T₂-weighted balanced SSFP imaging (T₂-TIDE) using variable flip angles^†

A new technique for acquiring T₂-weighted, balanced steady-state free precession (b-SSFP) images is presented. Based on the recently proposed transition into driven equilibrium (TIDE) method, T₂-TIDE uses a special flip angle scheme to achieve T₂-weighted signal decay during the transient phase. In combination with half-Fourier image acquisition, T₂-weighted images can be obtained using T₂-TIDE. Numerical simulations were performed to analyze the signal behavior of T₂-TIDE in comparison with TSE and b-SSFP. The results indicate identical signal evolution of T₂-TIDE and TSE during the transient phase. T₂-TIDE was used in phantom experiments, and quantitative ROI analysis shows a linear relationship between TSE and T₂-TIDE SNR values. T₂-TIDE was also applied to abdominal and head imaging on healthy volunteers. The resulting images were analyzed quantitatively and compared with standard T₂-weighted and standard b-SSFP methods. T₂-TIDE images clearly revealed T₂ contrast and less blurring compared to T₂-HASTE images. In combination with a magnetization preparation technique, STIR-weighted images were obtained. T₂-TIDE is a robust technique for acquiring T₂-weighted images while exploiting the advantages of b-SSFP imaging, such as high signal-to-noise ratio (SNR) and short TRs. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc.