SBBMBSpokes: Sequence building block for multiband spokes pTx pulses

Motivation: Spokes pTx pulse improve the homogeneity of 2D imaging at UHF, but there is a practical challenge to load slice-by-slice pulses sufficiently quickly. Multiband bipolar spokes face more challenges with slice modulation and RF-gradient timing delays. Goal(s): Develop a scanner software module to achieve a clinically-acceptable workflow for routine use of spokes pTx pulses. Approach: We develop a Sequence Building Block which uses spoke-individual modulation to allow MB bipolar spokes, and balanced trim blip corrections to tackle timing delays. Results: The SBB enables fast loading of spokes pulses. MB pTx bipolar spokes imaging was achieved with no extra artefacts. Impact: Our scanner software module greatly improves the pTx workflow in 2D imaging. The expanded functionality in multiband, integrated correction for system imperfection, and accelerated sequence preparation allow the use of spokes pTx pulses in routine research or clinical scans.