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Abstract #0148

Water-Independent Frequency- & Phase-Corrected Spectroscopic Averaging using Cross-Correlation & Singular Value Decomposition

Aaron T. Hess1, Andr J. W. van der Kouwe2, Ernesta M. Meintjes1

1MRC/UCT Medical Imaging Research Unit, Human Biology, University of Cape Town, Cape Town, South Africa; 2Radiology, Massachusetts General Hospital, Boston, MA, USA


In a single voxel spectroscopy scan voluntary and physiologic movement can induce frequency and phase variations between consecutive FIDs. These variations lead to destructive averaging and line broadening. We present a technique to robustly detect the frequency of each FID by using its spectral cross-correlation with a simulated spectrum. Further we recombined them in a phase-insensitive manner using a set of complex weights calculated from singular value decomposition. We demonstrate the spectral quality improvement using this method from a scan where the subject was particularly restless.