T1 Mapping in the Lungs using a Variable Flip Angle Approach with UTE-MRI

Motivation: We seek a rapid T1 parametric mapping of the lung for quantifying changes in response to ventilation with oxygen during free breathing. Goal(s): Evaluate the Variable Flip Angle (VFA) approach with 3D UTE as a reliable method for T1 mapping in reference standards and human lung. Approach: Reference standards (using Gadolinium) and four healthy participants were imaged using 3D UTE at multiple flip angles. T1 estimates were compared to values from reference standards using inversion recovery protocols. Results: T1 estimates using VFA matched predicted equations in experimental phantoms and expected range in human lung. T1 can be assessed with this free-breathing approach. Impact: The free-breathing VFA-UTE technique provides a simple and time-efficient approach to generate high-resolution 3D parametric mapping of lung parenchyma during free breathing that is sensitive to changes in physiological conditions.