Proton and hyperpolarized xenon pulmonary MRI at 0.55T

Project Summary/Abstract This project will develop pulmonary magnetic resonance imaging (MRI) methods on a novel 0.55 Tesla scanner using both conventional (proton) and hyperpolarized-xenon imaging. Rationale: Chronic lung diseases are the sixth leading cause of death in the USA, and there is an unmet clinical need for a single assessment that provides regional lung anatomy, tissue characterization, and function, preferably without ionizing radiation for safer application in children and pregnant women. Low-field MRI has the potential to meet this need. Innovation: NIH has developed a 0.55 Tesla MRI instrument that we propose will enable the conceptual leap from the current clinical standard – independent assessments of lung structure and global function – to concurrent visualization of regional lung structure and function, promoting new insights into pulmonary diseases. This will be achieved through the novel combination of improving spatial resolution and contrast of pulmonary imaging using a contemporary low-field MRI, and developing new hyperpolarized xenon MRI capabilities for this field strength. Approach: The overall goal of this project is to develop and evaluate new proton and hyperpolarized xenon MRI methods. Specifically, we will: 1 – Improve the achievable spatial resolution and image contrast of structural lung proton MRI by combining highly-efficient spiral sampling and neural networks for denoising; 2 – Develop methodology for hyperpolarized xenon imaging for the first time at this MRI field strength, including the characterization of physical properties; and 3 – Deploy our methods for a multi-site validation study in healthy subjects and subjects with lung disease, and for novel characterization of patients with lymphangioleiomyomatosis, a unique patient cohort at the NIH Clinical Center. Broader Impact: The proposed technology will include the first demonstration of hyperpolarized xenon imaging on a commercially-available lower-cost 0.55 Tesla MRI system. The technology may have widespread impact by improving the accessibility of advanced pulmonary imaging capabilities. The outcome will include fundamental advances in lung MRI by establishing 0.55T MRI as a single modality to regionally assess lung structure, function, and tissue properties, yielding a unique, clinically valuable approach to detect and manage lung diseases.