MR Imaging of Upper Airway Dynamics in Obstructive Sleep Apnea

描述（由申请人提供）：本研究的总体目标是：1）使用磁共振成像（MRI）表征阻塞性睡眠呼吸暂停（OSA）患者在觉醒和睡眠期间的上气道动力学; 2）确定在觉醒期间收集的数据是否可以预测OSA的发生。OSA的特征在于睡眠期间反复发生的部分或完全气道闭合，并且具有重要的临床意义，从睡眠中断伴日间后遗症过度嗜睡和生活质量差到不良心血管或代谢结果。虽然多导睡眠图和基于气道压力和阻力测量的研究已经提供了大量关于上气道生理学的信息，但是它们不能评估上气道的三维解剖结构及其在呼吸期间的构象变化。了解这种结构的形态和力学行为对于更全面地了解上气道阻塞的发生是必不可少的。这些信息可以通过成像技术获得，是本研究的重点。 我们建议使用最先进的MRI工具来量化三组受试者的上气道动力学：1）OSA患者; 2）打鼾志愿者; 3）健康年龄和体重匹配的对照组，以进行比较。受试者将接受MR成像，以评估清醒和自然睡眠期间潮式呼吸期间的上气道形态和气道大小变化，同时测量鼻-口气流分配和睡眠状态和阶段。将根据MR图像重建上气道形态测量的动态患者特定模型，并从中计算各种解剖标记。将评价各组之间和不同阶段（清醒与睡眠）之间这些标志物的差异。 在潮式呼吸期间表征上气道的构象变化的拟议的研究将提供一种新的手段来识别导致气流阻塞的几何异常。该建议是解决目前未满足的临床治疗指南需求的第一步，该指南考虑了上气道的动态性质。这些研究的完成也将为未来的建模研究奠定基础，这些研究将联合收割机患者特定的上气道动力学与详细的流动模拟相结合，以更好地了解上气道的生物力学特性和流动驱动机制，从而优化治疗。本研究开发的方法将直接适用于所有上气道功能障碍患者人群。

DESCRIPTION (provided by applicant): The overall objectives of this research are 1) to characterize upper airway dynamics during wakefulness and sleep in patients with obstructive sleep apnea (OSA) using magnetic resonance imaging (MRI) and 2) to determine if data collected during wakefulness can predict the occurrence of OSA. OSA is characterized by recurrent partial or complete airway closure during sleep, and has important clinical implications ranging from disruption of sleep with daytime sequelae of excessive sleepiness and poor quality of life to adverse cardiovascular or metabolic outcomes. While polysomnography and studies based on measurements of airway pressures and resistance have provided a wealth of information on upper airway physiology, they are unable to assess the three-dimensional anatomy of the upper airway and its conformational changes during breathing. Knowledge of the morphology and mechanical behavior of this structure is essential for a more complete understanding of the occurrence of upper airway obstruction. Such information can be obtained with imaging technology and is the focus of this study. We propose to use state-of-the-art MRI tools to quantify upper airway dynamics in three groups of subjects: 1) OSA patients; 2) snoring volunteers; and 3) healthy age and weight-matched controls for comparison purposes. Subjects will undergo MR imaging to assess upper airway morphometry and changes in airway size during tidal breathing both during wakefulness and natural sleep with simultaneous measurement of nasal-oral flow partition and sleep state and stages. Dynamic patient-specific models of upper airway morphometry will be reconstructed from the MR images from which various anatomical markers will be calculated. Differences in these markers between groups and between stages (awake vs. asleep) will be evaluated. The proposed studies of characterizing the conformational change of the upper airway during tidal breathing will provide a new means of identifying geometrical abnormalities that lead to airflow obstruction. This proposal is a first step in addressing a currently unmet clinical need for treatment guidelines tha take into account the dynamic nature of the upper airway. Completion of these studies will also lay the groundwork for future modeling studies that will combine patient-specific upper airway dynamics with detailed flow simulations to provide better insight in biomechanical properties of the upper airway and flow-driven mechanisms on which to optimize therapeutic treatment. The methods developed in this research will be directly applicable to all patient populations with upper airway dysfunction.