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Hyperpolarized Carbon-13 & Other Nuclei I Hall B Monday 14:00-16:00 Computer 7 14:00 3260. A DNP Polarizer Designed for Clinical Use Andrew M. Leach1, John Urbahn1, Denise Anderson1, Neil Clarke2, Timothy Skloss3, Jan Henrik Ardenkjaer-Larsen2 1GE Global Research, Niskayuna, NY, United States; 2GE Healthcare, Amersham, United Kingdom; 3GE Healthcare, Waukesha, WI, United States Provides a description of a novel hyperpolarizer design that incorporates specific characteristics required for clinical application including: 1) the ability to simultaneously process multiple doses; 2) no cryogen consumption; 3) a sterile product contained within a disposable fluid path; and 4) an integrated quality control system that rapidly measures six product characteristics to ensure agent safety and efficacy. The system has been demonstrated as a robust means to generate high volume doses for imaging studies. Device functionality and process capability will be discussed. Albert P. Chen1, Charles H. Cunningham2, James Tropp3, Kayvan Keshari4, Mark VanCriekinge4, John Kurhanewicz4, Ralph E. Hurd5 1GE Healthcare, Toronto, ON, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 3GE Healthcare, Fremont, CA, United States; 4Radiology, UCSF, San Francisco, CA, United States; 5GE Healthcare, Menlo Park, CA, United States The ability to accurately measure or predict the polarization of hyperpolarized 13C metabolic imaging substrates at the time of the MR experiment is necessary for quantitative kinetics data or metabolite concentrations. In this study, the feasibility of using asymmetry of the pyruvate C2 resonance (from 1% natural abundance of [1,2-13C2] pyruvate) to estimate the polarization of the [1-13C] pyruvate in vivo is demonstrated. Albert P. Chen1, Ralph E. Hurd2, Charles H. Cunningham3,4 1GE Healthcare, Toronto, ON, Canada; 2GE Healthcare, Menlo Park, CA, United States; 3Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 4Medical Biophysics, University of Toronto, Toronto, ON, Canada Metabolic imaging using pre-polarized substrates labeled with a 13C nucleus has proven to be a promising new tool. Often, chemical-shift imaging (CSI) acquisitions are used to map the 13C resonances over 2D or 3D volumes so that 13C metabolic data from various tissues can be compared. Due to the time constraints imposed by the relatively short lifetime of the hyperpolarized state, the spatial dimensions of these acquisitions are often encoded with small matrix sizes (e.g. 8 x 8 x 16), resulting in a relatively poor point-spread function (PSF). In this abstract, we have explored the use of non-Fourier spatial encoding to improve the PSF in both in-plane dimensions of hyperpolarized 13C CSI acquisitions. Phantom experiments showed an improved point-spread function and a rat study showed the feasibility of using the method for in vivo data acquisition. 15:30 3263. The Effects of Contrast Agents on Hyperpolarised [1-13C]-Pyruvic Acid Lanette Friesen Waldner1,2, Timothy Scholl3, Albert Chen4, Brian Rutt, 1,5, Charles McKenzie, 12 1Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada; 2Medical Biophysics, The University of Western Ontario, London, ON, Canada; 3Physics and Astronomy, The University of Western Ontario, London, ON, Canada; 4GE Healthcare, Toronto, ON, Canada; 5Diagnostic Radiology and Richard M Lucas Center for Imaging, Stanford University, Stanford, CA, United States The addition of small quantities of gadolinium based contrast agents (GBCA) to 13C-enriched samples containing trityl radical significantly increases the hyperpolarisation that can be obtained via dynamic nuclear polarisation. This study examined the effects of several contrast agents on T1 in solution and on relative hyperpolarisation in the solid state in [1-13C]-labeled pyruvic acid. T1 decreased with increasing contrast agent concentration with all contrast agents except Teslascan. Dotarem and ProHance showed a slight decrease in T1. MultiHance showed the largest increase in hyperpolarisation and the largest decrease in T1. The choice of contrast agent may depend on the application. Tuesday 13:30-15:30 Computer 7 Peter J. Shin1,2, Simon Hu2, Peder E. Z. Larson2, Kayvan R. Keshari2, John Kurhanewicz1,2, Daniel B. Vigneron1,2 1Joint Graduate Group in Bioengineering, University of California at San Francisco & Berkeley, San Francisco, CA, United States; 2Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, United States 13C-fructose has been recently proposed as a novel hyperpolarized 13C probe. The short T1 of 13C-fructose could impose additional challenges in designing data acquisition strategies. Here, we have optimized an acquisition scheme using a specialized simulation tool and showed that a T1 compensated RF excitation scheme together with compressed sensing can yield minimized spatial blurring with high SNR enough for in vivo 13C-fructose metabolic imaging. Eric Peterson1, Kang Wang2, Sean Fain2,3 1Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States; 2Medical Physics, University of Wisconsin - Madison, Madison, WI, United States; 3Radiology, University of Wisconsin - Madison, Madison, WI, United States Current hyperpolarized carbon protocols call for all of the scans to be performed in series, including the proton localizer and carbon metabolic image. The localizer image is typically acquired at a higher resolution than the carbon image, and eventually serves as an anatomical reference for the later carbon acquisition. By performing a simultaneous proton and carbon acquisition, several potential applications are possible such as continuous localization, motion tracking and compensation, or targeted excitation. Kang Wang1, Eric Peterson2, Jeremy Gordon1, Krishna Kurpad3, Ian Rowland3, Matthew Erickson3, Sean Fain1,3 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States Since hyperpolarized (HP) C-13 compounds exhibit non-equilibrium T1 decay and rapidly evolving spectral dynamics, fast imaging techniques such as radial acquisition have favorable characteristics which allow them to be combined with spectral imaging methods and thus follow the spectral dynamics. Due to the non-equilibrium of the magnetization, the acquired k-space will be modulated and the projection order needs to be designed to minimize spatial artifacts. In this work, we investigated, qualitatively and quantitatively, three different view-order schemes for 2D radial acquisitions. A superior scheme for minimizing artifacts in HP C-13 radial imaging was found. Kang Wang1, Eric Peterson2, Jeremy Gordon1, Krishna Kurpad3, Ian Rowland3, Matthew Erickson3, Sean Fain1 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States Hyperpolarized (HP) C-13 compounds exhibit non-equilibrium T1 decay and rapidly evolving spectral dynamics, and it is highly desirable to develop pulse sequences to image C-13 compounds in the spatial-spectral-time domain with high resolution in all dimensions. Non-Cartesian sampling methods, such as radial acquisition, are very attractive in this application due to their resistance to under-sampling artifacts. In this work, we proposed a radial acquisition method that is designed for HP C-13 time-resolved spectroscopic imaging and combined with HighlY constrained backPRojection reconstruction (HYPR). Wednesday 13:30-15:30 Computer 7 Subramaniam Sukumar1, Peder E.Z. Larson1, Kayvan R. Keshari1, John Kurhanewicz1, Daniel B. Vigneron1 1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States Single shot, chemical shift specific, images are demonstrated using EPI and spiral acquisition techniques at 14T. These methods address some of the problems encountered with hyperpolarized 13C MRSI at high fields related to wide spectral dispersion. Spectral-spatial pulses are designed to selectively excite only the resonances of interest. The fast, single shot acquisition methods provide high temporal resolution on the order of 50-200msec and will be applicable to time course studies involving hyperpolarized 13C. 14:00 3269. Influence of Injected Pyruvate Concentration on Metabolism Using Hyperpolarized 13C Martin Janich1,2, Eliane Weidl3, Florian Wiesinger4, Marion I. Menzel4, Jan Henrik Ardenkjaer-Larsen5, Steffen J. Glaser1, Rolf F. Schulte4, Markus Schwaiger3 1Department of Chemistry, Technische Universität München, Munich, Germany; 2Imaging Technologies, GE Global Research , Munich, Germany; 3Institute for Nuclear Medicine, Technische Universität München, Munich, Germany; 4Imaging Technologies, GE Global Research, Munich, Germany; 5MST-ASL MR, GE Healthcare, Copenhagen,, Denmark The aim of this study is to investigate the influence of injected hyperpolarized 13C pyruvate concentration on its cellular uptake and enzymatic conversion in rats. A 5 mL/kg rat mass solution was injected at concentration levels of 40 mM and 80 mM hyperpolarized 13C pyruvate. Concentration time curves of the metabolites pyruvate, lactate, alanine, and bicarbonate were measured with FID signals in slices through the heart, liver, and kidneys. A significant dependency of observed metabolite concentrations on injected pyruvate concentration was recognized in all slices. Mette Hauge Lauritzen1, Peter Magnusson1, Sadia Asghar Butt1, Jan Henrik Ardenkjær-Larsen2, Lise Vejby Søgaard1, Per Åkeson1 1Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark; 2GE Health Care, Hillerød, Denmark Magnetic resonance spectroscopy (MRS) using hyperpolarized 13C[pyruvate] was tested in a experimental rat model of acute myocardial infarction. MRS-images and dynamic time series was acquired before and after infarction to evaluate metabolic changes in the myocardium. After infarction the signal from lactate, alanine, and bicarbonate were absent in the infarcted region, whereas, in the region not affected by infarction, the signal levels were comparable to the levels in the MRS-images acquired before infarction. This study demonstrates that hyperpolarized 13C MRS can be used to visualize regional changes in cardiac metabolism in rats after myocardial infarction. 15:00 3271. Monitoring Response of Tumors to Anti-Glycolytic Therapies Using Hyperpolarized Pyruvate Aaron Keith Grant1, Pankaj K. Seth1, Elena Vinogradov1, Xiaoen Wang1, Robert E. Lenkinski1, Vikas P. Sukhatme1 1Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States Many cancers preferentially metabolize glucose via fermentative glycolysis (conversion of pyruvate into lactate) rather than oxidative metabolism, even when sufficient oxygen is available to support the TCA cycle. This phenomenon, known as the Warburg effect, may confer a survival advantage on tumor cells. It may be possible to selectively harm cancer cells using metabolic therapies that reverse this effect. Dichloroacetate (DCA) is a drug that up-regulates the activity of pyruvate dehydrogenase and hence may reduce the rate of fermentative glycolysis in cancer. Here we report on the use of hyperpolarized pyruvate to assess the response of tumors to DCA administration. Thursday 13:30-15:30 Computer 7 Ilwoo Park1,2, Myriam Chaumeil2, Tomoko Ozawa3, Sabrina M. Ronen1,2, Daniel B. Vigneron1,2, C. David James3, Sarah J. Nelson1,2 1Joint Graduate group in Bioengineering, University of California San Francisco/Berkeley, San Francisco, CA, United States; 2Surbeck Laboratory of Advanced Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 3Brain Tumor Research Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States We have demonstrated the feasibility of using DNP hyperpolarized 13C1-pyruvate to detect early response to Temozolomide treatment in an orthotopic human glioblastoma xenograft model in rat brain. The 13C data from the treated rats showed the ability to detect altered tumor metabolism as early as one day after TMZ treatment initiation, while the tumor volume from T1 post-Gd imaging showed the first sign of reduction at the 8th day after the initiation of treatment. Peder E. Z. Larson1, James Tropp2, Albert P. Chen3, Paul Calderon2, Simon Hu1, Galen Reed1, Sarah J. Nelson1, John Kurhanewicz1, Ralph Hurd2, Daniel B. Vigneron1 1Radiology and Biomedical Imaging, University of California - San Francisco, San Francisco, CA, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 3Applied Science Laboratory, GE Healthcare, Toronto, Ontario, Canada We have developed and tested custom hardware and methods for future prostate cancer patient studies with hyperpolarized 13C-pyruvate, including 13C coils for prostate imaging, clean room dissolution DNP system, and hyperpolarized 13C pulse sequences. Karlos X. Moreno1, Crystal E. Harrison1, Matthew E. Merritt1, Zoltan Kovacs1, Zengdun Shi2, Don C. Rockey2, A Dean Sherry1, Craig R. Malloy1,2 1Advanced Imaging Research Center, Univ of TX Southwestern Med Ctr, Dallas, TX, United States; 2Internal Medicine, Univ of TX Southwestern Med Ctr, Dallas, TX, United States Pentose phosphate pathway flux was studied using hyperpolarized δ-[1-13C]gluconolactone injected into an isolated perfused mouse liver. Control livers produced a significant amount of H13CO3-, a product indicative of pentose phosphate pathway flux and [1-13C]gluconate. Hydrogen peroxide damaged livers also produced H13CO3- and [1-13C]gluconate, though the bicarbonate was at lower amounts than the control. CCl4 treated livers did not produce any observable H13CO3-, but [1-13C]gluconate was produced. These studies show that the lactone is incorporated within the hepatocyte, phosphorylated and metabolized through the pentose phosphate pathway. Simon Hu1, Robert Bok1, Asha Balakrishnan2, Andrei Goga2, John Kurhanewicz1, Daniel B. Vigneron1 1Dept. of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Dept. of Medicine, Division of Hematology/Oncology, University of California, San Francisco, San Francisco, CA, United States Development of
hyperpolarized technology utilizing dynamic nuclear polarization has
enabled the measurement of 13C metabolism in vivo at
very high SNR. The most researched agent for in vivo applications has
been [1-13C]pyruvate. In this project, the role of cell
membrane transport on the conversion of [1-13C]pyruvate to
[1-13C]lactate and [1-13C]alanine in vivo
was investigated by using the monocarboxylate transporter inhibitor
α-cyano-4-hydroxy-cinnamate. Reduced hyperpolarized alanine and lactate
were detected after α-cyano-4-hydroxy-cinnamate administration,
indicating that this inhibitor approach can be used in vivo to
investigate the transport and intracellular conversion of [1-13C]pyruvate. Hall B Monday 14:00-16:00 Computer 8 Peder E. Z. Larson1, Simon Hu1, Michael Lustig2, Adam B. Kerr2, Sarah J. Nelson1, John Kurhanewicz1, John M. Pauly2, Daniel B. Vigneron1 1Radiology and Biomedical Imaging, University of California - San Francisco, San Francisco, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States In this project, we developed improved sampling and reconstruction strategies to provide finer temporal resolution for hyperpolarized carbon-13 3D time-resolved MRSI with compressed sensing and multiband excitation pulses. These improved compressed sensing strategies better exploit the temporal redundancy. Results are shown with a 32-fold acceleration for a 2 sec temporal resolution, 3D dynamic MRSI acquisition. Sadia Asghar Butt1, Lise Vejby Søgaard1, Mette Hauge Lauritzen1, Jan Henrik Ardenkjær-Larsen2, Lars H. Engelholm3, Susanne Holck4, Peter Magnusson1, Per Åkeson1 1Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark; 2GE Healthcare, Hillerød, Denmark; 3Bartholin Institute, Copenhagen Biocenter; 4Department of pathology, Copenhagen University Hospital Hvidovre There is a need for monitoring of disease progression and treatment response in breast cancer using metabolic biomarkers. We have applied the technique of time resolved hyperpolarised 13C metabolic MRS to the transgenic mammary cancer mouse model, MMTV-PymT. We use measurements of the lactate dehydrogenase (LDH) rate constant reflecting the conversion of hyperpolarized [1-13C]pyruvate to [1-13C]lactate in vivo to extract information about the metabolic the status of the tissue Our initial results show that we are able to monitor the changes in LDH kinetics during tumour development and indicate that the enzyme activity correlate to disease progression. 15:00 3278. In Vivo Detection of Rat Brain Metabolism Using Hyperpolarized Acetate - not available Mor Mishkovsky1,2, Arnaud Comment1,2, Rolf Gruetter1,3 1Laboratory for Functional and Metabolic Imaging , Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Department of Radiology, Université de Lausanne, Lausanne, Switzerland; 3Departments of Radiology, Universités de Lausanne et Genève, Lausanne and Genève, Switzerland In vivo localized 13C MRS of a rat brain was performed in a 9.4T animal scanner after infusion of a hyperpolarized 1-13C and 13C2 sodium acetate solution. It is demonstrated that hyperpolarized 13C-labeled acetate rapidly enters the brain and its metabolism can be detected within the time window defined by the lifetime of the carboxyl carbon hyperpolarized spin state. We present a new sequence designed to transfer the carboxyl nuclear polarization onto the methyl carbon spin of 13C2 acetate in order to assign the metabolic peaks observed in vivo. 15:30 3279. Toward Microtesla MRI of Hyperpolarized Carbon-13 for Real-Time Metabolic Imaging Vadim S. Zotev1, Tuba Owens1, Igor M. Savukov1, Andrei N. Matlashov1, John J. Gomez1, Michelle A. Espy1 1Applied Modern Physics Group, Los Alamos National Laboratory, Los Alamos, NM, United States Hyperpolarization of C-13 has enabled real-time metabolic imaging of C-13 labeled substances with unprecedented signal-to-noise levels. Because hyperpolarization is performed outside an MRI scanner, high magnetic fields of conventional MRI offer little advantage in terms of C-13 polarization. We propose an ultimate low-field MRI scanner for imaging hyperpolarized C-13. It uses only microtesla-range magnetic fields and employs SQUID sensors to measure MRI signals. We present the first images acquired by SQUID-based microtesla MRI with dynamic nuclear polarization. We also report the first NMR spectra of C-13 at microtesla fields. Our results demonstrate feasibility and potential of the proposed imaging approach. Tuesday 13:30-15:30 Computer 8 13:30 3280. A Bayesian Approach to Modeling the Delivery of a Hyperpolarized Substrate Matthew E. Merritt1,2, Crystal Harrison3, A Dean Sherry4,5, Craig R. Malloy4,6, G Larry Bretthorst7 1Advance Imaging Research Center, UT Southwestern Med. Center, Dallas, TX, United States; 2Radiology, UTSW Medical Center, Dallas, TX, United States; 3Physics, University of Texas at Dallas, Richardson, TX, United States; 4AIRC, UTSW Medical Center, Dallas, TX, United States; 5Chemistry, University of Texas at Dallas, Richardson, TX, United States; 6Cardiology, North Texas VA Hospital, Dallas, TX, United States; 7Radiology, Washington University in St. Louis, St. Louis, MO, United Kingdom A primary challenge to extracting quantitative metabolic fluxes from metabolism of a hyperpolarized substrate is modeling the delivery of the molecular imaging agent itself. Here, a tracer is co-infused with [1-13C] pyruvate. A model of the delivery and decay of the magnetization is analyzed with a Bayesian approach, yielding a delivery rate with the standard deviation. Such models are a necessary precursor to correct modeling of fluxes in vivo. 14:00 3281. Cerebral Dynamics and Metabolism of Hyperpolarized [1-13C] Pyruvate Using Time Resolved Spiral-Spectroscopic Imaging Ralph E. Hurd1, Dirk Mayer2,3, Yi-Fen Yen1, James Tropp1, Adolf Pfefferbaum2,4, Daniel Spielman3 1Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, United States; 2SRI International; 3Radiology, Stanford; 4Psychiatry and Behavioral Sciences, Stanford Dynamic hyperpolarized [1-13C]- pyruvate metabolic imaging in normal anesthetized rat brain is demonstrated on a clinical 3T MRI scanner. A 12 s bolus injection of hyperpolarized [1-13C]-pyruvate is imaged at a 3 s temporal resolution using 125 msec spiral spectroscopic images. The observed dynamics are evaluated with respect to cerebral blood volume, flow, transport, and metabolic exchange with the cerebral lactate pool. 14:30 3282. Metabolic Rate Constant Mapping of Hyperpolarized 13C Pyruvate Florian Wiesinger1, Isabelle Miederer2, Marion I. Menzel1, Eliane Weidl2, Martin Janich1,3, Jan-Henrik Ardenkjaer-Larsen4, Markus Schwaiger2, Rolf F. Schulte1 1Imaging Technologies, GE Global Research, Munich, Germany; 2Institute for Nuclear Medicine, Technical University Munich, Munich, Germany; 3Department of Chemistry, Technical University Munich, Munich, Germany; 4MST-ASL MR, GE Healthcare, Copenhagen, Denmark In this work, the two-side, kinetic exchange model is applied for hyperpolarized 13C pyruvate in a way such that it does not involve the pyruvate input function. In combination with time-resolved IDEAL spiral CSI, the method is demonstrated to generate spatially-resolved rate constant maps. Ultimately, the method might be particularly useful for the non-invasive localization and characterization of tumors and their response to therapy. Albert P. Chen1, Angus Z. Lau2, Wilfred L. Lam2, Nilesh R. Ghugre2, Graham A. Wright2, Charles H. Cunningham2 1GE Healthcare, Toronto, ON, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada It has recently been shown that pre-polarized [2-13C] pyruvate can be used to monitor TCA cycle metabolism in vitro and in vivo in rat hearts. In this study, the feasibility of obtaining dynamic cardiac MR spectroscopic data in vivo using hyperpolarized [2-13C] pyruvate in pigs on a clinical 3T MR system is demonstrated. Wednesday 13:30-15:30 Computer 8 13:30 3284. Quantitation of In-Vivo Metabolic Kinetics of Pyruvate Using Hyperpolarized 13C MRSI Tao Xu1, Dirk Mayer2,3, Meng Gu2, Yi-Fen Yen4, Sonal Josan2,3, Edvin Johansson5, Jim Tropp6, Ralph Hurd4, Daniel Spielman, 12 1Department of Electrical Engineering, Stanford University, Stanford, CA, United States; 2Department of Radiology, Stanford University, Stanford, CA, United States; 3Neuroscience Program, SRI International, Menlo Park, CA, United States; 4Global Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, United States; 5Medical Diagnostics R&D, GE Healthcare, Oslo, Norway; 6Global Applied Sciences Laboratory, GE Healthcare, Fremont, CA, United States Hyperpolarized MRSI of metabolically active substrates allows the study of both the injected substrate and downstream metabolic products in vivo. Although hyperpolarized 13C-pyruvate has been used to demonstrate metabolic activity, robust quantitation remains an important area of investigation. Most metrics proposed to date fail to capture enzyme saturation effects. In addition, the widely used small flip-angle excitation approach doesn’t model the inflow of fresh spins correctly. We developed a quantitative 90-excitation dynamic spectroscopic imaging approach, and demonstrated that the in-vivo conversion of pyruvate is well approximated by Michaelis-Menten kinetics with resulting estimated parameters being unbiased with respect to experimental conditions. 14:00 3285. Hyperpolarized [2-13C] Fructose: A Hemiketal Substrate for in Vivo Metabolic Imaging - not available Kayvan R. Keshari1, David M. Wilson, Albert P. Chen2, Robert Bok, Peder E.Z. Larson, Simon Hu, Mark Van Criekinge, Jeffrey M. Macdonald3, Daniel B. Vigneron, John Kurhanewicz 1University of California, San Francisco, San Francisco, Ca, United States; 2GE Healthcare; 3University of North Carolina, Chapel Hill In this study, [2-13C]-fructose was hyperpolarized using the DNP method and shown to have sufficiently long T1’s (≈ 14 sec) and polarizations (≈ 12%) for in vivo hyperpolarized 13C MRSI studies. After injection of [2-13C]-fructose in the TRAMP prostate cancer model, the resonance corresponding to the composite β-fructofuranose and β-fructofuranose-6-phosphate was higher in the regions of tumor as compared to the contralateral benign prostate. The hemiketal C2 of fructose demonstrates the first non-carbonyl to be hyperpolarized for use as a metabolic probe, providing the potential to measure changes in carbohydrate metabolism that occur with human disease. 14:30 3286. 19F-MRI Using Hyperpolarized Substrates and Field Cycling Thomas Trantzschel1, Ute Bommerich2, Joachim Bargon3, Johannes Bernarding1 1Dept. of Biometrics and Medical Informatics, Otto-von-Guericke-University, Magdeburg, Germany; 2Leibniz Institute for Neurobiology, Magdeburg, Germany; 3Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany The lack of natural background signal in body tissues qualifies fluorinated substrates as excellent reporter molecules for MRI and MRS investigations. As a further advantage many pharmaceuticals contain 19F allowing for detection of pharmacokinetics and metabolism as well as to investigate anatomical and physiological features, e.g. lung volume. However, due to the restricted in vivo substrate concentration the 19F-signals often remain weak. To overcome these restrictions we enhanced the 19F signal via ParaHydrogen Induced Polarization. Additionally, we increased the efficiency of the spin polarization transfer to this nucleus by applying a field cycling procedure which improves the SNR in 19F-MRI. 15:00 3287. Parallel MRI Acceleration of Dynamic and High Resolution Hyperpolarized 13C MRI Lanette Friesen Waldner1,2, Jian X. Wang3, Albert Chen4, Alexei Oriadov1, Matthew Fox1,5, Brian Rutt, 1,6, Timothy Scholl5, Giles Santyr1,7, Charles McKenzie, 12 1Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada; 2Medical Biophysics, The University of Western Ontario, London, ON, Canada; 3Global Applied Science Laboratory, GE Healthcare, London, ON, Canada; 4GE Healthcare, Toronto, ON, Canada; 5Physics and Astronomy, The University of Western Ontario, London, ON, Canada; 6Diagnostic Radiology and Richard M Lucas Center for Imaging, Stanford University, Stanford, CA, United States; 7Medical Imaging, The University of Western Ontario, London, ON, Canada Imaging with hyperpolarized agents requires extremely fast imaging techniques as the hyperpolarized state only lasts for tens of seconds. Parallel MRI reduces image encoding time, allowing hyperpolarized images to be acquired faster, or at higher spatial resolution than would otherwise be possible. Using a custom eight-element 13C array to acquire images of a rat following injection of hyperpolarized 13C enriched pyruvic acid, we demonstrate accelerated imaging, using self calibrated PMRI to achieve high spatial and temporal resolutions. These results represent the first hyperpolarized 13C PMRI experiments conducted with a receive array with more than 4 elements. Thursday 13:30-15:30 Computer 8 Helen Jennifer Atherton1, Michael S. Dodd1, Emma E. Carter1, Marie A. Schroeder1, Simon Nagel2, Nicola R. Sibson3, Kieran Clarke1, George K. Radda1, Damian J. Tyler1 1Physiology, Anatomy and Genetics, University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Nuffield Department of Clinical Medicine, University of Oxford, Oxford, Oxfordshire, United Kingdom; 3CRUK-MRC Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford, Oxfordshire, United Kingdom Hyperpolarized 13C-magnetic resonance spectroscopy (MRS) represents a powerful technique for studying metabolism in vivo. To assess pyruvate metabolism in rats, 1ml 80mM [1-13C]pyruvate is injected. This study investigated the metabolic effects of injecting supraphysiological pyruvate concentrations and found that circulating pyruvate concentration peaked 1min post infusion at ~250µM, equivalent to levels reached naturally within the body e.g. during exercise. The plasma concentration of glucose, insulin, triacylglycerides and NEFAs did not alter significantly up to 30min post infusion, however lactate and beta-hydroxybutyrate levels increased significantly 30min post infusion (p<0.01) and may be formed from excess circulating pyruvate and acetyl CoA respectively. 14:00 3289. Cerebral Perfusion Imaging with a Hyperpolarized Freely Diffusible Contrast Agent Aaron Keith Grant1, Elena Vinogradov1, Xiaoen Wang1, David C. Alsop1 1Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States Hyperpolarized contrast agents have a number of attractive features for application to perfusion imaging. Indeed, these agents provide high signal strength with virtually no endogenous background signal and therefore make excellent tracers for monitoring blood flow. Moreover, agents that can freely penetrate the blood-brain barrier are expected to have long tissue residence times and hence enable robust quantification of perfusion. Here we show that carbon-13 labeled tertiary butanol can be hyperpolarized using dynamic nuclear polarization and present in vivo images acquired in rat brain. 14:30 3290. Minimum-Norm IDEAL Spiral CSI for Efficient Hyperpolarized 13C Metabolic Imaging Florian Wiesinger1, Marion I. Menzel1, Eliane Weidl2, Martin Janich1,3, Markus Schwaiger2, Rolf F. Schulte1 1Imaging Technologies, GE Global Research, Munich, Germany; 2Institute for Nuclear Medicine, Technical University Munich, Munich, Germany; 3Department of Chemistry, Technical University Munich, Munich, Germany Hyperpolarized [1-13C]pyruvate has demonstrated significant potential for metabolic MR imaging. In-vivo metabolism converts pyruvate into a limited number of 13C detectable downstream metabolites (including lactate, alanine, bicarbonate) with singlet resonant peaks of known chemical shifts. With an in-vivo T1 of ~30s, it provides MR detectable signal only for a very limited time span. The relevant information is spread over five dimensions including chemical-shift (CS), three spatial dimensions and time. In this work, echo time shifted, single-shot spiral encoding is combined with spectrally-preconditioned, minimum-norm CS inversion (minimum-norm IDEAL spiral CSI) to efficiently master this encoding challenge. 15:00 3291. Saturation-Recovery Metabolic Imaging of Hyperpolarised 13C Pyruvate Rolf F. Schulte1, Marion I. Menzel1, Eliane Weidl2, Martin Janich1,3, Markus Schwaiger2, Florian Wiesinger1 1GE Global Research, Munich, Germany; 2Nuclear Medicine, Technische Universität München, Munich, Germany; 3Chemistry, Technische Universität München, Munich, Germany Mapping metabolic rate constants is of high physiological relevance, as for instance the metabolic activity is increased in tumours. In this work, spectral-spatial excitation is used to selectively excite, image and crush the downstream metabolites lactate and alanine. A small tip angle selective imaging of the injected [1-13C]pyruvate then gives the necessary reference for turnover images. Hall B Monday 14:00-16:00 Computer 9 14:00 3292. A New Volume Selective Sequence for Single-Shot Diffusion-Weighting by the Trace of the Diffusion Tensor - not available Julien Valette1,2, Mohamed Ahmed Ghaly2, Denis Le Bihan2, Franck Lethimonnier2 1CEA-MIRCen, Fontenay-aux-Roses, France; 2CEA-NeuroSpin, Gif-sur-Yvette, France Diffusion-weighted (DW) spectroscopy is a unique tool for exploring the intracellular micro-environment in vivo. In living systems, diffusion is generally anisotropic, since biological membranes may exhibit anisotropic orientation. In this work, a volume selective DW-sequence is proposed, allowing single-shot measurement of the trace of the diffusion tensor (which does not depend on the gradient orientation relative to the cells). Cross-terms between diffusion gradients and other gradients are cancelled out. In addition, an adiabatic version (similar to the LASER sequence, with diffusion gradients) is derived. Proof of concept is performed on anisotropic tissues by varying tissue orientation and intra-voxel shim. Xing Chen1, Anke Henning1, Susanne Heinzer-Schweizer1, Matteo Pavan1, Peter Bösiger1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland The quantification of metabolite concentrations of spatially specific 13C NMR spectra is questionable due to the low sensitivity. We propose a combined SNR enhancement by proton decoupling and ISIS-localized DEPT, aiming at muscle-group specific detection of unsaturated fatty acid in the calf muscle. Comparative measurements of four localized SNR enhancement sequences were performed with a 13C/1H dual-tune volume calf coil equipped with ERETIC. ERETIC signal intensity with and without proton decoupling as determined with TDFDfit was identical. This ISIS-localized DEPT combined with proton decoupling and the ERETIC reference standard technique can be easily extended to other muscle metabolites of interest. 15:00 3294. Enhancing Spectral Resolution in Proton MRSI of Human Calf Muscles Using SPREAD Zhengchao Dong1,2, Feng Liu1,2, Yunsuo Duan1,2, Alayar Kangarlu1,2, Bradley Peterson1,2 1Columbia University, New York, NY, United States; 2New York State Psychiatric Institute, New York, NY, United States In vivo proton magnetic resonance spectroscopy and spectroscopic imaging have been employed to assess extramyocellular lipid (EMCL) and intramyocellular lipid (IMCL) stores in human and animals, based on the effect of “bulk magnetic susceptibility” of EMCL. However, the inhomogeneities of the magnetic fields caused by the spatial variations of B0 lead to spectral line broadening and lineshape distortion that will decrease spectral resolution and hamper the separation of IMCL and EMCL. In this study, we applied the SPREAD method (Spectral Resolution Amelioration by Deconvolution) to improve the spectral resolution of proton MRSI data measured on human calf muscle at 3T. 15:30 3295. 1H Decoupled 13C MRS in Human Muscle at 7T Douglas E. Befroy1, Peter B. Brown1, Kitt F. Petersen1, Gerald I. Shulman1, Douglas L. Rothman1 1Yale University, New Haven, CT, United States MRS at increasing B0 field strengths is accompanied by an enhancement in signal/noise and spectral resolution. However, the concomitant increase in RF power mitigates these effects for J-coupled metabolites in-vivo since decoupling schemes tend to be prohibited by SAR restrictions. By taking advantage of the higher SAR limits for peripheral tissues and by using relatively small coil geometries to maximize the efficiency of RF transmission, we demonstrate that 1H decoupled 13C-MRS is feasible in superficial human skeletal muscles at 7T. Tuesday 13:30-15:30 Computer 9 Sven Biederer1, Timo Frederik Sattel1, Tobias Knopp1, Marlitt Erbe1, Thorsten M. Buzug1 1Institute of Medical Engineering, University of Luebeck, Luebeck, Germany Magnetic Particle Imaging is a new tomographic imaging technique. For spatial encoding a field free point is moved along a trajectory, as for instance a Lissajous curve. Due to tuning of the transmit coils the density and repetition time are currently fixed. In this contribution a method is presented, which allows for changing the density or the repetition time, respectively. This is realized by using shorter trajectories with different relative phases. By combining multiple shorter trajectories various densities can be achieved. Thus, less dense trajectories or high dense trajectories can be used without retuning the system coils. 14:00 3297. Magnetic Field Generation for Multi-Dimensional Single-Sided Magnetic Particle Imaging Timo Frederik Sattel1, Sven Biederer1, Tobias Knopp1, Thorsten M. Buzug1 1Institute of Medical Engineering, University, Luebeck, Germany Magnetic particle imaging is a method capable of determining the spatial distribution of super-paramagnetic iron oxide particles. For field generation and particle signal reception, a single-sided coil arrangement exists where the object of interest is positioned in front of a scanner head and not inside a scanning chamber. So far, a 1D-imaging device has been implemented which allows only for scanning a single line in space. In this contribution, different coil arrangements are shown, which extend the existing setup for 2D-imaging. Multi-dimensional single-sided MPI is the next step in development for small, hand-held or larger in-table MPI devices offering a broad field of applications. 14:30 3298. An MR Compatible Fluorescence Tomography System Yuting Lin1, Orhan Nalcioglu1, Gultekin Gulsen1 1Center for Functional Onco-Imaging, University of California, Irvine, CA, United States Multi-modality imaging is becoming a trend in developing new generation in vivo imaging techniques. Fluorescence tomography (FT) is becoming an important molecular imaging tool in recent years. It has been shown that the anatomical information provided by MRI can be used to improve the quantitative accuracy of FT. However, most of the current FT system design utilizes CCD as the detector, which is incompatible with MRI. To be able to build a hybrid MRI-FDOT system, it requires new hardware compatible with each other. In this work, a development toward an MR compatible fluorescence tomography system is presented. 15:00 3299. Development of Dual Modality MRI and SPECT for Pre-Clinical Molecular Imaging Dirk Meier1, Douglas J. Wagenaar2, Gunnar Maehlum1, Bjoern Sundal1, Bradley E. Patt2, Si Chen3, Jingyan Xu3, Jianhua Yu3, Benjamin M.W. Tsui3, Mark J. Hamamura4, Seunghoon Ha4, W. W. Roeck4, Orhan Nalcioglu4 1Gamma Medica - Ideas, Fornebu, Norway; 2Gamma Medica - Ideas, Northridge, CA, United States; 3Johns Hopkins University, MD, United States; 4University of California at Irvine, CA, United States We experimentally demonstrate the feasibility of operating a small animal SPECT system outside and inside a 3 Tesla MRI system with simultaneous data acquisition of both modalities. Unlike traditional SPECT systems, which are based on photomultiplier tubes, our SPECT system is based on MR-compatible semiconductor radiation detectors. The detectors surround the field-of-view and do not rotate. In the present study we acquired images from mice using the SPECT and the MRI. We investigate the performance of the SPECT system with and without the MRI. We believe that the combined SPECT/MRI system will open new opportunities in molecular imaging. Wednesday 13:30-15:30 Computer 9 13:30 3300. Grid-Free Interactive and Automated Data Processing for MR Chemical Shift Imaging Data Yann Le Fur1, Maxime Guye1, Sylviane Confort-Gouny1, Patrick J. Cozzone1, Frank Kober1 1Centre de Résonance Magnétique Biologique et Médicale (CRMBM) UMR CNRS 6612, Université de la Méditérranée, Marseille, France We propose real-time voxel shift for grid-free computer resource-efficient analysis of CSI data as an alternative to spatial Fourier-interpolation prior to analysis. Spectral information is extracted from CSI data at every mouse click at any location of the object to study with accurate display of the voxel shape and size. Voxel-shift applied sequentially has also permitted extraction of spectra from arbitrarily shaped compartments as well as calculation of B0-corrected metabolite maps using AMARES time-domain fitting. Yan Lin1, Mary Charlotte Stephenson1, Samuel James Wharton1, Olivier Mougin1, Antonio Napolitano2, Peter G. Morris1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom The purpose of the present study was to use the improved SNR and spectral resolution available at 7T to study changes in 1H metabolite levels in the visual cortex on visual stimulation. Specifically, the aim was to confirm and quantify the increase in glutamate/glutamine levels suggested by others, and to investigate further any lactate response to visual stimulation. We found a significant increase in glutamate of 6.13%¡À4.6% on visual stimulation, similar to that reported by Mangia et al (2007). However, we do not find evidence for the increase in glutamine and lactate, or a decrease in aspartate, as previously reported. 14:30 3302. PRESS Difference Spectroscopy Optimization Applied to GABA and Tau at 3 T Jeff Snyder1, Thomas Lange1, Jürgen Hennig1, Maxim Zaitsev1 1Dept. of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany A method to detect coupled spins is presented based on PRESS difference spectroscopy with variable refocusing flip angles at 3 T. The technique is optimized by numerical simulations of sixteen metabolite signals at multiple echo times and flip angles, with the end result of reduction of overlap with adjacent signals for the target metabolite while maintaining adequate yield. The procedure is demonstrated for gamma-aminobutyric acid and taurine. Timothy P.L. Roberts1, William Gaetz1, D J. Wang1, Nouha Salibi2, James Christopher Edgar1 1Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States; 2Siemens Medical Solutions GABA (gamma-aminobutyric acid) is a significant inhibitory neurotransmitter in the human brain. Its presence can be revealed using a spectral editing MR spectroscopy technique (MEGAPRESS), allowing it to be resolved from the overlapping Cr resonance. In this study GABA signal from visual and motor cortex was shown to correlate with gamma oscillation frequency determined by MEG and originating from the corresponding region. Further, both GABA magnitude and gamma frequency were shown to correlate negatively with subject age. This multimodal approach accesses the neurobiology underlying brain function. Thursday 13:30-15:30 Computer 9 13:30 3304. Full 1H to 31P Polarization Transfer on 7 Tesla. - not available Wybe van der Kemp1, Vincent Boer1, Peter Luijten1, Dennis Klomp1 1Department of Radiology, University Medical Center, Utrecht, Netherlands Full 1H to 31P polarization transfer was shown for phosphocholine and phosphoethanolamine, using the sRINEPT sequence. The sRINEPT sequence is a RINEPT in which the first inversion pulse on the proton channel is a selective inversion pulse, thus preventing polarization transfer losses caused by inter-proton coupling. Quantum chemical simulations on these compounds and their glycerol-derivatives shows that polarization transfer is at a maximum within an offset frequency range of 0.2 ppm for the selective pulse. Measurements on a phosphocholine phantom agree well with the simulations. Implementation of (segmented) BIR4 pulses on the 31P channel enhances the signal further. Bart Lowie van de Bank1, Vincent Oltman Boer1, Peter R. Luijten1, Dennis W.J. Klomp1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands A dedicated double-tuned double-channel transmit receive surface coil setup is developed that enables the use of high B1+-fields in multi nuclei MRS of the human brain at 7T. The available B1+ field of up to 40 ìT and 100 ìT for respectively 1H and 31P allowed the use of short and high bandwidth adiabatic RF pulses, which are insensitive to the inhomogeneous nature of the B1+-field. Therefore accurately localized 1H and 31P MR spectra with high sensitivity could be obtained at 7T. 14:30 3306. A New Paradigm for High Sensitivity 19F MRI of Perfluorooctylbromide Céline Giraudeau1, Julien Flament1, Benjamin Marty1, Fawzi Boumezbeur1, Sébastien Mériaux1, Caroline Robic2, Marc Port2, Nicolas Tsapis3, Elias Fattal3, Eric Giacomini1, Franck Lethimonnier1, Denis Le Bihan1, Julien Valette1 1NeuroSpin, I2BM, Commissariat à l'Energie Atomique, Gif-sur-Yvette, France; 2Guerbet, Research Division, Aulnay-sous-Bois, France; 3Université Paris Sud, UMR CNRS 8612, Faculté de Pharmacie, Châtenay-Malabry, France The NMR properties of perfluorooctylbromide (PFOB) are revisited to derive a high sensitivity MRI strategy. Relevance of the bandwidth of the 180° pulses in a spin echo sequence is evidenced to obviate harmful effects of J-coupling. The T2 of the CF3 resonance of PFOB is measured using a multi spin echo (MSE) sequence and shown to dramatically depend on TE. An optimized MSE imaging sequence is therefore derived and compared with short TE/TR gradient echo and chemical shift imaging sequences. The unparalleled sensitivity yielded by the MSE sequence is promising for future applications, particularly for targeted PFOB nanoparticles. 15:00 3307. Multi-Dimension Random Phase Encoding for Chemical Shift Imaging Cao Peng1,2, Condon Lau1,2, Ed X. Wu1,2 1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China This study aims to employ random phase encoding in MR Chemical Shift Imaging (CSI) to reduce measurement time without significantly sacrificing image quality. CSI is a good candidate because the 2D-CSI sequence has the freedom to independently set the two directions of phase encoding. Simulations show efficient suppression of intervoxel contamination at undersampling factors up to 65% while maintaining image quality at undersampling factors up to 50%. This results show that CSI can significantly reduce measurement time. Hall B Monday 14:00-16:00 Computer 10 Aaron Timothy Hess1, Ovidiu C. Andronesi2, Matthew Dylan Tisdall2, A Gregory Sorensen2,3, Andre J. van der Kouwe2, Ernesta M. Meintjes1 1University of Cape Town, Cape Town, South Africa; 2Martinos Center for Biomedical Imaging, Massachusetts General Hospital, MA; 3Department of Radiology, Harvard Medical School, MA Motion in spectroscopy and spectroscopic imaging introduces three categories of artefacts: i) a localising error; ii) a phase error arising from the excitation process; and iii) the disruption of the B0 field. We present a method to correct localisation and remove motion-induced phase errors by using an EPI navigator for motion correction in a spectroscopic imaging, LASER sequence. We show that by reacquiring scans where motion was detected the phase error artefacts can be removed. 14:30 3309. Metabolite T2 Relaxation Times of Coupled 1H Spin Systems in Human Brain at 7T Ralf Mekle1,2, Giulio Gambarota3, Lijing Xin1, Rolf Gruetter1,4 1Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Federale de Lausanne, Lausanne, Vaud, Switzerland; 2Department of Radiology, University of Lausanne, Lausanne, Vaud, Switzerland; 3GlaxoSmithKline Clinical Imaging Center, London, United Kingdom; 4Departments of Radiology, Universities of Lausanne and Geneva, Lausanne and Geneva, Vaud and Geneve, Switzerland The knowledge of the proton T2 relaxation time of coupled metabolites is valuable for improving spectral quantification not only in long TE MRS, but also in a number of MRS editing techniques, which are typically performed at moderate TEs. At the field strength of 7T, the T2 of singlets has already been reported, but not the systematic measurement of the T2s of coupled metabolites. In this study, measurement of the T2 of coupled spin resonances of metabolites in human brain at 7T using the spin echo full intensity acquired localized (SPECIAL) MRS technique is described for the first time. Deborah Diane Douglas1, Ivan Dimitrov1,2, Jimin Ren1, A. Dean Sherry1, Craig R. Malloy1 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Cleveland, OH, United States Highly inhomogeneous B1 pose challenges in 7T MRS, even more so when surface coils are used. Still, the high sensitivity of surface coils makes them a valuable tool in MRS. While the idea of B1-shimming with dielectric pads for imaging is well-known, their use in spectroscopy has not been evaluated. We demonstrate the use of D2O bags in directed extending the sensitivity volume of surface coils: using a coil under the calf of volunteers the SNR of tibial bone spectra was increased 4-fold when a D2O bag was put on top of the leg vs. when no bag was present. Anke Henning1, Christoph Barmet1, Alexander Fuchs1, Johanna Vannesjö1, Peter Boesiger1, Klaas Paul Pruessmann1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland It is investigated whether calibration data acquired using a recently proposed ultra-fast 3D B0 field monitoring camera allows for observation and direct correction of the modulation sideband artefact caused by gradient vibrations in 1H MRS data acquired without water suppression. Tuesday 13:30-15:30 Computer 10 Yanqin Lin1,2, Zhong Chen1, Jianhui Zhong2 1Physics, Xiamen University, Xiamen, Fujian, China; 2Imaging Sciences, University of Rochester, Rochester, NY, United States In human brains, intermolecular double-quantum coherences (iDQCs) can be used to acquire high-resolution localized magnetic resonance spectra (MRS) in the presence of large field inhomogeneity where conventional MRS methods fail. However, an intrinsic low SNR limits their practical applications. Here, we show that the SNR of iDQC MRS can be greatly improved through use of phased array coils. iDQC signal from a 32-channel phased array head coil was combined together using a nonparametric singular value decomposition algorithm. The results indicate that the iDQC spectra from the 32-channel coil have the SNR 1.6~2.5 times of that from a CP birdcage head coil. Qiuhong He1,2 1Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States The Selective Multiple Quantum Coherence transfer (Sel-MQC) method is modified for simultaneous mapping of polyunsaturated fatty acids (PUFA), lactate and choline in three unique Molecular Specific Coherence (MSC) transfer pathways with complete lipid and water suppression in a single scan. Choline signal is also detectable in a second spin echo to enhance lipid suppression. The method can be applied to study animal tumor models and human breast cancer or other extracranial cancers. Xi Chen1,2, Shaolin Yang1, Laura Rowland2, Yihong Yang1 1Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States; 2Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, United States A modified 2D multiple-quantum coherence sequence is proposed to achieve high-resolution selective GABA detection under inhomogeneous fields. The edited spectra of GABA with and without J splittings can be obtained from the sequence. Sparse sampling in the indirect dimension is utilized to reduce the entire acquisition time. A phantom experiment was performed to demonstrate the feasibility of the proposed method and its potential applications for in vivo studies. Xi Chen1, Meijin Lin1, Zhong Chen1 1Physics Department, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China A pulse sequence termed CT-iDH, which combines intermolecular double-quantum filtered sequence for efficient solvent suppression with a modified constant-time (CT) scheme, is designed to achieve fast acquisition of high-resolution intermolecular zero-quantum coherences (iZQCs) and intermolecular double-quantum coherences (iDQCs) spectra without strong coupling artifacts. Furthermore, double-absorption lineshapes are first realized in 2D intermolecular multi-quantum coherences spectra under inhomogeneous fields through a combination of iZQC and iDQC signals to double the resolution without loss of sensitivity. Experiments were performed to test the feasibility of the new method. The study suggests potential applications for in vivo spectroscopy. Wednesday 13:30-15:30 Computer 10 Frederick Shic1, Alexander P. Lin2, J. Bob Brown3, Stefan Bluml4, Brian D. Ross5 1Yale Child Study Center, Yale University School of Medicine, New Haven, CT, United States; 2Radiology, Brigham and Women's Hospital, Boston, MA, United States; 3Alcor Consulting, Inc., Fremont, CA, United States; 4Radiology, Keck School of Medicine of USC, Los Angeles, CA, United States; 5Huntington Medical Research Institutes, Pasadena, CA, United States 1H MRS data analysis research traditionally emphasizes novel and powerful, but complex, methods for quantifying spectroscopic data, creating barriers for less technical users. At the other extreme, many everyday users of MRS simply adopt manufacturer’s standards for data processing, resulting in widespread incompatibilities in cross-institutional comparability. Here, we emphasize the critical need for usability in MRS data processing and present an open-source platform which is intuitive, easy-to-use, yet complete, flexible, and powerful. We show that in vitro and in vivo variability is low, and suggest that this platform may serve to provide accessible, widespread, and consistent MRS data processing. 14:00 3317. Long-Term Reproducibility of MRS System Agnieszka Polnik1, Magdalena Wicher2, Tomasz Banasik2, Aleksandra Kieltyka2, Marek Konopka3, Maria Sokó³4 1Department of Medical Physics, Maria Sk³odowska-Curie Memorial Cancer cenetr and Institute of Oncology, Gliwice, Poland; 2Helimed Diagnostic Imaging, Katowice, Poland; 3Helimed Diagnosic Imaging, Katowice, Poland; 4Maria Sk³odowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland The puropse of this work was to assess long-term variability of magnetic resonance spectroscopy in vivo using a standard brain phantom. The measurements were performed from April 2006 to September 2009. Short and long echo time spectra were acquired from the volume of interest located in the isocentre. The total number of spectra measured for short echo time was equal to 99, while for long echo time – 96. LCModel software was used for estimation of the metabolite levels. Coefficients of variation did not exceed the value of 6% for any metabolite over three years of the experiment. 14:30 3318. Simple Correction of Chemical Shift Changes in Quantitation Andrii Lazariev1, Florence Fauvelle2, Martial Piotto3,4, Karim Elbayed4, Jacques Namer5, Dirk van Ormondt6, Danielle Graveron-Demilly1 1Laboratoire Creatis-LRMN; CNRS UMR 5220; INSERM U630; INSA de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France; 2CRSSA/BCM, Grenoble, France; 3Bruker BioSpin, Wissembourg, France; 4Institut de Chimie, Strasbourg, France; 5Department of Biophysics and Nuclear Medicine, University Hospitals of Strasbourg, Strasbourg, France; 6Delft University of Technology, Delft, Netherlands High-resolution magic angle spinning (HRMAS) 1H spectroscopy is playing an increasingly important role for diagnosis. This technique enables setting up metabolite profiles of ex vivo pathological and healthy tissue. Automatic quantitation of HRMAS signals will provide reliable reference profiles to monitor diseases and pharmaceutical follow-up. Nevertheless, for several metabolites chemical shifts often slightly differ according to the microenvironment in the tissue or cells, in particular with its pH. This hampers accurate estimation of the metabolite concentrations mainly when using quantitation algorithms based on a metabolite basis-set. In this work, a very simple method to circumvent this problem is proposed. 15:00 3319. Classification on Ex-Vivo MRS Signals of Glioma Samples Bernd Merkel1, Frauke Nehen2, Yasemin Oezdemir1, Markus Thorsten Harz1, Dieter Leibfritz2, Rudolf Fahlbusch3, Horst Karl Hahn1 1Fraunhofer MEVIS, Bremen, Germany; 2Institute of Organic Chemistry, University of Bremen, Bremen, Germany; 3International Neuroscience Institute, Hannover, Germany The goal of this work is the automated classification of glioma samples with high-resolution ex-vivo MR-spectroscopy. HR-MRS is a sensitive method to detect metabolite changes in different tumor and tissue types. Altogether 47 biopsates of healthy, tumor margin and tumor center tissue, measured on a 600 Mhz spectrometer, were analyzed. For further analysis, the lipophilic compounds were omitted and only the hydrophilic ones were analyzed. By the application of ICA and further classification and feature reduction techniques, we show that the tumor margin is distinctively different from the tumor center. Thursday 13:30-15:30 Computer 10 Bernardo Celda1,2, Juan Manuel Gil Cano1, MCarmen Martinez-Bisbal2, Beatriz Martinez-Granados1, eTUMOUR eTUMOUR-partners 1Physical Chemistry, University of Valencia, Burjassot, Valencia, Spain; 2Physical Chemistry, CIBER-BBN, Burjassot, Valencia, Spain The clinical evaluation of a Computer Aid Decision System (CADS) for brain tumours classification is presented. The fully automated CADS has been evaluated and excellent results from the users opinion about applicability and accuracy and final classification for meningioma, low grade and high grade glial brain tumours will be discussed. 14:00 3321. Dynamic Metabolic Modeling of Glucose Transport and Utilization in the Human Brain Alexander A. Shestov1, Uzay E. Emir1, Anjali Kumar1, Pierre-Gilles Henry1, Elizabeth R. Seaquist1, Gulin Oz1 1University of Minnesota, Minneapolis, MN, United States Determining the kinetics of cerebral glucose transport and utilization is critical for quantifying cerebral energy metabolism. We report kinetic parameters for glucose transport and utilization by fitting both dynamic and steady-state data with a reversible, non-steady-state Michaelis-Menten model. Dynamic data were obtained by measuring brain and plasma glucose time courses during glucose infusions in 5 healthy volunteers. Steady-state plasma vs. brain glucose concentrations were taken from literature. Maximum transport capacity for glucose through the BBB was nearly two-fold higher than maximum cerebral glucose utilization. The glucose transport and utilization parameters were consistent with previously published values for human brain. 14:30 3322. Refocused Double Quantum Filter Vincent O. Boer1, Peter R. Luijten1, Dennis W J Klomp1 1radiology, UMC Utrecht, Utrecht, Netherlands Double Quantum (DQ) filters provide a means to acquire signal of coupled spin systems with a superb suppression of (overlapping) non-coupled spin systems. Lactate detection in the presence of macromolecules and lipids is therefore possible. However, the DQ filters are associated with severe signal loss of the metabolite of interest. In this work we propose a refocused DQ filter with a higher detection sensitivity compared to previously proposed filters while suppression quality of overlapping resonances is even increased. Detection of lactate in low concentrations and in lipid rich environments therefore becomes possible. Baseline brain-lactate measurements are shown with suppression of all other resonances. 15:00 3323. Localized in Vivo 13C MRS of Brain Glycogen at 9.4 and 14.1 T: A Comparison Ruud B. van Heeswijk1, Yves Pilloud1, Florence D. Morgenthaler1, Rolf Gruetter1,2 1Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, VD, Switzerland; 2Radiology, Universities of Lausanne & Geneva, Lausanne & Geneva, Switzerland Localized 13C MR spectroscopy of rat brain glycogen at 9.4 and 14.1 T are compared. After pre-labeling at the C1 position and absolute quantification of the concentrations, the signal-to-noise ratio (SNR) of the glycogen and glucose C1 resonances are compared at the two field strengths. The T1 relaxation time and effective linewidth are also determined, and an overall comparison of the spectral quality is made. Spectroscopic Quantification Methodology I Hall B Monday 14:00-16:00 Computer 11 14:00 3324. Imaging Glutamine Synthesis Rates in the Hyperammonemic Rat Brain Cristina Cudalbu1, Vladimír Mlynárik2, Bernard Lanz2, Hanne Frenkel2, Nicolas Costers2,3, Rolf Gruetter2,4 1Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL) , Lausanne, Switzerland; 2Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; 3Katholieke Universiteit Leuven, Leuven, Belgium; 4Departments of Radiology, Universities of Lausanne and Geneva, Switzerland The aim of the study was to image for the first time the in vivo effect of hyperammonemia per se on 12 brain metabolites using short TE 1H SI . We also mapped the net glutamine synthesis rates during hyperammonemia. Contrary to other models of hyperammonemia associated with experimental acute liver failures, no changes in spatial distribution of metabolites were observed except of Gln increase (higher in cortex than in hippocampus). We imaged for the first time the net glutamine accumulation in vivo, and showed that the rates were significantly higher in the cortex than in the hippocampus. Christine Sandra Bolliger1, Daniel Guo Quae Chong1, Johannes Slotboom2, Chris Boesch1, Roland Kreis1 1Department of Clinical Research, University Bern, Bern, Switzerland; 2Departement Radiologie, Neuroradiologie, Nuklearmedizin (DRNN), Inselspital, Bern, Switzerland In addition to peak areas, full quantitation of in vivo MR spectra requires the measurement of individual metabolite T1’s, T2’s, and of the macromolecular baseline. Since this is time-consuming, these influences are mostly ignored in a clinical setting, leading to systematic inaccuracies. We propose simultaneous modeling of a combined dataset, called 2DJ-IR, consisting of a 2DJ series and a set of inversion recovery (IR) spectra. Since this allows a determination of relaxation effects and macromolecule baseline in reasonable time, the areas as determined by this method are inherently relaxation-corrected and can be directly interpreted as concentration ratios. Sung-Tak Hong1, Dávid Zsolt Balla1, Changho Choi2, Rolf Pohmann1 1High-Field Magnetic Resonance Center , Max-Planck Institute for Biological Cybernetics, Tuebingen, Baden-Wuerttemberg, Germany; 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States Localized in vivo 1H NMR spectroscopy requires significantly high number of averages compared to other MR imaging techniques. Precise analysis on spectra obtained at 16.4T was performed to determine the minimal number of averages, necessary for quantifying nineteen metabolites with average CRLBs of below 20%. The results demonstrated that 64 averages were sufficient to quantify most metabolites reliably except weakly represented metabolites such as alanine, glycine and phosphorylcholine. 15:30 3327. Quantitative Lithium Spectroscopy in the Normal Human Brain on a 3T Clinical Scanner Fiona Smith1, David Cousins2, Peter E. Thelwall1, I Nicol Ferrier2, Andrew M. Blamire1 1Newcastle MR Centre & Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom; 2Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom A quantitative protocol for localised 7Li of the human brain at 3T was developed. T1 relaxation of Li in healthy human brain was measured to be 2.0±0.4s. Brain Li concentration was measured to be 70% of plasma concentration. Tuesday 13:30-15:30 Computer 11 13:30 3328. Assessment of Lipids in Skeletal Muscle by LCModel and AMARES Jan Weis1, Lars Johansson1,2, Francisco Ortiz-Nieto1, Håkan Ahlström1 1Department of Radiology, University Hospital, Uppsala, Sweden; 2Astra Zeneca R&D Single-voxel MRS was used to obtain the spectra of the calf muscles. Unsuppressed water line was used as a concentration reference. A new prior knowledge for AMARES was proposed to estimate the absolute concentrations of extra- and intramyocellular lipids. The results were compared with the values estimated by LCModel. Very good correlation of the total fat and intramyocellular concentrations was achieved between both data processing approaches. Assessment of the absolute concentrations of muscular lipids by AMARES and LCModel can be performed with similar reliability. 14:00 3329. Measurement of Glycine in the Human Brain by 1H-MRS at 3T Changho Choi1, Deborah Douglas1, Aditya Patel1, Elizabeth Maher2, Ivan Dimitrov1,3 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Internal Medicine and Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Philips Medical Systems, Cleveland, OH, United States Glycine (Gly) in human brain was measured using an optimized PRESS (point-resolved spectroscopy) sequence at 3T. Echo time dependence of the coupled resonances of myo-inositol (mIns) was investigated, with numerical analyses, for TE1 and TE2 between 20 and 200 ms. The numerical simulation indicated that a pair of subecho times, (TE1, TE2) = (60, 100) ms, suppresses the mIns resonances at 3.5 – 3.6 ppm, providing an effective tool for measuring Gly and mIns simultaneously. In vivo tests of the method were carried out on six subjects. With LCModel fitting, [Gly]/[Cr] and [mIns]/[Cr] were estimated to be 0.08±0.01 and 0.70±0.07 (mean±SD, N = 3) for the occipital lobe, and 0.07±0.01 and 0.81±0.21 (N = 3) for the parietal lobe, respectively. The Cramér-Rao lower bounds (CRLB) of Gly were 9±1% (N = 6). Changho Choi1, Aditya Patel1, Deborah Douglas1, Ivan Dimitrov1,2 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Cleveland, OH, United States Proton T2 measurement and quantification of brain coupled-spin metabolites in the human brain, at 3T, is reported. Four pairs of PRESS (point resolved spectroscopy) subecho times, which were obtained with numerical analyses of the sequence for optimal separation between glutamate (Glu) and glutamine (Gln), were used for T2 measurement. Single-voxel measurements were carried out on the occipital cortex of five healthy volunteers. Spectra were analyzed with LCModel fitting. From monoexponential fitting of the LCModel estimates at the selected TE¡¯s, apparent T2¡¯s of Glu, Gln, and myo-inositol (mIns) were measured to be 160 - 170 ms. Further, the signal strengths measured with TR = 8 s were extrapolated to zero TE using the estimated T2 values. The concentration ratio with respect to creatine was estimated to be 8.2¡¾1.3, 4.6¡¾0.6, 9.5¡¾0.8, and 1.1¡¾0.1 (mean¡¾SD, N = 5) for Glu, mIns, NAA, and GPC+PC, respectively. Changho Choi1, Aditya Patel1, Deborah Douglas1, Ivan Dimitrov1,2 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Cleveland, OH, United States Measurement of the transverse relaxation times of brain metabolites including coupled-spin metabolites such as glutamate (Glu) and myo-inositol (mIns) in gray and white matter, at 3T, is reported. Four pairs of PRESS (point resolved spectroscopy) subecho times, which were obtained with numerical analyses of the sequence for optimal selectivity of Glu and mIns, were used for T2 measurement. Single-voxel measurements were carried out on the gray-matter (GM) and white-matter (WM) dominant regions in the occipital lobe of five healthy adult brains. The Glu T2 was measured to be similar between GM and WM (161±18 and 169±22 ms, respectively). Myo-inositol, creatine, and choline also exhibited similar T2 between GM and WM, but the T2 of N-acetylaspartate (2.01 ppm) was significantly different between GM and WM (262±16 and 326±21 ms, respectively), with p = 0.001. Wednesday 13:30-15:30 Computer 11 13:30 3332. In Vivo Detection of Serine in Human Brain by Constant-TE Difference Editing at 3T Changho Choi1, Deborah Douglas1, Aditya Patel1, Ivan Dimitrov1,2 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Dallas, OH, United States A proton MRS strategy for detection of serine (Ser) in human brain at 3T is proposed. Spectral difference of multiplet at different subecho times of triple refocusing at a constant total echo time was utilized to measure Ser and cancel the overlapping creatine (Cr) 3.92-ppm singlet via subtraction. A 50-ms non-spatially selective 180° RF pulse was applied between the 180° pulses of a PRESS sequence. A pair of subecho time sets, (TE1, TE2, TE3) = (70, 50, 135) and (35, 135, 85) ms, was obtained from density-matrix simulations. An in vivo test of this difference editing was conducted on the occipital cortex of a healthy adult brain. From spectral fitting of sub- and difference-spectra by LCModel, the serine to N-acetylaspartate concentration ratio was estimated as 0.05. Changho Choi1, Ivan Dimitrov1,2, Deborah Douglas1, Aditya Patel1 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Cleveland, OH, United States Measurement of glycine (Gly) in the human brain by 1H-MRS at 7T is reported. A point-resolved spectroscopy (PRESS) sequence with subecho times optimized for differentiation between Gly and myo-inositol was applied for measuring the metabolites in the prefrontal and left frontal cortices of a healthy adult brain, which are gray and white matter dominant, respectively. The Gly-to-creatine concentration ratios were observed to be approximately 2-fold higher in prefrontal than in left frontal. This result suggests that Gly may be present predominantly in gray matter compared to white matter. 14:30 3334. J Refocused Coherence Transfer Spectroscopic Imaging at 7T Jullie W. Pan1, Nikolai Avdievich1, Hoby P. Hetherington1 1Yale University School of Medicine, New Haven, CT, United States The detection of amino acids at ultra high field is enhanced due to improved spectral resolution in comparison to 3T. However, due to J-modulation and T2 losses short spin echo acquisitions are typically used at 7T. Unfortunately, broad macromolecule resonances, visible at short TE, can make accurate detection of the metabolites difficult. J refocused coherence transfer spectroscopy is known to suppress J-modulation of coupled spin systems, thereby allowing longer echo times and suppressing macromolecule contamination. We describe simulation and implementation of a J-refocused transfer sequence for spectroscopic imaging of glutamate and glutamine in the human brain at 7T. Kuan-Ting Wu1, Chen-Shuan Huang1, Stefan Posse2,3, Shang-Yueh Tsai1 1Department of Electrical Engineering, Chang Gung University, Tao Yuan, Taiwan; 2Department of Neurology, University of New Mexico School of Medicine, Alberquerque, NM, United States; 3Department of Electrical & Computer Engineering, University of New Mexico , Alberquerque, NM, United States A processing procedure is proposed to do the tissue type correction for metabolite concentrations on spectroscopic imaging. Tissue segmentation is first done on 3D high resolution T1 images (MPRAGE). Image registration provided by SPM8 software is then applied to generate GM, WM and CSF probability maps at corresponding slice of spectroscopic imaging for the correction of metabolite concentrations. Our results showed that concentration correction can be done well on two segmentation methods and integration of SPM into tissue type correction is useful for future application of MRSI at different locations and slice orientations. Thursday 13:30-15:30 Computer 11 Petra Pouwels1, Marjan Steenweg2, Frederik Barkhof3, Marjo van der Knaap2 1Physics & Medical Technology, VU University Medical Center, Amsterdam, Netherlands; 2Child Neurology, VU University Medical Center, Amsterdam, Netherlands; 3Radiology, VU University Medical Center, Amsterdam, Netherlands Absolute metabolite concentrations in human brain were obtained from short echo-time CSI (TR/TE 3000/30 ms, 6 averages, 19 minutes) using a phased-array headcoil. A voxel-wise calibration was based on a combination of transmitter amplitude and water reference scans obtained with both body- and headcoil (<1 minute each). This provided a reproducible and homogeneous quantification as demonstrated in a phantom. In vivo, high quality spectra were obtained in 37 subjects between 2 and 19 years. Metabolite concentrations showed similar regional distributions and age-related variations as previously observed with quantitative single-voxel MRS, demonstrating the applicability of CSI for quantitative MRS at high spatial resolution. Jack Knight-Scott1 1Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States The spectroscopic relaxation model for brain tissue is different from the imaging relaxation model. As many as three water compartments have been detected in imaging. Here we examine the sensitivity and stability of a fast spectroscopic relaxometry technique. Specifically, we explore the stability of the spectroscopy relaxation model of human brain tissue by examining its results when applied across an aging population and across different brain regions. 14:30 3338. Improved Metabolite Quantification Using VAPOR Water Suppression Yan Li1, Janine M. Lupo1, Duan Xu1, Douglas A.C. Kelley2, Sarah J. Nelson1,3 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 2Applied Science Laboratory, GE Healthcare, San Francisco, CA, United States; 3Department of Bioengineering & Therapeutic Sciences, University of California, San Francisco, CA, United States The availability of whole body MR scanners with field strengths of 7 Tesla offers the potential of higher SNR and better spectral resolution, but also introduces complications, such as the presence of increased sidebands from unsuppressed water. The purpose of this study was to evaluate the efficacy of VAPOR water suppression and to assess the improvements in the accuracy of metabolite quantification compared to conventional water suppression with CHESS. The data acquired using VAPOR water suppression have smaller residual water signals, less gradient-induced water sidebands, lower CRLB and coefficients of variance compared to that acquired using CHESS. VAPOR suppression is therefore a valuable tool for improving the accuracy of metabolite quantification. 15:00 3339. Neurotransmitter Profiling at 3T Using GABA Optimized PRESS Sequence Antonio Napolitano1, Walter Kockenberger2, Dorothee P. Auer1 1Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2SPMMRC, University of Nottingham, United Kingdom The spectroscopic detection of GABA is still challenging due to its low concentration, and the fact that all GABA peaks are overlapped by much stronger metabolite resonances at the field strength accessible for clinical studies. This study aims to simultaneously detect GABA as well as Glu, Gln pools using a standard PRESS localization pulse sequence with optimized timing parameters. Spectroscopic Quantification Methodology II Hall B Monday 14:00-16:00 Computer 12 14:00 3340. Quantification of Glutamate and Glutamine Using CT-PRESS at 3T Meng Gu1, Natalie M. Zahr2,3, Daniel M. Spielman1, Edith V. Sullivan2,3, Adolf Pfefferbaum2,3, Dirk Mayer1,3 1Radiology, Stanford University, Stanford, CA, United States; 2Psychiatry & Behavioral Sciences, Stanford University, Stanford, CA, United States; 3Neuroscience Program, SRI International, Menlo Park, CA, United States Quantifying and separating glutamate (Glu) and glutamine (Gln) using conventional magnetic resonance spectroscopy on clinical scanners is challenging. Constant-time point-resolved spectroscopy was developed at 3T to detect Glu but does not resolve Gln. To quantify Glu and Gln separately, a time-domain basis set was constructed taking into account T2 relaxation and dephasing from B0 inhomogeneity. Metabolite concentrations were estimated by fitting the basis magnitude spectrum to the measured spectrum. This method was validated using phantoms with different Glu and Gln concentrations. When applied to in vivo data, ethanol-exposed but not control rats showed increased Gln after exposure. 14:30 3341. LCModel Accuracy Testing for N-Acetyl Aspartyl Glutamate Measurement Using Phantom Study Namkug Kim1, Young-Hoon Sung1, Nivedita Agarwal1, Eric Jensen2, In Kyoon Lyoo3, Brent P. Forester2, Perry F. Renshaw1 1The Brain Institute, University of Utah, Salt Lake City, UT, United States; 2Department of Psychiatry, Harvard Medical School, Belmont, MA, United States; 3Department of Psychiatry, Seoul National University, Seoul, Korea, Republic of It is typically difficult to differentiate NAAG directly from NAA of standard MRS due to the low concentration of NAAG and overlap with other metabolites. Five repetitive scan trials of five phantom cases in which all the phantoms were scanned using CSI at one-day intervals to figure out the reproducibility and the accuracy of the measurement. The phantom cases contained a range of concentrations of Glu, NAAG, and constant concentrations of other ten metabolites. It was found that as the concentration of NAAG becomes smaller (especially below 1mmol/kg), the overestimation bias in measuring the NAAG gets stronger. 15:00 3342. Reliability of in Vivo Glutamate Detection with MRS at 3T Ruth L. O'Gorman1,2, Jonathan Noble3, James M. Stone4, David J. Lythgoe5, Mary A. McLean6, Fahmida A. Chowdhury7, Philip K. McGuire4, Mark P. Richardson7, Gareth J. Barker5 1Neuroradiology, King's College Hospital, London, United Kingdom; 2MR-Zentrum, University Children's Hospital, Zurich, Switzerland; 3Medical Engineering and Physics, King's College Hospital, London, United Kingdom; 4Psychological Medicine and Psychiatry, Institute of Psychiatry, London, United Kingdom; 5Centre for Neuroimaging Sciences, Institute of Psychiatry, London, United Kingdom; 6Institute of Neurology, London, United Kingdom; 7Epilepsy Research Group, Institute of Psychiatry, London, United Kingdom This study investigated the precision of glutamate (Glu) measurements for a PRESS protocol optimised for Glu/Gln separation (echo time (TE) =80 ms) and a standard short TE (30 ms) PRESS protocol, quantified using both frequency domain and time domain analysis methods. The longer TE improved Glu precision when time-domain fitting methods (AMARES/jMRUI) were used for quantitation, but offered little improvement when frequency-domain methods (LCModel) were used. The TE80 spectra processed with jMRUI offered the best precision for NAA and Choline, while the TE30 spectra processed with LCModel offered the best precision for Glu and Cr. 15:30 3343. Diurnal Stability of MEGA-PRESS Measurements of GABA Concentration Richard AE Edden1,2, C John J. Evans3,4, David J. McGonigle3,5 1Russell H Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins University, Baltimore, MD, United States; 2FM Kirby Research Center for Functional MRI, Kennedy Krieger Institute, Baltimore, MD, United States; 3CUBRIC, School of Psychology, Cardiff University, United Kingdom; 4GE HealthCare, Slough, United Kingdom; 5School of Biosciences, Cardiff University, United Kingdom Edited MRS measurements of GABA are being widely applied in clinical and basic neuroscience studies. GABA concentration is known to vary with the menstrual cycle, and GABA is key to the suprachiasmatic nuclei’s circadian ‘clock’, but no study has addressed diurnal GABA variation in cortical regions. In spite of this, it is rare to control for time-of-day in designing studies. This study measures GABA in visual and sensorimotor cortex in 8 individuals at 5 timepoints in a day, and concludes that methods are insensitive to any diurnal variation in GABA concentration, but that regional and inter-individual differences can be seen. Tuesday 13:30-15:30 Computer 12 13:30 3344. An Improved Magnetization Saturation Transfer Approach---T1nom for Rapidly Measuring and Quantifying CK Activity in the Rat Brain - not available Fei Du1,2, Qiang Xiong3, Xiao-Hong Zhu1, Wei Chen1 1Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Psychiatry, Harvard Medical School, Belmont, MA, United States; 3Biomedical Engineering, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States The chemical exchange reactions (PCr↔ATP↔Pi) catalyzed by the creatine kinase (CK) and ATPase enzymes play key roles in maintaining brain function. In vivo 31P-MRS combined with magnetization saturation transfer (ST) provides a unique tool for assessing the reaction rate constants (kf). The accurate quantification of kf usually requires a long repetition time (tr) for approaching a steady-state saturation condition, however, suffers from limited sensitivity for biomedical application. This problem could be partially solved by shortening tr and allowing more signal averages. However, the partial saturation effect independent of kf makes kf quantification more complicate. Therefore, it is crucial to develop different approaches able to rapidly measuring and quantifying CK and ATPase enzyme activities in vivo. In this work, we present an improved magnetization ST approach, i.e.T1nom approach, for correcting the partial saturation effect with short tr. The results indicate a simple, linear relation between kf and the magnetization ratio of control and saturated 31P spectra. This approach was tested in the rat brain. Qiang Xiong1, Fei Du1, Xiao-hong Zhu1, Jianyi Zhang1,2, Wei Chen1 1Center for Magnetic Resonance Research, Univ. of Minnesota, Minneapolis, MN, United States; 2Medicine, Lillehei Heart Institute, Univ. of Minnesota, Minneapolis, MN, United States A novel approach (T1nom) is presented for saturation transfer (ST) technique that is suitable for super fast measuring and quantifying enzyme kinetics in vivo. The T1nom approach features with arbitrarily repetition time, saturation time and flip angle while maintaining simple quantification algorithm that can be only achieved with very long TR and saturation time in the case of conventional ST approach. The T1nom approach was optimized by using numerical simulations. The results gave the guidelines for finding TR/flip angle pairs that can give rise to be most accurate measurements of kinetic rate constants within a given scan time. Finally, a practical procedure is given for intervention/stimulation experiments where changes of compound pool size ratios may be encountered. Lowri E. Cochlin1, Kieran Clarke1 1Cardiac Metabolism Research Group, University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, United Kingdom This work demonstrates an intuitive approach to weighting data according to precision achieved during quantification. Cardiac 31P-MRS is used as an example of data whose accurate fitting is often challenged by low SNR. The 1:1:1 ratio of á:â:ã-ATP peaks (excited uniformly with optimized RF-pulse, NAD and T1 corrected) constitutes three measures of the same molecule. Probability density functions generated for each integrated peak therefore combine as a ‘weighted’ average representing a maximum likelihood estimate of the true value. Data from 11 healthy volunteers processed probabilistically demonstrated reduced variance in every PCr/ATP, and reduced inter-subject PCr/ATP spread, compared to standard weighting. 15:00 3347. Decreased Energy Metabolism in Patients with Migraine Without Aura: A 31P MRS Study Harmen Reyngoudt1,2, Benedicte Descamps1,2, Yves De Deene3, Koen Paemeleire4,5, Eric Achten1,2 1Radiology, Ghent University, Ghent, Belgium; 2Ghent Institute for Functional and Metabolic Imaging, Ghent University, Ghent, Belgium; 3Radiotherapy, Ghent University, Ghent, Belgium; 4Basic Medical Sciences, Ghent University, Ghent, Belgium; 5Neurology, Ghent University Hospital, Ghent, Belgium Most studies emphasized on the quantification of phosphorus metabolites in migraine with aura patients. We re-evaluated the phosphorus metabolism, and its possible basal deficiencies, in a homogeneous migraine without aura (MwoA) patient group between attacks (interictally). We compared 22 MwoA patients with 22 controls. Spectra were acquired in the visual cortex. Absolute quantification was performed by using an external reference. The metabolic shifts found in this study point to a basal metabolic deficiency in MwoA patients Wednesday 13:30-15:30 Computer 12 Rani G. Sah1, Uma Sharma1, Rajinder Parshad2, Naranamangalam R. Jagannathan1 1Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India; 2Department of Surgery, All India Institute of Medical Sciences, New Delhi, Delhi, India The concentration of choline containing compounds (tCho) was calculated using in-vivo proton MRS in 155 women. tCho was observed in 96/101 malignant, 22/25 benign lesions and 16/29 normal volunteers. The mean concentration of tCho for malignant tissues (4.0 ± 2.9 mmol/kg) was significantly higher compared to benign (1.45 ± 0.92 mmol/kg) and normal breast tissues (0.57 ± 0.37 mmol/kg). Using ROC analysis, cut-off values of 2.24 mmol/kg and 1.02 mmol/kg were obtained for the differentiation of malignant from benign tissues and malignant versus normal tissues, respectively, suggesting that quantitative measurements provide unambiguous diagnosis of breast lesions. Michael James Reeves1, Alice E. Oates1, David A. Capener1, Janet E. Morris1, Jim M. Wild1, Martyn NJ Paley1, Elspeth H. Whitby1 1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom This study examines the technical feasibility of measuring the concentration of fetal pulmonary surfactant (lecithin) by proton magnetic resonance spectroscopy using a 1.5T clinical imaging system. The lower limit of detection of lecithin in vitro was found to be around 0.5mM using typical clinical sequence parameters. This is well above the physiological concentrations found in amniotic fluid samples. Non-invasive measurement of amniotic fluid lecithin concentration by 1.5T proton magnetic resonance spectroscopy using current clinical imaging parameters is therefore not considered to be practicable.
14:30 3350. ERETIC-Based Glycogen Quantification Using SNR-Enhanced and Localized 13C MRS Xing Chen1, Anke Henning1, Matteo Pavan1, Susanne Heinzer-Schweizer1, Marco Toigo2,3, Peter Bösiger1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 2Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland; 3Exercise Physiology, Institute of Human Movement Sciences, ETH Zurich, Switzerland 13C MRS glycogen was detected by combined ISIS-localized NOE and proton decoupling in human calf muscle, with the ERETIC signal as a synthetic reference standard for quantification. Reproducibility tests were performed regarding the quantified signal intensities, SNR enhancement factors and ERETIC signal stability. In conclusion, the combination of NOE and decoupling can enhance the glycogen signal at a reproducible level and enables higher fitting and thus quantification reliability. As ERETIC signal stability proved to be unaffected by SNT enhancement, it is promising to use the ERETIC signal as reference for absolute quantification among different subjects and experiments. 15:00 3351. T2 Determination of the J-Coupled Methyl Protons of Tibial Bone Marrow Lipids at 3 T Atiyah Yahya1,2, B. Gino Fallone1,2 1Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada; 2Department of Oncology, University of Alberta, Edmonton, Alberta, Canada Magnetic resonance spectroscopy of lipids has provided insight into a number of diseases. The methylene (CH2) to methyl (CH3) lipid proton ratio is a useful quantity. For accurate calculations of this ratio, reliable estimates of the T2 values of the protons are required. Determining a representative T2 for the methyl protons is challenging because of J-coupling contributions. In this work, we show how the T2 of the methyl protons of lipids can be measured at 3 T with minimal contributions from J-coupling evolutions. The efficacy of the technique was verified on tibial bone marrow of four healthy volunteers. Thursday 13:30-15:30 Computer 12 Ernesto Akio Yoshimoto Ninamango1, Chenguang Zhao2, Kaung-Ti Yung2, Weili Zheng2, Elena Ackley2, Stephen Dager3, John vanMeter4, Ulrike Dydak5,6, Keith Heberlein7, Shang-Yueh Tsai8, Fa-Hsuan Lin9,10, Lawrence Wald11, Andre Van Der Kouwe11, Juan Bustilo12, Stefan Posse1,3 1Electrical Engineering, University of New Mexico, Albuquerque, NM, United States; 2Department of Neurology, University of New Mexico, Albuquerque, NM, United States; 3Department of Radiology, University of Washington, Seattle, WA, United States; 4Department of Neurology, Georgetown University, Washington, DC, United States; 5Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States; 6School of Health Sciences, Purdue University, West Lafayette, IN, United States; 7Siemens Medical Solutions, Siemens, Erlangen, Germany; 8Department of Electrical Engineering, Chang Gung University, Tau Yuan, Taiwan; 9Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 10A. A. Martinos Center, Massachusetts General Hospital, MA, United States; 11MGH-HMS-MIT Athinoula A. Martinos Center for Biomedical Imaging; 12Department of Psychiatry, University of New Mexico, Albuquerque, NM, United States; 13Electrical and Computer Engineering Department, University of New Mexico This multicenter MRSI study presents the results of 3D metabolite mapping in the brain of healthy subjects at high-spatial resolution (voxels as small as 0.14 cc) and measurement times of less than 11 min. Data were acquired with short-TE PEPSI on 3T scanners equipped with large-scale head array coils (8 to 32 channels). The resolution of this method provides consistent spectral quality with narrow spectral width throughout the VOI and enables delineation of anatomical brain structures in metabolite maps. The short measurement times (as short as 7 min for 64x64x8 spatial matrix) makes this method attractive for clinical research studies. Ernesto Akio Yoshimoto Ninamango1, Andre Van Der Kouwe2, Fa-Hsuan Lin, 2,3, Lawrence Wald2, Stefan Posse, 1,4 1Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States; 2A. A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, United States; 3Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 4Department of Neurology, University of New Mexico, Albuquerque, NM, United States In this study we investigate the effects of CSF fraction on absolute quantification as a function of spatial resolution for voxel sizes of 0.3, 1.2 and 4.8 cc in data acquired with short TE (15 ms) PEPSI high-speed MRSI on a 3 T scanner equipped with 32 channel head array coil. Bias in pure GM and WM concentration estimates is shown to increase with increasing CSF fraction and voxel size. Increasing spatial resolution is advantageous for clinical studies, reducing sensitivity to partial volume correction when assessing metabolic changes in focal brain lesions and in normal appearing WM and GM. Jason C. Crane1, Marram P. Olson1, Sarah J. Nelson1,2 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States We present SIVIC (Spectroscopic Imaging, VIsualization and Computing), which is an open-source, cross-platform, DICOM MR spectroscopy software package. It provides an extensible framework for reading, processing, and visualizing MRS data from various non-DICOM sources, simplifying MRS workflows in multi-center environments. SIVIC’s open-source algorithm interface supports sharing and evaluation of new MRS methodologies. This standards-based framework enables clinicians and researchers to leverage PACS and other standard DICOM tools for storage, communication and discovery of spectroscopic data. Plug-ins for OsiriX and Slicer were developed using SIVIC to facilitate integration and visualization of MRS data within these commonly used software packages. Sandra Ortega-Martorell1,2, Iván Olier3, Alfredo Vellido4, Margarida Julià-Sapé2,5, Carles Arús1,2 1Grup d’Aplicacions Biomèdiques de la RMN (GABRMN), Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, Barcelona, Spain; 2Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain; 3Institut de Neurociències (INc), Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, Barcelona, Spain; 4Departament de Llenguatges i Sistemes Informàtics (LSI), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain; 5Grup d’Aplicacions Biomèdiques de la RMN (GABRMN), Departament de Bioquímica i Biologia Molecular , Universitat Autònoma de Barcelona (UAB), Cerdanyola del Vallès, Barcelona, Spain Spectral Prototype Extraction (SPE) is a novel feature extraction technique, offering the capability of creating spectral prototypes which correspond to known metabolites or groups of metabolites. Experimental results for discriminating glioblastomas from metastases in a SV 1H-MRS brain tumour database, for long and short echo times shows the following: 1) Most of the prototypes describing the dataset can be used as readily interpretable input features in classifiers and 2) SPE-based classification yields results that are comparable to those of PCA-based classification. MR Spectroscopy of Cells, Body Fluids, Etc. Hall B Monday 14:00-16:00 Computer 13 14:00 3356. NMR Investigations of Neuronal and Astroglial Metabolism in Nicotine Addiction Anant Bahadur Patel1, Mohammad Shameem1 1NMR Microimaging and Spectroscopy, Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India In this study we have used a novel approach of co-infusion of [U-13C6]glucose and [2-13C]acetate to investigate neuronal and astroglial metabolism in nicotine addiction. C57BL6 mice were injected (s.c.) with nicotine three times a day for a month. Measurements were carried out 2 days after the last treatment by infusing [2-13C]acetate and [U-13C6]glucose for 20 min. 13C Labeling of amino acids were measured with 1H-[13C]- and 13C-[1H]-NMR spectroscopy at 14T NMR spectrometer. Nicotine treatment did not alter the cerebral metabolites levels in the different brain regions. However, glutamatergic and GABAergic rate were increased in cortex with chronic nicotine treatment. 14:30 3357. Simultaneous Measurement of Neuronal and Astroglial Metabolism in Mouse Brain - not available Anant Bahadur Patel1, Puneet Bagga1, K.S. Varadarajan1, T.V. Rohith1 1NMR Microimaging and Spectroscopy, Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India In this study we have used a novel approach of co-infusion of [U-13C6]glucose and [2-13C]acetate in mice to study neuronal and astroglial metabolism simultaneously. 1H-[13C]- and 13C-[1H]-NMR spectroscopy were used to analyze the neurotransmitter turnover from labeled substrates in different brain regions. Half time for GluC4 and GABAC2 increased in the order; Cortex-SubCortex-Cerebellum while that of GlnC4 from [2-13C]acetate is in the order; SubCortex-Cortex-Cerebellum. Further, the initial synthesis rate of glutamate and GABA from glucose decreased in the order: Cortex-SubCortex-Cerebellum while that of glutamine from acetate increased in the order: Cortex-SubCortex-Cerebellum. Anu Malik1, Uma Sharma1, R Lakshmy2, Rajiv Narang3, Naranamangalam R. Jagannathan1 1Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India; 2Department of Cardiac Biochemistry, All India Institute of Medical Sciences, New Delhi, Delhi, India; 3Department of Cardiology, All India Institute of Medical Sciences, New Delhi, Delhi, India We explored the possibility of biomarkers using NMR spectroscopy to differentiate among different forms of coronary artery disease (CAD) like single vessel (SVD), double vessel (DVD) and triple vessel disease (TVD). Elevated levels of LDL/VLDL, Isoleucine/Leucine /Valine, Alanine and alpha-1 glycoprotein were observed in CAD patients (n=112) compared to controls (n=30). Levels of Alanine were significantly different between the three forms of CAD indicating that the chronic bouts of myocardial ischemia may induce alterations in myocardial amino acid metabolism and measurement of myocardial exchange of Glutamate; Alanine and Lactate can be suggested as a sensitive biochemical test. Pratima Tripathi1, Nirmal Gupta2, Raja Roy1, C.L. Khetrapal1 1CBMR, Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; 2Department of Cardiovascular and Thoracic Surgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India The study focuses on first application of 1H-NMR spectroscopy to human PCF obtained from patients undergoing open-heart surgeries, aiming at identifying metabolites under normal conditions. Total 107 patients were included of which 62 were adults and 45 pediatric patients. The differences in the concentrations of metabolites between adult and pediatric patients are discussed. PCF were also compared with the serum of these patients. Concentrations of lipid resonances were lesser in PCF as compared to serum while small molecular weight metabolites were more in PCF. This analysis may provide a baseline for better understanding of pericardial fluid physiology in diseased conditions. < > Tuesday 13:30-15:30 Computer 13 Xiaoyan Pan1, Martin Wilson1, Carmel McConville1, Marie-Anne Brundler2, Theodoros Arvanitis3, Risto Kauppinen4, Andrew Peet1,5 1School of Cancer Sciences, University of Birmingham, Birmingham, West Midlands, United Kingdom; 2Histology, Birmingham Children's Hospital NHS, Birmingham, West Midlands, United Kingdom; 3School of Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, West Midlands, United Kingdom; 4Radiology, Dartmouth College, Dartmouth, NH, United States; 5Oncology, Birmingham Children's Hospital NHS, Birmingham, West Midlands, United Kingdom Lipid droplets (LDs) have been associated with several important cellular processes. Previous NMR studies of extracted lipids have been performed on whole cells, which are dominated by membrane lipids. In this study, density-gradient ultracentrifugation was used to isolate LDs from other sub-cellular structures. 1H NMR was performed on whole cells, whole cell extracts and isolated LDs. An excellent agreement was observed between the lipid resonances present in the whole cell and isolated LD spectra supporting the claim that NMR-visible lipids originate from LDs. Spectra of the isolated LDs and whole cell extracts revealed differences between the ratio of cholesteryl compounds. 14:00 3361. 1H NMR Spectroscopic Studies on Human Seminal Plasma: A Probative Discriminate Function Analysis Classification Model - not available ashish gupta1, Abbas Ali Mahdi1, Kaleem Ahmad1, Kamla Kant Shukla1, S P. Jaiswar2, S N. Shankhwar3 1Department of Biochemistry, King George’s Medical University, Lucknow, UP, India; 2Department of Obstetric & Gynecology, King George’s Medical University, Lucknow, UP, India; 3Department of Urology, King George’s Medical University, Lucknow, UP, India Quantitative analysis of seminal plasma (n=175) profile was carried out using 1H NMR spectroscopy and clinical symptoms were also observed in same samples with standard laboratory method. Multivariate discriminant function analysis (DFA) was carried out for the NMR observed metabolites and clinical symptoms data of the infertile and control cases, to find out important signature descriptors for classification. A new “INFERTIX” classification model was developed and proposed which is based on the results obtained from DFA for the different classes of infertile patients, with very high sensitivity and specificity values. 14:30 3362. NMR Plasma Profiling of Newborns with Low Weight at Birth Jose Manuel Morales1, Carmen Ivorra2, Javier Chaves3, Consuelo Garcia-Vicent2, Maria Isabel Torro2, Jose Redon4, Empar Lurbe2, Daniel Monleon3 1Universitat de Valencia, Valencia, Spain; 2Hospital General Universitario de Valencia, Valencia, Spain; 3Fundacion Investigacion Hospital Clinico Valencia, Valencia, Spain; 4Hospital Clinico Universitario de Valencia, Valencia, Spain Blood pressure is significantly lower in those children with low birth at weight as compared to those in the other groups. In this communication we present a study of blood plasma NMR spectra for detecting the metabolic differences between low and normal weighted newborns. NMR spectra were obtained for plasma from 51 newborns, of which 20 exhibit weight at birth below 2800 g. Metabolic profiling of newborn blood plasma reveals statistically significant differences between low and normal weighted subjects including phenylalanine, citrulline, glutamine, glycerol and glucose. Interestingly, some of these metabolites are present in breast milk. Omkar B. Ijare1, Tedros Bezabeh1, Nils Albiin2, Annika Bergquist2, Urban Arnelo2, Bo Lindberg2, Ian C.P. Smith1 1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2Karolinska University Hospital, Karolinska Institutet, Huddinge, Stockholm, Sweden Bile acids, phospholipids and cholesterol are major lipid components in bile. We propose a robust method for the simultaneous quantification of glycine-conjugated bile acids (GCBAs), taurine-conjugated bile acids (TCBAs), total bile acids (TBAs) and phospholipids (PLs). GCBAs and TCBAs have been quantified using peak areas of their characteristic methylene signals resonating at 3.73 and 3.07 ppm, whereas TBA and PLs were quantified using their methyl and trimethylammonium signals resonating at 0.65 and 3.22 ppm respectively. The peak areas of these lipid signals were obtained simultaneously by deconvolution, making the method robust. This method could be extended to in vivo applications. Wednesday 13:30-15:30 Computer 13 Ritu Tyagi1, Poonam Rana1, Priyanka Saxsena2, M Memita Devi1, Sonia Gandhi1, Sunil Pal3, Subash Khushu1 1NMR Research Centre, INMAS, Delhi, India; 2Department of Nuclear Medicine, INMAS, Delhi, India; 3Division and Cyclotron & Radiopharmaceutical Sciences, INMAS, Delhi, India Thallium-201 (Tl-201) is routinely used in nuclear medicine scans. Physiologically, it acts as a potassium analog and gets accumulated in the cells leading to some alterations at metabolite levels. Present study was proposed to look upon the changes at metabolite levels in urine samples obtained from Tl-201 treated mice. Urine samples were collected from mice at 3 and 24 hrs post injection of Tl-201.The 1H NMR spectral analysis of urine presented many altered metabolites suggesting a change in energy, amino acid metabolism and gut flora. However, changes observed after Tl-201 injection are functional reversible physiological changes. Anca Ramona Croitor Sava1, Diana Maria Sima1, Bernardo Celda2,3, Sabine Van Huffel1 1ESAT-SCD-Biomed, Katholieke Universiteit Leuven, Heeverle, Leuven, Belgium; 2Departamento de Química-Física, Facultad de Química, Universitat de Valencia, Valencia, Spain; 3CIBER-BBN, ISC-III, Universitat de Valencia, Valencia, Spain Glial tumors have proved to be very heterogeneous, both in the malignancy grade and in the tumor tissue type. We analyze the mixture of different tumor tissue types (necrotic, high cellular and border tumor tissue) within HR-MAS spectra by separating between the different sources that contribute to the profile of each spectrum. Non-negative matrix factorization and independent component analysis are used to extract the constituent source profiles and their abundance distributions within all samples. Thus each feature vector is represented as a linear combination of profiles corresponding to constituent tissue types. Sonia Gandhi1, Memita Devi1, Shubhra Chaturvedi2, Subash Khushu1 1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 2Division and Cyclotron & Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India Cold stress is responsible for affecting multiple biochemical regulatory systems & triggering cardiovascular & respiratory disorders, cognitive impairment, anxiety. Present study investigates the changes in metabolic profiles of urine in rats due to acute cold stress using NMR & multivariate statistical analysis (PCA). Results indicate up regulation of TCA cycle decreasing pyruvate, citrate, 2-oxoglutrate, succinate & fumarate concentration. Creatinine & Hippurate levels were reduced altering gut microbiota. Decreased aromatic amino acids & TMAO also supports kidney dysfunction. Noninvasive monitoring of various biochemical pathways can be done & these results can be used to develop strategies to sustain cold stress. 15:00 3367. NMR Spectroscopy of Urine for the Detection of Urinary Tract Infection (UTI) in Children Tedros Bezabeh1, Omkar B. Ijare1, Martin Reed2, Tom Blydt-Hansen2, Ian C.P. Smith1 1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2University of Manitoba Children's Hospital, Canada Urinary tract infection (UTI) is the most common non-epidemic bacterial infection in adults and children. Due to the longer diagnostic wait time required for the gold standard – the culture method, dipstick methods are commonly used for the quick diagnosis of UTI. However, dipstick methods are commonly associated with false negative and/or false positive results. Therefore, other more rapid methods are desirable. 1H NMR based metabolic profiling of urine samples could be valuable in this regard. Elevated levels of trimethylamine-N-oxide, creatine, and an unassigned signal at 3.71 ppm have been observed in the urine samples with UTI compared to the control group. Thursday 13:30-15:30 Computer 13 13:30 3368. Toxicological Effect of Thallium in Mice by NMR-Based Metabolic Profiling of Urine Ritu Tyagi1, Poonam Rana1, Ahmad Raza Khan1, M Memita Devi1, Shubhra Chaturvedi2, Subash Khushu1 1NMR Research Centre, INMAS, Delhi, India; 2Division and Cyclotron & Radiopharmaceutical Sciences, INMAS, Delhi, India Thallium is a heavy metal that gets accumulated in liver and kidney after absorption and causes renal and hepatotoxicity. NMR spectroscopy based study has been conducted for identification of metabolite markers for thallium toxicity. Urine samples were collected from mice at 3, 24 and 96 hrs post injection of low and high dose of Tl2SO4. Spectral analysis showed dose dependent alterations in various metabolites involved in renal and hepatic toxicity and could be seen as early as 3 hrs post injection and may be further helpful in devising the protocol for decorporation of such harmful elements. Sonia Gandhi1, Poonam Rana1, Memita Devi1, Sunil Pal2, Subash Khushu1 1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India; 2Division and Cyclotron & Radiopharmaceutical Sciences, Institute of Nuclear Medicine and Allied Sciences, Delhi, India Heat stress exposure can affect physiological & cognitive performance in humans, alter neurotransmitters & hormone level, causes hypohydration affecting cognitive performance. Present study reveals the changes in metabolite pattern & identifies potential biomarkers in rat urine due to heat stress exposure by NMR & multivariate statistical analysis. Phenylalanine, creatinine, hippurate, pyruvate & citrate concentration was reduced indicating onset of thermoregulatory response, altered renal function & enhanced energy consumption. Increased formate indicates disturbed gut flora. These studies reveal the subtle interplay of functional metabolites & pathways leading to an understanding of the systemic response to external stimuli such as heat stress. Poonam Rana1, Ahmad Raza Khan1, M Memita Devi1, Sunil Pal2, Subash Khushu1 1NMR Research Centre, INMAS, Delhi, India; 2Division and Cyclotron & Radiopharmaceutical Sciences, INMAS, Delhi, India Regular monitoring of irradiated patient is essential for clinical management during illness phase of radiation sickness. The present study has been designed to explore metabolic perturbation in mice urine after three weeks of irradiation. The results based on urine NMR spectra analysis exhibited an altered energy, amino acid and gut microflora metabolism which could indicate renal and liver dysfunction. These changes could be the consequence of radiation induced damage to physiological systems during recurrence of clinical symptoms after recovery period. The information attained from the study along with biochemical assays could be very useful in assessing the organ dysfunction during radiation sickness. 15:00 3371. Compressed Sensing for Sparse Magnetic Resonance Spectroscopy Xiaobo Qu1, Xue Cao2, Di Guo3, Zhong Chen4 1Department of Communication Engineering,, Xiamen University, Xiamen, Fujian, China; 2School Of Software, Shanghai Jiao Tong University, Shanghai, China; 3Department of Communication Engineering, Xiamen University, Xiamen, Fujian, China; 4Department of Physics, Xiamen University, Xiamen, Fujian, China Multidimensional magnetic resonance spectroscopy (MRS) can provide additional information at the expense of longer acquisition time than 1D MRS. Assuming 2D MRS is sparse in wavelet domain, Iddo[1] first introduced compressed sensing (CS) [2][3] to reconstruct multidimensional MRS from partial and random free induction decay (FID) data. However, the darkness in 1D NMR spectra derives from the discrete nature of chemical groups [4]. Significant peaks in these MRS takes up partial location of the full MRS while the rest locations own very small or even no peaks. This type of MRS can be considered to be sparse itself, named sparse MRS. In the concept of sparsity and coherence for CS[5], we will demonstrate that wavelet is not necessary to sparsify sparse MRS and even makes the reconstructed MRS worse than without wavelet. Furthermore, a lp quasi-norm compressed sensing reconstruction is employed to improve the quality of reconstruction. Spectroscopic Localization & Imaging Methodology Hall B Monday 14:00-16:00 Computer 14 14:00 3372. In Vivo 31P-MRS at 7T by Single Voxel E-ISIS with GOIA Selection Pulses Wolfgang Bogner1, Marek Chmelik1, Ovidiu Cristian Andronesi2, Stephan Gruber1, Siegfried Trattnig1 1MR Center of Excellence, Radiology, Medical University, Vienna, Austria; 2Martinos Center for Biomedical Imaging, Radiology, Massachusetts General Hospital, Havard Medical School, Charlestown, MA, United States An image-selected in vivo spectroscopy (ISIS) sequence was developed for acquisition of localized 31P-MRS at 7T in vivo. For accurate localization (negligible contamination and chemical shift error) even with B1 inhomogeneous surface coils gradient offset independent adiabatic (GOIA) inversion pulses with high bandwidth were used. To allow short TR without increases in contamination due to “T1 smearing” an E-ISIS acquisition scheme was combined with adiabatic BIR-4 excitation. This allows localized 31P-MRS in clinically feasible measurement time (~3-4 min) and good spatial resolution (~2-2.5 cm isotropic) with high reproducibility. Marek Chmelík1,2, Wolfgang Bogner, 2,3, Stephan Gruber, 2,3, Siegfried Trattnig, 2,3, Martin Krššák, 2,3 1Department of Radiology, Medical University of Vienna, Vienna, Austria; 2MR Centre of Excellence, Medical University of Vienna, Vienna, Austria; 3Department of Radiology, Medical University of Vienna, Vienna, Austria It has been shown that in vivo muscle 31P T1 relaxation times decrease at higher magnetic field (7T) due to higher contribution of chemical shift anisotropy. The purpose of this study was to compare and optimize SNR-per-unit-time of 31P 3D MRSI in the human calf at 3T and 7T. Phantom experiments with comparable T1 times showed 94% increase of SNR-per-unit-time whereas in vivo muscle SNR-per-unit time was increased by 140%, partly due to shorter T1 relaxation. Both higher magnetic field and shorter T1 relaxation time contribute to improvement of 31P MRSI SNR-per-unit-time at 7T. Irina Brote1,2, Stephan Orzada1,2, Andreas K. Bitz1,2, Tom Scheenen1,3, Oliver Kraff1,2, Stefan Maderwald1,2, Mark E. Ladd1,2 1Erwin L. Hahn Institute for MRI, Essen, Germany; 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany; 3Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands High-field magnetic resonance spectroscopy (MRS) should provide enhanced neurochemical information based on increased sensitivity and higher spectral resolution. Problems arising in high-field MRI, such as B0 and B1 inhomogeneities, may however decrease spectral resolution and SNR. Multi-channel transmit systems have been introduced to overcome problems concerning B1 inhomogeneity. One multi-channel transmit method is RF shimming. In this study, this method is used for outer volume supression (OVS) at 7T in single voxel spectroscopy (SVS) using two interleaved RF shim settings. A suppression of the outer volume signals of more than 90% is achieved. Manoj K. Sammi1, Yosef Berlow1,2, Thomas Barbara1, John Grinstead1,3, Dennis Bourdette4, William D. Rooney1,2 1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2Department of Behavioral Neuroscience, Oregon Health & Science University; 3Siemens Medical Solutions; 4Department of Neurology, Oregon Health & Science University Methodology development for quantitative phosphorous MRSI in human brain at 7T Tuesday 13:30-15:30 Computer 14 13:30 3376. Tract-Based Spectroscopy of the Cingulum at 7 Tesla René Mandl1, Martijn van den Heuvel1, Dennis Klomp2, Vincent Boer2, Jeroen Siero3, Peter Luijten2, Hilleke Hulshoff Pol1 1Psychiatry, Rudolf Magnus Institute of neuroscience, UMC Utrecht, Utrecht, Netherlands; 2Radiology, UMC Utrecht, Utrecht, Netherlands; 3Neurosurgery, Rudolf Magnus Institute of neuroscience, UMC Utrecht, Utrecht, Netherlands Usage of fiber tracking for positioning and analyzing high spatial resolution 2D Chemical Shift Images of the cingulum at 7 Tesla. 14:00 3377. Optimized Spectroscopic RARE at 7 Tesla Applied to Rat Brain in Vivo Wolfgang Dreher1, Dieter Leibfritz1 1Dept. Chemistry, University of Bremen, Bremen, Germany The fast spectroscopic imaging method spectroscopic RARE was implemented on a 7-Tesla animal scanner and applied to rat brain in vivo. It is shown that various experimental problems occurring at higher B0 can be eliminated and, compared to earlier results at 4.7 T, the potential of a higher signal-to-noise ratio and increased spectral resolution can be exploited. As increased spectral resolution requires a larger number of kΩ -encoding steps and thus a longer minimum total measurement time, the use of phase corrected spectra calculated from asymmetric kΩ -sampling is considered as an alternative to magnitude spectra calculated from symmetrically sampled kΩ -data. 14:30 3378. Short-Echo, Single-Shot, Full-Intensity 1H MRS of the Human Brain at 4T Gulin Oz1, Ivan Tkac1 1University of Minnesota, Minneapolis, MN, United States Short echo times are advantageous for 1H MR spectroscopy because they facilitate quantification of metabolites with coupled spin systems and minimize signal loss due to T2 relaxation. A semi-adiabatic LASER sequence with short TE was developed and optimized for full intensity 1H MRS at 4T. Neurochemical profiles of the cerebellum and brainstem were measured in 23 healthy subjects using semi-LASER and STEAM pulse sequences. Neurochemical profiles acquired by these two techniques were nearly identical. A high correlation between metabolite concentrations quantified by these two techniques indicated the sensitivity to detect inter-subject variation in metabolite levels. 15:00 3379. Towards a Localized Low Power Adiabatic 2D TOCSY for In-Vivo Use on Clinical Platforms Ovidiu Cristian Andronesi1, Saadallah Ramadan2, Carolyn E. Mountford2, A Gregory Sorensen1 1Martinos Center for Biomedical Imaging, Radiology Department, Masschusetts General Hospital, Harvard Medical School, Boston, MA, United States; 2Center for clinical spectroscopy, Department of Radiology, Brigham and Women's Hospital, Harvard Medical Schoo, Boston, MA, United States Two-dimensional spectroscopy is important for unambiguous assignment of overlapping metabolites and could be more efficient than 1D spectral-editing. 2D TOCSY (TOtal-Correlation-SpectroscopY) is one of the most powerful experiments that reveals the full spin connectivity, but demands for a sustained spin-lock can prevent in-vivo applications. 1D spectral-edited TOCSY was demonstrated recently, although an in-vivo 2D TOCSY has not been realized yet. We propose a modified 2D version of the localized TOCSY, including a z filter and the use of gradient offset independent adiabaticity (GOIA) pulses to reduce SAR. Simulations and phantom measurements on a 3T Siemens MR clinical scanner are presented. Wednesday 13:30-15:30 Computer 14 13:30 3380. Reproducibility of ME-COSI in Human Brain and Phantom Gaurav Verma1, Scott Logan Lipnick2, Nagarajan Rajakumar3, Saad Ramadan4, Michael Albert Thomas3 1Biomedical Engineering, UCLA, Los Angeles, CA, United States; 2Biomedical Physics, UCLA, Los Angeles, CA, United States; 3Radiological Sciences, UCLA, Los Angeles, CA, United States; 4Radiology, Brigham & Women's Hospital, Cambridge, MA, United States The previously-introduced ME-COSI sequence acquires 2D spectra over a 2D spatial array. ME-COSI reproducibility was investigated in human brain with four volunteers and eight total scans, and in a physiological gray matter phantom with thirty-two scans. Data were post-processed and peak integral/volumes compared to creatine were quantified. Measured coefficients of variation across all scans ranged from 4-17% for single subject in vivo, 7-26% for multiple subjects and 6-25% for in vitro studies, at half the voxel volume. This is comparable to the performance reported from existing single-voxel 2D MRS methods. Scott Lipnick1, Gaurav Verma1, M. Albert Thomas1 1UCLA, Los Angeles, CA, United States The presented research details the differences between slice localized and volume localized EP-COSI data sets. Slice localization enables shorter echo times and thus signal acquisition with less T2 losses. The result is increased SNR in the resulting EP-COSI data set. The drawback is more leakage from outer volume signal. When outer volume suppression is achievable more SNR is achievable using slice localization, when it is not the ideal localization scheme is volume based. Both sequences are capable of differentiating J-coupled off diagonal resonances. 14:30 3382. Whole Brain Proton MRSI Using a Multiple 2D Sequence Zhengchao Dong1,2, Feng Liu1,2, Alayar Kangarlu1,2, Bradley Peterson1,2 1Columbia University, NEW YORK, United States; 2NEW YORK STATE PSYCHIATRIC INSTITUTE, NEW YORK, United States In this work, we present an extension of a widely used multi-planar MRSI sequence, which has limited brain coverage and spacing between slices. We show that by adjusting sequence parameters we can increase the number of slices without significant increase of total scan time and remove the spacing between slices without significant lose of signal-to-noise ratio. With these approaches, whole brain proton MRSI can be realized. We demonstrated the results with experimental data both on phantom and on human volunteers. 15:00 3383. Compensation of Offresonance Magnetization Transfer Artifact in SPECIAL at 7T - not available Alexander Fuchs1, Anke Henning1, David Brunner1, Peter Boesiger1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland The SPECIAL sequence is a 2 step ISIS like localization scheme that allows to measure 3D SV spectra at very short echo times. This is especially interesting for spectroscopy at ultra-high fields were metabolite relaxation complicates the detection of certain metabolites. It is demonstrated in this work that in SPECIAL without outer volume suppression the ISIS inversion pulse induces magnetization transfer effects between bound protons and skull lipids. This can lead to strong outer volume fat contamination of the actual spectrum. Furthermore a modification to the SPECIAL sequence is proposed to overcome these types of artifacts. Thursday 13:30-15:30 Computer 14 13:30 3384. Double-Shot Center-Out Echo Planar Spectroscopic Imaging at 3 Tesla Christian Labadie1,2, Stefan Hetzer1, Toralf Mildner1, Diana R. Amariei3, Monique Frécon4, Harald E. Möller1,2 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Faculty of Physics and Earth Science, University of Leipzig, Germany; 3Servei de Ressonància Magnética Nuclear, Universitat Autònoma de Barcelona, Spain; 4Laboratoire de Spectrométrie Ionique et Moléculaire, Université Claude Bernard Lyon 1, France A novel MRSI sequence, based on a double-shot echo planar spectroscopic readout, offers a full k-space sampling despite the limitation imposed by the spectral dwell-time of proton spectroscopy at 3 Tesla. In 61 sec, a spectroscopic image was acquired with a 12 x 12 matrix, TE of 33 ms, voxels of 4.91 mL and 16 steps EXOR phase cycling. The quantitation of the voxel spectra significantly determined NAA, creatine, choline and myo-inositol. A longer acquisition of 3 min 44 sec further permits to detect glutamine and glutamate. 14:00 3385. Improved Water and Lipid Suppression in Volumetric Brain 3D-EPSI Juan Wei1, He Zhu1, Ronald Ouwerkerk1, Peter B. Barker1 1Russell H Morgan Department of Radiology, The Johns Hopkins University, Baltimore, MD, United States 3D echo planar spectroscopic imaging (EPSI) was implemented with a new dualband water and lipid suppression with integrated outer volume suppression. Compared to conventional CHESS and inversion recovery lipid suppression, water suppression with the dualband sequence was a factor of 2.65 better, while lipid suppression was 8.61 better. Metabolic images recreated with the dualband acqusition showed markedly reduced lipid contamination artifacts compared to conventional methods. 14:30 3386. Scan Time Reduction in 3D-EPSI Using Reduced Phase-Encoding Juan Wei1, Peter B. Barker1 1Russell H Morgan Department of Radiology, The Johns Hopkins University, Baltimore, MD, United States A simple technique is described for scan time reduction in proton echo planar spectroscopic imaging (EPSI) of the human brain. Scan time is reduced by 25% while preserving spatial resolution and the field of view using a circular k-space phase-encoding pattern. Metabolic images created using square or circular-encoding are nearly indistinguishable. Scott Lipnick1, Gaurav Verma, M. Albert Thomas 1UCLA, Los Angeles, CA, United States The presented research details the differences between slice localized and volume localized EPSI data sets. Slice localization enables shorter echo times and thus signal acquisition with less T2 losses. The results show increased SNR in the acquired EPSI data set. The drawback is more leakage or contamination from outer volume signal, namely skull marrow lipids in brain. When outer volume suppression is achievable more SNR can be obtained using slice localization compared to volume localization. Hall B Monday 14:00-16:00 Computer 15 14:00 3388. Fluid-Suppressed 23Na MRI of Knee Joint at 7T Jae-Seung Lee1, Souheil Inati2, Ravinder Regatte3, Alexej Jerschow1 1Chemistry Department, New York University, New York, United States; 2Center for Brain Imaging, New York University, New York, United States; 3Center for Biomedical Imaging, New York University, New York, United States We demonstrate excellent fluid suppression in 23Na MRI at 7T by using inversion-recovery and quadrupolar contrast techniques. These methods will greatly improve quantification of tissue sodium concentrations, which in turn will help in providing diagnostic techniques for cartilage tissues. 14:30 3389. Lung Imaging in Humans at 3T Using Perfluorinated Gases as MR Contrast Agents Brian J. Soher1, Maureen Ainslie, James MacFall, Ralph Hashoian2, H. Cecil Charles1 1Radiology, Duke University Medical Center, Durham, NC, United States; 2Clinical MR Solutions We demonstrate the first images showing human lung ventilation using conventional ‘thermally’ polarized perfluorinated gases (PFx) mixed with oxygen as an inhaled inert MRI contrast agents. Lung airway disease clinical trials often require large numbers of subjects due to the limitations of global assessments or the presence of ionizing radiation in clinical imaging methodologies. Our results demonstrate the feasibility of using PFx to image regional ventilation characteristics throughout the lungs at a resolution and SNR (0.78 cm3 and 15:1 non-optimized) comparable to other imaging methodologies at less cost and with a straightforward path for repeat and cine-style dynamic data acquisitions. Siyuan Liu1,2, Sameer J. Shah2, Lisa J. Wilmes1, Vikram D. Kodibagkar3, Michael F. Wendland1, Christian C. Apfel2, Nola M. Hylton1, Harriet W. Hopf4, Ralph P. Mason3, Mark D. Rollins2 1Radiology, University of California, San Francisco, San Francisco, CA, United States; 2Anesthesia, University of California, San Francisco, San Francisco, CA, United States; 3Radiology, University of Texas at Southwestern, Dallas, TX, United States; 4Anesthesiology, University of Utah, Salt Lake City, UT, United States Hemoglobin based oxygen carriers (HBOCs) are being developed to reduce blood transfusion, yet HBOCs’ efficacy on organ oxygenation remain unknown. We used 19F MRI to quantify tissue oxygen (ptO2) changes during isovolemic anemic hemodilution using high and low affinity HBOCs or colloid control at 30% and 100% inspired oxygen in a rat model. Although ptO2 significantly increased with 100% vs 30% oxygen under all conditions, differences in ptO2 between HBOCs or colloid were insignificant. Our results highlight the impact of supplemental oxygen, emphasize need for further HBOC research, and demonstrate the value of 19F MRI in quantifying resuscitation interventions. 15:30 3391. Optimal Contrast for 23Na MRI Jae-Seung Lee1,2, Ravinder Regatte2, Alexej Jerschow3 1New York University, New York, NY, United States; 2Department of Radiology, New York University School of Medicine, New York, United States; 3Chemistry Department, New York University, New York, United States The sodium ions bound to tissues and organs can provide us with an invaluable information on the onset of disorder, such as osteoarthristis and degenerative disc diseases, through their concentration and quadrupolar interaction/relaxation. Slow motion of sodium ions may occur in cells, and its altered relaxation properties further provide important insights into cell viability, such as in the case of tumor tissue, or in the monitoring of muscle activity. In this paper, we are presenting two 23Na MRI contrast schemes, one selecting sodium ions with quadrupolar interation and the other with quadrupolar relaxation. Perfusion & Permeability Methodology Hall B Monday 14:00-16:00 Computer 16 14:00 3392. Parameter Influence in Dynamic-Contrast-Enhanced MRI Analyses Xin Li1, William D. Rooney1, Charles S. Springer, Jr. 1 1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States Simulations based on Gradient Recalled Echo (GRE) data acquisition and a three site water exchange model for pharmacokinetic interpretation are used to investigate parameter influence in DCE-MRI analyses. It is shown that the speed of contrast reagent (CR) extravasation plays the most important role in determining the nature and degree of parameter influence, while the MRI pulse sequence parameter values also have an effect. Iosif Alexandru Mendichovszky1, Habib Ashoor2, David L. Buckley3, Alan Jackson1 1Wolfson Molecular Imaging Centre, The University of Manchester, Manchester, United Kingdom; 2Physics Department, University of Bahrain, Bahrain; 3University of Leeds, Leeds, United Kingdom The aims of the study were (1) to investigate the validity of perfusion measurements for normal and pathological tissues using the upslope method (USM) in dynamic CT and MR from computer simulations in non-leaky and leaky capillaries and (2) to explore the effects of SNR and injection rate on the accuracy of perfusion estimates. The USM can be used to calculate perfusion in normal and pathological tissues and is most accurate in tissues with relatively long transit times. Its accuracy can be improved with the use of a rapid injection (sharp AIF) and is decreased by image noise. Ruobing Yang1, Andrew C. Yung1, Piotr Kozlowski1 1UBC MRI Research Centre, Vancouver, British Columbia, Canada Dynamic Contrast Enhanced MRI and pharmacokinetic modeling have shown promise for imaging tumours based on tissue vascularity. The current standard for measuring contrast agent concentration (T1 mapping) is prone to errors such as flip angle uncertainty and inter/intracellular water flow effects. We propose an alternative method for obtaining the AIF in the mouse by performing phase measurements in the artery of the mouse tail. We present experimental results, from a tail phantom, that demonstrate the feasibility of this technique. 15:30 3395. Impact of B1-Inhomogeneities on the Quantification of Ktrans and Ve Robert Merwa1, Thorsten Feiweier2, Franz Ebner3, Gernot Reishofer3, Karin Kapp4, Rudolf Stollberger5 1Medical Engineering, FH OÖ - Upper Austria University of Applied Sciences, Linz, Austria; 2Healthcare, Siemens AG, Germany; 3Department of Radiology, Medical University of Graz, Graz, Austria; 4Department of Radiation Therapy, Medical University of Graz, Graz, Austria; 5Institute of Medical Engineering, Graz University of Technology, Graz, Austria The determination of kinetic parameters depends strongly on the inhomogenities of the RF-field. Due to the local magnitude of these inhomogenities the values for the AIF and tissue concentrations are widespread which lead to an overestimation or underestimation of Ktrans and Ve. An essential improvement can be achieved if the dynamic data are corrected accordingly. The absolute difference of Ktrans and Ve obtained with the AIF in two comparable arteries can be improved by a factor up to 33 when using the correction procedure. Also the statistical evaluation of the data shows an improvement if B1 inhomogeneities are corrected. Hall B Monday 14:00-16:00 Computer 17 14:00 3396. Volume Microstrip RF Coil for MRI Microscopy - not available Krzysztof Jasinski1, Peter Latta2, Vyacheslav Volotovskyy2, Anna Mlynarczyk1, Wladyslaw P. Weglarz1, Boguslaw Tomanek, 12 1Institute of Nuclear Physics PAN, Kraków, Poland; 2Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, Canada A microstrip is made of a metallic strip on PCB surface creating a planar RF transmission line. The RF coils based on microstrip design, have been already applied to MRI and MRS. These coils produce homogenous RF field only within a very restricted field of view (FOV). The coil presented in this paper is based on a double microstip concept resembling a volume coil and generating homogenous RF field within a large FOV. Computer simulations of RF field and SNR are presented. An example of the application of the double microstrip volume microcoil to MR microscopy is also shown Xu Feng1, Carol Muehleman2, Richard Magin1 1Bioengineering, University of Illinois at Chicago, Chicago, IL, United States; 2Biochemistry, Rush Medical College, Chicago, IL, United States Recent publications have shown FA can reflect the orientation of the collagen fibers using DTI in MRI. However, the FA contrasts were low especially between the superficial and middle zone in those literatures. This was possibly because they selected the short diffusion time (δ < 10 ms). In our study, we increase the diffusion time from 10 ms to 30 ms so that the FA contrast increased by 4 times. We also suggest using the maximum diffusivity as a marker of hydration or PG loss of cartilage due to the less effect of the restricted diffusion. Jernej Vidmar1, Franci Bajd2, Aleš Blinc3, Dušan Šuput4, Andrej Vovk4, Igor Serša2 1Institute of Physiology, Ljubljana, Slovenia; 2Jožef Stefan Institute, Ljubljana, Slovenia; 3University Medical Centere Ljubljana, Slovenia; 4Institute of Pathophysiology, Ljubljana, Slovenia Thrombolysis of model blood clots in an artificial perfusion system was studied by MR and optical microscopy. Results of the study showed that thrombolysis is strongly flow dependent process in which biochemical clot dissolution is complemented by flow induced mechanical clot degradation manifested by dislodgement of cell agglomerates from the recanalization channel. 15:30 3399. Fiber Diameter Mapping of a White Matter Phantom Using D-PFG Filtered MRI Michal E. Komlosh1, Evren Ozarslan1, Martin J. Lizak2, Ferenc Horkay1, Peter J. Basser1 1NICHD, NIH, Bethesda, MD, United States; 2NINDS, NIH, Bethesda, MD, United States Double pulsed field gradient spin echo (d-PFG) MRI was used to measure pore diameters in glass microcapillary arrays. Simulations, taking into account all experimental and sample parameters were used to estimate the pore diameter, which agrees very well with optical microscopy measurements. Pore distribution images suggests a potential for using this new contrast mechanism and our modeling framework to map a useful feature of local material microstructure. Methodology for MR Elastography Hall B Monday 14:00-16:00 Computer 18 14:00 3400. Non-Invasive Measurement of Vitreous Humor Stiffness in the Mouse Using MR Elastography Erik Holt Clayton1, Qing Wang1, Sheng Kwei Song2, Philip V. Bayly1,3 1Mechanical Aerospace & Structural Engineering, Washington University in St. Louis, Saint Louis, MO, United States; 2Radiology/Radiological Sciences, Washington University in St. Louis, Saint Louis, MO, United States; 3Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, United States MR elastography (MRE) shows great promise for estimating the stiffness of various biological tissues. In this study, the shear modulus of the mouse eye vitreous humor was determined with MRE. A novel corneal actuation system was devised to non-invasively impart propagating shear waves into the vitreous. Spatial-temporal images of the corresponding wave field were acquired at 4.7T using a custom spin echo pulse sequence. Viscoelastic material parameters were extracted from the displacement field by a least-squares inversion method. Results show that MRE of the mouse vitreous is feasible, and suggest that MRE may be applicable to diagnosis of ocular disease. 14:30 3401. Development of a Method for Imaging Tissue Elasticity Using Tagged Magnetic Resonance Imaging - not available Ryosuke Nasada1, Tomoki Takeuchi1, Junfeng Zhang1, Takashi Tokuno2, Mitsunori Tada3, Youichi Yamazaki1, Kenya Murase1 1Department of Medical Physics and Engineering, Graduate School of Medicine, Osaka University , Suita, Osaka, Japan; 2Course of Precision Engineering, School of Science and Engineering, Chuo University, Tokyo, Japan; 3Digital Human Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan This study was undertaken to develop a method for generating the maps of Youngfs elastic modulus using tagged MRI. The maps were generated using the strain obtained by harmonic phase analysis and stress distribution. The accuracy of our method was investigated using silicone phantoms of different hardness. There was a good correlation between the strain obtained by our method and that measured using a material testing machine (r=0.99). The difference in hardness in phantoms was clearly demonstrated. Our method will be useful for evaluating the tissue elasticity, because it allows us to automatically generate the maps of elastic modulus. 15:00 3402. Is a Velocity Encoding of 5 Cm/sec Sufficient to Quantify Brain Motion? - not available Guillaume Calmon1,2, Marc Labrousse, 1,3, Gabriela Hossu4, Jacques Felblinger1,4, Marc Braun1,5 1IADI, Nancy, France; 2GE Healthcare, Buc, France; 3CHU Reims, France; 4INSERM CIT801, CIC-IT, Nancy, France; 5Nancy Université, Nancy, France Brain motion during cardiac cycle, linked to the one of cerebro-spinal fluid (CSF), presents interesting challenges and can have an interest to analyze brain “elastography”. In this study, we measured brain speed and motion in volunteers at the level of thalamus and brain stem. A velocity encoding of 5 cm/sec was sufficient to obtain brain values consistent with literature. Absolute brain tissue speeds were measured between 0.0002 and 0.17 cm/sec in thalami ROIs and between 0.0014 and 0.48 cm/sec in brain stem ROIs. There was a decreased of motion with cardiac frequency and with age in certain territories. 15:30 3403. Gas Content Dependence in Magnetic Resonance Elastography of the Lungs Marlies Friese1,2, Roberta Santarelli2, Lionel Martin2, Luc Darrasse2, Ralph Sinkus3, Xavier Maître2 1Center for Magnetic Resonance, The University of Queensland, Brisbane, Queensland, Australia; 2Imagerie par Résonance Magnétique et MultiModalités (UMR8081), Univ Paris-Sud, CNRS, Orsay, France; 3Institut Langevin (UMR 7587), ESPCI, Univ Denis Diderot, CNRS, Paris, France Magnetic resonance elastography is performed in a pig lung inflated with three different gases, helium-4 (4He), air and sulphur hexafluoride (SF6), in a phantom designed for voxel-by-voxel comparison. Proton MRI morphology and computed l, Gd and Gl maps were compared on a voxel-by-voxel basis by computing mean differences between corresponding voxels. Voxel-by-voxel comparison of Morphology data and l values shows good agreement between air/4He, Air/Air and Air/SF6 measurements while Gd and Gl values agree less well. Global values of Gl, Gd and l are in excellent agreement for the different gases, showing gas density does not affect MRE measurement. Tuesday 13:30-15:30 Computer 18 13:30 3404. Poroelastic MRE Reconstructions of Brain Acquired with Intrinsic Activation Adam J. Pattison1, Irina M. Perreard2, John B. Weaver, 12, Keith D. Paulsen1,2 1Thayer School of Engineering, Dartmouth College, Hanover, NH, United States; 2Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States Magnetic resonance elastography has recently shown great promise in measuring the mechanical properties of brain tissue. However, the skull and cerebral meninges dampen much of the intracranial motion that occurs. Utilizing the natural arterial pulsation (called “intrinsic activation) that occurs in the brain could allow for a more comfortable and reliable way of measuring mechanical properties of brain tissue. Here, a study consisting of three brains was performed using a phase-contrast gradient echo sequence to measure velocity and, thus, calculate the displacements. Two algorithms, one with linear elastic assumptions and the other with poroelastic assumptions, were used to estimate the shear modulus distribution. Results show that intrinsic activation does provide feasible results and that the poroelastic estimation is more symmetric and uniform than the linear elastic estimation. Also, the poroelastic estimates were consistent amongst the three cases. 14:00 3405. The Effect of Frequency on the Uniformity of Hepatic Shear Wave Illumination Kevin John Glaser1, David Stanley2, Jun Chen1, Meng Yin1, Richard Ehman1 1Radiology, Mayo Clinic, Rochester, MN, United States; 2GE Healthcare, Waukesha, WI, United States MR elastography (MRE) has emerged as a promising noninvasive tool for diagnosing hepatic fibrosis. However, making the distinction between healthy and mildly fibrotic livers can be difficult, partly due to the soft, highly attenuating nature of the liver tissue. In this work, the improvement in hepatic illumination achieved by decreasing the frequency of mechanical vibration was studied. The results show that a significant increase in the volume of hepatic tissue with high phase difference to noise ratio can be achieved by decreasing the frequency of vibration. 14:30 3406. Feasibility Study to Measure Changes in Intracranial Pressure Using Magnetic Resonance Poroelastography - not available Adam J. Pattison1, Phillip R. Perrinez1, Matthew DJ McGarry1, John B. Weaver, 12, Keith D. Paulsen1,3 1Thayer School of Engineering, Dartmouth College, Hanover, NH, United States; 2Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH; 3Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States Small changes in intracranial pressure (ICP) have large effects on neurological function. Having the ability to measure ICP noninvasively could lead to a much more reliable and efficient method to diagnosing diseases like hydrocephalus, where an increase in ICP and ventricle size can be misconstrued with other ex vacuo changes like periventricular leukomalacia or cerebral atrophy. Magnetic resonance poroelastography (MRPE) is a recent idea in which both a shear modulus and pore-pressure estimate are attainable. A feasibility study was done on tofu, which has been widely used to model brain tissue, in which different external pressures were applied in an enclosed container. Reconstructed values show an increase in average pressure as well as a lack of difference in shear modulus. This is an important indicator for future studies of hydrocephalus and other neurological diseases. 15:00 3407. Magnetic Resonance Elastography (MRE) of the Kidney in Healthy Volunteers Remi Souchon1, Mustapha Bouhrara1, Gaële Pagnoux2, Jean-Michel Ménager3, Richard L. Ehman4, Olivier Rouvière2 1INSERM, Lyon, France; 2Hospices Civils de Lyon; 3SCM IRM du Tonkin, Villeurbanne, France; 4Mayo Clinic, Rochester, MN, United States The feasibility of renal MR elastography (MRE) was investigated in 10 healthy volunteers. The study demonstrated that kidney MRE at low vibration frequencies (45-76 Hz) is feasible. It also provided evidence of a viscoelastic behavior.
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