Regional Reproducibility of Dissolved-Phase Hyperpolarised 129Xe MR Gas Imaging

Motivation: Hyperpolarized xenon-129 (129Xe) MRI enables regional assessment of pulmonary gas transfer, but its repeatability in different lung regions remains uncharacterized in patients. Goal(s): To quantify the regional repeatability of dissolved-phase 129Xe MRI measurements across different lung regions. Approach: We analysed paired same-session 129Xe MRI scans from 14 subjects using both traditional intraclass-correlation coefficient (ICC) analysis and the imaging intraclass correlation coefficient (I2C2) in six lung regions, with and without image registration. Results: We found excellent regional repeatability (median ICC 0.87) across all lung regions, with I2C2 values between 0.4-0.9, demonstrating that regional 129Xe MRI measurements are highly reproducible regardless of anatomical location. Impact: Regional 129Xe MRI measurements show excellent repeatability across all lung regions, validating its use for detecting localized pathology. This first comprehensive regional repeatability study establishes quantitative bounds for clinical interpretation of regional lung function measurements.