Format

Send to

Choose Destination
Magn Reson Med. 2015 Mar;73(3):929-938. doi: 10.1002/mrm.25615. Epub 2015 Feb 2.

RARE/turbo spin echo imaging with Simultaneous Multislice Wave-CAIPI.

Author information

1
Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Boston, MA, USA.
2
Department of Radiology, Harvard Medical School, Boston, MA, USA.
3
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
4
Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
5
Siemens Medical Solutions USA Inc., Charlestown, MA, USA.
6
Harvard-MIT Health Sciences and Technology, Cambridge, MA, USA.
#
Contributed equally

Abstract

PURPOSE:

To enable highly accelerated RARE/Turbo Spin Echo (TSE) imaging using Simultaneous MultiSlice (SMS) Wave-CAIPI acquisition with reduced g-factor penalty.

METHODS:

SMS Wave-CAIPI incurs slice shifts across simultaneously excited slices while playing sinusoidal gradient waveforms during the readout of each encoding line. This results in an efficient k-space coverage that spreads aliasing in all three dimensions to fully harness the encoding power of coil sensitivities. The novel MultiPINS radiofrequency (RF) pulses dramatically reduce the power deposition of multiband (MB) refocusing pulse, thus allowing high MB factors within the Specific Absorption Rate (SAR) limit.

RESULTS:

Wave-CAIPI acquisition with MultiPINS permits whole brain coverage with 1 mm isotropic resolution in 70 s at effective MB factor 13, with maximum and average g-factor penalties of gmax  = 1.34 and gavg  = 1.12, and without √R penalty. With blipped-CAIPI, the g-factor performance was degraded to gmax  = 3.24 and gavg  = 1.42; a 2.4-fold increase in gmax relative to Wave-CAIPI. At this MB factor, the SAR of the MultiBand and PINS pulses are 4.2 and 1.9 times that of the MultiPINS pulse, while the peak RF power are 19.4 and 3.9 times higher.

CONCLUSION:

Combination of the two technologies, Wave-CAIPI and MultiPINS pulse, enables highly accelerated RARE/TSE imaging with low SNR penalty at reduced SAR.

KEYWORDS:

CAIPIRINHA; MultiPINS; RARE/TSE/FSE; Wave-CAIPI; simultaneous multislice, multiband

PMID:
25640187
PMCID:
PMC4334698
DOI:
10.1002/mrm.25615
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center