Shan Xiang, Murphy Matthew C, Sui Yi, Zheng Keni, Hojo Emi, Manduca Armando, Ehman Richard L, Huston John, Yin Ziying
Department of Radiology, Mayo Clinic, Rochester, MN, USA.
Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
Eur Radiol. 2025 Jun;35(6):3613-3624. doi: 10.1007/s00330-024-11265-7. Epub 2024 Dec 10.
To evaluate MR elastography (MRE)-assessed biomarkers for detecting changes in skull-brain mechanical decoupling performance induced by repetitive head impacts (RHIs).
This prospective single-center study enrolled 80 asymptomatic participants (2017-2023) divided into three groups: no exposure (RHI(-)), low-impact (low RHI(+)), and high-impact (high RHI(+)). Four MRE-based parameters were evaluated to analyze the skull-brain decoupling performance: brain-to-skull rotational transmission ratio (Rtr), cortical shear strain (normalized OSS (octahedral shear strain)), cortical volumetric strain (normalized ONS (octahedral normal strain)), and the OSS-to-ONS ratio. Confounding factors (age/skull-brain distance, sex) were controlled with a linear regression model. One-way ANOVA with Tukey's post-hoc test was used for group comparisons.
The high RHI(+) showed a significantly increased adjusted Rtr compared to the RHI(-) and low RHI(+) (p < 0.001). Higher adjusted OSS-to-ONS ratios were found in the high RHI(+) in the frontal (q < 0.05), parietal (q < 0.001), and occipital (q < 0.05) lobes compared to the RHI(-), and in all regions compared to the low RHI(+) (q < 0.05). The high RHI(+) exhibited lower adjusted normalized ONS and OSS in the temporal lobe (q < 0.05) compared to the low RHI(+). These findings suggest that recent and prolonged RHI exposures may impair the skull-brain decoupling performance, affecting the capacity of the interface to isolate the brain by dampening skull-to-brain motion transmission and modulating brain surface deformation.
This study reveals evidence of impaired decoupling function at the skull-brain interface resulting from RHI exposure and demonstrates MRE-based biomarkers for early detection of this impairment.
Question The skull-brain interface is crucial for brain protection under impact, but its early mechanical responses to repetitive head impacts (RHIs) remain largely unknown. Findings Mechanical changes (more rotation and a shift in shear relative to volumetric strain) across the skull-brain interface were observed in participants under high RHI exposure. Clinical relevance Our study developed MR elastography (MRE)-based measurements to detect changes in the skull-brain interface caused by RHI, suggesting that MRE holds promise for noninvasively quantifying cumulative injury and potential future clinical interventions for individuals with high RHI exposure.
评估磁共振弹性成像（MRE）评估的生物标志物，以检测重复性头部撞击（RHI）引起的颅骨-脑机械解耦性能变化。
这项前瞻性单中心研究纳入了80名无症状参与者（2017 - 2023年），分为三组：无暴露组（RHI(-)）、低撞击组（低RHI(+)）和高撞击组（高RHI(+)）。评估了四个基于MRE的参数以分析颅骨-脑解耦性能：脑-颅骨旋转传递比（Rtr）、皮质剪切应变（归一化八面体剪切应变（OSS））、皮质体积应变（归一化八面体法向应变（ONS））以及OSS与ONS之比。使用线性回归模型控制混杂因素（年龄/颅骨-脑距离、性别）。采用单因素方差分析及Tukey事后检验进行组间比较。
与RHI(-)组和低RHI(+)组相比，高RHI(+)组的调整后Rtr显著增加（p < 0.001）。与RHI(-)组相比，高RHI(+)组在额叶（q < 0.05）、顶叶（q < 0.001）和枕叶（q < 0.05）的调整后OSS与ONS之比更高，与低RHI(+)组相比，在所有区域该比值均更高（q < 0.05）。与低RHI(+)组相比，高RHI(+)组颞叶的调整后归一化ONS和OSS更低（q < 0.05）。这些发现表明，近期和长期的RHI暴露可能会损害颅骨-脑解耦性能，影响该界面通过抑制颅骨到脑的运动传递和调节脑表面变形来隔离大脑的能力。
本研究揭示了RHI暴露导致颅骨-脑界面解耦功能受损的证据，并证明了基于MRE的生物标志物可用于早期检测这种损伤。
问题颅骨-脑界面对于撞击时的脑保护至关重要，但其对重复性头部撞击（RHI）的早期机械反应仍 largely未知。发现高RHI暴露的参与者在颅骨-脑界面观察到机械变化（更多旋转以及剪切相对于体积应变的变化）。临床意义我们的研究开发了基于磁共振弹性成像（MRE）的测量方法来检测RHI引起的颅骨-脑界面变化，表明MRE有望无创量化累积损伤，并为高RHI暴露个体提供潜在的未来临床干预。
