Development and in vivo proof-of-concept of delayed alternating nutation tailored excitation point resolved spectroscopy (dante-press): a frequency-selective single voxel spectroscopy sequence applied to in vivo measurements of naa and glu at 7.0 T.

objectiveSingle-voxel proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive in vivo imaging technique used to quantify the concentration of human brain metabolites. Frequency-selective 1H-MRS techniques reduce spectral complexity and simplify spectral modeling. We introduce a single-shot frequency-selective sequence known as Delays-Alternating-Nutation-Tailored-Excitation-Point-RESolved-Spectroscopy (DANTE-PRESS) and test its precision when measuring glutamate and NAA at 7 Tesla in phantoms and human brain in vivo. MATERIAL AND

methodsDANTE-PRESS was programmed within the software environment of the Siemens Magnetom 7 Tesla MR scanner at the Centre for Functional Metabolic Mapping in London, Ontario. Two scans were obtained on phantoms and in 4 healthy volunteers (20 × 20x20mm

resultsDANTE-PRESS preserves the signal of the metabolite of interest while suppressing unwanted signals via a narrow-band frequency-selective refocusing pulse. DANTE-PRESS produces metabolite spectral signatures with J-evolution equivalent to that seen in a PRESS sequence with less than half the echo time. The inter-individual coefficients of variance were low and Cramer-Rao Lower Bounds were less than 5.1% for glutamate and NAA. DISCUSSION: Future work involving test-retest in vivo study in healthy volunteers to get measurements of glutamate along with other metabolites such as glutathione and GABA.