Imaging Dynamic Expiration: Feasibility of MRI Spirometry Using Hyperpolarized Xenon Gas

Area of Science:

• Medical Imaging
• Pulmonary Medicine
• Functional Imaging

Background:

• Conventional spirometry provides global lung function measurements.
• Imaging-based spirometry offers potential for regional lung function assessment.
• Hyperpolarized 129Xe MRI enables visualization of gas distribution in the lungs.

Purpose of the Study:

• To assess the feasibility of imaging-based spirometry using high-temporal-resolution projection MRI and hyperpolarized 129Xe gas.
• To explore the derivation of regional lung spirometric maps.

Main Methods:

• Five healthy participants underwent a forced expiratory maneuver during inhaled hyperpolarized 129Xe MRI.
• Rapid 2D projection MRI captured lung images at intervals as short as 250 msec.
• Pulmonary function parameters (FEV1, FVC, FEV1/FVC) were calculated from volume-corrected images.

Main Results:

• A forced expiratory maneuver was successfully imaged using hyperpolarized 129Xe and high-temporal-resolution MRI.
• MRI-derived FEV1/FVC ratios were lower than conventional spirometry, potentially due to 129Xe retention.
• Inhaled 129Xe slightly reduced measured FEV1 and FEV1/FVC in conventional supine spirometry.

Conclusions:

• High-temporal-resolution MRI with hyperpolarized 129Xe is feasible for imaging lung spirometry.
• Derivation of regional lung spirometric maps is achievable with this technique.
• This method holds promise for detailed assessment of regional pulmonary function.