Pulmonary magnetic resonance imaging of obstructive airways disease

During the past several years, pulmonary magnetic resonance imaging (MRI) methods have been developed for the evaluation of obstructive lung disease including conventional proton (¹H) MRI approaches, that are widely available, and more specialized methods involving inhaled oxygen or hyperpolarized noble gas contrast agents, that have somewhat more limited availability with access restricted mainly to specialized MRI research centers. These non-invasive pulmonary imaging approaches are currently under development to provide coincident structural and functional measurements of the lung parenchyma and airways in both asthma and chronic obstructive lung disease (COPD) because of the dire need for new sensitive, precise and regional in vivo measurements of disease progression and response to therapy. Therefore, this review focuses on the stateof-the-art MRI and its application to clinical pulmonary research of COPD and asthma with a focus on the potential of these imaging methods and their challenges in demonstrating new types of information that might influence clinical decision making. Particular attention is given to the relative sensitivity, precision and practicality of the methods and the overall strengths and challenges of MRI applications compared to well-established pulmonary imaging techniques. Finally we summarize emerging imaging physics developments with high potential for clinical translation to asthma and COPD.