biostudies-literatureKammerman JNational Center for Advancing Translational SciencesNCATS NIH HHSNational Heart, Lung, and Blood InstituteNHLBI NIH HHSGE HealthcareNIH HHS1857-1867https://www.ebi.ac.uk/biostudies/studies/S-EPMC7329592biostudies-literatureUnknown84(4)<h4>Purpose</h4>The MR properties (chemical shifts and R2∗ decay rates) of dissolved-phase hyperpolarized (HP) ¹²⁹ Xe are confounded by the large magnetic field inhomogeneity present in the lung. This work improves measurements of these properties using a model-based image reconstruction to characterize the R2∗ decay rates of dissolved-phase HP ¹²⁹ Xe in healthy subjects and patients with idiopathic pulmonary fibrosis (IPF).<h4>Methods</h4>Whole-lung MRS and 3D radial MRI with four gradient echoes were performed after inhalation of HP ¹²⁹ Xe in healthy subjects and patients with IPF. A model-based image reconstruction formulated as a regularized optimization problem was solved iteratively to measure regional signal intensity in the gas, barrier, and red blood cell (RBC) compartments, while simultaneously measuring their chemical shifts and R2∗ decay rates.<h4>Results</h4>The estimation of spectral properties reduced artifacts in images of HP ¹²⁹ Xe in the gas, barrier, and RBC compartments and improved image SNR by over 20%. R2∗ decay rates of the RBC and barrier compartments were lower in patients with IPF compared to healthy subjects (P < 0.001 and P = 0.005, respectively) and correlated to DL_CO (R = 0.71 and 0.64, respectively). Chemical shift of the RBC component measured with whole-lung spectroscopy was significantly different between IPF and normal subjects (P = 0.022).<h4>Conclusion</h4>Estimates for R2∗ in both barrier and RBC dissolved-phase HP ¹²⁹ Xe compartments using a regional signal model improved image quality for dissolved-phase images and provided additional biomarkers of lung injury in IPF.Magnetic resonance in medicineTransverse relaxation rates of pulmonary dissolved-phase Hyperpolarized ¹²⁹ Xe as a biomarker of lung injury in idiopathic pulmonary fibrosis.PMC7329592RO1 HL126771UL1 TR002373S10 OD016394R01 HL126771UL1TR000427UL1 TR000427Kammerman JCadman RVHahn ADFain SBMalkus AMummy DfalseTransverse relaxation rates of pulmonary dissolved-phase Hyperpolarized ¹²⁹ Xe as a biomarker of lung injury in idiopathic pulmonary fibrosis.<h4>Purpose</h4>The MR properties (chemical shifts and R2∗ decay rates) of dissolved-phase hyperpolarized (HP) ¹²⁹ Xe are confounded by the large magnetic field inhomogeneity present in the lung. This work improves measurements of these properties using a model-based image reconstruction to characterize the R2∗ decay rates of dissolved-phase HP ¹²⁹ Xe in healthy subjects and patients with idiopathic pulmonary fibrosis (IPF).<h4>Methods</h4>Whole-lung MRS and 3D radial MRI with four gradient echoes were performed after inhalation of HP ¹²⁹ Xe in healthy subjects and patients with IPF. A model-based image reconstruction formulated as a regularized optimization problem was solved iteratively to measure regional signal intensity in the gas, barrier, and red blood cell (RBC) compartments, while simultaneously measuring their chemical shifts and R2∗ decay rates.<h4>Results</h4>The estimation of spectral properties reduced artifacts in images of HP ¹²⁹ Xe in the gas, barrier, and RBC compartments and improved image SNR by over 20%. R2∗ decay rates of the RBC and barrier compartments were lower in patients with IPF compared to healthy subjects (P < 0.001 and P = 0.005, respectively) and correlated to DL_CO (R = 0.71 and 0.64, respectively). Chemical shift of the RBC component measured with whole-lung spectroscopy was significantly different between IPF and normal subjects (P = 0.022).<h4>Conclusion</h4>Estimates for R2∗ in both barrier and RBC dissolved-phase HP ¹²⁹ Xe compartments using a regional signal model improved image quality for dissolved-phase images and provided additional biomarkers of lung injury in IPF.2020-01-01T00:00:00Z2020 Oct2024-02-15T15:43:13.65Z2022-02-11T11:30:39.896ZS-EPMC73295923216235710.1002/mrm.28246