Optimization of the power independent of number of slices presaturated ultrashort echo time (PINS-UTE) pulse sequence

Motivation: Ultrashort echo time (UTE) sequences are essential for short T2 imaging, but have resulted in long scan times. Simultaneous multi-slice techniques can reduce scan times, but until the recent development of the PINS-UTE sequence, they been incompatible with UTE sequences. Goal(s): We aim to optimize the slice profiles of the PINS-UTE sequence. Approach: We investigate the effects of minimum radiofrequency subpulse duration, repetition time (TR), and gradient areas on in-vivo slice profiles. Results: A minimum subpulse duration of 153.6 µs, TR of 250 ms with crusher gradients, and spoiler gradients with areas of 11.7 ms*mT/m on in-plane axes resulted in optimal slice profiles. Impact: Power independent of number of slices (PINS) presaturation enables simultaneous multi-slice ultrashort echo time acquisitions and can reduce scan times for short T2 imaging. In this work, out-of-slice signal artifacts are reduced by optimizing elements of the PINS-UTE sequence.