Meeting Banner
Abstract #2022

3D Metabolic Mapping of the Brain at 7T by Pulse-Cascaded Hadamard Encoding with Short Acquisition Delay

Gilbert Hangel1, Bernhard Strasser1, Stephan Gruber1, Marek Chmelik1, Siegfried Trattnig1, Wolfgang Bogner1, 2

1MR Centre of Excellence, Medical University of Vienna, Vienna, Austria; 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States

This work compares metabolic maps of pulse-cascaded four-slice Hadamard Spectroscopic Imaging (HSI) with short acquisition delay to standard single slice 2D-CSI at 7T. HSI overcomes point-spread function problems in slice encoding direction and enables the measurement of few slices with high in-plane resolution in acceptable measurement time making full use of the high SNR at 7T. Pulse cascading reduces B1 requirements, specific absorption rates, and chemical shift displacement errors. The short acquisition delay maximizes SNR and avoids J-coupling effects. Measurements in eight volunteers show the good comparability of metabolic maps between HSI and CSI as well as the Hadamard-specific SNR-increase.

Abstract PDF Poster PDF

Keywords

absolute absorption achieved acquisition addition address adjacent advanced advantages allows amounts amplitude approximately artifacts ascending audience averaging background bandwidth better biomedical brain cascaded causes central channel chemical chosen coil combination comparability comparable computation conducted confirm consecutive consistent contamination contrast coupling cranial delay delays derived development displacement displayed distorted enables encoding enhance enhancing equal errors excellence excellent excitation expected extra featuring fourth future general gilbert good gradient head healthy henning hospital imperfect implementation improvements induced insignificant instead intrinsic investigate investigated lead lies limit limitations lipid localization long male mapping maps matrix maximizes measured medical metabolic minutes mode movement nominal offering parallel peaks phantoms potential practical probable processed profile properties proposed pulse pulses quality radiology readout reason recently reduce reducing reduction renders requires resolution resolutions school scientists selective short shorter slice slices software spatial spectra spectral spectroscopic structure superposition suppression target theoretically third trading trajectories unit volunteer volunteers water white