# Small flip-angle spokes with SAR constraints

### Citation

Guérin B, Gebhardt M, Cauley S, Adalsteinsson E, Wald LL (2014). "Local specific absorption rate (SAR), global SAR, transmitter power, and excitation accuracy trade‐offs in low flip‐angle parallel transmit pulse design." Magnetic Resonance in Medicine 71(4): 1446-1457.

### What this code does

This Matlab code (no MEX, no GPU code) computed least-squares and magnitude least-squares pTx spoke pulses. The MLS problem can be solved using the phase adoption approach of Setsompop et al. or a full optimization strategy (see the file spokes_3/run_spokes.m and options therein). Spokes can be optimized for several frequencies (spatio-spectral design) in order to build in robustness to off-resonance effects.

### Download files

The code can be downloaded here. A test dataset can be downloaded here.