Detection of Parameters Related to Lung Functions and Structures as Applied to Emphysema Model Mice with Hyperpolarized Xe MRS Observed under Spontaneous Respiration

Introduction: Recent significant progress in hyperpolarized (HP) noble gas MRI has made it possible to exploit a novel method of evaluating lung function or structure and to have a deep understanding of lung physiological changes. Xe has inherent features of high solubility in lung tissues and large chemical shift distribution. It has been shown that measurement of recovery process of dissolved-phase Xe signal after pre-saturation, which is related to the diffusion of Xe from gas space to tissue, is extremely useful for evaluating various physiological parameters. In the present study, a chemical shift saturation recovery (CSSR) method suggested by Patz et al [1] is applied to spontaneously breathing mice, and an attempt is made to detect physiological changes encountered in emphysema model mice.