Preclinical MRI Using Hyperpolarized 129Xe

Abstract

Although critical for development of novel therapies, understanding altered lung function in disease models is challenging because the transport and diffusion of gases over short distances, on which proper function relies, is not readily visualized. In this review we summarize progress introducing hyperpolarized 129Xe imaging as a method to follow these processes in vivo. The work is organized in sections highlighting methods to observe the gas replacement effects of breathing (Gas Dynamics during the Breathing Cycle) and gas diffusion throughout the parenchymal airspaces (3). We then describe the spectral signatures indicative of gas dissolution and uptake (4), and how these features can be used to follow the gas as it enters the tissue and capillary bed, is taken up by hemoglobin in the red blood cells (5), re-enters the gas phase prior to exhalation (6), or is carried via the vasculature to other organs and body structures (7). We conclude with a discussion of practical imaging and spectroscopy techniques that deliver quantifiable metrics despite the small size, rapid motion and decay of signal and coherence characteristic of the magnetically inhomogeneous lung in preclinical models (8).

Functional imaging for assessing regional lung ventilation in preclinical and clinical research

“…Many pre-clinical studies have used hyperpolarized gas MRI to help elucidate the dynamic process by which gas diffusion and transport occurs and further understand the pathophysiology of pulmonary diseases ( 42 ). Mouse models studies have included hyperpolarized gas MRI to map the lungs anatomy and optimize quantitative measures of ventilation and diffusion ( 43 ).…”