Comparison of in vivo lung morphometry models from 3D multiple b‐value 3He and 129Xe diffusion‐weighted MRI. Issue 5 (4th December 2018)

• Record Type: Journal Article
• Authors: Chan, Ho‐Fung; Collier, Guilhem J.; Weatherley, Nicholas D.; Wild, Jim M.
• Is Part Of: Magnetic resonance in medicine. Volume 81:Issue 5(2019)
• Page Start: 2959
• Page End: 2971
• Publication Date: 2018-12-04
• Subjects: cylinder model -- hyperpolarized129Xe -- hyperpolarized3He -- lung morphometry -- stretched exponential model; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.27608
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To compare in vivo lung morphometry parameters derived from theoretical gas diffusion models, the cylinder model and stretched exponential model, in a range of acinar microstructural length scales encountered in healthy and diseased lungs with 3 He and 129 Xe diffusion‐weighted MRI. Methods: Three‐dimensional multiple b‐value 3 He and 129 Xe diffusion‐weighted MRI was acquired with compressed sensing at 1.5 T from 51 and 31 subjects, respectively, including healthy volunteers, ex‐smokers, idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease patients. For each subject, the stretched exponential model–derived mean diffusive length scale ( LmD ) was calculated from the diffusion signal decay, and was compared with the cylinder model–derived mean chord length ( Lm ) and mean alveolar diameter ( LAlv ) in order to determine the relationships among the different lung morphometry parameters. Results: For both 3 He and 129 Xe diffusion‐weighted MRI, the mean global LmD value was significantly related ( P < .001) to Lm in a nonlinear power relationship, whereas the LAlv demonstrated excellent linear correlation ( P < .001) with LmD . A mean bias of +1.0% and - 2.6% toward LmD was obtained for Bland‐Altman analyses of 3 He and 129 Xe LmD and LAlv values, suggesting that the two morphometric parameters are equivalent measures of mean acinar dimensions. Conclusion: Within the experimental range of parameters considered here for both 3 He and 129 Xe, the stretched exponential model–derived LmD is related nonlinearly to cylinder model–derived Lm, and demonstrates excellent agreement with the cylinder model–derived LAlv .