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

• Published in: Magnetic resonance in medicine Vol. 75; no. 4; pp. 1434 - 1443
• Main Authors: Kaushik, S Sivaram, Robertson, Scott H, Freeman, Matthew S, He, Mu, Kelly, Kevin T, Roos, Justus E, Rackley, Craig R, Foster, W Michael, McAdams, H Page, Driehuys, Bastiaan
• Format: Journal Article
• Language: English
• Published: United States 01.04.2016
• Subjects: Adult; Aged; Algorithms; Erythrocytes - cytology; Erythrocytes - physiology; Female; Humans; Imaging, Three-Dimensional - methods; Lung - blood supply; Lung - diagnostic imaging; Lung - physiology; Magnetic Resonance Imaging - methods; Male; Middle Aged; Xenon Isotopes - therapeutic use; Young Adult; Hyperpolarized xenon; 3D Radial; 1-point Dixon
• ISSN: 1522-2594
• DOI: 10.1002/mrm.25675

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). 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. 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. 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.