Optimized detection of lactate at 3 Tesla using the PRESS Sequence
Edden R, Barker P
Johns Hopkins University, Kennedy Krieger Institute
Single-voxel PRESS spectroscopy can be used to detect an inverted lactate signal at echo times of 1/J. The chemical shift artifact causes the slices selected by the two refocusing pulses of the sequence to differ for the two lactate signals. This disturbs the evolution of coupling, decreasing the signal intensity and compromising its inversion. At 3 Tesla, the artifact is sufficient that the lactate doublet has only 40% intensity and is not inverted, using traditional sinc-gauss pulses. Inversion and 70% detection efficiency can be achieved by using high-bandwidth frequency-modulated pulses. Experimental results agreed well with simulations of the lactate doublet.