MRgFUS Vim thalamotomy is a novel, effective, minimally invasive therapeutic option for patients with essential tremor (ET). Among the selection criteria, some parameters related to the patient's anatomy, such as the skull density ratio (SDR), are well recognized. The role of brain tissue interposed between the target and the ultrasound transducers has never been explored. Therefore, the purpose of our study was to evaluate the correlation and the possible predictive value between brain tissue volumes (grey matter – GM, white matter – WM, and cerebrospinal fluid – CSF) and several treatment-related variables (periprocedural parameters, MRI imaging findings, and the clinical outcome). We analysed data from thirty ET patients previously submitted to MRgFUS thalamotomy. Pre-treatment images were automatically segmented in sopra-tentorial (ST) WM, GM, and CSF using SPM 12.

The most significant findings were a positive correlation of the ST-GM with the Accumulated Thermal Dose (ATD) (p < 0,001) and a negative correlation of the ATD temperature with ST-CSF and ST-TIV (p < 0,001).

Ultrasound propagation speed is lower in fluids than brain tissues. Also, WM has an attenuation rate of 1.5 higher than the GM. Therefore, the difference in the ATD may be explained by the different acoustic properties of normal brain tissues interposed between the transducers and the VIM.

MRgFUS Vim 丘脑切开术是针对特发性震颤 (ET) 患者的一种新颖、有效、微创的治疗选择。在选择标准中，一些与患者解剖结构相关的参数，例如颅骨密度比 (SDR)，得到了很好的认可。从未探索过插入目标和超声换能器之间的脑组织的作用。因此，我们研究的目的是评估脑组织体积（灰质 - GM、白质 - WM 和脑脊液 - CSF）与几个治疗相关变量（围手术期参数、MRI 成像）之间的相关性和可能的​​预测值结果和临床结果）。我们分析了 30 名先前接受 MRgFUS 丘脑切开术的 ET 患者的数据。预处理图像在天幕 (ST) WM 中自动分割，

最重要的发现是 ST-GM 与累积热剂量 (ATD) 的正相关 (p < 0,001) 以及 ATD 温度与 ST-CSF 和 ST-TIV 的负相关 (p < 0,001)。

超声波在流体中的传播速度低于脑组织。此外，WM 的衰减率比 GM 高 1.5。因此，ATD 的差异可以用插入换能器和 VIM 之间的正常脑组织的不同声学特性来解释。