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

MRS of the CNS 2

Wednesday 14 May 2014
Blue 1 & 2  16:00 - 18:00 Moderators: Richard A. E. Edden, Ph.D., Jürgen K. Hennig, Ph.D.

16:00 0692.   
Longitudinal monitoring of metabolic alterations in cuprizone mouse model of Multiple Sclerosis using 1H magnetic resonance spectroscopy
Jasmien Orije1, Firat Kara1, Caroline Guglielmetti1, Jelle Praet1, Marleen Verhoye1, Peter Ponsaerts2, and Annemie Van der Linden1
1Bio-Imaging Lab, University of Antwerp, Wilrijk, Antwerp, Belgium, 2Laboratory of Experimental Hematology, University of Antwerp, Wilrijk, Antwerp, Belgium

In this study, we employed quantitative in vivo 1H MRS to longitudinally monitor metabolic changes in the corpus callosum of C57BL/6 mice receiving a 0.2% cuprizone supplemented diet. Significant alterations in N-acetylaspartate, glycerophosphorylcholine, taurine and macromolecules and lipids were observed in the early demyelination phase (week 4 and 6) in the cuprizone fed mice compared to control mice, fed with standard rodent chow. Six week after the cuprizone withdrawal, these metabolic changes were no longer present suggesting that metabolic changes observed with 1H MRS reflect key pathological features, such as demyelination, inflammation and axonal injury, caused by the cuprizone treatment.

16:12 0693.   Correlations between BOLD and neurochemical responses measured in the human visual cortex at 7T
Petr Bednarik1,2, Ivan Tkac1, Federico Giove3,4, Dinesh K Deelchand1, and Silvia Mangia1
1CMRR - Dept. of Radiology, University of Minnesota, Minneapolis, MN, United States, 2CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 3Magnetic Resonance for Brain Investigation Lab, Enrico Fermi Center, Roma, Italy, 4Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy

Functional magnetic resonance spectroscopy (fMRS) is able to measure very small changes of metabolite concentrations during visual stimulation. These changes are ascribed to increased energetic neuronal oxidative metabolism. The aim of the current study was to correlate the neurochemical responses measured by fMRS with the metabolic/hemodynamic responses measured by the BOLD effect. Significant correlation between BOLD-fMRI signals and glutamate concentration changes during visual stimulation was found. Additionally, higher baseline GABA concentration measured at baseline predicted lower BOLD responses.

16:24 0694.   1D Diffusion Weighted Magnetic Resonance Spectroscopy along the arcuate fasiculus in the human brain at 7T
Jannie P Wijnen1,2, Itamar Ronen2, Anaree Techawiboonwong3, Andrew Webb2, Dennis WJ Klomp1, Hilleke E Hulshoff Pol4, Rene S Kahn4, and Rene CW Mandl4
1Radiology, University Medical Centre Utrecht, Utrecht, Utrecht, Netherlands, 2Radiology, Leiden University Medical Centre, Leiden, Netherlands,3Electrical Engineering, Mahidol University, Salaya, Nakhon Pathom, Thailand, 4Psychiatry, Brain Center Rudolf Magnus, University Medical Centre Utrecht, Utrecht, Utrecht, Netherlands

This study shows the feasibility of 1D Diffusion Weighted Spectroscopy in an array along a specific fiber tract that was visualized on the fly using Diffusion Tensor Imaging with fiber tracking. This approach could be used to measure difference between parallel and perpendicular diffusion of various metabolites in specific fiber tracts.

16:36 0695.   
An Investigation of Microstructural Tissue Damage in Systemic Lupus Erythematosus (SLE) with Neurological and Psychiatric Symptoms using Diffusion Weighted Spectroscopy (DWS) at 7T
Ece Ercan1, Emily T. Wood2,3, Mark van Buchem4, Andrew G. Webb1, and Itamar Ronen1
1C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 2NINDS, National Institutes of Health, Bethesda, Maryland, United States, 3Dept of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States,4Department of Radiology, Leiden University Medical Center, Leiden, Netherlands

Conventional MRI from SLE patients with neurological and psychiatric symptoms (SLEwNP) frequently appear normal and fail to explain the clinical symptoms, making the diagnostic procedure rather difficult and restricted to per exclusionem. Here we utilize DWS of brain metabolites in normal appearing white matter in the CC to investigate the tissue microstructural correlate of SLEwNP for the first time. The results suggest a disruption of astrocytic structure or physiology, which is in line with the inflammatory nature of the disease and show that ADC(tCho) may potentially become a biomarker for SLEwNP.

16:48 0696.   
Age Dependence of the Metabolite Diffusion Tensor in Human Brain using Proton-Echo-Planar-Spectroscopic-Imaging
Alec Landow1, Elena Ackley2, Stephen R. Dager3, Dennis Shaw3,4, Mindy Dixon4, and Stefan Posse1,2
1Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, United States, 2Department of Neurology, University of New Mexico, Albuquerque, NM, United States, 3Department of Radiology, University of Washington, Seattle, WA, United States, 4Seattle Children's Hospital, Seattle, WA, United States

Diffusion tensor spectroscopic imaging (DTSI) in human brain provides intracellular markers for studying axonal development. DTSI was implemented at 3 Tesla using cardiac gated proton-echo-planar-spectroscopic-imaging (PEPSI). Movement-related phase and amplitude errors were corrected using spatially localized navigators. Data were acquired in 6 healthy volunteers (age range: 3 months – 58 years) using 1-4.5 cc voxel size, bmax = 1734 s/mm2, and 6 gradient directions. The apparent diffusion coefficients of Cho, Cr and NAA in a 3-month old subject were significantly higher and the fractional anisotropy values were lower than those in the adults, consistent with studies of water diffusion.

17:00 0697.   Lower glutathione (GSH) concentration in the posterior cingulate cortex of healthy human elders measured at 7 T - permission withheld
Malgorzata Marjanska1 and Melissa Terpstra1
1Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States

Oxidative stress occurs at an early stage of age related cognitive decline. Ascorbate (Asc, vitamin C) and glutathione (GSH) are key contributors to the antioxidant network. Although lower 1H MRS GSH signal has been measured in the occipital cortex (OCC) of an elder cohort, that finding could have been confounded by differing transverse relaxation (T2). The purpose of this work was to utilize short echo time 1H MRS to overcome confounding by age associated difference in T2 to quantify GSH concentration in the aging brain in OCC and posterior cingulate cortex (PCC, pertinent to the pathology of Alzheimer’s disease).

17:12 0698.   
Investigating white matter degeneration in healthy aging by combining diffusion-tensor imaging and diffusion-weighted spectroscopy in the human corpus callosum at 7 T
Francesca Branzoli1, Ece Ercan2, Emily T. Wood3, Mathijs Buijs2, Andrew Webb2, and Itamar Ronen2
1Centre de Neuro-imagerie de Recherche de l’Institut du Cerveau et de la Moelle Epiniere, Paris, France, 2C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 3Neuroimmunology Branch (NINDS), National Institutes of Health, Bethesda, MD, United States

In this study we compare the diffusion properties of water and the neuronal metabolite N-acetylaspartate (NAA) in the corpus callosum of elderly and young subjects, measured at 7T by combining diffusion tensor imaging and diffusion-weighted spectroscopy. Thanks to the specificity of NAA as a probe of intra-axonal space, the method employed here allows to distinguish axonopathy from other processes such as demyelination, which has been previously associated to the observed increase in water mean diffusivity and decrease in water fractional anisotropy in aging. The decrease in NAA axial diffusivity observed in aging for the first time in this study is likely to be related to the presence of structural disruptions associated with axonal degeneration in WM of elderly subjects.

17:24 0699.   Effect of physical exercise on cerebral antioxidant status in older adults - permission withheld
In-Young Choi1,2, Phil Lee1,3, Eric D Vidoni4, William M Brooks1,2, and Jeffrey M Burns2
1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States, 2Neurology, University of Kansas Medical Center, Kansas City, KS, United States, 3Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States, 4Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States

GSH is a key cerebral antioxidant that protects cells from oxidative stress, a central process contributing to aging and neurodegeneration, and a reduction in GSH is noted in brain tissue undergoing oxidative stress. Physical exercise has been suggested as a neuroprotective strategy against loss of antioxidants. In this study, we measured the influence of aerobic exercise on cerebral GSH levels in older adults using doubly-selective multiple quantum GSH CSI at 3T. The GSH levels were significantly increased after exercise intervention, providing insights into the effect of exercise on the cerebral antioxidant system to promote brain health of the aging population.

17:36 0700.   Macromolecule Suppressed GABA Editing using Spectral Spatial RF Pulses
Meng Gu1, Adam B. Kerr2, Ralf E. Hurd3, and Daniel M. Spielman1
1Radiology, Stanford University, Stanford, California, United States, 2Electrical Engineering, Stanford University, Stanford, California, United States, 3GE Healthcare, Menlo Park, California, United States

MEGA PRESS has been used to edit the GABA resonance at 3ppm. Due to the wide transition bandwidth of the editing pulse, macromolecule resonances are coedited. To suppress macromolecule signals, a symmetric suppression method has been proposed resulting in reduced GABA signal. We present a new editing method by incorporating spatial and spectral selectivity into the PRESS refocusing RF pulses to achieve both GABA editing and macromolecule suppression. Phantom studies showed higher edited GABA signal compared with MEGA PRESS and 90% macromolecule suppression. In-vivo studies demonstrated significantly higher edited GABA signal compared with MEGA PRESS.

17:48 0701.   Spectroscopic Localization by Simultaneous Acquisition of the Double-Spin and Stimulated Echoes
Assaf Tal1 and Oded Gonen2
1NYU Langone School of Medicine, New York, NY, United States, 2Radiology, NYU Langone School of Medicine, New York, NY, United States

Localization is an essential requirement for almost all proton magnetic resonance spectroscopy (MRS) acquisitions. Localization modules either acquire the spin echo (e.g., PRESS, LASER, semi-LASER, etc) or the stimulated echo (STEAM). We propose a localization module which acquires both coherence pathways. Compared to PRESS, this substantially reduces chemical shift displacements, specific absorption rates, minimum TE and increases B1+ immunity, much like STEAM, but at only a modest reduction in signal to noise (i.e. without the 50% signal loss associated with STEAM).