Three-layer model with absorption for conservative estimation of the maximum acoustic transmission coefficient through the human skull for transcranial ultrasound stimulation.
Three-layer model with absorption for conservative estimation of the maximum acoustic transmission coefficient through the human skull for transcranial ultrasound stimulation.
复制标题
具有吸收功能的三层模型，用于保守估计经颅超声刺激通过人体颅骨的最大声传输系数。
DOI：
10.1016/j.brs.2022.12.005
复制
发表时间：
2023
影响因子：
7.7
通讯作者：
Attali D
中科院分区：
文献类型：
--
作者：
Attali D
经颅超声刺激（TUS）已被证明是一种安全有效的非侵入性浅表和深部脑刺激技术。安全有效地翻译到人类需要估计人类头骨的声衰减。然而，没有国际准则来估计头骨的影响。美国食品药品监督管理局开发了一种独立于组织的任意降额，以考虑诊断超声的组织吸收（0.3 dB/cm-MHz）。然而，对于经颅超声成像的情况，FDA模型没有考虑由颅骨引起的插入损耗，也没有考虑脑组织的吸收。因此，估计的吸收量过于保守，如果采用相同的准则，可能会限制TUS的应用。在这里，我们提出了一个三层模型，包括骨吸收计算的最大压力传输通过人类头骨的频率范围在100 kHz和1.5 MHz之间。计算的压力传输随频率和骨的厚度而减小，每个厚度的峰值对应于波长的一半的倍数。在20个人类颅骨的可及表面上，针对颅骨表面上的12种典型直径的超声波束，计算第95百分位数的最大透射率，并且在40%和78%之间变化。为了便于安全调整短超声脉冲的声压，例如经颅成像或经颅超声刺激，表格总结了每个超声波束直径和每个频率的最大压力传输。
Transcranial ultrasound stimulation (TUS) has been shown to be a safe and effective technique for non-invasive superficial and deep brain stimulation. Safe and efficient translation to humans requires estimating the acoustic attenuation of the human skull. Nevertheless, there are no international guidelines for estimating the impact of the skull bone. A tissue independent, arbitrary derating was developed by the U.S. Food and Drug Administration to take into account tissue absorption (0.3 dB/cm-MHz) for diagnostic ultrasound. However, for the case of transcranial ultrasound imaging, the FDA model does not take into account the insertion loss induced by the skull bone, nor the absorption by brain tissue. Therefore, the estimated absorption is overly conservative which could potentially limit TUS applications if the same guidelines were to be adopted. Here we propose a three-layer model including bone absorption to calculate the maximum pressure transmission through the human skull for frequencies ranging between 100 kHz and 1.5 MHz. The calculated pressure transmission decreases with the frequency and the thickness of the bone, with peaks for each thickness corresponding to a multiple of half the wavelength. The 95th percentile maximum transmission was calculated over the accessible surface of 20 human skulls for 12 typical diameters of the ultrasound beam on the skull surface, and varies between 40% and 78%. To facilitate the safe adjustment of the acoustic pressure for short ultrasound pulses, such as transcranial imaging or transcranial ultrasound stimulation, a table summarizes the maximum pressure transmission for each ultrasound beam diameter and each frequency.