Traditional Posters: Miscellaneous

Gigi Galiana¹, Robert Todd Constable<sup>1

1</sup>Diagnostic Radiology, Yale University, New Haven, CT, United States

We report a method to quantify and characterize lipids in vivo. The method can generate simultaneous maps of saturated lipid, unsaturated lipid, and water, or it can also be run as a spectroscopic sequence to generate high resolution and very edited spectra. We present results from both implementations and show that the method can be used to discriminate lipids that are indistinguishable by other means.

969. Exotic Phase Cycling in ¹H MRS

Sarah Andrea Wijtenburg^1,2, Jack Knight-Scott<sup>1

1</sup>Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States; ²Biomedical Engineering, University of Virginia, Charlottesville, VA, United States

Exotic phase cycling refers to utilizing more complex phase cycling schemes to eliminate signals from unwanted coherence pathways. Here, we outline the general steps for designing an exotic phase cycle.

970. Wavelet-Encoded MR Spectroscopic Imaging Incorporating Parallel Imaging to Further Reduce Acquisition Time: In-Vitro Results.

Yao Fu^1,2, Hacene Serrai<sup>1

1</sup>National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Electrical and Computer Engineering, University of Manitoba, Winnipeg, Manitoba, Canada

We here report our recent phantom results using wavelet encoding (WE) combined with parallel imaging (PI, WE-PI) to acquire 1D magnetic resonance spectroscopic imaging (MRSI). Two sets of experiments are performed with the same acceleration factor (R = 2) and two different resolutions (N = 4 and N = 8). The results confirm that WE-PI reduces further the acquisition time by approximately the acceleration factor R, and preserves the spatial metabolite distribution with minimal loss of the signal-to-noise ratio (SNR) as compared to the WE-SI technique.

971. In-Vivo Wavelet Encoding Spectroscopic Imaging Results at 3 Tesla: Comparison to Chemical Shift Imaging.

Yao Fu^1,2, Hacene Serrai<sup>1

1</sup>National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Electrical and Computer Engineering, University of Manitoba, Winnipeg, Manitoba, Canada

We present our first in vivo results demonstrating wavelet encoded 3D spectroscopic imaging (WE-SI) at high magnetic field (3T) compared with standard, Fourier-encoded, chemical shift imaging (CSI). As previously demonstrated with phantom results, we confirm a reduction in acquisition time and pixel bleed for equivalent number of encodes as compared to CSI, with the predicted drop in SNR. In-vivo results show that WE-SI preserves metabolite signal distributions while reducing acquisition time, demonstrating that WE-SI is providing accurate MRSI results with higher sensitivity at higher fields.

972. Trapzoidal Volume Selection Using Adiabatic Pulses

Bu S. Park¹, Jun Shen<sup>1

1</sup>National Institute of Mental Health (NIMH), National Institute of Health (NIH), Bethesda, MD, United States

Because of high immunity to RF inhomogeneity and excellent slice profiles, adiabatic pulses are widely used for special localization in MR spectroscopy. Here we propose a scheme for selecting a trapezoidal volume using adiabatic ð pulses since non-rectangular volume is often preferred in localized spectroscopy. In this scheme, a time-varying gradient orthogonal to a stationary slice-selection gradient is used to change the initial and final boundaries of the slice profile from parallel to non-parallel.

973. SAR-Reduced Spectroscopic FAST Imaging with Variable Flip Angles