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Investigation of the PSF‐choice method for reduced lipid contamination in prostate MR spectroscopic imaging
Author(s) -
Panych Lawrence P.,
Roebuck Joseph R.,
Chen Nankuei,
Tang Yi,
Madore Bruno,
Tempany Clare M.,
Mulkern Robert V.
Publication year - 2012
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24132
Subject(s) - voxel , magnetic resonance spectroscopic imaging , imaging phantom , computer science , point spread function , nuclear magnetic resonance , biomedical engineering , materials science , nuclear medicine , magnetic resonance imaging , physics , artificial intelligence , medicine , radiology
The purpose of this work was to evaluate a previously proposed approach that aims to improve the point spread function (PSF) of MR spectroscopic imaging (MRSI) to avoid corruption by lipid signal arising from neighboring voxels. Retrospective spatial filtering can be used to alter the PSF; however, this either reduces spatial resolution or requires extending the acquisition in k‐space at the cost of increased imaging time. Alternatively, the method evaluated here, PSF‐choice, can modify the PSF localization to reduce the contamination from adjacent lipids by conforming the signal response more closely to the desired MRSI voxel grid. This is done without increasing scan time or degrading SNR of important metabolites. PSF‐choice achieves improvements in spatial localization through modifications to the radiofrequency excitation pulses. An implementation of this method is reported for MRSI of the prostate, where it is demonstrated that, in 13 of 16 pilot prostate MRSI scans, intravoxel spectral contamination from lipid was significantly reduced when using PSF‐choice. Phantom studies were also performed that demonstrate, compared with MRSI with standard Fourier phase encoding, out‐of‐voxel signal contamination of spectra was significantly reduced in MRSI with PSF‐choice. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.