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Three-Dimensional Phase Resolved Functional Lung Magnetic Resonance Imaging
Published on: June 21, 2024
Imaging alveolar-duct geometry during expiration via ³He lung morphometry
A J Hajari1, D A Yablonskiy, J D Quirk
1Department of Physics, Washington University, St. Louis, MO 63110, USA.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|February 26, 2011
Summary
Lung acinar duct radius shrinks by 19% and alveolar depth increases by 9% as lung volume decreases. This study used helium-3 lung morphometry to reveal changes in lung microstructure during deflation.
Area of Science:
- Pulmonary Physiology
- Medical Imaging
- Morphometry
Background:
- Acinar geometry changes during lung inflation/deflation remain poorly understood.
- Non-destructive lung microstructure evaluation is crucial for understanding lung physiology and disease.
- Hyperpolarized helium-3 (3He) diffusion MRI offers a novel approach to lung morphometry.
Purpose of the Study:
- To quantify changes in acinar duct and alveolar dimensions during lung volume changes.
- To assess the utility of 3He lung morphometry for evaluating lung microstructure.
- To provide a foundation for in vivo human studies of lung physiology.
Main Methods:
- Utilized 3He lung morphometry on six excised canine lungs at various physiological volumes.
- Measured acinar duct radius and alveolar depth.
- Validated imaging findings with serial microscopic section analysis.
Main Results:
- A 37% decrease in lung volume led to a 19% reduction in acinar duct radius (P < 0.0001).
- During the same volume decrease, alveolar depth increased by 9% (P < 0.05).
- Microscopic validation confirmed the accuracy of the MRI-based morphometry.
Conclusions:
- 3He lung morphometry accurately quantifies dynamic changes in lung acinar geometry.
- Significant alterations in acinar duct and alveolar dimensions occur with lung deflation.
- This technique holds promise for in vivo human studies of respiratory physiology and disease.
