多序列MRI信号强度比值作为前庭神经鞘瘤听前庭功能障碍的候选影像学相关指标

文献信息

中文摘要

引言： 前庭神经鞘瘤（VS）通常引起渐进性感音神经性听力损害和前庭功能障碍。然而，能够反映内耳病理改变、临床可应用的无创候选影像标志物尚未很好建立。本研究旨在系统探讨经多序列内耳磁共振成像（MRI）获得的迷路信号强度比值与确诊VS患者听前庭功能缺陷之间的相关关系。
方法： 本回顾性观察研究连续纳入22例经影像学确诊的VS患者。所有受试者接受3.0 T内耳MRI检查，涵盖三种脉冲序列：T2加权成像（T2WI）、增强前三维液体衰减反转恢复（3D-FLAIR）以及钆剂给药后4小时时间点采集的延迟增强后3D-FLAIR。测量信号强度比值（耳蜗、前庭和半规管与脑干之比；CBR、VBR、SBR），并与纯音测听、冷热试验和视频头脉冲试验（vHIT）结果进行相关性分析。
结果： 与对侧未受累耳相比，患侧耳在延迟增强后和增强前3D-FLAIR序列上均显示信号比值显著升高（所有p < 0.001），提示血-迷路屏障破坏；而T2WI比值显著降低（p < 0.001），提示蛋白质含量增加等结构改变。相关性分析显示，增强前3D-FLAIR CBR与听力损失程度呈中度正相关（r = 0.582，p = 0.037），而T2WI SBR与冷热试验评估的低频前庭功能障碍相关（r = 0.440，p = 0.040）。相比之下，所评估的MRI指标均未显示与vHIT测量的高频前庭功能显著相关。
结论： 这些发现表明，特定的内耳MRI信号比值可作为VS中听觉损害和低频前庭缺陷的有前景的候选影像学相关指标。增强前3D-FLAIR和T2WI序列分别提供了关于炎症性渗漏和结构损伤的不同见解。这些指标指导个体化管理策略的潜力仍有待未来研究评估。因此，需要纳入组织病理学验证的大规模多中心研究来剖析这些潜在机制并开发预测性预后框架。

英文摘要

INTRODUCTION: Vestibular schwannoma (VS) typically induces gradual sensorineural hearing impairment and vestibular dysfunction. Nevertheless, clinically applicable non-invasive candidate imaging markers capable of reflecting pathological alterations within the inner ear have not yet been well established. The present study sought to systematically investigate the correlative relationships between labyrinth signal intensity ratios acquired from multi-sequence inner ear magnetic resonance imaging (MRI) and audiovestibular functional deficits in patients diagnosed with VS.
METHODS: A total of 22 patients with radiologically confirmed VS were consecutively enrolled for this retrospective observational study. All subjects received 3.0 T inner ear MRI examinations covering three pulse sequences: T2-weighted imaging (T2WI), pre-contrast three-dimensional fluid-attenuated inversion recovery (3D-FLAIR), and delayed post-contrast 3D-FLAIR acquired at the 4-h time point after gadolinium administration. Signal intensity ratios (cochlea-, vestibule-, and semicircular canal-to-brainstem; CBR, VBR, SBR) were measured and correlated with pure-tone audiometry, caloric testing, and video head impulse test (vHIT) results.
RESULTS: Compared to contralateral unaffected ears, affected ears exhibited significantly elevated signal ratios on both delayed post-contrast and pre-contrast 3D-FLAIR sequences (all p < 0.001), indicating blood-labyrinth barrier disruption, while T2WI ratios were significantly reduced (p < 0.001), suggesting structural alterations like increased protein content. Correlation analysis revealed that pre-contrast 3D-FLAIR CBR exhibited a moderate positive correlation with the degree of hearing loss (r = 0.582, p = 0.037), whereas T2WI SBR showed a correlation with low-frequency vestibular dysfunction assessed by caloric testing (r = 0.440, p = 0.040). In contrast, none of the evaluated MRI metrics demonstrated significant correlations with high-frequency vestibular function measured by vHIT.
CONCLUSION: These findings demonstrate that specific inner ear MRI signal ratios serve as promising candidate imaging correlates for auditory impairment and low-frequency vestibular deficits in VS. Pre-contrast 3D-FLAIR and T2WI sequences offer distinct insights into inflammatory leakage and structural damage, respectively. The potential for these metrics to guide personalized management strategies remains to be evaluated in future studies. Large-scale multicenter investigations incorporating histopathologic verification are therefore needed to dissect these underlying mechanisms and develop predictive prognostic frameworks.