SAR Reduction in Parallel Transmission by Allowing Spatial Phase Variation

Haldun Ozgur Bayindir¹, Yigitcan Eryaman¹, Celal Alp Tunc¹, Ergin Atalar¹

In this work, a new SAR reduction method for parallel transmission is presented. Spatial phase variations in the excitation samples do not cause significant image degradation when phase variations are forced to be in an interval small enough (0-60 degrees interval is chosen in this work). The new method reduces SAR by releasing the phase constraints of the excitation samples. Method is tested for different time reduction factors. Results show that SAR reduction increases as time reduction factor gets higher. Optimal excitation profiles are tested with Bloch simulations and excitation errors caused by spatial phase variations are evaluated.