Regional quantification of 129Xe Gaussian broadening in the lungs with time-domain Voigt fitting of 3D CSI

Motivation: Frequency-domain dissolved 129Xe CSI suffers from low spectral resolution, which can result in inaccuracies in the fitted spectral parameters. Time-domain Voigt fitting of CSI can improve accuracy and enable regional quantification of Gaussian broadening of 129Xe lung spectra. Goal(s): To quantify regional Gaussian broadening of 129Xe resonances in the lung airspaces and adjacent lung parenchyma. Approach: Time-domain Voigt fitting was performed on 129Xe 3D CSI data from the lungs of healthy volunteers. Results: Gaussian broadening contributed to 75-80% and 45% of the total linewidth for the gas and membrane 129Xe resonances, respectively, over all healthy volunteers. Corresponding Voigt T2 values were also quantified. Impact: We have demonstrated regional quantification of 129Xe Gaussian broadening in the lungs. Knowledge of this should enhance accuracy of spectral parameters computed for lung disease metrics while offering potential utility as a metric itself.