Keywords: RF Pulse Design & Fields, RF Pulse Design & Fields
Motivation: Parallel transmit allows efficient radiofrequency pulse designs that produce uniform excitations. However, for 2D acquisitions with thin slices, long sub-pulse durations are needed to satisfy gradient system limitations which increases sensitivity to off-resonance.
Goal(s): To improve flip-angle uniformity in thin slices using asymmetric pTx spoke pulses.
Approach: Symmetric and asymmetric pTx spoke pulses were designed with B0 correction. Bloch simulations were performed to evaluate excitation fidelity targeting 0.5-mm and 0.35-mm slice thickness.
Results: Tailored asymmetric pTx spokes can achieve uniform slice excitation particularly in regions where off-resonance effects are prominent when targeting thin imaging slices down to 0.35-mm thick.
Impact: Parallel transmit is well known for efficient radiofrequency pulse designs that produce uniform excitations. We show that asymmetric spokes can mitigate off-resonance effects and generate uniform excitation for 0.5-mm and 0.35-mm thick slices.
How to access this content:
For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.
After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.
After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.
Keywords