流体向头颈部迁移对睡眠呼吸影响的MRI研究

发布时间：2018-05-12 00:00

本文选题：流体迁移 + 头颈部磁共振成像　；参考：《首都医科大学》2013年硕士论文

【摘要】：阻塞性睡眠呼吸暂停（OSA）是一种常见的呼吸系统疾病。患者在睡眠状态下呼吸道反复塌陷、阻塞造成的周期性缺氧会引起一系列严重后果，包括导致心血管系统的严重疾病。近年国外研究发现，当由站或坐姿改变为卧姿时，人体下部肢体的液体会向头颈部迁移，引起呼吸道截面变窄，从而可能会加重睡眠状态下上气道阻塞的倾向。对于流体迁移这一问题，目前除了香港研究人员所做的一项研究，国内尚未见到其它与此相关的研究工作发表。在国外研究中，通常利用抗休克裤对腿部施加压力迫使流体向颈部迁移，以及使用咽声反射仪测量上气道截面积。这些方法存在一些明显弱点。本研究的目的，是要探究体位改变导致的流体向头颈部迁移对上气道形态及呼吸功能的影响。为达此目的，我们提出将磁共振三维容积成像方法应用到流体迁移研究中，并在研究方案中采用了一种自然流动的方式来实现流体自下肢向头颈部的迁移。在现有实验中，研究人员观察到了流体自下肢向头颈部迁移时可以引起颈围增加。但有一个没被注意到，而又必须要理清的重要问题是，对于不同个体来说，流体迁移导致颈围的增加是否总是伴随着气道截面积的显著减小，或反过来，是否气道截面的减小总是伴随着颈围的明显增加。这个问题在临床上至为重要，因为它涉及到是否可以根据患者体位改变后颈围的变化来评估流体迁移对其气道形态与呼吸功能影响的程度。对此我们提出了一个有关颈围与气道截面积变化不具有较强相关性的假设。为验证假设，我们使用三维扰相梯度回波序列（3D-SPGR）容积扫描方式对50例健康受试者（男性30名，女性20名）头颈部自鼻腔顶部至喉结处进行四种状态下的横断面磁共振成像，即平卧参考状态，将双腿抬起大于50o角并分别持续1分钟和8分钟之后的流体重新分布状态，，以及回复到双腿放下的平卧状态。我们对图像有关组织进行边界分割，从选定横断面的图像上提取四种状态下上气道截面和颈围边界的坐标，进而计算气道横截面积以及颈围周长。通过对数据进行统计学分析，研究流体重新分布引起的上气道截面积及颈围尺度的变化。实验结果证实了我们的假设。数据表明，与通常想象的不同，流体迁移引起颈围明显增加时，并不一定伴随着气道截面积的显著下降，反之亦然。除了获得的重要结果，本研究提出的使用磁共振三维扰相梯度回波序列容积扫描来研究流体迁移对上气道形态影响的方法也为探讨体位改变对睡眠呼吸功能的影响提供了新的思路。
[Abstract]:Obstructive sleep apnea (OSA) is a common respiratory disease. During sleep, the respiratory tract collapses repeatedly, and the periodic hypoxia caused by blockage can lead to a series of serious consequences, including serious cardiovascular diseases. In recent years, it has been found that when the body changes from standing position or sitting position to lying position, the liquid of the lower limb of the human body will migrate to the head and neck, which may lead to the narrow section of the respiratory tract, which may aggravate the tendency of obstruction of the upper airway during sleep. As for the problem of fluid migration, no other related research work has been published in China except for one by Hong Kong researchers. In foreign studies, anti-shock pants are usually used to exert pressure on the legs to force the fluid to migrate to the neck, and to measure the cross section of the upper airway by using the pharyngeal acoustic reflectometer. There are some obvious weaknesses in these methods. The aim of this study was to investigate the effects of fluid migration to head and neck on upper airway morphology and respiratory function. In order to achieve this goal, we propose to apply Mr three-dimensional volumetric imaging to the study of fluid migration, and adopt a natural flow method to realize the migration of fluid from lower extremity to head and neck in the research scheme. In existing experiments, researchers have observed that fluid migration from the lower extremities to the head and neck can lead to increased neck circumference. But an important question that has not been noticed and has to be sorted out is whether, for different individuals, increased neck circumference due to fluid migration is always accompanied by a significant decrease in airway cross-sectional area, or vice versa. Whether the airway section decreases is always accompanied by a significant increase in the neck circumference. This issue is of clinical importance because it involves assessing the extent to which fluid migration affects airway morphology and respiratory function based on changes in the neck circumference of patients with postural changes. We propose a hypothesis that there is no strong correlation between neck circumference and airway cross-sectional area. To verify the hypothesis, we performed transversal magnetic resonance imaging of the head and neck of 50 healthy subjects (30 males and 20 females) from the top of the nasal cavity to the laryngeal node in four different states using three-dimensional disturbed phase gradient echo sequence 3D-SPGR. Namely the supine reference state, the fluid redistribution state after lifting the legs at a angle of more than 50 o for 1 minute and 8 minutes, respectively, and returning to the supine state where the legs are put down. We segment the relevant tissues of the image and extract the coordinates of upper airway section and neck border from the selected cross section images, and then calculate the cross section area and the circumference of the neck. The changes of upper airway cross-sectional area and neck circumference caused by fluid redistribution were studied by statistical analysis of the data. The experimental results confirm our hypothesis. The data show that fluid migration does not necessarily accompany a significant decrease in airway cross-sectional area when the neck circumference is significantly increased as a result of fluid migration, and vice versa. In addition to the important results, The method proposed in this study to study the effect of fluid migration on the morphology of upper airway by using three-dimensional disturbed phase gradient echo sequence volumetric scanning also provides a new way to study the effect of posture change on sleep respiratory function.
【学位授予单位】：首都医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R766;R445.2

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