Discordant definitions of small airway dysfunction between spirometry and parametric response mapping: the HRCT-based...

Area of Science:

• Pulmonary Medicine
• Radiology
• Medical Imaging

Background:

• Small airway dysfunction (SAD) is a key indicator of early lung disease.
• Spirometry and parametric response mapping (PRM) are methods used to define SAD.
• High-resolution computed tomography (HRCT) can visualize lung structural changes associated with SAD.

Purpose of the Study:

• To analyze lung structural differences in SAD defined by spirometry versus PRM using HRCT.
• To identify predictive factors for SAD using clinical data and HRCT.
• To develop and evaluate predictive models for SAD.

Main Methods:

• A prospective study of 388 participants undergoing pulmonary function tests (PFT) and inspiratory-expiratory chest CT scans.
• Comparison of clinical data and HRCT assessments for SAD patients defined by spirometry and PRM.
• Construction of logistic regression-based prediction models for SAD.

Main Results:

• SAD was identified in 122 individuals by spirometry and 158 by PRM.
• HRCT revealed higher incidences of emphysema, tree-in-bud sign, and bronchial wall thickening in SAD patients.
• Spirometry-SAD showed thicker airway walls and fewer bronchi; PRM-SAD indicated slender blood vessels. Predictive models achieved AUCs of 0.855 (spirometry-SAD) and 0.808 (PRM-SAD).

Conclusions:

• Spirometry-defined SAD is closely linked to airway morphology, while PRM is sensitive to early dysfunction but can be influenced by pulmonary vessels.
• HRCT provides valuable insights into lung structural changes in SAD.
• Combined patient information and HRCT features yield robust predictive models for SAD.