Oxygen‐enhanced 3D radial ultrashort echo time magnetic resonance imaging in the healthy human lung

<jats:p>The purpose of this work was to use 3D radial ultrashort echo time (UTE) MRI to perform whole‐lung oxygen‐enhanced (OE) imaging in humans.</jats:p><jats:p>Eight healthy human subjects underwent two 3D radial UTE MRI acquisitions (<jats:italic>T</jats:italic>E = 0.08 ms): one while breathing 21% O<jats:sub>2</jats:sub> and the other while breathing 100% O<jats:sub>2</jats:sub>. Scans were each performed over 5 min of free breathing, using prospective respiratory gating. For comparison purposes, conventional echo time (<jats:italic>T</jats:italic>E = 2.1 ms) images were acquired simultaneously during each acquisition using a radial " outward‐inward" <jats:italic>k</jats:italic>‐space trajectory. 3D percent OE maps were generated from these images.</jats:p><jats:p>3D OE maps showing lung signal enhancement were generated successfully in seven subjects (technical failure in one subject). Mean percent signal enhancement was 6.6% ± 1.8%, near the value predicted by theory of 6.3%. No significant enhancement was seen using the conventional echo time data, confirming the importance of UTE for this acquisition strategy.</jats:p><jats:p>3D radial UTE MRI shows promise as a method for OE MRI that enables whole‐lung coverage and isotropic spatial resolution, in comparison to existing 2D OE methods, which rely on a less time‐efficient inversion recovery pulse sequence. These qualities may help OE MRI become a viable low‐cost method for 3D imaging of lung function in human subjects. Copyright © 2014 John Wiley & Sons, Ltd.</jats:p>