Making High Resolution T2 and T2* Maps Through the Use of Accelerated Gradient-Echo Asymmetric Spin-Echo (GREASE) Pulse Sequences

Daniel Lee Shefchik¹, Andrew Scott Nencka¹, Andrzej Jesmanowicz¹, James S. Hyde¹

The gradient-echo asymmetric spin-echo pulse sequence (GREASE) allows for the production of T2 and T2* maps. In order to obtain high resolution maps, while maintaining signal, the GREASE sequence was modified to accelerate the acquisition of the images three different ways. The modifications included partial k-space GREASE [2], generalized autocalibrating partially parallel acquisitions (GRAPPA) Grease [3], and partial k-space GRAPPA GREASE. The sequences are implemented and compared to the original GREASE sequence to determine the best technique to obtain quality T2 and T2* maps.