Purpose: To evaluate the reproducibility and regional variation of parameters obtained from localized 129 Xe chemical shift saturation recovery (CSSR) MR spectroscopy in healthy volunteers and patients with chronic obstructive pulmonary disease (COPD) and to compare the results to 129 Xe dissolved-phase MR imaging.
Methods: Thirteen healthy volunteers and 10 COPD patients were scanned twice using 129 Xe dissolved-phase imaging, CSSR, and ventilation imaging sequences. A 16-channel phased-array coil in combination with the regularized spectral localization achieved by sensitivity heterogeneity (SPLASH) method was used to perform a regional analysis of CSSR data. Lung function and microstructural parameters were obtained using Patz model functions and their reproducibility was assessed.
Results: The Patz model alveolar wall thickness parameter shows good reproducibility on a regional basis with a median coefficient of variation of 6.5% in healthy volunteers and 12.4% in COPD patients. Significant regional differences of lung function parameters derived from localized CSSR were found in healthy volunteers and correlations with spirometric indices were found.
Conclusion: Localized 129 Xe CSSR provides reproducible estimates of alveolar wall thickness and is able to detect regional differences of lung microstructure.
Keywords: CSSR; SPLASH; hyperpolarized 129Xe; lung function; lung microstructure; reproducibility.
© 2018 International Society for Magnetic Resonance in Medicine.