Asynchronous changes of normal lung lobes during respiration based on quantitative computed tomography (CT).

Area of Science:

• Pulmonary imaging and anatomy
• Respiratory physiology

Background:

• Understanding lung lobe mechanics during respiration is crucial for pulmonary anatomy insights.
• Quantitative computed tomography (CT) offers a method to analyze these in vivo actions.

Purpose of the Study:

• To explore the coordinated and independent actions of lung lobes during respiration.
• To enhance in vivo understanding of pulmonary anatomy using quantitative CT.

Main Methods:

• Retrospective analysis of 70 cases with normal pulmonary function tests (PFTs) and CT scans.
• Quantitative CT measurements of lung volume (LV) and mean lung density (MLD) for total lung, left lung, right lung, and 5 lobes during inspiration and expiration.
• Evaluation of differences in measures between bilateral lungs and among lobes.

Main Results:

• The left lung (LL) exhibited smaller inspiratory and expiratory volumes than the right lung (RL) (P<0.001).
• Bilateral lower lobes demonstrated consistency in lung volume and mean lung density, indicating high ventilation function.
• The right middle lobe (RML) showed the largest differences compared to other lobes and the least change in lung volume and mean lung density during respiration.

Conclusions:

• Lung lobes function non-synchronously during respiration, with varying contributions to ventilation.
• The left lung assumes a higher workload during ventilation.
• Bilateral lower lobes share similarities and possess high ventilation capacity, while the RML exhibits minimal dynamic changes.