Uncovering a third dissolved-phase Xe resonance in the human lung: Quantifying spectroscopic features in healthy subjects and patients with idiopathic pulmonary fibrosis.

Purpose: The purpose of this work was to accurately characterize the spectral properties of hyperpolarized Xe in patients with idiopathic pulmonary fibrosis (IPF) compared to healthy volunteers.

Methods: Subjects underwent hyperpolarized Xe breath-hold spectroscopy, during which 38 dissolved-phase free induction decays (FIDs) were acquired after reaching steady state (echo time/repetition time = 0.875/50 ms; bandwidth = 8.