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.
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http://dx.doi.org/10.1002/mrm.25675 | DOI Listing |
J Vis Exp
October 2024
Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center; Department of Biomedical Engineering, University of Cincinnati; Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati; Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center;
Acad Radiol
December 2024
Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio 45221, Cincinnati, Ohio 45229, USA; Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio 45221, USA; Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA. Electronic address:
Magn Reson Med
October 2024
POLARIS, Division of Clinical Medicine, School of Medicine & Population Health, University of Sheffield, Sheffield, UK.
Purpose: To characterize the dependence of Xe-MRI gas transfer metrics upon age, sex, and lung volume in a group of healthy volunteers.
Methods: Sixty-five subjects with no history of chronic lung disease were assessed with Xe-MRI using a four-echo 3D radial spectroscopic imaging sequence and a dose of xenon titrated according to subject height that was inhaled from a lung volume of functional residual capacity (FRC). Imaging was repeated in 34 subjects at total lung capacity (TLC).
Int J Radiat Oncol Biol Phys
September 2024
Medical Physics Graduate Program; Department of Biomedical Engineering, Duke University, Durham, North Carolina; Radiology, Duke University Medical Center, Durham, North Carolina.
Purpose: Radiation-induced lung injury has been shown to alter regional ventilation and perfusion in the lung. However, changes in regional pulmonary gas exchange have not previously been measured.
Methods And Materials: Ten patients receiving conventional radiation therapy (RT) for lung cancer underwent pre-RT and 3-month post-RT magnetic resonance imaging (MRI) using an established hyperpolarized Xe gas exchange technique to map lung function.
Magn Reson Med
October 2023
Radiology, Duke University Medical Center, Durham, North Carolina, USA.
Purpose: Xe MRI and MRS signals from airspaces, membrane tissues (M), and red blood cells (RBCs) provide measurements of pulmonary gas exchange. However, Xe MRI/MRS studies have yet to account for hemoglobin concentration (Hb), which is expected to affect the uptake of Xe in the membrane and RBC compartments. We propose a framework to adjust the membrane and RBC signals for Hb and use this to assess sex-specific differences in RBC/M and establish a Hb-adjusted healthy reference range for the RBC/M ratio.
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