Chronic Obstructive Pulmonary Disease: Lobar Analysis with Hyperpolarized ¹²⁹Xe MR Imaging

Area of Science:

• Pulmonary Medicine
• Radiology
• Medical Imaging

Background:

• Chronic Obstructive Pulmonary Disease (COPD) significantly impacts lung function.
• Accurate assessment of regional lung ventilation and tissue characteristics is crucial for COPD management.
• Quantitative imaging techniques are increasingly important for evaluating lung disease.

Purpose of the Study:

• To compare lobar ventilation and apparent diffusion coefficient (ADC) from hyperpolarized 129-xenon (¹²⁹Xe) MR imaging with quantitative CT metrics.
• To assess the correlation between ¹²⁹Xe MR imaging parameters and pulmonary function test (PFT) results in COPD patients.
• To evaluate the utility of ¹²⁹Xe MR imaging for characterizing regional lung changes in COPD.

Main Methods:

• Twenty-two COPD patients (GOLD stage II-IV) underwent ¹²⁹Xe MR imaging, quantitative CT, and PFTs.
• Automated segmentation was used to derive lobar ventilation and ADC values from ¹²⁹Xe MR images.
• Quantitative CT assessed emphysema and bronchial wall thickness; Pearson correlation coefficients analyzed relationships between imaging and PFTs.

Main Results:

• Lobar ¹²⁹Xe MR imaging showed correlations between ventilated volume/ADC and CT-derived emphysema (r = -0.32, P < .001 and r = 0.75, P < .0001).
• Whole-lung ADC correlated with PFTs, including transfer factor for carbon monoxide (Tlco) (r = -0.61, P < .005) and functional residual capacity (r = 0.47, P < .05).
• Whole-lung CT emphysema also correlated significantly with predicted Tlco (r = -0.65, P < .005).

Conclusions:

• Lobar ventilation and ADC values from ¹²⁹Xe MR imaging correlate with quantitative CT emphysema.
• ¹²⁹Xe MR imaging parameters show significant correlations with whole-lung PFT results.
• Hyperpolarized ¹²⁹Xe MR imaging is a valuable tool for assessing regional lung changes in COPD.