ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

ELECTRONIC POSTER SESSION • MR SPECTROSCOPY
3955 -3978 Methodology of Spectroscopic Localization & Imaging
3979 -4001 MR Spectroscopic Imaging
4002 -4025 MRS Potpourri
4026 -4049 MRS & Metabolism

ELECTRONIC POSTER SESSION • MR SPECTROSCOPY
Wednesday, 24 April 2013 (10:00-11:00) Exhibition Hall
Methodology of Spectroscopic Localization & Imaging

  Computer #  
3955.   49 Diffusion Tensor Spectroscopic Imaging of Multiple Metabolites in Rat Brains
Yoshitaka Bito1, Yuko Kawai2, Koji Hirata1, Toshihiko Ebisu3, Yosuke Otake1, Satoshi Hirata1, Toru Shirai1, Yoshihisa Soutome1, Hisaaki Ochi1, Masahiro Umeda2, Toshihiro Higuchi4, and Chuzo Tanaka4
1Central Research Laboratory, Hitachi, Ltd., Kokubunji-shi, Tokyo, Japan, 2Medical Informatics, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan, 3Neurosurgery, Nantan General Hospital, Nantan-shi, Kyoto, Japan, 4Neurosurgery, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan

 
Diffusion tensor spectroscopic imaging (DTSI), using diffusion-weighted echo-planar spectroscopic imaging with a pair of bipolar diffusion gradients (DW-EPSI with BPGs), was applied to measure diffusion tensor images (DTIs) of N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) in normal rat brains. The DTIs of NAA and Cr were successfully measured, however, the DTI of Cho was deteriorated by gradually decreasing the signal of Cho. The measured DTIs of NAA and Cr are very similar to the DTI of water in most brain regions but show differences in the detail, i.e., cortex and corpus callosum. These results suggest that this DTSI technique is effective in investigating microstructures of tissue.

 
3956.   50 Diffusion Tensor Spectroscopic Imaging in Human Brain
Stefan Posse1,2, Elena Ackley1, Jingjing Michele Zhang3, and Tongsheng Zhang1
1Neurology, University of New Mexico, Albuquerque, NM, United States, 2Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States, 3Department of Biomedical Physics, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, United States

 
Diffusion tensor spectroscopic imaging (DTSI) in human brain was developed using high-speed proton-echo-planar-spectroscopic-imaging (PEPSI) with ECG gating, correction of movement-related phase errors using spatially localized echo-planar navigator signal acquisition and compensation of the variability in T1-saturation, which results from cardiac gating. DTSI was implemented on a 3 Tesla clinical scanner equipped with a 32-channel array coil. Data in a phantom and in 3 healthy volunteers were acquired using a 32x32 spatial matrix, 1 cc voxel size, bmax = 1734 s/mm2, and 6 gradient directions. Apparent diffusion coefficients and fractional anisotropy values of Cho, Cr, NAA and tissue water measured in a supraventricular slice were in the ranges reported in previous studies using single voxel methods and using diffusion tensor MRI. 3D DTSI is currently under development.

 
3957.   51 Impact of Acquisition Orientation on Whole Brain Metabolite Maps Obtained by Short Echo Time Echo Planar Spectroscopy Imaging (EPSI)
Angèle Lecocq1, Yann Le Fur1, Andrew A. Maudsley2, Sulaiman Sheriff2, Mohammad Sabati2, Virginie Callot3, Monique Bernard4, Maxime Guye1, and Jean-Philippe Ranjeva1
1CRMBM, CNRS, Aix-Marseille Univ, MARSEILLE, France, 2Department of radiology, Miller School of Medicine, University of Miami, MIAMI, Florida, United States, 3Aix-Marseille University, MARSEILLE, France, 4Aix-Marseille Université, MARSEILLE, France

 
One major MRSI limitation is the artifact related to magnetic susceptibility effects leading to metabolite map distortions and signal drop out. The use of a short echo time helps to reduce signal loss and minimize phase differences. This susceptibility artifact could also be minimized by the choice of the MRSI data orientation. We aimed here to evaluate the impact of MRSI orientation on quality of whole brain of major metabolites maps between acquisitions performed along the AC-PC line and along the AC-PC+15°line using a recent whole brain MRSI sequence called Echo Planar Spectroscopy Imaging (EPSI) with short echo time (20ms).

 
3958.   52 Partial Volume SLIM for Separating Water and Lipid Compartmental Signals in Breast MRS
Patrick J. Bolan1, Gregory J. Metzger1, Steen Moeller1, and Michael Garwood1
1Radiology, CMRR, University of Minnesota, Minneapolis, MN, United States

 
This work explores the feasibly of using reconstructions based on Spectral Localization by Imaging (SLIM) to separate the spectral signals from the aqueous and lipid compartments in the breast. Fat fraction and B0 maps derived from high-resolution water-fat imaging are used to create a geometric model of the breast. A conventional CSI spectral data set is then reconstructed using SLIM and the geometric model to create discrete spectra for the water and lipid compartments. The feasibility of this approach is demonstrated through simulation and in vivo measurements.

 
3959.   53 Nonuniformly Under-Sampled (NUS) Echo Planar J-Resolved Spectroscopic Imaging (EP-JRESI) of Prostate Cancer Patients and Compressed Sensing Reconstruction
Rajakumar Nagarajan1, Daniel J.A. Margolis1, Stevan S. Raman1, Nidhi Jain1, Robert E. Reiter2, and M. Albert Thomas1
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Urology, University of California Los Angeles, LOS ANGELES, CA, United States

 
Due to its prevalence in the male population as well as its unpredictable clinical course, early detection and diagnosis of prostate cancer have become a priority for many health care professionals. The one-dimensional (1D) MRS combined with two-dimensional (2D) or three-dimensional (3D) spatial encoding is popularly known as MR Spectroscopic Imaging (MRSI) and a drawback of 1D MRS is the overlap of metabolite signals due to the limited spectral dispersion. The inherent acceleration in the echo-planar spectroscopic imaging (EPSI) can be further accelerated using non-uniform undersampling (NUS) imposed on incremented spatial and spectral dimensions of the 4D EP-JRESI sequence. The CS-reconstructed data using the split-Bregman non-linear reconstruction algorithm showed an excellent reproduction of multiple 2D J-resolved spectra with the 2D diagonal and cross peaks at the expected locations. The 25% undersampled CS-reconstructed EP-JRESI data using the endorectal “receive” coil showed excellent 2D J-resolved spectral quality demonstrating the clinically acceptable time (6-12 minutes) with 1ml voxel resolution.

 
3960.   54 Undersampled Spectroscopic Imaging with Model-Based Reconstruction
Itthi Chatnuntawech1, Berkin Bilgic1, and Elfar Adalsteinsson2,3
1EECS, Massachusetts Institute of Technology, Cambridge, MA, United States, 2EECS, MIT, Cambridge, MA, United States, 3Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States

 
In this work, a two-step model-based method that leads to an accurate reconstruction from undersampled spectroscopic imaging data is proposed. This method takes advantage of a fast water reference scan to estimate a subset of (non-linear) unknowns, leaving only a few, linear unknowns to be determined in the next step. Then, a regularized optimization problem with prior knowledge on the structure of the data is formulated to reconstruct the spectroscopic imaging data. This method reduces acquisition time by undersampling while preserving high reconstruction quality. The proposed method yields significantly lower root mean square error than that of the conventional method which finds the minimum-norm solution without regularization.

 
3961.   55 Serial Magnetic Resonance Spectroscopy of the Human Brain – Atlas-Based Automated Volume Registration with High Precision and Reproducibility.
Chris Hanstock1 and Myrlene Gee1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

 
A challenge for serial MRS studies is volume placement reproducibility. Typically, this has relied on visual registration which is prone to significant operator bias. Therefore the consistency of placement can be relatively poor both intra- and inter-centre. As a result the comparison of data from study to study has been prone to huge variability with studies for the same volunteer cohort. Our new Talairach Atlas-based automated protocol allows the exact volume placement prior to the scan and then exact co-registration for subsequent scan sessions. Moreover this procedure can be utilized across scanner platforms for multi-centre studies giving identical volume placement.

 
3962.   56 Parallel 2D-RF Excitation for Arbitrarily Shaped Region–of-Interest MR Spectroscopy at 16.4 T
Dinesh K. Deelchand1, Xiaoping Wu1, Pierre-Gilles Henry1, and Pierre-Francois Van de Moortele1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

 
In this study we demonstrate with phantom experiments the feasibility of selectively exciting arbitrary shaped voxel using 2D-RF pulse design (segmented radial k-space trajectory) with parallel RF excitation at 16.4 T while achieving sufficient excitation bandwidth for 1H MR spectroscopy. A novel simulation guided segment-wise RF pulse design is introduced to tackle the issue of gradient imperfection and is shown to preserve the excitation quality in the presence of gradient waveform deviations.

 
3963.   57 Short TE Whole Brain MRSI with High-Bandwidth Adiabatic SLR Refocusing and Echo Planar Readout
Meng Gu1, Priti Balchandani1,2, Sulaiman Sheriff3, Mohammad Sabati3, Daniel Spielman1, and Andrew Maudsley3
1Radiology, Stanford University, Stanford, CA, United States, 2Radiology, Mount Sinai School of Medicine, New York, NY, United States, 3Radiology, University of Miami, Miami, FL, United States

 
MR spectroscopic imaging with localization schemes using conventional RF pulses suffer from B1 inhomogeneity and chemical shift localization error due to bandwidth limitations. Adiabatic refocusing RF pulses have been introduced to overcome the B1 inhomogeneity. However, conventional hyperbolic secant adiabatic refocusing pulses are limited by long pulse-width, prohibiting acquisition with short TE. Here, we present a localization scheme using adiabatic SLR refocusing pulses with broad bandwidth and short pulse-width. This localization scheme was incorporated into a volumetric MRSI sequence with echo planar readout. In vivo study showed high quality spectra and metabolite maps were obtained throughout the brain.

 
3964.   58 31P MR Spectroscopic Imaging of the Human Brain at 7 T with Nuclear Overhauser Enhancement
Tom W.J. Scheenen1,2, Pascal Sati3, Steve Li4, Jun Shen4, and Daniel S. Reich3
1Radiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands, 2Lab of Functional and Molecular Imaging, National Institute of Neurologiocal Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States, 3Translational Neuroradiology Unit, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States, 4MRS Core Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States

 
31P-MRSI of the human brain with a dual 1H-31P TxRx volume coil at 7T was explored in five healthy volunteers. The combined coil setup allowed 1H irradiation of water during TR to enhance the signal of 31P metabolites. This Nuclear Overhauser Enhancement was explored in phantoms and quantified in several deep brain areas of healthy volunteers, allowing the acquisition of good quality spectra of the whole brain with a spatial resolution of 10.6 cc in 21 minutes.

 
3965.   59 3D TWIRL: A Novel K-Space Trajectory for Imaging of Fast Relaxing Nuclei
Sandro Romanzetti1, Daniel P. Fiege1, and Nadim Jon Shah1,2
1Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich, Jülich, Germany, 2JARA - Faculty of Medicine, RWTH Aachen University, Aachen, Germany

 
In this work we present a novel centric 3D sequence called 3DTWIRL. This sequence is based on Twisted Projection Imaging (TPI) technique and as such it combines the ultra-short echo time capability of projection imaging (PI) with a constant sampling density of k-space. The new method, however, requires the calculation of only the innermost TPI cone. The k-space is then sampled by rotating this cone by the appropriate polar and azimuthal angles. Initial results show that the 3DTWIRL sequence has a reduce sensitivity to off-resonances and ease of implementation.

 
3966.   60 Implications of MRSI Compressed Sensing Reconstruction on Spatial Resolution Using a Modified Technique
Keith Wachowicz1,2, Amr Heikal3, and B. Gino Fallone2,4
1Oncology, University of Alberta, Edmonton, Alberta, Canada, 2Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada, 3Physics, University of Alberta, Edmonton, Alberta, Canada, 4Physics and Oncology, University of Alberta, Edmonton, Alberta, Canada

 
The implications of compressed sensing (CS) reconstruction in spectroscopic imaging on spatial resolution have not been quantitatively investigated in the literature. Modulation transfer analyis in this work is used to demonstrate that dramatic loss of modulation transfer across the range of spatial frequencies can occur with CS. A modification to the CS algorithm (CMaCS) involving further constraints on the randomization of k-space and mapping of unpaired conjugate data is introduced and shown to recover much of this lost modulation.

 
3967.   61 B0-Adjusted and Sensitivity-Encoded Spectral Localization by Imaging  -permission withheld
Peter Adany1, Phil Lee2, and In-Young Choi3
1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States, 2Department of Molecular & Integrative Physiology, Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States, 3Department of Neurology, Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States

 
An extended non-Fourier based spectral localization technique is proposed for fast and accurate measurements of neurochemicals from non-rectangular, arbitrary shaped brain regions of interest (e.g., gray and white matter) in the human brain in vivo. The proposed spectral localization by imaging (SLIM)-based technique takes into account both inhomogeneous coil sensitivity with the use of multiple-channel receiver coils and B0 inhomogeneity. Thus, full recovery of the MRS signal quality, which is otherwise compromised, is achievable to assess gray and white matter differences of metabolite concentrations with a reduced number of phase-encoding steps and cross-compartmental contamination.

 
3968.   62 Metabolite Map Estimation from Undersampled Spectroscopic Imaging Data Using N-Compartment Model
Itthi Chatnuntawech1, Berkin Bilgic1, Borjan Gagoski2, Trina Kok1, Audrey Peiwen Fan1, and Elfar Adalsteinsson1,3
1EECS, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 3Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States

 
Specific physiological abnormalities could be detected by irregular change of metabolite concentration in specific brain regions. The combination between fully sampled spectroscopic imaging data and segmented structural image has been used to estimate metabolite value at each voxel. This abstract presents an N-compartment-model method with polynomial masks to obtain metabolite maps from undersampled spectroscopic imaging data. With the assumption that metabolite value within the same tissue type is slowly varying, the information of tissue boundaries is obtained from segmented structural image. Then, a regularized reconstruction with priors is formulated to reconstruct the metabolite maps. By acquiring only a subset of k-space samples, the acquisition process is sped up, while high reconstruction quality is retained via prior knowledge of tissue boundary and structure of data.

 
3969.   63 3D Zero J-Modulation Echo Planar Chemical Shift Imaging (3D ZJ-EPSI)
Hamed Mojahed1,2, Fernando Arias-Mendoza2, and Truman R. Brown3
1Department of Biomedical Engineering, Columbia University, New York, NY, United States, 2Department of Radiology, Columbia University, New York, NY, United States, 3Department of Radiology and Radiological Science, Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States

 
A new three dimensional zero J-modulation echo planar chemical shift imaging (3D ZJ-EPSI) pulse sequence is implemented on a conventional 3T MR scanner. Water suppressed 1H spectra of the human brain using a CHESS pulse (RF 80°-80°-145°) is acquired using a Sense head coil in quadrature mode. Lipid suppression is achieved using ten saturation bands around the skull. Spatial resolution of 7.5×7.5×6 mm3 is achieved in 10:28 min with TR=1500 ms and TE<1 ms. Having an echoless data and zero J-modulation increases the SNR, improves the T2*, and makes it easier to quantify spectra in the fast 3D ZJ-EPSI sequence.

 
3970.   64 Detection of Lipids in Various Tissues in Calf in One Measurement by 2D CSI with FID and Long Echo Time Acquisition at 7T
Ivica Just Kukurová1,2, Ladislav Valkovic1,3, Martin Gajdosik1, Martin Krssák4, Stephan Gruber1, Tibor Liptaj2, Siegfried Trattnig1, and Marek Chmelík1
1MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, 2Department of NMR and MS, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovakia, 3Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, 4Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria

 
The study aim was to simultaneously assess the composition of fatty acids from the extramyocellular lipids, bone marrow and subcutaneous adipose tissue in the calf at 7T and analyze their saturation profiles. Right calf of four volunteers was scanned using a 2D-CSI sequence with FID and long echo-time acquisition. Ratios of unsaturated fatty-acids (UFA) to CH3 group, polyunsaturated fatty-acids (PUFA) to CH3 group, and PUFA to UFA+PUFA were calculated in: subcutaneous fat, bone marrow and calf muscles. The new 2D-CSI sequence was found suitable for detecting lipids in various tissues for their composition analysis with no extra time needed.

 
3971.   65 Increased Intramyocellular Lipids and Decreased Unsaturation Indices and Choline in Diabetes Type 2 and Obesity
Rajakumar Nagarajan1, Christian Roberts2, Cathy C. Lee3,4, Theodore Hahn3,4, and M. Albert Thomas1
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Exercise and Metabolic Disease Research Laboratory, School of Nursing, University of California Los Angeles, Los Angeles, California, United States, 3Department of Medicine, University of California Los Angeles, Los Angeles, California, United States, 4Geriatrics, Research, Education and Clinical Center (GRECC ), VA Greater Los Angeles Healthcare System, Los Angeles, California, United States

 
Type 2 diabetes (T2D) has progressed into a major cause of preventable death in recent decades, expected to reach 21 million cases in the U.S. in 2010 with an estimated additional 7 million undiagnosed. In obese individuals with insulin resistance (IR) and in patients with T2D, skeletal muscle insulin-stimulated glucose uptake is markedly blunted. Intramyocellular lipids (IMCL) in skeletal muscle can be measured non-invasively by single voxel (SV) based 1H magnetic resonance spectroscopy (MRS) or multi-voxel based magnetic resonance spectroscopic imaging (MRSI). However, SV-based MRS and conventional MRSI recording 1D MRS suffer from severe overlap of the IMCL and extramyocellular lipid (EMCL) signals hampering accurate quantitation of saturated and unsaturated portions of IMCL. Also, the total time required for SV-MRS acquisition in multiple voxels would be impractical. We have evaluated a novel four-dimensional multi-echo echo-planar spectroscopic imaging (MEEP-COSI) to record multi-voxel based 2D MRS in T2D, obese and healthy subjects. Significantly increased intramyocellular lipids (IMCL) and extramyocellular lipids (EMCL), and decreased IMCL unsaturation indices and choline were observed in this pilot study.

 
3972.   66 J-Difference Editing of GABA: Simulated and Experimental Multiplet Patterns
Richard Anthony Edward Edden1,2, Jamie Near3, C. John Evans4, Nicolaas A. J. Puts2,5, and Peter B. Barker1,2
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 2F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 3Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, Quebec, Canada, 4CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom, 5Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States

 
In this abstract, we investigate factors that influence the multiplet pattern observed in J-difference editing of GABA. Density matrix simulations were applied to investigate the shape of the 3 ppm multiplet as a function of the editing sequence’s slice-selective refocusing pulse properties, in particular bandwidth, transition width, and flip angle. Conclusion: The 3 ppm GABA multiplet pattern observed in the MEGA-PRESS experiment depends quite strongly on the properties of the slice selective refocusing pulses used. Under some circumstance the central peak can be quite large; this does not necessarily indicate inefficient editing, or a subtraction artifact, but should be recognized as a property of the pulse sequence itself.

 
3973.   67 Localization Errors in MR Spectroscopic Imaging Due to the Drift of the Main Magnetic Field and Their Correction
Assaf Tal1 and Oded Gonen2
1Radiology, NYU Langone School of Medicine, New York, NY - New York, United States, 2Radiology, New York University, New York, NY - New York, United States

 
B0 field instabilities lead to sizable localization errors in prolonged phase-encoded spectroscopic imaging, in contrast to line-broadening observed in single-voxel studies. We demonstrate these errors in vivo and in a phantom, and propose an efficient and quick way to correct for them.

 
3974.   68 7T Spectroscopic Imaging of the Human Amygdala and Midbrain
Jullie W. Pan1 and Hoby P. Hetherington2
1Neurosurgery, Yale University School of Medicine, New Haven, CT, United States, 2Yale University, New Haven, CT, United States

 
In the brain, the amygdala is believed to function in the processing of emotion and memory, and has been shown to be dysfunctional in many psychological and psychiatric disorders such as post-traumatic stress and bipolar disorders. The MR evaluation of the amygdala can be challenging however, because of its inferior temporal-frontal location lateral to the cavernous sinus, and is particularly problematic for ultra-high field studies. In this study we describe implementation of high degree shimming to perform J-refocused spectroscopic imaging using in the region of the midbrain and amygdala at 7T.

 
3975.   69 Three Dimensional Multi-Voxel Proton Hadamard Spectroscopic Imaging in the Human Brain at 3T
Ouri Cohen1,2, Assaf Tal1, and Oded Gonen3
1Center for Biomedical Imaging, NYU, New York, NY, United States, 2Biomedical Engineering, Columbia University, New York, NY, United States, 3Center for Biomedical Imaging, New York University, New York, NY, United States

 
Transverse Hadamard spectroscopic imaging (T-HSI) has been shown to overcome the intrinsic signal-to-noise loss and increased bleed of chemical shift imaging by virtue of its approaching-ideal point-spread-function. However, because it uses a superposition of pulses, it is less suited for higher fields where the available B1 is smaller. In this work we demonstrate a method that overcomes this limitation and allows maintaining the benefits of T-HSI despite the higher (3T) field strength.

 
3976.   70 Two-Dimensional Semi-LASER Correlated Spectroscopy with Well-Maintained Cross-Peaks
Meijin Lin1, Anand Kumar1, and Shaolin Yang1,2
1Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Radiology, University of Illinois at Chicago, Chicago, IL, United States

 
Two-dimensional (2D) localized chemical shift correlated spectroscopy (L-COSY) is one of the simplest and the most useful methods applied for 2D magnetic resonance spectroscopy (MRS). L-COSY spectra provide more separated peaks with cross-peaks for spectral quantification. Keeping the cross-peak intensities from attenuation is critical for reliable and accurate quantification of metabolites. In this abstract, however, we demonstrated that using limited-bandwidth (BW) of radiofrequency (RF) pulses for slice selection might attenuate the intended cross-peaks in L-COSY spectra. We further demonstrated using semi-localization by adiabatic selective refocusing (sLASER) pulses for localization in COSY can maintain the intended cross-peaks from attenuation.

 
3977.   
71 Double Quantum Magic Angle Sodium MRI of the Human Brain
Adrian Tsang1, Rob Stobbe1, and Christian Beaulieu1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

 
Selective detection of sodium signal from nuclei in ordered environments that exhibit non-zero residual quadrupole interactions is possible with a double-quantum magic-angle (DQ-MA) sequence. We show that DQ-MA signal from sodium is only detected in xanthan gum (ordered macromolecular environment) and not in either saline or 4% agar gel (disordered). We then demonstrate the first DQ-MA images of human brain acquired in 18 minutes at 4.7T in 3 healthy volunteers. This selective sodium measurement may provide novel insight into alterations of the microscopic ordered tissue microstructure of the brain.

 
3978.   72 The Feasibility of Phosphorus-31 SWIFT and ZTE Dental MRI
Yi Sun1,2, Djaudat Idiyatullin3, Donald R. Nixdorf4,5, X.Frank Walboomers6, Egbert Oosterwijk2, Michael Garwood3, and Arend Heerschap1
1Radiology, Radboud University Medical Center Nijmegen, Nijmegen, Netherlands, 2Urology, Radboud University Medical Center Nijmegen, Nijmegen, Netherlands, 3Center for Magnetic Resonance Research, University of Minnesota, Minnespolis, MN, United States, 4Department of of Diagnostic & Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States, 5Department of Neurology, Medical School, University of Minnesota, Minneapolis, MN, United States, 6Dentistry, Radboud University Medical Center Nijmegen, Nijmegen, Netherlands

 
Dental X-ray has several disadvantages, including an increased risk for meningioma, necessitating to consider other imaging options. It has been demonstrated that 1H MRI by the SWIFT technique can offer high-resolution diagnostic images of human teeth. However, dental MRI focuses on 1H, while the main content of human tooth is crystalline calcium phosphate. Therefore we explored the feasibility of 31P SWIFT and ZTE MRI of teeth to obtain direct information of phosphate constituents. We demonstrate that this is possible and in combination with 1H MRI can identify the anatomy of tooth and has the potential to determine bone phosphate density.

 

ELECTRONIC POSTER SESSION • MR SPECTROSCOPY
Wednesday, 24 April 2013 (11:00-12:00) Exhibition Hall
MR Spectroscopic Imaging

  Computer #  
3979.   49 Fast Whole Brain Quantitative Proton Density Mapping to Normalize 1H MR Spectroscopic Imaging
Angèle Lecocq1, Yann Le Fur1, Alexis Amadon2, Alexandre Vignaud2, Monique Bernard3, Maxime Guye1, and Jean-Philippe Ranjeva1
1CRMBM, CNRS, Aix-Marseille Univ, MARSEILLE, France, 2LRMN/NeuroSpin/I2BM/CEA, GIF SUR YVETTE, France, 3Aix-Marseille Université, MARSEILLE, France

 
In order to normalize CSI water spectrum to obtain signal normalized MR spectroscopic imaging, absolute ρ-maps have to be computed from T1 and T2* maps accounting for B0 and B1 corrections. In this work, we present a very fast method to generate these ρ-maps. A method called XEP recently proposed to obtain fast B1-maps, was combined with a DESPOT1 sequence, an optimized variable flip angle T1 mapping sequence and a conventional T2* mapping sequence. We first validated this method on phantom, and determined proton density maps in three healthy volunteers also explored by CSI technique.

 
3980.   50 Mapping of Brain Metabolite Distribution by Short Echo Time Echo Planar Spectroscopy Imaging (EPSI)
Angèle Lecocq1, Yann Le Fur1, Andrew A. Maudsley2, Sulaiman Sheriff2, Mohammad Sabati2, Virginie Callot3, Monique Bernard4, Maxime Guye1, and Jean-Philippe Ranjeva1
1CRMBM, CNRS, Aix-Marseille Univ, MARSEILLE, France, 2Department of radiology, Miller School of Medicine, University of Miami, MIAMI, Florida, United States, 3Aix-Marseille University, MARSEILLE, France, 4Aix-Marseille Université, MARSEILLE, France

 
Detection of abnormal global quantification of metabolites in case of diffusive pathologies, or abnormal metabolites spatial distribution for local pathologies, required the knowledge of variations in metabolites relative concentration across whole healthy brains. Nevertheless, there is a lack of metabolite quantitative information using a short echo time technique. In this study, we aimed to provide normative values of three major metabolites (Choline, N-Acetyl-Aspartate and Creatine) using a recent whole brain MRSI sequence called Echo Planar Spectroscopy Imaging (EPSI) with short echo time (20ms).

 
3981.   51 Statistical Strategy to Overcome Estimation Bias in CRLB Threshold Approach for LCModel Analysis of MRS
Ping-Chang Lin1, Phil Lee1,2, Wen-Tung Wang1, William Brooks1,3, and In-Young Choi1,2
1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States, 2Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States, 3Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States

 
in vivo 1H MRS, particularly acquired at high magnetic fields, is beneficial to noninvasive study of changes in neurochemicals such as characterization of the disease progression and diagnosis of disease in early stages. LCModel analysis has been subject of intense activity in analyzing 1H MRS; however, there is no agreement in valid exhibition of metabolite concentrations in statistics. In this work we utilize weighted analysis of rat brain 1H MRS to demonstrate alternative exhibition of the concentration averages for the neurochemical profiles, in addition to investigation of the effect of threshold values on the averaged metabolite concentrations.

 
3982.   52 Multi-Center Reproducibility of Short Echo Time Single Voxel 1H MRS of the Human Brain at 7T with Adiabatic Slice-Selective Refocusing Pulses
B.L. van de Bank1, Uzay E. Emir2, Vincent Oltman Boer3, Jack JA van Asten1, Jannie P. Wijnen3,4, H.E. Kan4, G. Öz2, Dennis W. J. Klomp3, and Tom W.J. Scheenen1,5
1Radiology, Radboud Nijmegen Nijmegen Medical Center, Nijmegen, Netherlands, 2Center for Magnetic Resonance Research, Minneapolis, Minnesota, United States, 3Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 4Radiology, Leiden University Medical Center, Leiden, Netherlands, 5Erwin L. Hahn Institute, Essen, Germany

 
The reproducibility and robustness of the semi-LASER sequence was investigated at 7T. Seven volunteers were scanned twice each at 4 different 7T systems (2 Siemens & 2 Philips). Excellent quality spectra were obtained from gray and white matter at all sites. The within-subject variations and hence within-institution variations were low, meaning that the technique is robust and reproducible. Few between-institution variations were found.

 
3983.   53 Quantification and Reproducibility of L-COSY in Human Brain at 7T
Gaurav Verma1, Hari Hariharan2, Rajakumar Nagarajan3, Manoj K. Sarma3, Ravi Prakash Reddy Nanga2, Edward James Delikatny2, M. Albert Thomas3, and Harish Poptani1
1Department of Radiology and Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 3Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States

 
Localized correlated spectroscopy (L-COSY) was developed for use in 7T whole-body scanners. L-COSY was tested for reproducibility in the occipital lobe of six healthy volunteers, and tested for versatility by scanning differing anatomy including basal ganglia, frontal lobe, dorso-lateral prefrontal cortex and parieto-occipital region in two volunteers. 2D spectra showed distinct resonances of gamma-aminobutyric acid, glutathione, lysine, isoleucine, choline group and other metabolites with voxels as small as 15.6ml. After quantification with prior-knowledge based peak fitting, coefficients of variation of metabolite ratios were found comparable to existing L-COSY studies at lower field strengths.

 
3984.   54 Detection of Glutamate and Glutamine by RF Suppression and TE Optimization at 7T
Li An1, Shizhe Li1, James B. Murdoch2, and Jun Shen1
1National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States, 2Toshiba Medical Research Institute USA, Mayfield Village, OH, United States

 
Recently, Choi et al. proposed to use a TE optimized PRESS method at 7T to resolve glutamate and glutamine, taking advantage of the chemical shift offset artifact to suppress overlapping signals from the aspartyl moiety of NAA. In this work, we propose to suppress spectral interference from the aspartyl moiety of NAA by a selective RF pulse placed at the resonance frequnecy of the NAA aspartyl CH proton at 4.38 ppm, which alters the J-evolution of the NAA aspartyl CH2 multiplet at 2.5 ppm. The flip angle of this suppression pulse along with the sub-TEs are optimized for the detection of Gln and Glu.

 
3985.   55 ‘Glx’ Measured by J-Editing/MEGA-PRESS Is Primarily ‘Pure’ Glutamate…Or Is It?
Dikoma C. Shungu1, Xiangling Mao1, Meng Gu2, Matthew S. Milak3, Nora Weiduschat1, Dirk Mayer2,4, Daniel Spielman2, J. John Mann3, and Lawrence S. Kegeles3
1Radiology, Weill Cornell Medical College, New York, NY, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Psychiatry, Columbia University, New York, NY, United States, 4SRI International, Menlo Park, CA, United States

 
This study was undertaken to investigate the contribution of glutamine (Gln) to the combined glutamate (Glu)+Gln resonance (Glx) that is detected by the standard J-editing/MEGA-PRESS sequence. Toward this purpose, spectra of “pure” Glu were acquired with CT-PRESS and those of Glx were acquired with J-editing from the same voxels, in the same subjects, to assess the extent to which the two measures may correlate. A strong correlation would suggest that ‘Glx’ likely represents primarily "pure" Glu levels and, thus, can probably be interpreted as such.

 
3986.   56 Quantification of High-Resolution 1H[13C] NMR Spectra from Rat Brain Extracts
Robin A. de Graaf1, Golam M.I. Chowdhury1, and Kevin L. Behar1
1Yale University, MRRC, New Haven, CT, United States

 
Quantification of high-resolution 1H[13C] (or POCE) NMR spectra poses a number of challenges that are not addressed by currently available spectral fitting algorithms. The challenges pertain to the presence of 13C isotope shifts, decoupling sidebands and the need for independent multiplet amplitudes due to differential 13C label accumulation. The spectral fitting algorithm presented here can quantitatively accommodate all features of 1H[13C] NMR and provides a robust method for the automated processing of fractional enrichments and concentrations from in vitro and in vivo 1H[13C] NMR spectra.

 
3987.   57 7 Tesla In-Vivo Short-Echo-Time Single-Voxel 1H SemiLASER Spectroscopy: A Test/Retest Reproducibility Study
Jacob Penner1,2, Andrew T. Curtis1,2, Kyle M. Gilbert1, L. Martyn Klassen1, Joseph S. Gati1, Michael Borrie3,4, and Robert Bartha1,2
1Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, Ontario, Canada, 2Medical Biophysics, Western University, London, Ontario, Canada, 3Medicine, Western University, London, Ontario, Canada, 4Division of Aging, Rehabilitation, and Geriatric Care, Lawson Health Research Institute, London, Ontario, Canada

 
The purpose of this study was to quantify the metabolite level measurement test/retest reproducibility for a short-echo-time single-voxel 1H semiLASER spectroscopy protocol in human subjects at 7T. MRS data were obtained from the parietal-occipital region of 6 young healthy volunteers (mean age 28.0 ± 2.7 years). The same-day percent differences and the 1-week percent differences were found to range from 3 - 10%. The semiLASER MRS protocol produced high SNR at 7 Tesla and can be used to measure metabolite concentrations with high reproducibility, ideal for measuring metabolic changes in neuropathological conditions.

 
3988.   58 Quantitative Comparison of Shim Algorithms for In Vivo 1H-MRS
Xiaodong Zhong1, Yevgeniya M. Lyubich2, Timothy DeVito3, Saurabh Shah4, and Jack Knight-Scott2
1MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 2Department of Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States, 3Siemens Canada Limited, London, Ontario, Canada, 4MR R&D Collaborations, Siemens Healthcare, Chicago, IL, United States

 
In this study, we examined the robustness of three automated shimming techniques for single-voxel spectroscopy at 3T: FASTESTMAP, GRESHIM, and a standard vendor-offered product. Quantitative results across multiple brain regions over twelve participants – anterior and posterior cingulate, centruum semiovale, and temporal lobe along the sylvian fissure – showed that FASTESTMAP and GRESHIM provided the robustness and reliability necessary for quantitative assessment of spectra, while the vendor-supplied shimming technique had the poorest performance. Our results show that FASTESTMAP and GRESHIM greatly improve the reliability of clinical spectroscopy

 
3989.   59 Unsupervised Brain Tumor Tissue Differentiation Based on MRSI with Correction for the Chemical Shift Displacement Artifact
Diana M. Sima1,2, Sofie Van Cauter3, Yuqian Li4, Anca R. Croitor-Sava1,2, Uwe Himmelreich5, and Sabine Van Huffel1,2
1Electrical Engineering / ESAT-SCD, KU Leuven, Heverlee, Leuven, Belgium, 2Future Health Department, iMinds, Heverlee, Leuven, Belgium, 3Department of Radiology, University Hospitals Leuven, Leuven, Belgium, 4School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu, China, 5Department of Imaging & Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium

 
We propose and validate a new computational method for unsupervised tissue differentiation for brain tumor patients, based on short echo time 2D magnetic resonance spectroscopic imaging data, which takes into account possible spectral distortions due to significant Chemical Shift Displacement artifact.

 
3990.   60 Glycogen Chemical Exchange Effects in 1H-MRS and Glyco-CEST at 3T and 7T
Ronald Ouwerkerk1, Yee Kai Tee2, and Craig K. Jones3,4
1Biomedical and Metabolic Imaging Branch, NIH/NIDDK, Bethesda, MD, United States, 2Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom, 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 4Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States

 
Glycogen can be measured in vivo with localized 1<\sup>H-MRS or glycoCEST imaging. The chemical exchange between water and glycogen makes glycoCEST possible, but could lead to errors in water-suppressed 1H-MRS. We used glycoCEST and water-suppressed 1<\sup>H-MRS on glycogen phantoms in physiological buffers to investigate this error source. The CEST effect was limited to the downfield H1 proton of glycogen. Varying water-suppression RF power level showed saturation transfer H1, but not on the upfield glycogen protons. The glycoCEST water reduction correlated with the concentrations estimated with 1H-MRS on the upfield peaks. Thus, both methods could be used to study glycogen metabolism.

 
3991.   61 in-vivo Detection of GABA Using Short-TE MRS at 3 Tesla
Jamie Near1, Phil Cowen2, and Peter Jezzard3
1Centre d'Imagerie Cérébrale, Douglas Institute, McGill University, Montreal, Quebec, Canada, 2Department of Psychiatry, University of Oxford, Oxford, OXON, United Kingdom, 3FMRIB Centre, University of Oxford, Oxford, OXON, United Kingdom

 
In this study, we investigate the reproducibility of short-TE MRS measurements of GABA in the human brain at 3 Tesla. These investigations are performed through a) comparison of short-TE GABA measurements with gold-standard edited GABA measurements in the same voxel in-vivo, and b) assessment of within-session reproducibility of short-TE GABA measurements. Across 14 subjects, a significant positive relationship was observed between short-TE and edited GABA measurements (R=0.58, p<0.05), and the average coefficient of variation of multiple within-session short-TE GABA measurements was 8.7 ± 4.9%. These results suggest that short-TE MRS may provide a reliable option for quantitative detection of GABA at 3T.

 
3992.   63 The Influence of Chemical Shift Displacement on 1H MRS Quantitation at 3T Using a Simulated Basis Set
Martin Wilson1,2, Theodoros N. Arvanitis2,3, and Andrew C. Peet1,2
1School of Cancer Sciences, Birmingham, West Midlands, United Kingdom, 2Birmingham Children's Hospital, Birmingham, West Midlands, United Kingdom,3School of Electronic, Electrical & Computer Engineering, University of Birmingham, Birmingham, West Midlands, United Kingdom

 
In this study the effects of chemical shift displacement (CSD) on simulated basis set analyses are demonstrated for short-echo 3T MRS data collected from phantoms and patients. An improvement in fit quality was observed on metabolite phantom data when CSD effects are modelled in basis set simulation. A bias in lactate and lipid measurements was also apparent in brain tumour MRS data when CSD effects are omitted. In conclusion, CSD modelling is an important consideration for the measurement of coupled metabolites at 3T using simulated basis sets.

 
3993.   64 in vivo and Longitudinal Assessment of Brain Metabolism in Hepatic Encephalopathy Using 1H MRS
Cristina Cudalbu1, Valérie A. McLin2, Olivier Braissant3, and Rolf Gruetter4,5
1Laboratory for Functional and Metabolic Imaging (LIFMET), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, 2Département de l'Enfant et de l'Adolescent, Unité de Gastroentérologie, Hépatologie et Nutrition, Hôpitaux Universitaires de Genève (HUG), Geneva, Geneva, Switzerland, 3Service of Biomedicine, Lausanne University Hospital, Lausanne, Vaud, Switzerland, 4Laboratory for Functional and Metabolic Imaging (LIFMET), Center for Biomedical Imaging (CIBM), École Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 5University of Lausanne, University of Geneva, Lausanne, Geneva, Switzerland

 
We characterized for the first time the in vivo and longitudinal progression of HE in a model of CLD using 1H MRS and histology and consequently we were able to monitor changes in the brain osmolytes, neurotransmitters, antioxidants and cell swelling.

 
3994.   65 7T MR Spectroscopic Imaging in Localization of Surgically Treated Epilepsy
Jullie W. Pan1, R Bradley Duckrow1, Jason Gerrard2, Caroline Ong1, Lawrence Hirsch3, Stanley Resor, Jr4, Ognen Petroff3, Susan S. Spencer3, Hoby P. Hetherington5, and Dennis D. Spencer2
1Yale University School of Medicine, New Haven, CT, United States, 2Neurosurgery, Yale University School of Medicine, New Haven, CT, United States,3Neurology, Yale University School of Medicine, New Haven, CT, United States, 4Neurology, Columbia University School of Medicine, New York, NY, United States, 5Neurosurgery, Yale University, New Haven, CT, United States

 
The challenge in the surgical management of intractable epilepsy remains accurate localization. While the anatomically restricted location in medial temporal lobe epilepsy makes it a relatively well defined target, in neocortical epilepsy, accurate localization remains difficult. We have implemented 7T MR moderate echo TR/TE 1.5s/40ms spectroscopic imaging to study n=25 intractable epilepsy patients. The concordance between MRSI-identified metabolic abnormality and surgical resection was compared with patient outcome as defined by ILAE classes I-III (good) and IV-VI (poor). In n=25 patients we found a significant (p<0.001) relationship between outcome with concordance between NA/Cr abnormalities and surgical resection

 
3995.   66 Occipital Lobe Metabolic Aberrations in Alcohol Dependents: An in-vivo Proton Magnetic Resonance Spectroscopy Study
Deepika Bagga1, Namita Singh1, Shilpi Modi1, Pawan Kumar1, Debajyoti Bhattacharya2, Mohan Lal Garg3, and subash khushu1
1NMR Research Centre, INMAS, New Delhi, New Delhi, India, 2Department of psychiatry, Base Hospital, New Delhi, New Delhi, India, 3Department of Biophysics, Panjab University, chandigarh, chandigarh, India

 
Proton in vivo Magnetic Resonance Spectroscopy (MRS) study on occipital lobe was performed on alcohol dependents and healthy controls to look for the metabolic aberrations underlying the visual information processing deficits observed in alcohol dependents as assessed by PGIBBD(PGI-Battery of Brain Dysfunction).A significant reduction in NAA/Cr and Glx/Cr ratios and a significant increase in Cho/Cr and Ins/Cr ratios was observed which could possibly account for impaired visual skills (as indicated by higher dysfunction rating scores) in alcohol dependents.

 
3996.   67 in vivo MRSI Confirmation of Post Mortem Results for Metabolic Changes in Parkinson’s Disease
Adriane Gröger1, Rupert Kolb1, Rita Schäfer1, and Uwe Klose1
1Department of Diagnostic and Interventional Neuroradiology, Magnetic Resonance Research Group, University Hospital Tübingen, Tübingen, Germany

 
Parkinson’s disease (PD) is a frequent neurological disorder and cause of neuron loss is not understood yet. Discovering metabolic changes within the substantia nigra (SN) could help for early diagnosis. In previous work we performed 3D-MRSI in SN region and found significant differences in biochemical profiles of PD patients compared to age-matched controls and compared to patients with atypical Parkinsonian syndromes. These phenomenological results did not allow biochemical interpretation. Therefore, we refined the analysis of obtained 3D-MRSI spectra and found the expected decreases of NAA, creatine, glutathione and dopamine in PD patients in good agreement with post mortem data.

 
3997.   68 Interferon-Alpha Induced Metabolic Alterations in Basal Ganglia
Li Wei1, Anne Wilson2, Xiaoping P. Hu1, and Ebrahim Haroon2
1Department of Biomedical Engineering, Emory University, Atlanta, GA, United States, 2School of Medicine, Emory University, Atlanta, GA, United States

 
Chronic administration of interferon (IFN)-alpha (a pro-inflammatory cytokine) for the treatment of hepatitis C virus (HCV) infection is associated with depression and fatigue in 40-50% of patients. These behavioral outcomes have been correlated with alterations in glucose metabolism in basal ganglia (BG). In this study, we investigated metabolites changes in BG before and after IFN-alpha treatment in HCV infection patients. The result shows that Glx/Cre increased and mI/Cre decreased after 4 weeks of IFN-alpha treatment, likely indicating that interferon-alpha reduces the astrocyte function in BG and induces depression in HCV infection patients.

 
3998.   
69 Neuronal and Astrocytic Metabolites Exhibit Different Diffusion Behavior, as Observed by Diffusion-Weighted Spectroscopy at Ultra-Long Diffusion Times.
Chloé Najac1,2, Charlotte Marchadour1,2, Martine Guillermier1,2, Diane Houitte1,2, Philippe Hantraye1,2, Vincent Lebon1,2, and Julien Valette1,2
1CEA-MIRCen, Fontenay-aux-Roses, France, 2CEA-CNRS URA 2210, Fontenay-aux-Roses, France

 
Due to the specific intracellular compartmentation of brain metabolites, diffusion-weighted NMR spectroscopy is a unique tool to explore the intracellular space. In the present study, the dependence of the apparent diffusion coefficient (ADC) on the diffusion time td was measured for five brain metabolites up to ultra-long td (~2 s), in order to explore long-range cell geometry. Our data suggest that metabolites exhibit different behaviors depending on their compartmentation in neurons or astrocytes, probably arising from the different long range geometry (in particular spatial extension) of these two cell types.

 
3999.   70 Brain Metabolites Diffuse "Freely" in White and Grey Matters: New Insights Into Cellular Architecture by Diffusion-Weighted Spectroscopy in the Human Brain.
Chloé Najac1,2, Francesca Branzoli3, Itamar Ronen4, and Julien Valette1,2
1CEA-MIRCen, Fontenay-aux-Roses, France, 2CEA-CNRS URA 2210, Fontenay-aux-Roses, France, 3C. J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands, 4C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands

 
Diffusion-weighted spectroscopy allows probing the intracellular environment. Here we investigate the diffusion of NAA, creatine and choline at long td (from 100 to 720 ms) in two voxels containing different proportions of white matter (WM) and grey matter (GM) in the Human brain. Metabolite apparent diffusion coefficient (ADC) barely depends on td, neither in predominantly WM, nor predominantly GM voxels. The stability of metabolites ADC with td suggests that, in both tissues, observed metabolite diffusion is essentially free, as would occur parallel to long fibers. This study offers a unique insight into WM and GM cellular architecture.

 
4000.   71 Baseline Estimation in 1H-MR Spectroscopy Imaging of the Normal Brain; a Correlation Study Between Different Regions
Reza Rafiei1, Alireza Madadi1, Shaghayegh Karimi1,2, and Hamidreza Saligheh Rad1,2
1Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Tehran University of Medical Sciences, Tehran, Iran, 2Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran

 
Magnetic resonance spectroscopy (MRS) signal in the brain contains a wideband baseline, mainly originating from macromolecules and lipids, which overlaps major metabolites’ peaks and builds errors for the quantification process. In this paper, we have estimated the baseline of the MRS signal acquired from normal brains employing a frequency-domain algorithm, and exhibited the correlation between the baseline spectra estimated in different regions; white matter, gray matter, cerebellum and CSF of the normal brain, to be mapped to corresponding T2-weighted anatomical images, and resulting in a high correlations among the spectra in a specific tissue and low correlations otherwise.

 
4001.   72 Heterogeneity of Phosphorus-Containing Compounds Across Gray and White Matter in the Human Brain
Jonathan A. Dudley1,2, James C. Eliassen1,2, Melissa P. DelBello2, Stephen M. Strakowski1,2, Caleb M. Adler1,2, Wade Weber2, Martine Lamy1, Elizabeth M. Fugate1, Wen-Jang Chu1,2, and Jing-Huei Lee1,2
1Center for Imaging Research, University of Cincinnati, Cincinnati, OH, United States, 2Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States

 
Concentrations of phosphorus-containing metabolites were estimated in pure gray and white matter tissue by performing tissue regression analysis on combined anatomic and phosphorus MRSI data from thirty-six healthy subjects. Significant heterogeneity was observed for all metabolites as well as intracellular pH. The results indicate substantial differences in the brain bioenergetics and phospholipid metabolism between these tissue types which may partially elucidate various results from previous studies of various pathologies such as schizophrenia and Alzheimer's disease.

 

ELECTRONIC POSTER SESSION • MR SPECTROSCOPY
Wednesday, 24 April 2013 (10:00-11:00) Exhibition Hall
MRS Potpourri

  Computer #  
4002.   73 In Vivo 1H MRS Metabolic Profiles in Gad1 Haploinsufficient Mouse Brain
Su Xu1,2, Elizabeth M. Powell3, Andrew D. Marshall1,2, Rolicia F. Martin3, and Rao P. Gullapalli1,2
1Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States, 2Core for Translational Research in Imaging @ Maryland, Baltimore, Maryland, United States, 3Department of Anatomy & Neurobiolog, University of Maryland School of Medicine, Baltimore, Maryland, United States

 
The B6-Gad1tm1.1Bgc mouse expresses decreased levels of glutamic acid decarboxylase (Gad67), the main enzyme that converts glutamate to GABA and presumably are found in epilepsy, schizophrenia and bipolar disorders. Although effective therapies seek to increase GABA levels in vivo, GABA levels have never been established in vivo, nor has the potential compensatory regulation of excitatory neurotransmitters, such as glutamate in this animal model. In the present study, we demonstrate the feasibility of using in vivo high resolution localized 1H MRS in studies of B6-Gad1tm1.1Bgc mouse brain at 7 Tesla to show regional differences in neurotransmitter levels.

 
4003.   74 Evolution of the Hepatic Lipid Profile of the Adult Mouse - in Vivo and in Vitro 1H MRS Assessments at 14.1T
Ana Francisca Soares1, Hongxia Lei2, and Rolf Gruetter3,4
1LIFMET, EPFL, Lausanne, Vaud, Switzerland, 2Department of Radiology, University of Geneva, Geneva, Geneva, Switzerland, 3LIFMET, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 4University of Lausanne, Lausanne, Vaud, Switzerland

 
The hepatic lipid content and composition were assessed in healthy mice throughout adulthood. It was found that aging and obesity contributed to increase the amount of lipids in the liver while decreasing the poly-unsaturation degree. The combination of in vivo 1H MRS assessments with in vitromeasurements on tissues extracts illustrated the important contribution of membrane lipids to the total poly-unsaturation degree of the fatty acyl chains. Changes of the unsaturation profile of cytosolic lipids can be monitored by in vivo 1H MRS, which is of interest for the study of genetic and diet-induced mice models of metabolic diseases.

 
4004.   75 In Vivo 1H MRS at 14.1T for the Accurate Characterization of the Lipid Profile of the Mouse Liver
Ana Francisca Soares1, Hongxia Lei2, and Rolf Gruetter3,4
1LIFMET, EPFL, Lausanne, Vaud, Switzerland, 2Department of Radiology, University of Geneva, Geneva, Geneva, Switzerland, 3LIFMET, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 4University of Lausanne, Lausanne, Vaud, Switzerland

 
1H MRS was employed at 14.1T to non-invasively quantify the lipid content of small samples (8-15 µl). In the mouse liver, good spectral stability was achieved by running individual scans within one breathing cycle. Ultra short TE STEAM with water suppression was used to estimate the unsaturation profile of the fatty acyl chains. This method was in good agreement with in vitro measurements in phantoms. High field is advantageous to accurately characterize the lipid profile of small samples such as the volumes selected in the liver of mice, with no need to increase the acquisition time for sensitivity gain.

 
4005.   76 A Multiparametric MR Approach for Comparative Assessment of Neurometabolites and Brain Microstructural Changes in Mice Model for Cranial and Whole Body Radiation Exposure
Poonam Rana1, Mamta Gupta1, Richa Trivedi1, B.S.Hemanth Kumar1, Ravi Soni2, Ram Kishore Singh Rathore3, Rajendra P. Tripathi1, and Subash Khushu1
1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, Delhi, India, 2Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, Delhi, India, 3Department of Mathematics and Statistics, Indian Institute of Technology, Kanpur, Uttar Pradesh, India

 
Understanding the early differential response of brain during radiation exposure is significant for better injury management during accidental or intentional exposure to ionizing radiation. The present study based on DTI and 1H MRS was conducted to investigate the early microstructural and metabolic profiles in mouse brain following whole body radiation or cranial radiation exposure. The results exhibited more DTI based FA and MRS based metabolic changes in whole body radiation group compared to cranial irradiation group. This disparity in response could be due to involvement of systemic inflammatory response of central nervous system in case of whole body irradiation only.

 
4006.   77 Antidepressant Like Effects of Magic ‘K’ Drug at Subanaesthetic Doses in CMS Rat Model of Depression as Detected by In Vivo 1H-MRS at 7T.
B.S. Hemanth Kumar1, Neha Sharma1, Renu Yadav1, Poonam Rana1, Rajendra P. Tripathi1, and Subash Khushu1
1NMR Research Centre, INMAS-DRDO, Newdelhi, Newdelhi, India

 
Chronic Mild Stress (CMS) regime was applied to develop depression model in rats and the model was validated using behavioural studies. Magnetic Resonance Spectroscopy (MRS) was acquired on (8 each) Control, CMS, Ctrl+Sal, Ctrl+Ket, CMS+Sal and CMS+Ket rats in hippocampus region to look for the neurometabolite changes during the early onset of depression and to effect of ketamine in depression. The concentrations of the neurometabolites were calculated for analysis. Primarily, the study revealed the metabolite fluctuations, altering the glial physiology in hippocampus of CMS rats later they started to revert back after the ketamine infusion. We conclude that there could be a neuroinflamation process occurring in the glia and the neurons but they started recovering after ketamine injection suggesting a repair process taking place because of ketamine drug.

 
4007.   78 Whole Body Radiation Exposure Induced Neuometabolic Alteration in Murine Brain: An in-vivo Approach of 1H and 31P MR Spectroscopy
Ahmad Raza Khan1, Poonam Rana1, Hemanth BS Kumar1, Shilpi Modi1, Saleem Javed2, and Subash Khushu1
1NMR Research Centre, Institute of nuclear medicine and allied sciences, Delhi, Delhi, India, 2Department of Biochemistry, Jamia hamdard, New Delhi, Delhi, India

 
Past few decades greater exploitation of nuclear material leads to intentional and unintentional radiation exposure cause bad impact on human health. Present study was performed to ascertain neurometabolic alteration in normal appearing brain after whole body radiation exposure. The study utilizes whole body exposure of 3 and 5 Gy radiation dose on mice and neurometabolites level were quantified in brain with 1H/31P MR Spectroscopy. The study reveals significant decrease in NAA level of hippocampus of the brain at day 30 post irradiation in both the groups while disturbed brain energy metabolism was observed in 5 Gy dose group only.

 
4008.   79 Comparison of 3D Imaging Sequences for 23Na MRI of in Vivo Kidney at 9.4 T
Raffi Kalayciyan1, Sabine Neudecker2, Norbert Gretz2, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2Medical Research Center, Heidelberg University, Mannheim, Germany

 
Sodium (23Na) MRI is a unique imaging modality giving essential information on cellular level, which may help to understand renal physiology, pathologies, as well as the pharmacological effect of drugs. In this study we compared the Gradient Echo (GRE-3D) and the Chemical Shift Imaging (CSI-3D) sequences with the Ultra-Short Time-to-Echo (3D-UTE) sequence regarding effective spatial resolution in a resolution phantom, and regarding SNR/time in rodent kidney tissue.

 
4009.   80 In Vivo 3D Spectroscopic Imaging of 19F Compounds Using Backprojection
Muhammed Yildirim1,2, Raquel Díaz-López3, Klaas Nicolay2, and Rolf Lamerichs3,4
1MR Development, Advanced Diagnostic Imaging, Philips Healthcare, Best, Netherlands, 2Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands, 3Philips Research, Eindhoven, Netherlands, 4Academic Medical Center, Amsterdam, Netherlands

 
Combination of Fluorine ultrafast Turbo Spectroscopic Imaging (F-uTSI) sequence with backprojection acquisition and reconstruction allows 3D fluorine hot-spot images to be obtained in shorter times and with higher sensitivity in comparison to all phase encoded 3D acquisition. The technique has been used to image orally administered perfluoro octyl bromide (PFOB) containing polymeric microcapsules in the gastro-intestinal tract of black mice. In vivo results revealed a scan time reduction of 40% and SNR gain up to 75%, with excellent spatial resolution of 1 mm along all imaging axes.

 
4010.   
81 A 3T Sodium and Proton Breast Array
Joshua D. Kaggie1,2, J. Rock Hadley1, James Badal3, John R. Campbell3, Daniel J. Park3, Dennis L. Parker1, Glen Morrell1, Rexford D. Newbould4, Alexandra F. Wood3, and Neal K. Bangerter1,3
1Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, 2Physics, University of Utah, Salt Lake City, UT, United States, 3Electrical and Computer Engineering, Brigham Young University, Provo, UT, United States, 4Imanova Centre for Imaging Sciences, London, United Kingdom

 
This work presents a novel dual resonant breast coil design for combined sodium and proton breast MRI with increased SNR. The coil consists of a 7-channel sodium receive phased array, a large sodium transmit coil, and a 4-channel hydrogen transceive array. A coil layout with intersecting sodium and proton elements to decrease sodium shielding effects is also demonstrated. The new phased array coil demonstrates a 2-5x improvement in SNR for sodium imaging when compared to a simple single-loop dual resonant design. Improved sodium SNR will potentially enable better assessment of small breast lesions and more accurate measures of tissue.

 
4011.   82 Measurement of Brain Metabolites Using a Lactate Enhanced Detection Chemical Shift Imaging (LED-CSI) Pulse Sequence
Xian-Feng Shi1,2, Andrew Paul Prescot2,3, Young-Hoon Sung1,2, Douglas Kondo1,2, Seong-Eun Kim3, Eun-Kee Jeong2,3, and Perry F. Renshaw1,2
1Department of Psychiatry, University of Utah, Salt Lake City, Utah, United States, 2The Brain Institute, University of Utah, Salt Lake City, Utah, United States, 3Department of Radiology, University of Utah, Salt Lake City, Utah, United States

 
Numerous reports indicate that the elevated brain lactate levels are present in patients with psychiatric disorders. One hypothesis is that oxidative metabolism using glucose is dysfunctional. Therefore, glycolytic conversion of pyruvate to lactate acid is activated to compensate for an insufficient energy supply in order to maintain normal brain activity. The challenge associated with lactate detection at TE=135 ms is signal nulling due to the four compartment artifact. A lactate enhanced detection chemical shift imaging pulse sequence (LED-CSI) is developed by applying a nonselective RF pulse to minimize the four compartment artifact and enhance lactate signal detection.

 
4012.   83 In Vivo Cardiac Cine 23Na MRI in Rats
Maurits A. Jansen1, Urte Kägebein1, Friedrich Wetterling2, Gillian A. Gray1, and Ian Marshall1
1Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, Midlothian, United Kingdom, 2Faculty of Engineering, Trinity College Dublin, Dublin, Leinster, Ireland

 
Absolute tissue sodium concentration is elevated in myocardial infarction and has been suggested as a biomarker for cell viability. We show here for the first time a new 23Na chemical shift imaging method for imaging of the in vivo rat heart during several different phases of the cardiac cycle with sufficient spatial resolution. This method offers a new tool for studying myocardial ion homeostasis in vivo and may be of interest for different areas of cardiovascular disease, e.g. myocardial infarction, myocardial hypertrophy, but could also be used to study other organs like kidney, liver or tumours.

 
4013.   84 A Novel Method to Obtain High Resolution 2D MRS Through 3D Acquisition Under Large Inhomogeneous Magnetic Fields
Yanqin Lin1, Liandi Zhang1, Shuhui Cai1, and Zhong Chen1
1Department of Electronic Science, Xiamen University, Xiamen, Fujian, China

 
High resolution magnetic resonance spectroscopy (MRS) plays an important role in in vivo study. However, in many cases, the inherent heterogeneity of the samples or living organisms under investigation leads to field fluctuations and losses of local homogeneity. This would degrade spectral quality. Here, a pulse sequence based on coherence transfer and spin echo is designed to obtain high-resolution 2D MRS in the presence of large field inhomogeneity. The resulting spectrum display chemical shift differences and J coupling splitting in two orthogonal dimensions. The technique developed here can be applied potentially for in vivo high resolution MRS under inhomogeneous field.

 
4014.   85 An Optimized Room-Temperature RF-Surface Resonator for in vivo Potassium-39 MRI at 9.4 T - Simulation and Measurement Study for Cryogenic Coils
Ibrahim A. Elabyad1, Raffi Kalayciyan1, Nagesh Shanbhag2, Lothar Schilling2, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2Division of Neurosurgical Research, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany

 
Potassium-39 (39K) Magnetic Resonance Imaging (MRI) is a non-invasive technique which could potentially allow for detecting intracellular physiological variations in common human pathologies such as stroke and cancer. However, the low signal-to-noise ratio (SNR) achieved in 39K-MR images hampered data acquisition with sufficiently-high spatial and temporal resolution in animal models so far. In order to improve the detector SNR gain, its optimal size, geometry, and temperature were determined via electromagnetic (EM) simulations and bench-top measurements. An optimized single-loop room-temperature surface resonator was then developed and tested for 39K-MRI of a healthy live rat brain. Compared to the previous published results of a triple resonant coil (1H, 23Na, and 39K), the developed resonator improve the SNR eight times with twice faster acquisition time. As experienced in the EM-simulations cryogenic-cooling of the optimal single-loop coil could further improve the SNR gain three-fold at 77 K and up to six-fold at 20 K. These significant results could further improve the available signal in future 39K-MR imaging studies of the rat brain at 9.4 T.

 
4015.   86 Empirical Modeling of B1 Inhomogeneity Correction for Absolute Quantitation of Hepatic Glycogen Using Non-Localized 13C MRS
Navin Michael1, Pola Arunima1, Sendhil S. Velan1,2, and Adam Schwarz3
1Singapore Institute for Clinical Sciences, 30, Medical Drive, Singapore, 2Clinical Imaging Research Centre, 14, Medical Drive, Singapore, 3Eli Lilly and Company, Indianapolis, IN, United States

 
The different thickness of subcutaneous fat is a confounding factor in the absolute quantitation of hepatic glycogen using non localized 13C spectroscopy, due to the B1 field inhomogeneity of the 13C surface coils.This makes the comparison of glycogen levels across different subjects difficult. In this work, a new empirical B1 correction model is proposed that can be used to compensate the effect of the B1 inhomogeneity for different coil-liver distances. The proposed model has the advantage of being easily incorporated into post-processing protocols and does not require additional B1 field mapping sequences during the in-vivo scans.

 
4016.   87 In Vivo 3D 31P MR Spectroscopic Imaging of Human Brain Tumors Growing Orthotopic in the Mouse
Andor Veltien1, Morteza Esmaeili2, Bob C. Hamans1, Anneke C. Navis3, Tone Frost Bathen2, Ingrid Susann Gribbestad4, William P. Leenders3, and Arend Heerschap1
1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 2Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, 3Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 4Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway

 
By In vivo 31P MRS it is possible to observe the resolved signals of some key lipid and high energy metabolites and therefore this is an important technique to study tumor biology, to evaluate treatments and to identify diagnostic biomarkers. For studies of brain tumors it is also relevant to be able to perform localized 31P MRS of orthotopically growing tumors in the brain of mouse. In this work we demonstrate that 31P MRSI of high quality can be obtained of 4 different human glioma growing in the mouse brain.

 
4017.   88 Effect of J-Coupling on Lipid Composition Determination in vivo Using Proton MRS
Atiyah Yahya1,2
1Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada, 2Department of Oncology, University of Alberta, Edmonton, Alberta, Canada

 
Lipid measurements by proton MRS are relevant to the study of a number of diseases. Most lipid protons exhibit scalar coupling interactions complicating their response to in-vivo MRS pulse sequences such as PRESS. The presented educational abstract describes J-coupling effects on the quantification of lipid peaks and consequently on lipid composition determination. In addition, methods that have been employed to compensate for these effects are described in addition to their limitations.

 
4018.   89 Metabolomics of Breast Cancer Serum Using 1H Nuclear Magnetic Resonance Spectroscopy
Ashish Gupta1, Pooja Ramakant2, Pushplata Sankhwar3, and Navneeta Bansal4
1Centre of Biomedical Magnetic Resonance, SGPGIMS Campus, Lucknow, UP, India, 2Endocrine and Breast Surgery, Department of Surgery, Christian Medical College, Vellore, Tamil Nadu, India, 3Department of Obstetrics & Gynecology, King George’s Medical University, Lucknow, UP, India, 4Department of Biochemistry, King George’s Medical University, Lucknow, UP, India

 
A novel combining approach of 1H NMR spectroscopy of serum metabolite profile and linear multivariate discriminant function analysis (DFA) was carried out to identify the differential biomarkers of breast cancer (BC). The study was conducted on 60 healthy women and women with breast disorders-mainly malignant (n = 60) and fibroadenoma and cystosarcoma phylloides (n = 65). DFA reveals that 1H NMR measured metabolites can differentiate (99.9%) not only between healthy controls and breast disordered samples but also malignant and non-malignant breast tumors (99%). This novel approach may serve as a rapid and promising surrogate diagnostic probe for screening breast disorders.

 
4019.   90 Differentiation of Cervical Tubercular with Non-Reactive Lymphadenitis Tissues by Proton HR-MAS NMR Spectroscopy
Raja Roy1, Shatakshi Srivastava1, Kushagra Gaurav2, Surender Kumar2, Madhu M. Goel3, Rajiv Garg3, and Abhinav A. Sonkar2
1Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India, 2General Surgery, King George’s Medical University, Lucknow, Uttar Pradesh, India, 3King George’s Medical University, Lucknow, Uttar Pradesh, India

 
In the present work, proton HR-MAS NMR spectroscopic studies have been performed on human cervical lymph nodes incisional biopsy tissues specimens, obtained from 109 patients, for the identification of metabolic fingerprints in cervical tubercular lymphadenitis. Thirty metabolites were identified. Significant decrease in myo-inositol and increase in amino acids were observed in the spectra of tubercular tissues. The proton NMR spectra were then subjected to PCA and PLS-DA multivariate analysis. The validated model allowed >98% correct classification of tubercular from non-reactive tissues when compared with gold standard histopathological examination

 
4020.   91 Studies on Metabolic Alterations Due to Chronic Cold Stress: An NMR Based Metabonomics Apporach
Sonia Gandhi1, Subash Khushu1, Shubhra Chaturvedi2, and Rajendra P. Tripathi3
1NMR Research Centre, Institute of Nuclear Medicine & Allied Sciences, Delhi, Delhi, India, 2Division and Cyclotron & Radiopharmaceutical Sciences, INMAS, Delhi, Delhi, India, 3NMR Research Centre, INMAS, Delhi, Delhi, India

 
Chronic cold stress exposure results in increased sympathetic activity, immune suppression, gastrointestinal mucosal damage, affects central nervous system (CNS), hypovolemia, negative electrolyte balance & potential dysfunction to organs. Our study investigates the changes in metabolic profiles of urine in rats due to chronic cold stress & recovery using NMR spectroscopy. Results showed an increase & then decrease in metabolites such as 2-oxoglutrate, citrate, fumarate & N-methylnicotinamide indicating inhibition of TCA cycle & acclimatization to cold exposure. Significant increase in branched amino acid indicates kidney dysfunction. These studies can detect early biomarkers for cold stress injuries & develop strategies to combat variable climatic conditions.

 
4021.   92 Is the Metabolite Profile of a Single Muscle Biopsy Representative for the Tissue Under Investigation? a Reproducibility Study Using HR-MAS
Gaëlle Diserens1, Martina Vermathen2, Nicholas Thomas Broskey3, Chris Boesch1, Francesca Amati1,3, and Peter Vermathen1
1Depts. Clinical Research and Radiology, University Bern, Bern, Switzerland, 2Dept. of Chemistry & Biochemistry, University Bern, Bern, Switzerland, 3Dept. of Physiology, University of Lausanne, Lausanne, Switzerland

 
High resolution magic angle spinning was used to study how far the metabolite profile of a single biopsy can be considered representative for the tissue under investigation, i.e. how much do metabolites from biopsies of the same tissue vary. Metabolite variability was tested for separate human muscle biopsies collected from the same needle puncture by HR-MAS. Same needle biopsies harvested from the same muscles demonstrated similarities but also some differences in the metabolites content as obtained from HR-MAS. Therefore, the variability needs to be taken into account as different type of muscle cells will lead to differences in spectra.

 
4022.   93 Quantification of 1H NMR Spectra from Human Blood Plasma
Robin A. de Graaf1, Cosimo Giannini1, Sonia Caprio1, and Raimund I. Herzog1
1Yale University, MRRC, New Haven, CT, United States

 
1H NMR is a popular technique to detect several dozen metabolites in blood plasma. However, in order to become a quantitative and high-throughput method 1H NMR has to overcome several challenges, related to a dominant lipoprotein baseline and automated and objective spectral quantification. Here we present an approach that measures the lipoprotein signals separate from metabolite signals based on the large difference in diffusion. After the lipoprotein spectrum has been parameterized, it can be used as part of a spectral basis set in the subsequent quantification of the total (metabolites + lipoprotein) 1H NMR spectrum.

 
4023.   94 Tungsten Alloy Based Heavy Metals in Ammunition and Armament May Cause Metabolic Disturbances: A Urinary Metabolomic Approach
Ritu Tyagi1, Poonam Rana1, Mamta Gupta1, Ahmad Raza Khan1, Deepak Bhatnagar2, Rajendra P. Tripathi1, and Subash Khushu1
1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (INMAS), Delhi, Delhi, India, 2School of Biochemistry, Devi Ahilya University, Indore, Madhya Pradesh, India

 
HMTAs are composed of a mixture of tungsten (91–93%), nickel (3–5%) and either cobalt (2–4%) or iron (2–4%) particles which are increasingly adopted as the raw material to make parts of military products. 1H NMR spectroscopy based study has been conducted for identification of metabolite markers for tungsten alloy based heavy metals toxicity. Urine sample were collected at 8, 24, 72 and 120 h p.d. of low and high dose of tungsten alloy based heavy metals. Spectral Analysis exhibits impairment of energy metabolism which is suggestive of metabolic disturbances caused by tungsten alloy based heavy metals.

 
4024.   95 Stress Induced Alterations in the Metabolic Profile of Human Monocytes
Savita Singh1, Sujeet R. Mewar2, Uma Sharma2, Naranamangalam R. Jagannathan2, and H Krishna Prasad1
1Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India

 
Stress activates hypothalamic-pituitary-adrenal-axis; inducing production of glucocorticoids such as cortisol, The aim of the study was to identify metabolite, biomarker(s) of stress. Experiments were designed to assess the effect of dexamethasone, a synthetic glucocorticoid on the metabolic profile of monocytic THP1 cells. The metabolites generated by cells cultured in the presence/absence of dexamethasone were monitored by high-resolution NMR spectroscopy. Twenty-six metabolites were identified by 1D and 2D TOCSY plots. Seven metabolites namely, lactate, alanine, glutamine, glutamate, glutathione, choline and phosphorylethanolamine were significantly decreased in dexamethasone treated cells while three metabolites acetate, aspartate, and myo-inositol significantly increased in dexamethasone treated cells.

 
4025.   96 Optimizing the MAS Spinning Rate for NMR Studies of Live Spermatazoa
Jack Pearson1, Steven Reynolds2, Adriana Bucur2, Alan Pacey1, and Martyn Paley2
1Academic Unit of Reproductive & Developmental Medicine, University of Sheffield, Sheffield, Yorkshire, United Kingdom, 2Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom

 
 

ELECTRONIC POSTER SESSION • MR SPECTROSCOPY
Wednesday, 24 April 2013 (11:00-12:00) Exhibition Hall
MRS & Metabolism

  Computer #  
4026.   73 1H-MRS with Visual Stimulation in the Study of Brain Bioenergetics and Glu-Gln Dynamics in 3T
Felipe Rodrigues Barreto1 and Carlos Ernesto Garrido Salmon1
1Physics Department, University of Sao Paulo, Ribeirao Preto, SP, Brazil

 
Uncoupling between local blood flow and metabolic rate of oxygen consumption in the brain during increased neuronal activity suggests that non-oxidative metabolism should supply the additional energetic demand. In this study we evaluate metabolic changes in the visual cortex induced by photic stimulation in healthy young subjects using 1H-MRS in 3T. A total of 7 metabolites (NAA, Cho, Cr, Glu, Gln and Lac) were quantified and changes in Glu and Gln caused by stimulation were detected. Lac showed no statistical significant change during stimulation, however the correlation between Lac and Glu suggests coupling between both metabolites during increased neuronal activity.

 
4027.   74 Intracellular Redox State Revealed by 31P MR Spectroscopy Measurement of NAD+ and NADH Contents In Vivo  -permission withheld
Ming Lu1,2, Xiao-Hong Zhu1,2, Yi Zhang1,2, and Wei Chen2,3
1Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, Minnesota, United States, 2Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota, United States, 3Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States

 
NAD+ and NADH play key roles in cellular respiration of all living organisms. Intracellular redox state (RX) defined by the NAD+/NADH ratio is considered reflecting the cellular metabolic status and function, and it fluctuates in response to alterations in the physiology and/or pathology. To date, a non-invasive approach for directly measuring RX has been unavailable. In this study, we developed a novel 31P MRS-based method for non-invasive quantification of NAD+ and NADH contents in vivo. Using this approach, RX (2.6~3.0) and absolute contents of NAD+ (0.38~0.39 mM) and NADH (0.14~0.15 mM) were obtained in normal cat brains at 16.4T and 9.4T. Our results also indicated similar T1 values of NAD+ and NADH in normal cat brains at either magnetic field (1.58 s vs. 1.50 s at 9.4T; 0.82 s vs. 0.87 s at 16.4T). In summary, this new 31P MRS approach allows direct measurements of absolute NAD+ and NADH contents in vivo. For the first time, it provides an opportunity to non-invasively investigate the role of RX in brain functions and diseases. Also, it could readily be applied to study healthy or diseased human brains and other organs.

 
4028.   75 Fast & Localized 31P Saturation Transfer at 7T Reveals Slower Hepatic Metabolic Rates in NASH Patients
Ladislav Valkovic1,2, Martin Gajdosik1, Stefan Traussnigg3, Marek Chmelík1, Ivan Frollo2, Michael Trauner3, Siegfried Trattnig1, and Martin Krssák1,3
1MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, 2Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, 3Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria

 
The goal of this study was to test the feasibility of magnetization transfer (MT) for non-invasive distinction of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH). 31P-MRS MT measurements of ten suspected NAFLD/NASH and of four healthy subjects were performed on 7T system using surface coil (1H/31P). The NASH patients had significantly lower forward rate constants as compared to NAFLD patients and healthy volunteers. The measured chemical exchange rate between Pi and ATP as determined by the MT experiment correlated well with the histological data from liver biopsy, thus liver MT could be used for future NAFLD and NASH differentiation.

 
4029.   76 Quantification of Phosphoenolpyruvate in the Human Liver and Its Application in a Meal Study Employing 31P MRS
Alessandra Laufs1, Roshan Livingstone2, Maria Fritsch3, Julia Szendroedi4, Juergen Bunke5, Michael Roden1,6, and Jong-Hee Hwang1
1Institute for Clinical Diabetology, German Diabetes Center, Düsseldorf, Germany, 2Department of Radiology, Christian Medical College, Vellore, India,3Medical University of Vienna, Vienna, Austria, 4Institute for Energy Metabolism, German Diabetes Center, Düsseldorf, Germany, 5Philips Healthcare, Hamburg, Germany, 6Department of Metabolic Deseases, University Clinics Düsseldorf, Düsseldorf, Germany

 
Changes in phosphoenolpyruvate (PEP) concentrations of the liver were quantified before and after a high-carbohydrate meal using 31P MRS in six healthy subjects at 3T. Quantification of PEP was performed using matching phantoms and an external reference in order to correct for excitation pulse profile, coil loading, B1 field inhomogeneity, T1 relaxation time (T1 = 0.82 ± 0.16 s, separately assessed, N = 5)and the amount of liver fat. The concentration of PEP 140 min after the meal was significantly decreased from 1.14 ± 0.22 mmol/l to 0.86 ± 0.22 mmol/l (N = 6, p = 0.01, paired t-test).

 
4030.   77 Metastatic Breast Cancer Cells Have Higher Mitochondrial Function Than Isogenic Non-Metastatic Cells
Rui V. Simoes1, Ellen Ackestaff1, Inna Serganova2, Alexander A. Shestov3, Natalia Kruchevsky1, George Sukenick4, Ronald G. Blasberg2,5, and Jason A. Koutcher1,6
1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Neurology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States, 4NMR Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 5Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 6Weill Cornell Medical College, Cornell University, New York, NY, United States

 
Recent work with two isogenic breast cancer cell lines, 4T1 (highly metastatic) and 67NR (non-metastatic), showed that 4T1 cells have higher glycolytic activity and oxygen consumption than 67NR, although revealing no significant differences in relative growth in response to glucose and/or glutamine deprivation. Here we investigated the mitochondrial metabolism of both cell lines, using 13C MR spectroscopy with labeled substrates, oxygen consumption rate measurements and specific inhibitors of the mitochondrial respiratory complexes, and assessed the expression of succinate dehydrogenase by Western Blot. Our results support the association between increased mitochondrial metabolism and metastatic potential, observed recently in breast cancer patients.

 
4031.   78 Comprehensive Spectroscopic Investigation of Liver Metabolism – a Feasibility Study
Andreas Boss1, Ayse Sila Dokumaci1, Tania Buehler1,2, Roland Kreis1, and Chris Boesch1
1Depts Clinical Research and Radiology, University Bern, Bern, Switzerland, 2Institute of Myology, AIM and CEA, Paris, France

 
A comprehensive investigation of liver metabolism was performed using a triple tuned 1H/13C/31P-MRS surface coil to assess intrahepatic lipids (1H), glycogen (13C), phosphorous metabolites and the rate constant kPiright arrowATP using saturation transfer (31P). The coil and optimized protocol allowed a full examination in acceptable scan times (~1.5h) without repositioning. In a cross-over design, 6 male subjects were measured before and 3h after intake of either glucose or fructose to test the feasibility of this approach.

 
4032.   79 Editing Cancer Biomarker, 2-Hydroxyglutarate, with a Novel Proton Magnetic Resonance Spectroscopy
Napapon Sailasuta1, Jackson Hamilton2, Edward F. Jackson2, Pratip Bhattacharya2, William Perman3, Niki Zacharias2, Brian D. Ross1, and Ralph Noeske4
1HMRI, Pasadena, CA, United States, 2MD Anderson Cancer Center, University of Texas, Houston, TX, United States, 3Radiology, Saint Louis University, St. Louis, MO, United States, 4GEHealthcare, Berlin, Germany, Germany

 
We introduce a novel approach to measure 2-hydroxyglutarate,a cancer biomarker, using a oneshot simple proton MRS method suitable for human scan.

 
4033.   80 Left-Right Bias in Triglyceride Composition of Adipose Tissue Measured by 1H MRS
Gavin Hamilton1, Michael S. Middleton1, and Claude B. Sirlin1
1Department of Radiology, University of California, San Diego, San Diego, California, United States

 
In vivo Proton Magnetic Resonance Spectroscopy (1H MRS) can quantity the composition of triglyceride in adipose tissue in the human body. In this study we examine whether, at clinical filed strengths (3T), the location of the MRS voxel within the body has an effect on spectral uniformity and hence the measured composition of triglyceride, and whether using a reduced spectral range removes spatially introduced bias. We find using the full fat spectrum to measure triglyceride composition introduces a left-right bias which is removed if the fat peaks in the 0.5-3.0 ppm range are used.

 
4034.   81 Assessment of Nonalcoholic Fatty Liver Disease by 1H-MRS Hepatic Lipid Profiling; a Preliminary Animal Study at 9.4T
Yunjung Lee1 and Hyeonjin Kim1,2
1Radiology, Seoul National University Hospital, Seoul, Korea, 2Medical Sciences, Seoul National University, Seoul, Korea

 
The applicability of in-vivo 1H-MRS hepatic lipid profiling (MR-HLP) in nonalcoholic fatty liver disease (NAFLD) was investigated by estimating the relative fractions of diunsaturated (fdi), monounsaturated (fmono) and saturated (fsat) fatty acids in the livers of CCl4-treated rats at 9.4T. Steatosis and fibrosis are positively correlated with fmono and negatively correlated with fdi. In statistical analyses, MR-HLP parameters discriminated with 100% prediction accuracy those rats with severe steatosis and fibrosis from those with different severity of steatosis and fibrosis including those with severe steatosis and mild fibrosis. These findings support potential applicability of in-vivo MR-HLP at high field in NAFLD.

 
4035.   82 Quantitative 31P Magnetic Resonance Spectroscopy Stratifies Treatment Response to a PI3K/mTOR Inhibitor in Two Distinct Breast Cancer Xenografts  -permission withheld
Morteza Esmaeili1, Tone Frost Bathen1, Olav Engebråthen2,3, Gunhild Maelandsmo2, Ingrid Susann Gribbestad4, and Siver A. Moestue1
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, 2Institute for Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway, 3Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital Radiumhospital, Oslo, Norway, 4Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway

 
The phosphatidylinositol-3-kinase (PI3K) signaling pathway promotes cell proliferation and survival of cancer cells. Inhibitors of this pathway are under investigation as targeted anticancer treatments. The aim of this study was to develop a phosphorus high resolution magic angle spinning (31P HR MAS) magnetic resonance spectroscopy (MRS) protocol for quantifying phosphorylated metabolites of importance in two distinct breast cancer xenografts, and to use this method for identifying biomarkers for response to PI3K inhibition. In basal-like xenografts, BEZ235 treatment induced a significant decrease in PE whilst PC and GPC were significantly increased. No significant metabolic changes were observed in luminal-like xenografts.

 
4036.   83 31P MRS Shows Low Phosphocholine/Glycerophosphocholine in Paediatric Optic Pathway Gliomas
Jan Novak1,2, Martin Wilson1,2, Nigel Davies1,2, Theodoros N. Arvanitis2,3, and Andrew C. Peet1,2
1Cancer Sciences, University of Birmingham, Birmingham, West Midlands, United Kingdom, 2Birmingham Children's Hospital, Birmingham, West Midlands, United Kingdom, 3School of Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, West Midlands, United Kingdom

 
A 31P MRSI protocol has been developed using both phantoms and volunteers for the study of paediatric brain tumours in a clinically-acceptable timescale. This protocol was sensitive enough to pick up subtle differences in metabolite levels in different regions of the brain. The protocol has subsequently been implemented in paediatric patients with optic pathway gliomas with the data showing a low phosphocholine/glycerophosphocholine ratio. This is a potential biomarker indicating low grade nature despite the lesions being large enhancing tumours with a high total choline peak measured by 1H MRS, which are usually associate with high grade tumours.

 
4037.   84 Sex-Linked Difference of Metabolic Concentrations in Hippocampus in Sprague-Dawley Rats: A High Resolution in Vivo Proton MRS Study at 7 Tesla
Su Xu1,2, Andrew D. Marshall1,2, Nicholas Hilker1,2, and Rao P. Gullapalli1,2
1Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States, 2Core for Translational Research in Imaging @ Maryland, Baltimore, Maryland, United States

 
Although significant in vivo imaging research relies on the rodent model, very little has been reported on the gender based differences in neurometabolites among healthy rodents. The purpose of this study was to compare the metabolic concentrations obtained from normal age-matched Sprague-Dawley (SD) male, virgin female, and post-weaning female SD rats in hippocampus. We demonstrated a sex-linked difference of metabolic taurine concentration. The finding in our present study emphases the importance of sex-matching for studies investigating differences in neurometabolic concentrations.

 
4038.   85 Spatial Dependence of Metabolite Concentrations in Wild Type and ApcMin/+ Mouse GI Tissues: An ex-Vivo HR-MAS 1H NMR Spectroscopic Study
Basetti Madhu1, Uribe-Lewis Santiago1, Murrell Adele1, Griffiths R. John1, and Griffiths R. John1
1Cancer Research UK Cambridge Institute, Cambridge, United Kingdom

 
The ApcMin/+ mouse is a genetically engineered cancer mouse model that spontaneously develops tumours in the gastrointestinal (GI) tract. Here we have investigated the spatial dependence of the metabolic characteristics of the GI tissues of wild type and ApcMin/+ mice using HRMAS 1H NMR spectroscopy. We found metabolite concentration gradients of alanine, choline, Glx (glutamine and glutamate) and total-creatine (t-Cr) as we moved from stomach to colon along the small intestine in both wild type and ApcMin/+ mice. These metabolite variations were maintained in normal tissues adjacent to the tumours in ApcMin/+mice but were disrupted in tumour tissues themselves. In addition all the estimated metabolites were found to be higher in tumour tissue, significantly greater with increased distance from the stomach, which correlates with increased tumour frequency in the distal part of the small bowel GI tract of ApcMin/+.

 
4039.   86 Quantitative Two-Dimensional Correlated Spectroscopy in Gliomas with IDH Gene Mutation
Hyeon-Man Baek1, Yun-Ju Lee1, Eun-Hee Kim1, Chaejoon Cheong1, and Seung-Ho Yang2
1Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chungbuk, Korea, 2Neurosurgery St. Vincent's Hospital, Catholic University, Suwon, Gyeonggi-do, Korea

 
We present here that 900MHz 2D-COSY NMR can be used to obtain quantitative information of 2HG and to detect metabolic alterations in gliomas with IDH1/2 gene mutation. The measured 2HG levels in this work ranged from 0.12 to 5.64 (mean plus-or-minus sign SD, 2.38 plus-or-minus sign 1.63) lower case Greek mumol/g, which is consistent with our 1D 1H-NMR value (e.g., 0.29 plus-or-minus sign 5.79 lower case Greek mumol/g). The present study demonstrates the feasibility of multi-dimensional NMR technique in the detection and quantification of 2HG as a novel biomarker of IDH1/2 mutation status in glioma. In addition, our analysis revealed that a significant decrease in the concentrations of Glu, PC and Tau, and a significant increase of GPC, were observed in the IDH1/2 mutated tumors (P < 0.05).

 
4040.   87 Glutamate, GABA and NAAG in Medicated Patients with Obsessive-Compulsive Disorder
Mona A. Mohamed1, Nicolaas A. J. Puts1, James Robert Brasic2, Manuel O. Uy3, Jarunee Intrapiromkul1, Gerald Nestadt4, Richard Anthony Edward Edden5, and Peter B. Barker5
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States, 2Radiology, Johns Hopkins Medical Institutions, Baltimore, MD, United States, 3Applied Physics Laboratory, JHU, Laurel, MD, United States, 4Psychiatry, Johns Hopkins Medical Institutions, Baltimore, MD, United States, 5The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States

 
Through magnetic resonance spectroscopy (MRS) editing technique for GABA, NAA and NAAG, our findings suggests that there is no significant differences found in these brain metabolites concentrations in the anterior cingulate cortex (ACC) or the basal ganglia/thalamus (BG/TH) regions of OCD patients as compared to controls.

 
4041.   88 Environmental Stimulation During Development Modulates Individual Behavioural and Neurochemical Responses to Cannabinoid Agonists in Mice: A 1H MRS Study
Luisa Altabella1, Chiara Ceci1, Simone Macri'1, Rossella Canese2, and Giovanni Laviola1
1Cell Biology and Neuroscience, Istituto Superiore di Sanita', Rome, Rome, Italy, 2Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Rome, Italy

 
Adverse environmental conditions may increase the vulnerability towards the effects of the consumption of psychoactive drugs. Conversely, stimulating environmental conditions may exert a protective or compensatory role. Hypothalamic-pituitary-adrenal (HPA) system and the endocannabinoid system (ECS) interact to modulate the expression of emotions. An adolescence treatment in mice with endocannabinoid JWH-018 is studied in adulthood with 1HMRS in combination with a neonatal corticosterone administration (LC) or environmentally enriched (EE) housing after weaning. Major finding indicates that both stresses (LC or EE) can revert the JWH-018 effects in several metabolite concentrations in PFC and Hip.

 
4042.   89 High-Resolution Localized 1H Magnetic Resonance Spectroscopy of Red Bone Marrow Via IDQC Technique at 7T
Jianfeng Bao1, Congbo Cai2, Shuhui Cai1, Xiaohong Cui1, and Zhong Chen1
1Department of Electronic Science, Xiamen University, Xiamen, Fujian, China, 2Department of Communication Engineering, Xiamen University, Xiamen, Fujian, China

 
The local B0 field within red bone marrow is very inhomogeneous and common localized 1H magnetic resonance spectroscopy (MRS) can only give two rough peaks (water and fat peak). Other fat peaks which may contain more information for clinic diagnosis are not well resolved. We proposed a novel localized 1H MRS method based on intermolecular double quantum coherence technique to enhance the resolution of red bone marrow spectrum. Contrast to common MRS, six additional fat peaks including monounsaturated (5.3 ppm) and polyunsaturated (3.0 ppm) fat peaks are well resolved.

 
4043.   90 13C-NMR Spectroscopy in the Detection of 2-Hydroxyglutarate as a Novel Biomarker of IDH Mutation Status in Glioma
Hyeon-Man Baek1, Yun-Ju Lee1, Eun-Hee Kim1, Chaejoon Cheong1, and Seung-Ho Yang2
1Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chungbuk, Korea, 2Neurosurgery St. Vincent's Hospital, Catholic University, Suwon, Gyeonggi-do, Korea

 
We present here that the data analysis of 1H- and 13C-NMR spectra of the tumor extracts can demonstrate a significant increase in the concentration of 2HG in IDH mutated tumors. On 13C-NMR spectra, 2HG peaks for each of the 5 carbons were detected in the IDH1 mutated but not IDH wild type tumors. 2HG 13C-resonances (C3, C4, C2, C1, and C5) were detected at 31.70, 34.18, 72.79, 181.95, and 183.56 ppm. It is expected that 2HG may be actively being produced during the period of 13C-substrate infusion (e.g., [U-13C]-glucose). Therefore, the present study demonstrates the feasibility of 1H- and 13C-NMR spectroscopy in the detection of 2HG as a novel biomarker of IDH mutation status in glioma.

 
4044.   91 31P MRS Indicates Possible Effects of Transcranial Laser Therapy in an Animal Model
Dionyssios Mintzopoulos1, Clark E. Tedford2, Timothy E. Gillis1, and Marc J. Kaufman1
1McLean Imaging Center, McLean Hospital, Harvard Medical School, Belmont, MA, United States, 2PhotoThera Corporation, Carlsbad, CA, United States

 
Transcranial Laser Therapy (TLT) is a phototherapy exhibiting beneficial brain effects in stroke clinical trials and in preclinical studies of major depression, Alzheimer’s Disease, and traumatic brain injury. TLT stimulates mitochondrial metabolism by increasing cytochrome C oxidase (CCO) activity. We used phosphorus magnetic resonance spectroscopy to assess bioenergetic effects of acute and subchronic TLT in adult beagle dogs. Subchronic but not acute TLT increased anterior cingulate phosphocreatine/beta-nucleoside triphosphate ratios, which may reflect increased energy efficiency, possibly mediated by slowly evolving phenomena such as CCO protein transcription. Our findings warrant additional studies to further characterize TLT’s effects on brain metabolism.

 
4045.   92 Water Exchange Kinetics in the Isolated Heart Correlate with Na+/K+ ATPase Activity: Potentially High Saptiotemporal Resolution in Vivo MR Access to Cellular Metabolic Actiivity
Yajie Zhang1 and James A. Balschi1
1Medicine, Brigham and Women's Hospital, Boston, MA, United States

 
The extracellular relaxation agent, GdDTPA2- was used to distinguish intra- and extracellular 1H2O signals by altering their T1 values. Equilibrium trans-plasma membrane water exchange kinetics were quantified using two-site-exchange analysis to obtain the mean intracellular water life time (ôi ). Our studies found that ôi-1 (water exchange) correlated with Na+/K+ ATPase activity in isolated perfused rat hearts. Thus, ôi-1 acts as a biomarker for the cellular membrane transport activity. Potentially ôi-1 is altered in pathological states. ôi can be determined from pharmacokinetic analyses of in vivo 1H2O DCE-MRI studies. These findings could enable high resolution functional metabolic imaging.

 
4046.   93 Single Voxel MEGA-Edited GABA and Short TE 1H MRS in Hippocampus and Other Brain Regions Implicated in Bruxism
Shalmali Dharmadhikari1,2, Ulrike Dydak1,2, Mario Dzemidzic2,3, Laura Romito4, and Kenneth Byrd4,5
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, 3Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, United States,4Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, IN, United States, 5Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States

 
To establish the feasibility of in vivo GABA and other metabolite quantification in the brain regions implicated in bruxism, short TE and MEGA-edited GABA 1H MRS measurements were performed in bruxer and control subjects at 3 T. In vivo GABA measurement was successfully achieved in the hippocampus and group differences in major metabolites were detected in the hippocampus and thalamus.

 
4047.   94 Effect of Withania Somnifera on Seminal Plasma Metabolites of Infertile Males: A Proton NMR Study
Ashish Gupta1, Abbas Ali Mahdi2, Mohammad K. Ahmad2, Navneeta Bansal2, Pushplata Sankhwar3, and Satya Narain Sankhwar4
1Centre of Biomedical Magnetic Resonance, SGPGIMS Campus, Lucknow, UP, India, 2Department of Biochemistry, King George’s Medical University, Lucknow, UP, India, 3Department of Obstetrics & Gynecology, King George’s Medical University, Lucknow, UP, India, 4Department of Urology, King George’s Medical University, Lucknow, UP, India

 
Efficacy of Withania sonmifera (W. somnifera) were evaluated on metabolic profile of seminal plasma of infertile patients (n=180). Patients were administered (5g/day) W. somnifera root powder for three months. Lactate, alanine, choline, citrate, glycerophosphocholine (GPC), glutamine, tyrosine, histidine, phenylalanine, and uridine were measured in seminal plasma using 1H NMR spectroscopy. W. somnifera therapy repairs the disturbed concentration of lactate, alanine, citrate, GPC, histidine and phenylalanine in seminal plasma and recovers the quality of semen of post-treated infertile men with compared to pre-treated. Results suggest that W. somnifera may be used as an empirical therapy for infertility treatment and clinical management.

 
4048.   
95 Mitochondria-Targeted Antioxidant Promotes Recovery of Skeletal Muscle Mitochondrial Function After Burn Trauma
Valeria Righi1,2, Caterina Constantinou1,3, Dionyssios Mintzopoulos1,2, Laurence G. Rahme3, Hazel H. Szeto4, Ronald G. Tompkins5, and Aria A. Tzika1,2
1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, Massachusetts, United States, 2Department of Radiology, Athinoula A. Martinos Center of Biomedical Imaging, Boston, Massachusetts, United States,3Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, Massachusetts, United States, 4Department of Pharmacology, Joan and Sanford I, Weill Medical College of Cornell University, New York, NY, United States,5Department of Surgery, Massachusetts General Hospital and Shriners Burn Institute, Harvard Medical School, Boston, Massachusetts, United States

 
Severe burn injury causes a major systemic catabolic response that is associated with mitochondrial dysfunction in skeletal muscle. We investigated the effects of the mitochondria-targeted peptide antioxidant, SS-31, on skeletal muscle in a mouse model of burn using in vivo 31P NMR spectroscopy, to noninvasively measure high-energy phosphates, and mitochondrial aconitase activity measurements which directly correlates with TCA cycle flux. At 6 hours after burn, ATP synthesis rate was significantly increased in burned mice injected with a single dose of SS-31, as compared to burned mice alone. SS-31 administration in burned animals decreased mitochondrial aconitase activity back to control levels.

 
4049.   96 Cerebral Metabolic Changes in Diabetes Type 2 Studied Using in-vivo Proton MRS
Meera Ekka1, Uma Sharma2, Sanjiv Sinha1, and Naranamangalam R. Jagannathan2
1Department of Medicine, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India

 
In-vivo proton MR spectroscopy of brain in patients with diabetes type 2 and controls demonstrated significant changes in the concentration of N acetyl aspartate (NAA), glutamate (Glu) and glutamine (Gln) and glucose (Glc) metabolites in right frontal and right parieto-occipital regions of brain. The reduction in NAA reflects axonal or neuronal dysfunction or loss in neuronal density. Glucose may be increased during osmotic disturbances related to hyperglycemia in diabetes patients. Our findings demonstrated that Type 2 diabetes mellitus may cause cerebral metabolic changes which are indicative of slowly progressive neuronal dysfunction through an ischemic/hypoxic mechanism due to chronic hyperglycemia.