的目的是评价 usghfu 相控阵系统在焦平面上的瞄准精度。
在评价临床 usghfu 相控阵系统的靶向精度时, 采用了沿临床相关光束路径的牛马氏标记嵌入幻影。一个在角落有四个球的正方形模型被制造出来, 并与牛肌肉结合, 嵌入到透明的幻影中。根据在处理平面上重建的美国图像中识别的四个球的中心位置, 选择一个规则六边形作为目标。hifu 超声后, 对幻影的治疗平面进行扫描, 并在扫描图像中确定病变的边界以及四个球的位置。通过测量目标中心和病变中心之间的距离, 以及三个导数参数, 可以评估目标精度。
与基于单焦点的方法相比, 该方法比使用机器人运动与特定参考对象11、17、18 进行定位误差的测量更简单, 在临床上更相关点消融在一个均匀的幻影10。该方法可用于评价 usghifu 相控阵系统的瞄准精度。它还可用于其他配备自聚焦 hifu 传感器的 usghifu 系统。
Protocol
Representative Results
Discussion
机器人部件已被用于体外 usghifu 系统。为了评估这些系统的靶向精度,单独或联合使用了参考标记11、12、18、体外组织17、肿瘤模拟模型和温度敏感幻影10,20。与这些研究中的协议相比, 这种方法在临床上的相关性更高, 便于量化焦平面上的目标误差。通过将参考标记?…
Disclosures
The authors have nothing to disclose.
Acknowledgements
这项工作得到了国家自然科学基金 (81402522)、上海市科技委员会 (17441907400)、上海交通大学上海关键技术研发项目 (17441907400) 和上海交通大学的部分支持。医疗工程研究基金 (yg2017qn40, YG2017QN40)。中汇医疗科技 (上海) 有限公司也因提供 usghifu 系统而被公认。作者感谢朱文珍和董俊辉对实验的准备和帮助。
Materials
| Acrylamide | Amresco | D403-2 | |
| Acrylic baseboard | LAO NIAO STORES | customized | |
| Acrylic cylindrical water tank | LAO NIAO STORES | customized | |
| Ammonium persulfate | Yatai United Chemical Co., Ltd (Wuxi, China) | 2017-03-01 | |
| Beaker | East China Chemical Reagent Instrument Store | ||
| Bis-acrylamide | Amresco | M0172 | |
| Bovine muscle | Market | ||
| Chopping board | JIACHI | JC-ZB40 | |
| Cylindrical plastic phantom holder | QIYINPAI | customized | |
| Degassed deionized water | made by the USgHIFU system | ||
| Electric balance | YINGHENG | 11119453359 | |
| Glass rod | East China Chemical Reagent Instrument Store | ||
| Knife | SHIBAZI | SL1210-C | |
| Mask | Medicom | 2498 | |
| N,N,N’,N’–Tetramethylethylenediamine | Zhanyun Chemical Co., Ltd (Shanghai, China) | ||
| Rubber glove | AMMEX | YZB/MAL 0587-2018 | |
| Scanner | Fuji Xerox | DocuPrint M268dw | |
| Screwdriver | Stanley | T6 | |
| Silica gel | GE | 381 | |
| Square model | QIYINPAI | customized | |
| Stainless steel spoons | East China Chemical Reagent Instrument Store | ||
| Sucker | East China Chemical Reagent Instrument Store | ||
| Swine muscle | Market | ||
| USgHIFU system | Zhonghui Medical Technology (Shanghai) Co., Ltd. | SUA-I |
References
- Wang, S. B., He, C. C., Li, K., Ji, X. Design of a 112-channel phased-array ultrasonography-guided focused ultrasound system in combination with switch of ultrasound imaging plane for tissue ablation. 2014 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications (SPAWDA). , 134-137 (2014).
- Choi, J. W., et al. Portable high-intensity focused ultrasound system with 3D electronic steering, real-time cavitation monitoring, and 3D image reconstruction algorithms: a preclinical study in pigs. Ultrasonography. 33 (3), 191-199 (2014).
- Hand, J. W., et al. A random phased array device for delivery of high intensity focused ultrasound. Physics in Medicine and Biology. 54 (19), 5675-5693 (2009).
- Khokhlova, V. A., et al. Design of HIFU transducers to generate specific nonlinear ultrasound fields. Physics Procedia. 87, 132-138 (2016).
- Melodelima, D., et al. Thermal ablation by high-intensity-focused ultrasound using a toroid transducer increases the coagulated volume results of animal experiments. Ultrasound in Medicine and Biology. 35 (3), 425-435 (2009).
- McDannold, N., et al. Uterine leiomyomas: MR imaging-based thermometry and thermal dosimetry during focused ultrasound thermal ablation. Radiology. 240 (1), 263-272 (2006).
- Köhler, M. O., et al. Volumetric HIFU ablation under 3D guidance of rapid MRI thermometry. Medical Physics. 36 (8), 3521-3535 (2009).
- Lu, M., et al. Image-guided 256-element phased-array focused ultrasound surgery. IEEE Engineering in Medicine and Biology Magazine. 27 (5), 84-90 (2008).
- Tong, S., Downey, D. B., Cardinal, H. N., Fenster, A. A three-dimensional ultrasound prostate imaging system. Ultrasound in Medicine and Biology. 22 (6), 735-746 (1996).
- Sakuma, I., et al. Navigation of high intensity focused ultrasound applicator with an integrated three-dimensional ultrasound imaging system. Medical Image Computing and Computer-Assisted Intervention. , 133-139 (2002).
- Masamune, K., Kurima, I., Kuwana, K., Yamashita, H. HIFU positioning robot for less-invasive fetal treatment. Procedia CIRP. 5, 286-289 (2013).
- Li, K., Bai, J. F., Chen, Y. Z., Ji, X. The calibration of targeting errors for an ultrasound-guided high-intensity focused ultrasound system. 2017 IEEE International Symposium on Medical Measurements and Applications (MeMeA). , 10-14 (2017).
- Ellens, N. P. K., et al. The targeting accuracy of a preclinical MRI-guided focused ultrasound system. Medical Physics. 42 (1), 430-439 (2015).
- McDannold, N., Hynynen, K. Quality assurance and system stability of a clinical MRI-guided focused ultrasound system: Four-year experience. Medical Physics. 33 (11), 4307-4313 (2006).
- Gorny, K. R., et al. MR guided focused ultrasound: technical acceptance measures for a clinical system. Physics in Medicine and Biology. 51 (12), 3155-3173 (2006).
- Kim, Y. S., et al. MR thermometry analysis of sonication accuracy and safety margin of volumetric MR imaging-guided high-intensity focused ultrasound ablation of symptomatic uterine fibroids. Radiology. 265 (2), 627-637 (2012).
- Chauhan, S., ter Haar, G. FUSBOTUS: empirical studies using a surgical robotic system for urological applications. AIP Conference Proceedings. 911, 117-121 (2007).
- An, C. Y., Syu, J. H., Tseng, C. S., Chang, C. J. An ultrasound imaging-guided robotic HIFU ablation experimental system and accuracy evaluations. Applied Bionics and Biomechanics. 2017, 5868695 (2017).
- Li, D. H., Shen, G. F., Bai, J. F., Chen, Y. Z. Focus shift and phase correction in soft tissues during focused ultrasound surgery. IEEE Transactions on Biomedical Engineering. 58 (6), 1621-1628 (2011).
- N’Djin, W. A., et al. Utility of a tumor-mimic model for the evaluation of the accuracy of HIFU treatments. results of in vitro experiments in the liver. Ultrasound in Medicine and Biology. 34 (12), 1934-1943 (2008).
- Tang, T. H., et al. A new method for absolute accuracy evaluation of a US-guided HIFU system with heterogeneous phantom. 2016 IEEE International Ultrasonics Symposium (IUS). , 1-4 (2016).
- Li, K., Bai, J. F., Chen, Y. Z., Ji, X. Experimental evaluation of targeting accuracy of an ultrasound-guided phased-array high-intensity focused ultrasound system. Applied Acoustics. 141, 19-25 (2018).
