Benchmarking acinar airway measurements from inhaled nanoparticles with hyperpolarized 129Xe diffusion-weighted MRI

Airspace Dimension Assessment with inhaled nanoparticles (AiDA) and hyperpolarized ¹²⁹Xe diffusion-weighted (DW)-MRI was performed in twenty-three healthy volunteers to benchmark measurements from AiDA against those from ¹²⁹Xe DW-MRI. Significant correlations were observed between AiDA derived root mean square distal airspace radius, and ¹²⁹Xe apparent diffusion coefficient and diffusion model derived acinar airway dimensions. Furthermore, the AiDA recovery at zero-second breath-hold significantly correlated with ¹²⁹Xe alpha index from the stretched exponential model, a marker of acinar airspace heterogeneity. This benchmarking study demonstrates the potential of AiDA as an alternative method for the clinical evaluation of acinar airway microstructure changes.