Optimization of signal behavior in the transition to driven equilibrium in steady-state free precession sequences.
A new technique to avoid the initial signal fluctuations in steady-state free precession (SSFP)-sequences, such as trueFISP, FIESTA, and refocused FFE, is presented. The "transition into driven equilibrium" (TIDE) sequence uses modified flip angles over the initialization phase of a SSFP experiment, which not only avoids image artifacts but also improves the signal-to-noise ratio (SNR) and contrast behavior compared to conventional approaches. TIDE is demonstrated to be robust against variations of T(1) and T(2), and leads to a monotonous signal evolution for off-resonance spins. The basic principles can also be applied repetitively to optimize continuous 3D acquisitions.
Hennig
Juergen
J
Dept of Diagnostic Radiology, Section of Medical Physics, University of Freiburg, Freiburg, Germany. hennig@nz11.ukl.uni-freiburg.de
Speck
Oliver
O
Scheffler
Klaus
K
D006257:Head / Q000033:anatomy & histology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012815:Signal Processing, Computer-Assisted