A head template for computational dose modelling for transcranial focused ultrasound stimulation.
A head template for computational dose modelling for transcranial focused ultrasound stimulation.
复制标题
用于经颅聚焦超声刺激计算剂量建模的头部模板。
DOI：
10.1016/j.neuroimage.2023.120227
复制
发表时间：
2023
期刊：
影响因子：
5.7
通讯作者：
Hosseini S
中科院分区：
文献类型：
--
作者：
Hosseini S
低强度的经颅聚焦超声刺激（TUS）是一种新型的无创脑刺激方法，具有比现有的经颅刺激方法更高的空间分辨率，并且能够选择性地刺激脑深部区域。准确控制TUS声波的焦点位置和强度对于有效利用高空间分辨率和确保安全至关重要。由于人体颅骨会引起强衰减和畸变，因此需要对透射波进行模拟，以准确确定颅腔内的TUS剂量分布。模拟需要颅骨形态及其声学特性的信息。理想情况下，他们可以通过个体头部的计算机断层扫描（CT）图像获得信息。然而，合适的个人成像数据往往不容易获得。出于这个原因，我们在这里介绍并验证了一个头部模板，该模板可用于估计人群中头骨对TUS声波的平均影响。该模板由29个不同年龄（20-50岁）、性别和种族的个体的头部CT图像创建，使用迭代非线性共配准程序。为了验证，我们将基于模板的声学和热模拟与所有29个单独数据集的模拟结果的平均值进行了比较。利用EEG 10-10系统，对一个500 kHz驱动的聚焦换能器模型进行了声学模拟，并将其放置在24个标准位置。为了进一步证实，在16个位置使用了250千赫和750千赫的额外模拟。在相同的16个换能器位置估计500 kHz的超声诱导加热量。我们的结果表明，模板在大多数情况下都能很好地代表来自个体的声压和温度图的中位数。这巩固了模板在健康年轻人研究中规划和优化TUS干预措施的有用性。我们的结果进一步表明，个体模拟结果之间的可变性取决于位置。具体来说，模拟超声诱导的颅骨内加热在靠近中线的三个后侧位置表现出强烈的个体间变异性，这是由局部颅骨形状和组成的高度变异性引起的。在基于模板解释模拟结果时，应该考虑到这一点。
Transcranial focused Ultrasound Stimulation (TUS) at low intensities is emerging as a novel non-invasive brain stimulation method with higher spatial resolution than established transcranial stimulation methods and the ability to selectively stimulate also deep brain areas. Accurate control of the focus position and strength of the TUS acoustic waves is important to enable a beneficial use of the high spatial resolution and to ensure safety. As the human skull causes strong attenuation and distortion of the waves, simulations of the transmitted waves are needed to accurately determine the TUS dose distribution inside the cranial cavity. The simulations require information of the skull morphology and its acoustic properties. Ideally, they are informed by computed tomography (CT) images of the individual head. However, suited individual imaging data is often not readily available. For this reason, we here introduce and validate a head template that can be used to estimate the average effects of the skull on the TUS acoustic wave in the population.The template was created from CT images of the heads of 29 individuals of different ages (between 20–50 years), gender and ethnicity using an iterative non-linear co-registration procedure. For validation, we compared acoustic and thermal simulations based on the template to the average of the simulation results of all 29 individual datasets. Acoustic simulations were performed for a model of a focused transducer driven at 500 kHz, placed at 24 standardized positions by means of the EEG 10–10 system. Additional simulations at 250 kHz and 750 kHz at 16 of the positions were used for further confirmation. The amount of ultrasound-induced heating at 500 kHz was estimated for the same 16 transducer positions. Our results show that the template represents the median of the acoustic pressure and temperature maps from the individuals reasonably well in most cases. This underpins the usefulness of the template for the planning and optimization of TUS interventions in studies of healthy young adults. Our results further indicate that the amount of variability between the individual simulation results depends on the position. Specifically, the simulated ultrasound-induced heating inside the skull exhibited strong interindividual variability for three posterior positions close to the midline, caused by a high variability of the local skull shape and composition. This should be taken into account when interpreting simulation results based on the template.