Systems for lung volume standardization during static and dynamic MDCT-based quantitative assessment of pulmonary...

Area of Science:

• Pulmonary imaging and functional assessment
• Medical device engineering for respiratory diagnostics

Background:

• Multidetector-row computed tomography (MDCT) enables quantitative assessment of lung diseases like COPD and asthma.
• Accurate MDCT metrics for parenchymal destruction, air trapping, and airway remodeling require standardized lung volumes during breathholds.
• Existing methods face challenges, necessitating development of improved breathhold control systems.

Purpose of the Study:

• To develop and evaluate systems for precise control of lung volumes during computed tomography (CT) scans.
• To ensure accurate and reproducible quantitative assessment of lung structure and function in respiratory diseases.
• To compare the efficacy of a turbine-based system and a dual-piston system for breathhold control.

Main Methods:

• Development of a computer-monitored turbine-based flow meter system for static lung volume control.
• Design and implementation of a dual rolling seal piston system for dynamic xenon CT studies.
• Laboratory and human subject trials to test the performance and reliability of both systems.

Main Results:

• The turbine-based system successfully controlled lung volumes in 32/37 subjects, showing linear reproducibility for CT-measured air volume.
• The dual-piston system adequately controlled lung volume in 31/41 subjects.
• Study failures were primarily due to subject noncompliance and gas leaks, highlighting the importance of patient coaching.

Conclusions:

• The turbine-based system is effective for static lung volume control but not for dynamic xenon CT.
• The dual-piston spirometer system effectively controls lung volume for multibreath wash-in xenon CT studies.
• These systems, combined with patient coaching, enhance CT's utility for quantifying regional lung structure and function.