3D interslab echo-shifted FLASH sequence for susceptibility weighted imaging.

ABSTRACT

PURPOSE: To develop a novel three-dimensional (3D) sequence for susceptibility weighted imaging that is able to reduce scan time substantially while maintaining high image signal-to-noise ratio (SNR). METHODS: The proposed fast T2 *-weighted sequence was based on a 3D full-balanced gradient frame and a pair of crusher gradients. The pair of crusher gradients were used to shift MR signal from the repetition time where the MR signal was originated to a later repetition time to enhance T2 * weighting. To avoid image SNR reduction due to the repeated signal excitations by later RF pulses, as it would occur for typical echo-shifted (ES) FLASH, an interslab scan mode for the fast T2 *-weighted sequence was introduced for signal acquisition. The effectiveness of this novel sequence was evaluated by comparing it with 3D FLASH and ES-FLASH sequences. RESULTS: The proposed interslab ES T2 *-weighted sequence was able to reduce the scan time by half with a SNR comparable to the typical multislab FLASH. Besides, it yielded a higher image SNR than the traditional multislab ES-FLASH and was more flexible than the whole-volume ES-FLASH. CONCLUSION: An interslab ES sequence was developed with high time efficiency and relatively high image SNR compared with the conventional acquisition sequences. Magn Reson Med 76222-228, 2016. © 2015 Wiley Periodicals, Inc.