Variable Flip Angle Steady State Free Precession Imaging for Reduction of SAR

Suguru Yokosawa¹, Yo Taniguchi¹, Yoshitaka Bito¹

We have proposed two VFA schemes to reduce the SAR while maintaining both the SNR and image contrast for both gated and non-gated SSFP imaging. The main idea of the technique is to use a high flip angle for echoes around the center of a k-space and at times prior to when the echo for the center was obtained. We examined the SNR and contrast of the healthy volunteer images by comparing a VFA scheme to a constant flip angle scheme. The results show that the proposed schemes reduced the SAR by 30% while maintaining the SNR and image contrast.