Spin Lock Adiabatic Correction (SLAC) for B-insensitive pulse design at 7T.
Green, Edward M;Blunck, Yasmin;Tahayori, Bahman;Farrell, Peter M;Korte, James C;Johnston, Leigh A;
journal of magnetic resonance (san diego, calif : 1997)2019Vol. 308pp. 106595
164
green2019spinjournal
Abstract
A new framework for B insensitive adiabatic pulse design is proposed, denoted Spin Lock Adiabatic Correction (SLAC), which counteracts deviations from ideal behaviour through inclusion of an additional correction component during pulse design. SLAC pulses are theoretically derived, then applied to the design of enhanced BIR-4 and hyperbolic secant pulses to demonstrate practical utility of the new pulses. At 7T, SLAC pulses are shown to improve the flip angle homogeneity compared to a standard adiabatic pulse with validation in both simulations and phantom experiments, under SAR equivalent experimental conditions. The SLAC framework can be applied to any arbitrary adiabatic pulse to deliver excitation with increased B insensitivity.