Affiliation:
1. Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences‐Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan China
2. University of Chinese Academy of Sciences Beijing China
3. Department of Radiology Changzheng Hospital of the Second Military Medical University Shanghai China
4. Department of Respiratory and Critical Care Medicine Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan China
5. School of Biomedical Engineering Hainan University Haikou China
Abstract
BackgroundLung compliance, a biomarker of pulmonary fibrosis, is generally measured globally. Hyperpolarized 129Xe gas MRI offers the potential to evaluate lung compliance regionally, allowing for visualization of changes in lung compliance associated with fibrosis.PurposeTo assess global and regional lung compliance in a rat model of pulmonary fibrosis using hyperpolarized 129Xe gas MRI.Study TypeProspective.Animal ModelTwenty Sprague–Dawley male rats with bleomycin‐induced fibrosis model (N = 10) and saline‐treated controls (N = 10).Field Strength/Sequence7‐T, fast low‐angle shot (FLASH) sequence.AssessmentLung compliance was determined by fitting lung volumes derived from segmented 129Xe MRI with an iterative selection method, to corresponding airway pressures. Similarly, lung compliance was obtained with computed tomography for cross‐validation. Direction‐dependencies of lung compliance were characterized by regional lung compliance ratios (R) in different directions. Pulmonary function tests (PFTs) and histological analysis were used to validate the pulmonary fibrosis model and assess its correlation with 129Xe lung compliance.Statistical TestsShapiro–Wilk tests, unpaired and paired t‐tests, Mann–Whitney U and Wilcoxon signed‐rank tests, and Pearson correlation coefficients. P < 0.05 was considered statistically significant.ResultsFor the entire lung, the global and regional lung compliance measured with 129Xe gas MRI showed significant differences between the groups, and correlated with the global lung compliance measured using PFTs (global: r = 0.891; regional: r = 0.873). Additionally, for the control group, significant difference was found in mean regional compliance between areas, eg, 0.37 (0.32, 0.39) × 10−4 mL/cm H2O and 0.47 (0.41, 0.56) × 10−4 mL/cm H2O for apical and basal lung, respectively. The apical‐basal direction R was 1.12 ± 0.09 and 1.35 ± 0.13 for fibrosis and control groups, respectively, indicating a significant difference.Data ConclusionOur findings demonstrate the feasibility of using hyperpolarized gas MRI to assess regional lung compliance.Evidence Level2Technical EfficacyStage 1
Funder
Youth Innovation Promotion Association of the Chinese Academy of Sciences
National Key Research and Development Program of China
National Natural Science Foundation of China