磁共振测温在磁共振引导的超声空化治疗中的应用。
Magnetic Resonance Thermometry Targeting for Magnetic Resonance-Guided Histotripsy Treatments.
机构信息
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA.
出版信息
Ultrasound Med Biol. 2023 May;49(5):1102-1107. doi: 10.1016/j.ultrasmedbio.2022.12.009. Epub 2023 Feb 19.
OBJECTIVE
The potential of transcranial magnetic resonance (MR)-guided histotripsy for brain applications has been described in prior in vivo studies in the swine brain through an excised human skull. The safety and accuracy of transcranial MR-guided histotripsy (tcMRgHt) rely on pre-treatment targeting guidance. In the work described here, we investigated the feasibility and accuracy of using ultrasound-induced low-temperature heating and MR thermometry for histotripsy pre-treatment targeting in ex vivo bovine brain.
METHODS
A 15-element, 750-kHz MRI-compatible ultrasound transducer with modified drivers that can deliver both low-temperature heating and histotripsy acoustic pulses was used to treat seven bovine brain samples. The samples were first heated to an approximately 1.6°C temperature increase at the focus, and MR thermometry was used to localize the target. Once the targeting was confirmed, a histotripsy lesion was generated at the focus and visualized on post-histotripsy MR images.
DISCUSSION
The accuracy of MR thermometry targeting was evaluated with the mean/standard deviation of the difference between the locus of peak heating identified by MR thermometry and the center of mass of the post-treatment histotripsy lesion, which was 0.59/0.31 mm and 1.31/0.93 mm in the transverse and longitudinal directions, respectively.
CONCLUSION
This study determined that MR thermometry could provide reliable pre-treatment targeting for transcranial MR-guided histotripsy treatment.
目的
在先前的猪脑离体研究中，通过切除的人颅骨，已经描述了经颅磁共振（MR）引导的聚焦超声（histotripsy）在脑应用中的潜力。经颅 MR 引导的聚焦超声（tcMRgHt）的安全性和准确性依赖于预处理靶向引导。在本文所描述的工作中，我们研究了使用超声诱导的低温加热和 MR 测温法进行离体牛脑 histotripsy 预处理靶向的可行性和准确性。
方法
使用具有改进驱动器的 15 元件 750kHz MRI 兼容超声换能器，该驱动器可以同时传递低温加热和 histotripsy 声脉冲，用于治疗七个牛脑样本。首先将样品加热到焦点处约 1.6°C 的温度升高，并使用 MR 测温法定位目标。一旦确认了靶向性，就在焦点处产生 histotripsy 损伤，并在 post-histotripsy MR 图像上可视化。
讨论
通过 MR 测温法定位的 locus of peak heating 与 post-treatment histotripsy 损伤的质心之间的差异的平均值/标准偏差来评估 MR 测温法靶向的准确性，在横向和纵向方向上分别为 0.59/0.31mm 和 1.31/0.93mm。
结论
这项研究确定了 MR 测温法可以为经颅 MR 引导的 histotripsy 治疗提供可靠的预处理靶向。
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