Using a Shinnar LeRoux Pulse for 3D Multi Ultra-short TE Look-locker Inversion Recovery for T1-Mapping in the human lungs

Motivation: Lung T1(TE) quantification using 2D UTE was demonstrated as an interesting tool but needs expansion to 3D UTE for better comparability and coverage. However, streaking artefacts originating from the edges of the Field of View are particularly problematic in Lung T1(TE) maps. Goal(s): To reduce streakings in T1(TE) maps caused by B0 inhomogeneities. Approach: A Shinnar LeRoux (SLR) minimum phase pulse was used to limit excitation to a 320mm slab in the Multi Ultra-short TE Look-Locker Inversion Recovery sequence. Results: T1(TE) maps produced using sagittal SLR excitation showed less streakings than using transverse SLR excitation and rectangular pulses, but still had residual streaking. Impact: Inhomogeneity streakings in 3D UTE lung T1(TE) maps were greatly reduced by employing a SLR pulse. With additional efforts during reconstruction, it may be possible to remove the remaining artefacts and quickly acquire parameter maps of the entire lungs.