Arán-Tapia Ismael, Pérez-Muñuzuri Vicente, Muñuzuri Alberto P, Soto-Varela Andrés, Otero-Millan Jorge, Roberts Dale C, Ward Bryan K
Group of Non-Linear Physics, University of Santiago de Compostela, Santiago de Compostela, Spain.
Galician Center for Mathematical Research and Technology (CITMAga), Santiago de Compostela, Spain.
Commun Med (Lond). 2025 Jan 21;5(1):27. doi: 10.1038/s43856-024-00667-9.
High-field magnetic resonance imaging (MRI) is a powerful diagnostic tool but can induce unintended physiological effects, such as nystagmus and dizziness, potentially compromising the comfort and safety of individuals undergoing imaging. These effects likely result from the Lorentz force, which arises from the interaction between the MRI's static magnetic field and electrical currents in the inner ear. Yet, the Lorentz force hypothesis fails to explain observed eye movement patterns in healthy adults fully. This study explores these effects and tests whether the Lorentz force hypothesis adequately explains magnetic vestibular stimulation.
We developed a mathematical model integrating computational fluid dynamics, fluid-structure interaction solvers, and magnetohydrodynamic equations to simulate the biomechanical response of the cristae ampullares. Using high-resolution micro-CT data of the human membranous labyrinth, we ensured anatomical accuracy. Experimental validation involved measuring horizontal, vertical, and torsional slow-phase eye movements in healthy subjects exposed to varying magnetic field intensities and head positions.
Our model accurately replicates observed nystagmus patterns, predicting slow-phase eye velocities that match experimental data. Results indicate that Lorentz force-induced stimulation of individual cupulae explains variability in eye movements across different magnetic field intensities and head orientations.
This study empirically supports the Lorentz force hypothesis as a valid explanation for magnetic vestibular stimulation, offering new insights into the effects of high-field MRI on the vestibular system. These findings provide a foundation for future research and improved clinical practices.
高场磁共振成像（MRI）是一种强大的诊断工具，但会引发意想不到的生理效应，如眼球震颤和头晕，这可能会影响接受成像检查者的舒适度和安全性。这些效应可能是由洛伦兹力引起的，洛伦兹力源于MRI静磁场与内耳电流之间的相互作用。然而，洛伦兹力假说并不能完全解释健康成年人中观察到的眼球运动模式。本研究探讨了这些效应，并测试洛伦兹力假说是否能充分解释磁前庭刺激。
我们开发了一个数学模型，该模型整合了计算流体动力学、流固相互作用求解器和磁流体动力学方程，以模拟壶腹嵴的生物力学反应。利用人类膜迷路的高分辨率微型计算机断层扫描（micro-CT）数据，我们确保了解剖学准确性。实验验证包括测量暴露于不同磁场强度和头部位置的健康受试者的水平、垂直和扭转慢相眼球运动。
我们的模型准确地复制了观察到的眼球震颤模式，预测的慢相眼球速度与实验数据相符。结果表明，洛伦兹力对单个壶腹帽的刺激解释了不同磁场强度和头部方向下眼球运动的变异性。
本研究通过实证支持了洛伦兹力假说，认为它是磁前庭刺激的有效解释，为高场MRI对前庭系统的影响提供了新的见解。这些发现为未来的研究和改进临床实践奠定了基础。
