Sino-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, China.
Key Laboratory of Medical Image Computing of Northeastern University (Ministry of Education), Shenyang, China.
Biomed Res Int. 2018 Aug 5;2018:7428609. doi: 10.1155/2018/7428609. eCollection 2018.
Dispositions of inhalable particles in the human respiratory tract trigger and exacerbate airway inflammatory diseases. However, the particle deposition (PD) in airway of subjects with tracheal bronchus (TB) and chronic obstructive pulmonary diseases (COPD) is unknown. We therefore propose to clarify the disrupted PD associated with TB and COPD using the computational fluid dynamics (CFD) simulation. Totally nine airway tree models are included. Six are extracted from CT images of different individuals (two with TB, two with COPD, and two healthy controls (HC)). The others are the artificially modified models (AMMs) generated by the virtual lesion. Specifically, they are constructed through artificially adding a tracheal bronchus or a stenosis on one HC model. The deposition efficiency (DE) and deposition fraction (DF) in these models are obtained by the Euler-Lagrange approach, analyzed, and compared across models, locations, and particle sizes (0.1-10.0 micrometers). It is found that the PD in models with TB and COPD has been disrupted by the geometrical changes and followed airflow alternations. DE of the tracheal bronchus is higher for TB models. For COPD, the stenosis location determines the effects on DE and DF. Higher DF at the trachea is observed in TB1, TB2, and COPD2 models. DE increases with the particle size, and DE of the terminal bronchi is higher than that of central regions. Combined with AMMs, the CFD simulation using realistic airway models demonstrates disruptions of DP. The methods and findings might help understand the etiology of pulmonary diseases and improve the efficacy of inhaled medicines.
可吸入颗粒物在人体呼吸道中的分布会引发和加剧气道炎症性疾病。然而，患有气管支气管（TB）和慢性阻塞性肺疾病（COPD）的患者的气道中的颗粒沉积（PD）情况尚不清楚。因此，我们拟使用计算流体动力学（CFD）模拟来阐明与 TB 和 COPD 相关的 PD 变化。总共纳入了 9 个气道树模型。其中 6 个是从不同个体的 CT 图像中提取的（2 个患有 TB，2 个患有 COPD，2 个健康对照（HC））。其余的是通过虚拟病变生成的人工修改模型（AMM）。具体来说，它们是通过在一个 HC 模型上人工添加一个气管支气管或狭窄来构建的。通过欧拉-拉格朗日方法获得这些模型中的沉积效率（DE）和沉积分数（DF），并在模型之间、位置之间和颗粒大小（0.1-10.0 微米）之间进行分析和比较。结果发现，TB 和 COPD 患者的 PD 受到几何形状变化和气流变化的影响而发生改变。TB 模型中气管支气管的 DE 更高。对于 COPD，狭窄位置决定了对 DE 和 DF 的影响。在 TB1、TB2 和 COPD2 模型中，气管处的 DF 更高。DE 随颗粒尺寸的增加而增加，且终末细支气管的 DE 高于中央区域。结合 AMM，使用真实气道模型进行的 CFD 模拟表明 DP 存在破坏。这些方法和发现可能有助于了解肺部疾病的病因，并提高吸入药物的疗效。
