Fabian Niess1, Albrecht Ingo Schmid1, Graham Kemp2, Ewald Moser1, Maxim Zaitsev1, and Martin Meyerspeer1
1High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria, 2Department of Musculoskeletal & Ageing Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
1High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria, 2Department of Musculoskeletal & Ageing Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
Double quantum filtered 1H MRS using adiabatic refocusing pulses at 7 T was successfully implemented. Fibre orientation-dependent quantification of lactate in meat for four different, clinically relevant angles relative to B0 was demonstrated.
Integrated signal area of the lactate doublet at 1.3 ppm as a function of the echo time (TE = τ1 + τ2). The coloured lines represent different combinations of τ1 and τ2 to achieve the effective TE with either τ1 = τ2 (red), holding τ2 constant (blue) or τ1 constant (green). The measurements were repeated with four different orientations of the RF coil (grey box) relative to the main magnetic field (0° to 45°) with estimated fibre orientations ranging from 42° to 16° (projections to the coronal plane hatched in red).
Averaged 1H MR spectra (n = 30, TR = 3 s) acquired using semi-LASER (left) and with the adiabatically refocused DQF acquisition scheme (right). Spectra were acquired from
(a) lithium lactate solution in a spherical phantom (d = 160 mm, 96mM LiLac in H2O) and (b) sodium lactate (60 %) injected into a pork meat specimen. Only lactate is visible (at 1.3 ppm) in spectra from both experiments with a peak splitting of 7.3 Hz for lactate in solution and 13 Hz for lactate injected in meat.
