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

Magn Reson Med. 2016 Jul;76(1):222-8. doi: 10.1002/mrm.25872. Epub 2015 Aug 24.

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 76:222-228, 2016. © 2015 Wiley Periodicals, Inc.

Keywords: echo shifting; fast T2*-weighted sequence; interslab scan mode.

Publication types

  • Evaluation Study

MeSH terms

  • Algorithms*
  • Brain / anatomy & histology*
  • Diffusion Magnetic Resonance Imaging / instrumentation
  • Diffusion Magnetic Resonance Imaging / methods*
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods*
  • Imaging, Three-Dimensional / methods*
  • Phantoms, Imaging
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Signal Processing, Computer-Assisted*
  • Signal-To-Noise Ratio