Figure 5.

Slice selectivity verification and high resolution imaging using multi-spoke pTX RF pulses. (A) experimental (circles) and simulated (curve) slice profiles of a 3-spoke RF pulse designed for another subject. The experimental slice profile corresponds to the projection of a 3D GRE dataset on the slice selective axis (i.e., Z-axis). The numerical prediction was based on 1D Bloch simulations. Note the high consistency between prediction and experiment, especially within the excited slice; (B) higher spatial resolution obtained in a 2D GRE image using the same 3-spoke pulse. Relevant imaging parameters were FOV =38×28.5 cm², resolution =0.8 mm isotropic, TR/TE =14/1.66 ms, averages =10, GRAPPA =2 and partial Fourier =6/8. Total acquisition time was 21 s. Note the higher conspicuity of liver vasculature.