Single-breath clinical imaging of hyperpolarized (129)Xe in the airspaces, barrier, and red blood cells using an interleaved 3D radial 1-point Dixon acquisition.

PURPOSE: We sought to develop and test a clinically feasible 1-point Dixon, three-dimensional (3D) radial acquisition strategy to create isotropic 3D MR images of (129)Xe in the airspaces, barrier, and red blood cells (RBCs) in a single breath. The approach was evaluated in healthy volunteers and subjects with idiopathic pulmonary fibrosis (IPF). METHODS: A calibration scan determined the echo time at which (129)Xe in RBCs and barrier were 90° out of phase. At this TE, interleaved dissolved and gas-phase images were acquired using a 3D radial acquisition and were reconstructed separately using the NUFFT algorithm. The dissolved-phase image was phase-shifted to cast RBC and barrier signal into the real and imaginary channels such that the image-derived RBC:barrier ratio matched that from spectroscopy. The RBC and barrier images were further corrected for regional field inhomogeneity using a phase map created from the gas-phase (129)Xe image. RESULTS: Healthy volunteers exhibited largely uniform (129)Xe-barrier and (129)Xe-RBC images. By contrast, (129)Xe-RBC images in IPF subjects exhibited significant signal voids. These voids correlated qualitatively with regions of fibrosis visible on CT. CONCLUSIONS: This study illustrates the feasibility of acquiring single-breath, 3D isotropic images of (129)Xe in the airspaces, barrier, and RBCs using a 1-point Dixon 3D radial acquisition.

Duke Scholars

Author Scott Robertson Radiology

Author Craig Rackley Medicine, Pulmonary, Allergy, and Critical Care Medicine

Author Holman Page McAdams Radiology, Cardiothoracic Imaging

Author Bastiaan Driehuys Radiology