Respiratory Medicine Department, School of Medicine, University of Nottingham, Queen's Medical Centre Campus, Nottingham, UK; NIHR Nottingham Biomedical Research Centre, Queen's Medical Centre, Nottingham NG7 2UH, UK.
NIHR Nottingham Biomedical Research Centre, Queen's Medical Centre, Nottingham NG7 2UH, UK; Sir Peter Mansfield Imaging Centre, University of Nottingham, University Park, Nottingham, UK.
Eur J Radiol. 2020 Sep;130:109196. doi: 10.1016/j.ejrad.2020.109196. Epub 2020 Jul 25.
The diaphragm is the most important muscle of respiration. Disorders of the diaphragm can have a deleterious impact on respiratory function. We aimed to evaluate the use of an open-configuration upright low-field MRI system to assess diaphragm morphology and function in patients with bilateral diaphragm weakness (BDW) and chronic obstructive pulmonary disease (COPD) with hyperinflation.
The study was approved by the National Research Ethics Committee, and written consent was obtained. We recruited 20 healthy adult volunteers, six subjects with BDW, and five subjects with COPD with hyperinflation. We measured their vital capacity in the upright and supine position, after which they were scanned on the 0.5 T MRI system during 10-s breath-holds at end-expiration and end-inspiration in both positions. We developed and applied image analysis methods to measure the volume under the dome, maximum excursion of hemidiaphragms, and anterior-posterior and left-right extension of the diaphragm.
All participants were able to complete the scanning protocol. The patients found scanning in the upright position more comfortable than the supine position. All differences in the supine inspiratory-expiratory parameters, excluding left-right extension, were significantly smaller in the BDW and COPD groups compared with healthy volunteers. No significant correlation was found between the postural change in diaphragm morphology and vital capacity in either group.
Our combined upright-supine MR imaging approach facilitates the assessment of the impact of posture on diaphragm morphology and function in patients with BDW and those with COPD with hyperinflation.
横膈膜是呼吸最重要的肌肉。横膈膜功能障碍会对呼吸功能产生有害影响。我们旨在评估使用开放式直立低场 MRI 系统评估双侧横膈膜无力（BDW）和伴有过度充气的慢性阻塞性肺疾病（COPD）患者的横膈膜形态和功能。
该研究获得了国家伦理委员会的批准，并获得了书面同意。我们招募了 20 名健康成年志愿者、6 名 BDW 受试者和 5 名 COPD 伴有过度充气的受试者。在直立和仰卧位测量他们的肺活量，然后在这两个位置上，在 0.5T MRI 系统上进行 10 秒的呼气末和吸气末屏气扫描。我们开发并应用了图像分析方法来测量穹顶下的体积、半横膈膜的最大运动幅度以及横膈膜的前后和左右延伸。
所有参与者都能够完成扫描方案。与仰卧位相比，患者发现直立位扫描更舒适。与健康志愿者相比，BDW 和 COPD 组仰卧位吸气-呼气参数的所有差异（除左右延伸外）均显著较小。在两组中，都没有发现膈形态的体位变化与肺活量之间存在显著相关性。
我们联合的直立-仰卧位 MRI 成像方法有助于评估体位对 BDW 患者和伴有过度充气的 COPD 患者横膈膜形态和功能的影响。
