A new T2 preparation technique for ultrafast gradient-echo sequence.

The T2 contrast in images obtained with driven equilibrium (90degreesx-180degreesx-90degreesx) prepared ultrafast gradient-echo sequence is compromised by the longitudinal magnetization build-up after the second 90degreesx pulse, which does not carry T2 information. This paper describes a new T2 contrast preparation technique for ultrafast gradient-echo sequence that suppresses the signal arising from the build-up. By dephasing in the preparation and rephasing in the acquisition of the gradient echoes, the new technique eliminates signals that are not dictated by the T2 contrast in a driven-equilibrium approach. Consequently, it generates an image that is essentially T2-weighted. Phantom and in vivo experiments were conducted to validate the technique and to demonstrate its clinical utility. These studies indicate that the technique works properly and can be used for in vivo studies.