Suryanarayana Umesh Rudrapatna1, Robin de Graaf1, Terrance Nixon1, and Christoph Juchem1
Spatially selective multi-dimensional excitation with large flip angles is challenging, as current RF pulse design methods are computationally involved and typically yield low time-bandwidth product (TB < 10) pulses. The difficulty stems from Bloch equation non-linearity and the inflexibility in B0 pattern generation using linear gradients. This study uses the dynamic multi-coil technique (DYNAMITE), that provides unprecedented B0 shaping flexibility, facilitating the use of 1-dimensional Shinnar-Le Roux (SLR) pulses for 2-dimensional excitation. Selective mouse brain excitation was accomplished by adaptively designing the SLR pulse and the underlying B0 fields generated by DYNAMITE. The resultant zoomed MRI achieved more than two-fold acquisition acceleration at < 4% undesired excitation with TB > 12 pulses.
