基于磁共振的全向水听器
The Magnetic-Resonance-Based, Omni-Directional Hydrophone
- Brigham Young University（杨百翰大学）
- University of Utah（犹他大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究提出基于磁共振的全向水听器（MRbOH），通过构建方程组实现对任意角度声波的检测与量化，实验验证了其在不同角度下的压力重建能力，并提出了统计噪声模型。
AI中文摘要：
本研究旨在提高磁共振水听器（MRH）方法的方向灵敏度，使其能够检测和量化相对于MRI孔轴以任意角度传播的波。这样做可以更好地将MRH技术整合到经颅聚焦超声神经调控治疗中。现有的MRH实现仅编码沿MRI孔轴传播的声波，无法用于宽孔径换能器或时间性颅窗。本研究将MRH技术扩展为基于MR的全向水听器（MRbOH），可量化以任意角度传播的波的幅度压力和相位。MRbOH方法围绕独特敏感图像建立方程组，求解后可引入对斜向声波的灵敏度。该方法在凝胶体模中进行了实验测试，体模分别以相对于MRI孔轴0°、45°和90°的角度被照射。该方法重建了所有三个传播角度的压力图，包括峰值压力、部分反射和波束宽度等特征。MRbOH方法测得的平均波束宽度为16.2毫米，而水听器测得的波束宽度为14.5毫米。感兴趣区域内水听器测得的平均压力为416.19 ± 78.07 kPa。同一区域内MRbOH在0°、45°和90°下测得的平均压力分别为：285.5 ± 49.5 kPa、193.13 ± 43.55 kPa和194.7 ± 47.38 kPa。此外，本研究提出并实验验证了一个统计噪声模型，该模型预测均值的R² = 0.85，预测标准差的R² = 0.83。
英文摘要：
This study aims to improve the directional sensitivity of magnetic resonance hydrophone (MRH) methods and allow for detection and quantification of waves traveling at any angle relative to the MRI bore-axis. Doing so may better integrate MRH technology into transcranial focused ultrasound neuromodulation therapies. Existing MRH implementations only encode acoustic waves propagating along the MRI bore-axis, precluding use with wide aperture transducers or temporal skull windows. This study expands the MRH technique into a MR-based Omni-directional Hydrophone (MRbOH) that can quantify the magnitude pressure and phase of waves propagating at any angle. The MRbOH method formulates a system of equations around uniquely sensitized images that, when solved, introduce sensitivity to oblique acoustic waves. The method was tested experimentally in a gel phantom that was insonated at $0^o$, $45^o$, and $90^o$ relative to the MRI bore-axis. The method reconstructed pressure maps at all three angles of propagation, including features such as peak pressure, partial reflections, and beamwidth. The MRbOH method measured an average beamwidth of 16.2 mm while the hydrophone measured a beamwidth of 14.5 mm. Average hydrophone-measured pressure within a region of interest was 416.19 $\boldsymbol{\pm}$ 78.07 kPa. Average MRbOH measured pressure in the same region at $0^o$, $45^o$, and $90^o$, respectively, were: 285.5 $\boldsymbol{\pm}$ 49.5 kPa, 193.13 $\boldsymbol{\pm}$ 43.55 kPa, 194.7 $\boldsymbol{\pm}$ 47.38 kPa. In addition, the study presents and experimentally verifies a statistical noise model that predicted the mean with $R^2 = 0.85$, and standard deviation with $R^2 = 0.83$.
