Spectroscopy scanning on the Nottingham 7T scanner
1H MRS in the Human Brain
We routinely acquired 1 H spectra from various regions of the human brain including the visual cortex, posterior and anterior cingulated, insula and from deep grey matter structures, with voxel sizes down to 10x8x8mm and acquisition times from 10-20 minutes. The increased field strength at 7T provides improved spectral resolution which allows the peaks from glutamate and glutamine, which are extremely difficult to separate at lower fields to be easily quantified.
Metabolites quantifiable
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 1H MR Spectrum from the posterior cingulate. Voxel =30x25x25mm, acquisition time = 15mins 2Hz. Lorentzian line broadening applied |
13 C MRS in the Human Brain
Due to the low signal and low natural abundance of 13 C, human brain studies are carried out using infusions of labelled substrates. We have previously carried out studies investigating TCA cycle and glutamate-glutamine cycling rates using labelled glucose infusions both at rest and during visual activation. We are currently developing techniques and protocols to enable further investigation in these areas, utilizing the increased signal and improved spectral resolution available at 7T.
3T time series experiment showing incorporation of 13 C label into the TCA cycle.
(Chhina et al , J Neurosci Res 66, 737 - 746 , 2001)
1 H MRS in Skeletal Muscle
We can accurately determine levels of intra- and extra myocellular lipid levels in the human calf and thigh tissue, which is of interest when investigating healthy and diseased lipid metabolism in muscle. Scan times are of the order of 10 minutes for a 30x30x50mm voxel
Identifiable metabolites
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 7T calf muscle spectrum. Acquisition time < 3min. |
Natural Abundance 13 C MRS in skeletal muscle
We routinely measure natural abundance concentrations of glycogen in the human calf and thigh muscle. These scans are approximately 15 minutes in duration and are often used to monitor changes in levels due to interventions.
Glycogen Spectrum from Calf muscle at 7T with TR=800ms
NSA=1200, Acq time = 16min, 20Hz LB
