Magnetic resonance imaging-based spirometry for regional assessment of pulmonary function

Area of Science:

• Medical Imaging
• Pulmonary Physiology
• Biomedical Engineering

Background:

• Assessing regional pulmonary mechanical function typically requires invasive methods.
• Noninvasive techniques for dynamic lung function monitoring are limited.
• Understanding regional ventilation is crucial for diagnosing and managing lung diseases.

Purpose of the Study:

• To present and validate Magnetic Resonance Imaging (MRI)-based spirometry as a noninvasive method for assessing regional pulmonary mechanical function.
• To develop and apply advanced imaging and motion-tracking techniques for dynamic lung analysis.
• To evaluate the accuracy of MRI-derived regional volume calculations against traditional methods.

Main Methods:

• Modified SPAMM (Spatial Modulation of Magnetization) tagging sequence for continuous dynamic lung imaging during respiration.
• Development of a motion-tracking algorithm to analyze material regions in time-resolved, grid-tagged images.
• Calculation of volumetric strain from displacement maps during quiet breathing to derive regional lung volumes.

Main Results:

• Successful dynamic imaging of lung motion during respiration using modified MRI sequences.
• Accurate tracking of regional lung displacements and calculation of volumetric strain.
• Regional volume calculations derived from MRI spirometry showed good agreement with segmented volume calculations.

Conclusions:

• MRI-based spirometry is a promising noninvasive tool for assessing regional lung ventilation.
• This technique has the potential for clinical application in evaluating pulmonary diseases affecting regional mechanical function.
• Further development could enhance its utility in diagnosing and monitoring lung conditions.