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Investigation of coil phase compensation in 3D imaging at very high acceleration factors
Author(s) -
McDougall Mary Preston,
Wright Steven M.
Publication year - 2007
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20938
Subject(s) - electromagnetic coil , compensation (psychology) , phase (matter) , computer science , signal (programming language) , signal to noise ratio (imaging) , acoustics , physics , optics , psychology , quantum mechanics , psychoanalysis , programming language
Purpose To investigate the confounding effect of the coil phase in highly accelerated parallel imaging with small coils, contextualize the effect in terms of single‐echo acquisition (SEA) imaging, and show that it can be managed in the case of 3D imaging. Materials and Methods The effects of the coil phase variations in a 64‐channel array of surface microcoils were modeled. Fully encoded 64 × 128 × 64 ( N phase enc × N readout × N slice enc ) 3D data sets were obtained, from which factor of 64 accelerated 3D image sets (1 × 128 × 64 each) were extracted from single phase‐encoding lines, each representing a different phase compensation value. Results A comparison of the SEA images indicates that the choice of a compromise value for phase compensation successfully enabled a straightforward extension of SEA imaging to three dimensions. The use of the single compromise compensation value in the 3D acquisition resulted in a signal‐to‐noise ratio (SNR) penalty ranging from 6% to 41% through the slab when compared to the highest SNR possible using any phase compensation value. Conclusion The coil‐related phase shift issues inherent to highly accelerated imaging will require further study, but this work indicates the general nature of the problem and, more auspiciously, shows that it can be mitigated for at least this application. J. Magn. Reson. Imaging 2007;25:1305–1311. © 2007 Wiley‐Liss, Inc.