Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy

MRS of the CNS 1

Monday 12 May 2014
Blue 1 & 2  10:45 - 12:45 Moderators: Peter B. Barker, D.Phil., Graham Galloway, Ph.D.

10:45 0062.   Regional Metabolism During Healthy Aging in Mice Brain: A 1H-[13C]-NMR Study
Anant Bahadur Patel1, Pandichelvam Veeraiah1, Mohammad Shamim1, and M Jerald Mahesh Kumar1
1NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India

Despite key role of neurotransmitters in brain function, brain energy metabolism has not been explored during healthy aging. In this study, we have investigated neuronal and astroglial metabolism in the cerebral cortex, hippocampus and striatum of adult and aged C57BL6 mice by using 1H-[13C]-NMR spectroscopy together with infusion of 13C labeled substrates. The 13C turnover of amino acids was analyzed using a three compartment metabolic model to derive the metabolic rates. Aging is associated with an increased in astroglial flux and decrease in glutamatergic and GABAergic rates across different brain regions.

10:57 0063.   Manganese Induced Changes In Thalamic GABA Levels Influence Cognitive and Motor Performance
Ruoyun Ma1,2, Ann-Kathrin Stock3, S.Elizabeth Zauber4, James B. Murdoch5, Shalmali Dharmadhikari1,2, Zaiyang Long1,2, Christian Beste3, and Ulrike Dydak1,2
1School of Health Sciences, Purdue University, West Lafayette, IN, United States, 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Cognitive Neurophysiology Department of Child and Adolescent Psychiatry, Technical University Dresden, Dresden, Germany, 4Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, United States, 5Toshiba Medical Research Institute USA, Mayfield Village, OH, United States

Chronic occupational exposure to Manganese (Mn) has been associated with cognitive and motor disorders similar to Parkinson disease. Based on a previous observation of elevated GABA levels in Mn-exposed workers, this study investigates the connection between thalamic GABA levels measured by MRS, motor function, and behavior measures of action control and inhibition in typical US welders. The significant correlations between these measures indicate that GABA may serve as biomarker for early diagnosis of Mn-induced neurotoxicity.

11:09 0064.   High field MRS is more sensitive to progression of neurodegeneration than clinical decline in spinocerebellar ataxia type 1 (SCA1)
Dinesh K Deelchand1, Uzay E Emir1,2, Diane Hutter1, Christopher M Gomez3, Lynn E Eberly4, Khalaf O Bushara5, and Gulin Oz1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 3Department of Neurology, University of Chicago, Chicago, IL, United States, 4Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States, 5Department of Neurology, Medical School, University of Minnesota, Minneapolis, MN, United States

In this study, MR spectroscopy was used to monitor disease progression in SCA1 patients. Subjects were scanned at baseline and after an ~18 month follow-up on 3 T. We found that in pons, [tNAA]/[Ins] was significantly reduced in SCA1 at visit #2 vs. visit #1 while no difference was detected in controls. The change in ataxia rating scale between the two visits did not reach significance suggesting that MRS is more sensitive to detect a small change due to disease progression than clinical assessment.

11:21 0065.   Caloric Restriction Impedes Age-related Decline of Neuronal Function and Energy Demand
Ai-Ling Lin1, Daniel Coman2, Lihong Jiang2, Douglas L Rothman2, and Fahmeed Hyder2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, 2Magnetic Resonance Research Center, Yale University, New Haven, CT, United States

While caloric restriction extends mammalian lifespan, its effect on neuronal function and energy demand especially in healthy aging remains largely unknown. Using 1H[13C] MRS techniques, we show that healthy aging rats had significantly lower rates of neuronal energy production and neurotransmission relative to their younger counterparts; however, caloric restriction mitigated the age-related deceleration of brain physiology. These results provide a rationale for caloric restriction-induced sustenance of brain health with extended lifespan.

11:33 0066.   
Absolute Quantification of Brain Metabolites in Small MRS Voxels
Niklaus Zoelch1, Andreas Hock1,2, and Anke Henning1,3
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zurich, Zurich, Switzerland, 3Max Planck Institute for Biological Cybernetics, Tuebingen, Germany

The goal of this work was to enable absolute quantification of brain metabolites in small voxels, which is desirable in the clinical routine, especially to improve the diagnosis of brain lesion. For this purpose, non-water suppressed MRS via the metabolite cycling technique was combined with the calibration method ERETIC. The combination of these two techniques was tested invivo in 6 healthy volunteers. The concentrations obtained with MC and ERETIC are in good agreement with concentrations determined from water suppressed spectra by using the internal water as reference.

11:45 0067.   A method for quantifying average metabolite concentrations in anatomically-defined brain regions
Ryan J. Larsen1, Michael Newman1,2, Chao Ma3,4, and Bradley Sutton1,5
1Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Beckman Institute, Urbana, IL, United States, 4Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 5Department of Biomedical Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States

Much work has been performed to use structural MRI scans as prior knowledge to construct anatomically-constrained metabolites maps from multi-voxel Magnetic Resonance Spectroscopy Imaging scans. In many implementations, the anatomical reconstruction is performed on the signal from the metabolite, without quantitation. We demonstrate a post-processing pipeline that combines both quantitation and anatomical reconstruction based on prior knowledge. Our technique employs water-scaling to quantify the distribution of metabolites. We then apply a Projection on a Convex Set (POCS) algorithm that revises the metabolite distribution by using prior knowledge from the MRI scan. The final result is average metabolite concentration values within anatomically distinct regions of the brain.

11:57 0068.   
Lipid suppression for brain MRI and MRSI by means of a dedicated crusher coil
Vincent O. Boer1, Tessa N. van de Lindt1, Peter R. Luijten1, and Dennis W.J. Klomp1
1radiology, UMC Utrecht, Utrecht, Utrecht, Netherlands

Lipid suppression in MRI and MRSI is generally associated with delays in the sequence and increased TRs. In this work we apply a crusher coil for lipid suppression where a switchable local distortion of the magnetic field in the skull is induced instead of RF excitation or inversion. With the crusher coil lipid suppression is possible without increases in SAR, or lengthening of the sequences. For MSRI this allows a shortening of the TR of an order of magnitude, leading to the possibility to acquire very high resolution MRSI of the human brain.

12:09 0069.   Detection of cerebral NAD+ by in vivo 1H NMR spectroscopy
Robin A. de Graaf1 and Kevin L. Behar1
1Yale University, New Haven, CT, United States

Nicotinamide adenine dinucleotide (NAD+) has a central role in cellular metabolism and energy production and is related to gene expression, calcium mobilization, aging, cell death and timing of metabolism via the circadian rhythm. The in vivo detection of NAD+ has been limited and has only recently become feasible with high-field 31P NMR spectroscopy. Here 1H NMR spectroscopy is presented as a simple, but robust alternative for the in vivo detection of NAD+. Special attention is given to the interaction between NAD+ and water magnetization. Perturbation of the water protons should be minimized to ensure full NAD+ signal detection efficiency.

12:21 0070.   
Metabolite Proton T1 Relaxation Times in the Rat Brain in vivo at 17.2 Tesla
Alfredo Liubomir Lopez Kolkovsky1, Boucif Djemai1, and Fawzi Boumezbeur1
1CEA/Saclay/Neurospin, Commissariat a l'Energie Atomique, Gif-sur-yvette, Essonne, France

At ultra-high magnetic fields such as 17.2 T, it is crucial to establish T1 and T2 relaxation times in order to optimize MRS acquisition parameters and to achieve proper quantification. In this study we present measurements of T1 relaxation times of 20 metabolites and macromolecules in the rat brain in vivo at 17.2T. Results show a convergence of T1 relaxation times to 1690 ms, with the exception of Taurine (2212 99 ms) and Cr-CH2 (1152 32 ms). T1 values were slight longer than those measured at lower magnetic fields, which is consistent with the Bloembergen-Purcell-Pound theory of dipolar relaxation.

12:33 0071.   
Assessment of Macromolecular and Metabolic Alterations during Normal Brain Aging in the Dark Agouti Rat using 1H MRS at 17.2 Tesla
Alfredo Liubomir Lopez Kolkovsky1, Boucif Djemai1, and Fawzi Boumezbeur1
1CEA/Saclay/Neurospin, Commissariat a l'Energie Atomique, Gif-sur-yvette, Essonne, France

Normal brain aging is usually associated with a decline in brain function. Yet, the neural basis of age-related cognitive dysfunction in normal brain aging remains to be entirely elucidated. In this study, we sought to explore further these metabolic alterations in the brain of healthy rats with in vivo short echo time 1H MRS at 17.2 T. Comparing metabolic profiles from young and elderly rats (1 and 16 months old respectively), it was found a decrease in neurotransmitters (Gln+Glu, GABA) and increase in Ins and tCho consistent with decline of neural function and chronic low-level glial activation consistent with previous observations in humans.