Division of Image Processing, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
Respir Med. 2012 May;106(5):677-86. doi: 10.1016/j.rmed.2011.11.013. Epub 2011 Dec 5.
Bronchial dimensions measured in CT images generally do not take inspiration level into consideration. However, some studies showed that the bronchial membrane is distensible with airway inflation. Therefore, re-examination of the elasticity of bronchi is needed.
To assess the influence of respiration on bronchial lumen area (defined as distensibility) in different segmental bronchi and to explore the correlations between distensibility and both lung function and emphysema severity.
In 44 subjects with COPD related to alpha-1-antitrypsin deficiency (AATD), bronchial lumen area was measured in CT images, acquired at different inspiration levels. Measurements were done at matched locations in one apical and two basal segmental airways (RB1, RB10 and LB10). Airway distensibility was calculated as lumen area difference divided by lung volume difference.
Bronchial lumen area in the lower lobes (RB10 and LB10) correlated positively with FEV(1)%predicted (p=0.027 for RB10; and p=0.037 for LB10, respectively). Lumen area is influenced by respiration (p=0.006, p=0.045, and, p=0.005 for RB1, RB10 and LB10, respectively). Airway distensibility was different between upper and lower bronchi (p<0.001), but it was not correlated with lung function.
Lumen area of third generation bronchi is dependent on inspiration level and this distensibility is different between bronchi in the upper and lower lobes. Therefore, changes in lumen area over time should be studied whilst accounting for the lung volume changes, in order to estimate the progression of bronchial disease while excluding the effects of hyperinflation.
在 CT 图像中测量的支气管尺寸通常不考虑吸气水平。然而，一些研究表明，支气管膜在气道充气时具有可扩展性。因此，需要重新检查支气管的弹性。
评估呼吸对不同节段支气管支气管管腔面积（定义为可扩展性）的影响，并探讨可扩展性与肺功能和肺气肿严重程度之间的相关性。
在 44 例因α-1-抗胰蛋白酶缺乏症（AATD）引起的 COPD 患者中，在不同吸气水平的 CT 图像上测量支气管管腔面积。在一个尖段和两个基底段气道（RB1、RB10 和 LB10）的匹配位置进行测量。气道可扩展性通过管腔面积差除以肺容积差计算得出。
下叶（RB10 和 LB10）的支气管管腔面积与 FEV（1）%预测值呈正相关（分别为 RB10 时 p=0.027；LB10 时 p=0.037）。管腔面积受呼吸影响（分别为 RB1、RB10 和 LB10 时 p=0.006、p=0.045 和 p=0.005）。气道可扩展性在上、下支气管之间存在差异（p<0.001），但与肺功能无关。
第三级支气管的管腔面积取决于吸气水平，而上、下支气管的可扩展性不同。因此，为了估计支气管疾病的进展，同时排除过度充气的影响，应该在考虑肺容积变化的情况下研究管腔面积随时间的变化。
