Abstract:
:Echo-planar spectroscopic imaging (EPSI) can be used for fast spectroscopic imaging of water and fat resonances at high resolution to improve structural and functional imaging. Because of the use of oscillating gradients during the free induction decay (FID), spectra obtained with EPSI are often degraded by Nyquist ghost artifacts arising from the inconsistency between the odd and even echoes. The presence of the spectral ghost lines causes errors in the evaluation of the true spectral lines, and this degrades images derived from high-resolution EPSI data. A technique is described for reducing the spectral ghost artifacts in EPSI of water and fat resonances, using echo shift and zero-order phase corrections. These corrections are applied during the data postprocessing. This technique is demonstrated with EPSI data acquired from human brains and breasts at 1.5 Tesla and from a water phantom at 4.7 Tesla. Experimental results indicate that the present approach significantly reduces the intensities of spectral ghosts. This technique is most useful in conjunction with high-resolution EPSI of water and fat resonances, but is less applicable to EPSI of metabolites due to the complexity of the spectra.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Du W,Du YP,Fan X,Zamora MA,Karczmar GSdoi
10.1002/mrm.10485subject
Has Abstractpub_date
2003-06-01 00:00:00pages
1113-20issue
6eissn
0740-3194issn
1522-2594journal_volume
49pub_type
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