ISMRM 21st Annual Meeting & Exhibition ○ 20-26 April 2013 ○ Salt Lake City, Utah, USA
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY
1938 -1946 | MRS of Neurological Disease
1947 -1954 | Human MRS: In Vivo & In Vitro
1955 -1972 | MRS & Metabolism
1973 -1981 | MRS of Animal Models
1982 -1995 | ESR & Multinuclear
1996 -2001 | MRS & Relaxation
2002 -2029 | Methodology of Spectroscopic Localization & Imaging
2030 -2043 | Methodology of Spectroscopic Quantitation
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
MRS of Neurological Disease
1938. | Proton MR Spectroscopy Correlates Diffuse Axonal Injury with Post-Concussive Symptoms in Mild Traumatic Brain Injury Ivan I. Kirov1, Assaf Tal1, James S. Babb1, Joseph Reaume1, Tamara Bushnik2, Teresa A. Ashman2, Steven Flanagan2, Robert I. Grossman1, and Oded Gonen1 1Radiology, New York University, New York, NY, United States, 2Rusk Institute of Rehabilitation Medicine, New York University, New York, NY, United States There are no established biomarkers for mild traumatic brain injury (mTBI), in part because post-concussive symptoms (PCS) are subjective and conventional imaging is typically unremarkable. To test whether diffuse axonal injury (DAI) quantified with three-dimensional (3D) proton magnetic resonance spectroscopic imaging (1H-MRSI) correlated with patients’ PCS we retrospectively studied 26mTBI patients (mean Glasgow Coma Scale score of 14.7), 18–56 years old, 3 – 55 days post injury and 13 controls. All were scanned at 3 Tesla with T1-andT2-weighted MRI and 3D 1H-MRSI (480 voxels over 360 cm3, ~30% of the brain). On scan day patients completed a symptom questionnaire and those indicating at least one of the most common subacute mTBI symptoms (headache, dizziness, sleep disturbance, memory deficits, blurred vision) were grouped as PCS-positive. Global gray- and white matter (GM/WM) absolute concentrations of N-acetylaspartate (NAA), choline (Cho), creatine (Cr) and myo-inositol (mI) in PCS-positive and PCS-negative patients were compared to age- and gender-matched controls using two-way analysis of variance. The results showed that PCS-negative group (n=11) and controls (n=8) did not differ in any GM or WM metabolite level. The PCS-positive patients (n=15) had lower WM NAA than the controls (n=12): 7.0±0.6 versus 7.9±0.5mM (p=0.0007). Global WM NAA, therefore, showed sensitivity to the DAI sequelae associated with common PCS in patients with mostly normal neuroimaging as well as GCS scores. This suggests a potential biomarker role in a patient population in which objective measures of injury and symptomatology are currently lacking.
1939. | 7 T 1H MRS Detects a Human Brain Glutathione (GSH) Response to N-Acetylcysteine, an Antioxidant Precursor, in Patients with Gaucher and Parkinson’s Disease Melissa Terpstra1, Mary Holmay1, Lisa Coles1, Usha Mishra1, Matthew Ahlskog1, James Cloyd1, Paul Tuite1, and Gulin Oz1 1University of Minnesota, Minneapolis, MN, United States One distinguishing attribute of MR is its utility to noninvasively monitor therapeutic response. N-acetylcysteine (NAC) is under investigation for the treatment of several conditions. One possible mechanism for efficacy against neurodegenerative disease is as a precursor for the formation of the antioxidant glutathione (GSH). In this study, human brain GSH concentrations were measured using 7 T 1H MRS throughout intravenous infusion of NAC. The occipital cortex GSH concentration increased by at least 10 % (mean 33 %, SD 17 %) in all 8 participants after delivery of NAC, indicating a strong group effect (p < 0.001).
1940. | Volumetric MR Spectroscopic Imaging with Reduced K-Space Acquisitions: Variability and Pathologic Detectability in Mild Traumatic Brain Injuries Mohammad Sabati1, Jiping Zhan1, Varan Govind1, Kristopher L. Arheart2, and Andrew A. Maudsley1 1Radiology, University of Miami, Miami, FL, United States, 2Epidemiology and Public Health, University of Miami, Miami, FL, United States Several parallel imaging (PI) techniques have been developed for MRSI to reduce data acquisition times. MRSI methods, however, are often sensitivity-limited, and only a few reports have studied the resultant impact that PI may have when applied to MRSI on the outcome of diagnostic accuracy. It therefore remains unknown whether the clinical diagnostic value is maintained for PI-enabled MRSI to detect subtle pathology? This question is addressed by implementing a GRAPPA-MRSI within a fully-automated data processing pipeline and evaluating it using subjects with mild traumatic brain injury who represents a patient group for which the metabolic changes are relatively subtle and diffuse.
1941. | The Longitudinal Relaxation Time of GABA in vivo at 3T Nicolaas A. J. Puts1,2, Peter B. Barker1,2, and Richard Anthony Edward Edden1,2 1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, United States, 2FM Kirby Centre for functional neuroimaging, Kennedy Krieger Institute, Baltimore, Maryland, United States The longitudinal relaxation time of GABA was measured in vivo using a MM-suppression method and a saturation recovery experiment.
1942. | Reduced Basal Ganglia GABA in Attention Deficit Hyperactivity Disorder Steffen Bollmann1,2, Carmen Ghisleni1,2, Simon S. Poil1,2, Peter Klaver1,3, Lars Michels1,4, Richard Anthony Edward Edden5, Ernst Martin1,2, Dominique Eich-Höchli6, Juliane Ball7, Daniel Brandeis7,8, and Ruth L. O'Gorman1,2 1Center for MR-Research, University Children's Hospital, Zurich, Zurich, Switzerland, 2Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland, 3Institute of Psychology, University of Zurich, Zurich, Switzerland, 4Institute of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland, 5Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 6Psychiatric University Hospital, University of Zurich, Zurich, Switzerland,7Department of Child & Adolescent Psychiatry, University of Zurich, Zurich, Switzerland, 8Central Institute of Mental Health Mannheim, Medical Faculty Mannheim/ Heidelberg University, Mannheim, Germany This study examines differences in basal ganglia GABA levels between adults with ADHD and healthy participants, and evaluates the association between GABA levels and ADHD symptom scores. GABA-edited MR spectra were acquired with MEGA-PRESS, and symptom scores were evaluated with the Wender Utah Rating scale and Conners symptom inventories. GABA/Cr levels in the basal ganglia were lower in ADHD patients relative to controls, and GABA levels correlated negatively with WURS hyperactivity scores and Conners hyperactive, impulsive, and inattentive scores, indicating that patients with ADHD have reduced inhibitory neurotransmitter levels in the left basal ganglia which are related to behavioural dysfunction.
1943. | Longitudinal Evaluation of Mild Traumatic Brain Injury: A H-MRS Study Elijah George1,2, Steven Roys1,3, Jiachen Zhuo1, Chandler R. Sours4, Jacqueline Janowich1, Teodora Stoica1, and Rao P. Gullapalli1 1Magnetic Resonance Research Center, University of Maryland School of Medicine, Baltimore, MD, United States, 2Bioengineering, University of Maryland, College Park, MD, United States, 3Diagnostic Radiology & Nuclear Medicne, University of Maryland School of Medicine, Baltimore, MD, United States, 4Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States Mild traumatic brain injury (mTBI) patients represent 75% of the viable TBI population. The aim of the current study is to carry out a longitudinal evaluation of mTBI by monitoring metabolic markers of mTBI and their evolution over time such that the findings realized herein will aid improved clinical evaluation of the pathology. We combined neuro-metabolic information with neuropsychological test (NPT) data for the purpose of understanding how current metabolic state affects ongoing cognitive capability, and to determine the efficacy of neuro-metabolic information acquired acutely in predicting outcome of mTBI patients.
1944. | Age-Related Metabolite Alterations in Adolescents with High Functioning Autism, an 1H-MRS Study Evelien M. Barendse1, Albert P. Aldenkamp1, Roy PC Kessels2, Marc P.H. Hendriks2, Geert Thoonen1, Paul A.M. Hofman3, Walter H. Backes3, and Jacobus F.A. Jansen3 1Epilepsy Centre Kempenhaeghe, Heeze, NB, Netherlands, 2Neuropsychology, Radboud University Nijmegen, Nijmegen, Ge, Netherlands, 3Radiology, Maastricht University Medical Center, Maastricht, Li, Netherlands In this cross-sectional study, we investigate the effect of age and intelligence on occipital metabolite concentrations in adolescents (aged 13-19y) with high functioning autism (HFA) and healthy controls. We observed that 1H-MRS provides evidence of atypical membrane metabolism development in HFA, which potentially underlies the observed atypical behavioral development in autism.
1945. | Neurochemical Changes in Rat Brain After 5-Fluorouracil Chemotherapy Assessed by 1H MR Spectroscopy at 9.4 T Ryutaro Nakagami1,2, Masayuki Yamaguchi1, Yoshifumi Abe3, Tatsuhiro Hisatsune3, Akira Furukawa2, and Hirofumi Fujii1 1Division of Functional Imaging, National Cancer Center Hospital East, Kashiwa, Chiba, Japan, 2Graduate School of Health Sciences, Tokyo Metropolitan University, Arakawa-ku, Tokyo, Japan, 3Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan Recent studies have reported that some cancer patients who received chemotherapy experienced mild cognitive impairment. Although the mechanism of this type of cognitive impairment is not fully understood, preliminary studies suggested that chemotherapy may induce neurotransmitter deficits, damaging cognitive function. Investigation of brain metabolite changes using in vivo MR spectroscopy may help to understand the mechanism of chemotherapy-induced cognitive impairment. In this study, we assessed metabolite changes in the brains of rats that received 5-FU (100 mg/kg) chemotherapy using 1H MR spectroscopy at 9.4 Tesla.
1946. | Effects of Binge Acute Ethanol Intoxication on Cerebral Neurochemical Profile in Rats: Evidence from in vivo Proton Magnetic Resonance Spectroscopy Do-Wan Lee1, Jae-Hwa Kim2, Sang-Young Kim1, Dai-Jin Kim2,3, Jinyoung Jung1, and Bo-Young Choe1 1Department of Biomedical Engineering, The Catholic University of Korea, College of Medicine, Seoul, Seoul, Korea, 2Department of Biomedical Science, The Catholic University of Korea, College of Medicine, Seoul, Seoul, Korea, 3Department of Psychiatry, Seoul St. MaryˇŻs Hospital, The Catholic University of Korea, College of Medicine, Seoul, Seoul, Korea This study aimed to quantitatively assess the cerebral neurochemical effects in hippocampal region in binge ethanol-intoxicated rats by using a 4.7-T 1H-MR Spectroscopy. Our results showed that total choline (tCho; phosphocholine+glycerophosphocholine) concentrations, and tCho/total N-acetylaspartate (tNAA: NAA+N-acetylaspartylglutamate [NAAG]) ratios were significantly lower in binge ethanol group than that in control group. Significantly low tCho concentrations and tCho/tNAA ratios may indicate the cell membrane turnover abnormalities of phosphatidylcholine and changed adaptive mechanism in the hippocampus of binge ethanol intoxicated rats. Thus, we provide quantitative in vivo evidence that binge ethanol exposure causes cerebral neurochemical profile changes in rats, in hippocampal region.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
Human MRS: In Vivo & In Vitro
1947. | Therapeutic Blood Glucose Control Effects Cerebral Glycolysis Following Traumatic Brain Injury Stephanie M. Wolahan1, David McArthur1, Paul Vespa1, Neil A. Martin1, and Thomas C. Glenn1 1Department of Neurosurgery, UCLA, Los Angeles, CA, United States Managing glucose after traumatic brain injury (TBI) is a major concern and the effect of two glycemic control strategies (tight vs. loose) on TBI patients are compared. We hypothesize that cerebral glucose is metabolized differently depending on plasma glucose levels and that lactate is increasingly metabolized when systemic glucose is low. Results show that when glucose is kept low (tight glycemic control) there is increased glycolytic glucose metabolism but less lactate released into the blood than when glucose is at higher levels. This supports the theory that the injured brain generates energy from lactate when systemic glucose is low.
1948. | Cholesterol and Its Esters as Serum Biomarkers in Malignant Obstructive Jaundice: A Single Step 1H NMR Metabonomic Approach Abhinav A. Sonkar1, Shatakshi Srivastava2, Santosh Kumar Singh1, Hari Om Gupta1, Devendra Singh1, Jitendra Kushwaha1, Abhijit Chandra3, and Raja Roy2 1SURGERY, KG MEDICAL UNIVERSITY, Lucknow, UTTAR PRADESH, India, 2CBMR, SGPGI, Lucknow, UTTAR PRADESH, India, 3GASTROSURGERY, KG MEDICAL UNIVERSITY, Lucknow, UTTAR PRADESH, India The paucity of biomarkers for malignant obstructive jaundice results in formidable morbidity and mortality rates. Therefore, alternative diagnostic measures are required for pre-operative management of patients. In the present study, 1H NMR-based metabonomics approach has been applied to investigate small metabolites, cholesterol and bile acid metabolism in benign and malignant causes of obstructive jaundice (OBJ) for identification of serum and bile biomarkers for improved clinical interpretation. A newer, rapid and single step method for serum cholesterol : cholesterol esters estimation has been found to be efficient in differentiating malignancy.
1949. | NMR-Based Metabolite Profiling of Fecal Extracts from Colorectal Cancer in China: An Initial Study Yan Lin1, ChengKang Liu1, ZhiWei Shen1, and RenHua Wu1 1Medical Imaging Department, Second Affiliated Hospital, Shantou University Medical College, Shantou, Guang Dong, China This preliminary results based on 1H NMR spectroscopy and partial least squares discriminant analysis (PLS-DA) demonstrated that metabolites differences of fecal extracts between CRC patients and healthy controls can be identified that may be important in the early detection of CRC in China. The observed low levels of SCFA (acetate, butyrate and propionate) are consistent with previous reports[3,4], which has been associated with the development of colorectal cancer, seems to be the most effective marker of fecal extracts for differentiating CRC patients from healthy controls.
1950. | Fast Determination of Absolute Metabolite Concentrations by Spatially-Encoded 2D NMR: Application to Breast Cancer Cell Extracts Serge Akoka1, Adrien Le Guennec1, Illa Tea1, Estelle Martineau1, Benoit Charrier1, Meerakhan Pathan1, and Patrick Giraudeau1 1Chemistry, Université de Nantes, Nantes, France Absolute metabolite concentrations from complex metabolic mixtures were measured using an approach based on a “multi-scan single shot” (M3S) strategy (derived from ultrafast 2D NMR). The analytical performance was compared to the one of conventional 2D NMR. On model metabolic mixtures, the precision was in the 1-4% range (versus 5-18% for the conventional approach), highlighting the superiority of the M3S approach for quantitative analysis. The M3S COSY approach was then applied to measure the absolute metabolite concentration of 14 major metabolites in three breast cancer cell line extracts, showing significant differences between cell lines.
1951. | A Multimodal Investigation of Neuronal/Axonal Integrity Using Structural T1-Weighted Imaging, Diffusion Tensor Imaging, and 1H MR Spectroscopy Soyoung Choi1, Anand A. Joshi2, Chitresh Bhushan2, Vincent J. Schmithorst3, Stefan Bluml4, David W. Shattuck5, Richard M. Leahy2, Hanna Damasio1, Ashok Panigrahy3, and Jessica L. Wisnowski3,6 1Dana and David Dornsife Cognitive Neuroscience Imaging Institute, University of Southern California, Los Angeles, California, United States, 2Signal and Image Processing Institute, University of Southern California, Los Angeles, California, United States, 3Radiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States, 4Department of Radiology, Children Hospital of Los Angeles, Los Angeles, CA, United States, 5Laboratory of Neuro Imaging, UCLA School of Medicine, Los Angeles, CA, United States, 6Brain and Creativity Institute, University of Southern California, Los Angeles, California, United States Multimodal magnetic resonance (MR) imaging is increasingly becoming the standard in clinical practice and research yielding synergistic information regarding brain structure and brain function. We examined the relations among the absolute concentration of of n-acetyl-aspartate (NAA; quantitated from MR spectroscopy), fractional anisotropy (FA) and diffusivity metrics (ADC, AD, RD) calculated from DTI scans and volumetric and cortical surface area measurements computed from T1-weighted scans in standardized GM and WM regions. Our most significant findings were of associations between NAA and both FA and RD metrics in the white matter and suggest that together these metrics reflect neuronal/axonal packing density.
1952. | Assessment of Hippocampal Activation and Resting State Glutamate Concentration by Using Functional MRI and 1H MR Spectroscopic Imaging Alexander Gussew1, Gerd Wagner2, Andreas Deistung3, Reinhard Rzanny1, Patrick Hiepe1, Marianne Cleve1, Karl-Jürgen Bär4, and Jürgen R. Reichenbach1 1Medical Physics Group, Department of Diagnostic and Interventional Radiology I, Jena University Hospital, Jena, Thuringia, Germany, 2Centre for Neuroimaging, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Thuringia, Germany, 3Medical Physics Group, Department of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Thuringia, Germany, 4Pain & Autonomics group, Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Thuringia, Germany The present work describes multimodal fMRI and 1H-CSI measurements of memory task induced functional alternations in hippocampal activity and relationships of these changes to the resting state concentrations of the excitatory neurotransmitter glutamate in a group of healthy volunteers. Significant positive BOLD activations were detected bilaterally in the posterior hippocampus. Task induced activation revealed positive correlation with glutamate concentration, indicating regulation of neuronal activity by the excitatory neurotransmitter turnover.
1953. | GABA Measured by 1H-MRS Is Not Affected by Tiagabine. C. John Evans1, Jim F. M. Myers2, Nicola Kalk2, Richard Anthony Edward Edden3, and Anne Lingford-Hughes4 1CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom, 2Psychopharmacology Unit, University of Bristol, Bristol, United Kingdom, 3Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 4Neuropsychopharmacology Unit, Imperial College London, London, United Kingdom Tiagabine, an antiepileptic drug, acts by blocking the reuptake of inhibitory neurotransmitter GABA from the synapse, thus increasing GABA concentration at the synaptic cleft. We performed J-difference edited 1H-MRS before and after tiagabine administration to investigate whether MRS was sensitive to changes in extracellular GABA concentration. Ten participants were studied, and MRS data were acquired from occipital and limbic voxels. No significant change was detected in GABA, thus indicating that although tiagabine has GABAergic action, it does not affect the total GABA concentration.
1954. | Metabolic Trends in Thalamic Development from Infancy to Adulthood Measured Using Magnetic Resonance Spectroscopy Andrew J. Degnan1,2, Vince Lee2, Rafael C. Ceschin2, Vincent J. Schmithorst2, Stefan Blüml3, and Ashok Panigrahy2 1University of Pittsburgh Medical Center, Pittsburgh, PA, United States, 2Department of Radiology, Children's Hospital of Pittsburgh, Pittsburgh, PA, United States, 3Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States Magnetic resonance spectroscopy is capable of offering insight into the developing brain. In this study, we report changes in the metabolite concentrations within the thalamus from healthy term neonates to young adults. In this study we note a more mature metabolite profile in the thalamus in neonates when compared with grey and white matter, consistent with other knowledge of the key role of thalamic development in early life. Knowledge of normal metabolic changes within this key structure explained by this study is essential in understanding thalamocortical deficits in the setting of preterm injury.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
MRS & Metabolism
1955. | Metabolite Concentration Changes During Motor Activation Using Functional Magnetic Resonance Spectroscopy (FMRS) at 7T Benoît Michel Schaller1, Lijing Xin2, Kieran O'brien3, and Rolf Gruetter4 1Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland, 2Department of Radiology, University of Lausanne, Lausanne, Vaud, Switzerland, 3Centre d'Imagerie BioMédicale, University of Geneva, Geneva 14, Geneva, Switzerland, 4Laboratory of Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland Functional Magnetic Resonance Spectroscopy (fMRS) allows to investigate the small metabolite changes (<0.2µmol/g) following a physiological stimulation, by acquiring continuously MR spectra, and provides direct insights into brain metabolism. In this study, a group analysis revealed an increase of [Lac] of 28±3% and of [Glu] 3±1% during motor activation.This study establishes that it is possible to investigate the neurochemical profile changes during motor activation. [Lac] and [Glu] increase as has been observed during visual stimulation.
1956. | Increased Brain Lactate Concentrations Without Increased Lactate Oxidation During Hypoglycemia in Type 1 Diabetic Individuals with Hypoglycemia Unawareness Henk M. De Feyter1, Graeme F. Mason2, Gerald I. Shulman3, Douglas L. Rothman4, and Kitt Falk Petersen5 1Diagnostic Radiology, Yale University, New Haven, CT, United States, 2Dept. of Psychiatry, Yale University, New Haven, CT, United States, 3Howard Hughes Medical Institute, Yale University, New Haven, CT, United States, 4Diagnostic Radiology, Yale University, New Haven, Connecticut, United States, 5Internal Medicine, Yale University, New Haven, CT, United States Previous 13C MRS studies have lead to the hypothesis that upregulation of blood-brain barrier monocarboxylic acid (MCA) transport may contribute to maintenance of brain energetics during hypoglycemia in subjects with hypoglycemia unawareness. We examined transport and metabolism of [3-13C]-lactate in brain of type 1 diabetic patients with hypoglycemia unawareness and non-diabetic control subjects during a hypoglycemic clamp using 13C MRS. We found that brain lactate concentrations were markedly increased in type 1 diabetic subjects. Surprisingly we observed no increased oxidation of blood-borne lactate in the type 1 diabetic subjects suggesting that other metabolic adaptations may contribute to hypoglycemia unawareness.
1957. | In Vivo Determination of de Novo Lipogenesis in Rat Liver Using Localized 1H-[13C] Magnetic Resonance Spectroscopy Sharon M. Janssens1, Klaas Nicolay1, and Jeanine J. Prompers1 1Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands De novo lipogenesis is the primary pathway in which excess carbohydrates are being converted to fat in liver. The aim of this study was to develop a non-invasive method for the direct in vivo measurement of de novo lipogenesis in rat liver using localized 1H MRS with 13C editing. Before and after the oral administration of [U-13C6] glucose for 5 days, total and 13C-enriched intrahepatocellular lipid (IHCL) content were measured with 1H-[13C] MRS. After 5 days of [U-13C6] glucose administration, total as well as 13C-enriched IHCL was increased, the latter being the result of de novo lipogenesis.
1958. | Can 13C MRS Be Used to Monitor Changes in Hepatic Glycogen Levels Following a Low Dose Oral Glucose Challenge? S. Bawden1, Mary C. Stephenson1, Elisabetta Ciampi2, J. Lane2, Luca Marciani3, P Morris1, I MacDonald4, Guru P. Aithal4, K. Hunter2, and Penelope A. Gowland1 1SPMMRC, University of Nottingham, Nottingham, Notts, United Kingdom, 2Unilever Discover, Bedford, Beds, United Kingdom, 3NDDC Biomedical Research Unit, University of Nottingham, Nottingham, Notts, United Kingdom, 4Medical School, University of Nottingham, Nottingham, Notts, United Kingdom This study investigates the lower limits of sensitivity in measuring changes in hepatic glycogen levels following an oral glucose challenge using in vivo natural abundance Carbon-13 MR spectroscopy. Subjects were scanned following an overnight fast for baseline values and then hourly for five hours following either a 50g glucose dose or control using a multi-nuclear surface coil. Spectra glycogen peak areas over the timecourse were compared between groups. Changes in gastric content and liver volume we also monitored to consider other related effects. Results show that hepatic glycogen AUCs were significantly higher in the glucose challenge group compared with control.
1959. | Quantification of Fatty Acids in Human Calf Adipose Tissue and Muscle by 13C MRS Using J-Refocused PRESS DEPT and ERETIC Xing Chen1, Peter Boesiger1, and Anke Henning2,3 1Institute for Biomedical Engineering, Zurich, Zurich, Switzerland, 2University and ETH Zurich, Zurich, Zurich, Switzerland, 3Max Planck Institute of Biological Cybernetics, Tübingen, Tübingen, Germany A J-refocused proton PRESS localized DEPT sequence is applied to achieve reliably localized and SNR enhanced signals by in vivo 13C MRS using volume coil, with the combination of optically transmitted and inductively coupled ERETIC as a reference for absolute quantification. The proposed method is used to assess the fatty acids from human deeper locations: calf tibial bone marrow and skeletal muscle, among omnivores, vegetarians and vegans. Both relative percentages and absolute molar concentrations are evaluated and analyzed. The results demonstrate the applicability of quantitative, SNR enhanced and localized 13C MRS for large scale noninvasive investigation of the impact of dietary intake, physical exercise or pathology on fatty acid metabolism and related diagnosis.
1960. | In Vivo Magnetic Resonance Spectroscopy of Lipid Handling in Steatotic Rat Liver Sharon M. Janssens1, Richard AM Jonkers1, Mattijs Heemskerk2, Sjoerd A. van den Berg2, Ko Willems van Dijk2, Natal A. van Riel3, Klaas Nicolay1, and Jeanine J. Prompers1 1Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands, 2Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands,3Eindhoven University of Technology, Eindhoven, Netherlands Hepatic steatosis is het abnormal and excessive accumulation of triglycerides in the liver and is a hallmark of non-alcoholic fatty liver disease (NAFLD). The aim of this study was to determine differences in in vivo lipid metabolism in steatotic livers of rats on different high-fat diets using 1H MRS with 13C editing in combination with the oral administration of 13C-labeled lipids. Animals on a high-fat diet developed liver steatosis accompanied by a significantly reduced lipid turnover in the liver.
1961. | Human Studies of Functional MRS at 7T with Semi-LASER Petr Bednarik1,2, Ivan Tkac1, Andrea Grant1, Uzay E. Emir1, Dinesh K. Deelchand1, and Silvia Mangia1 1CMRR - Dept. of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Molecular and Functional Imaging Laboratory, CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic In the present work we measured brain metabolite concentrations during a visual stimulation paradigm at 7 T with a full-intensity 1H MRS sequence, semi-LASER. In excellent agreement with our previous findings obtained with STEAM sequence, we observed significant concentration changes within Â± 0.2 Âµmol/g for lactate, glutamate, aspartate and glucose. However, we could not detect changes in glutathione, glycine, glutamine and GABA as reported in other studies, despite higher MRS sensitivity. We conclude that the latter concentration changes are likely to be ascribed to the particular settings of the visual stimulation paradigm.
1962. | Spectroscopic Imaging of Metabolites with 2D Heteronuclear Multiple Quantum Coherence in Mouse Hirohiko Imai1, Yuki Takayama1, and Tetsuya Matsuda1 1Department of Systems Science, Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto, Japan We demonstrate a spatially encoded 2D heteronuclear multiple quantum coherence (HMQC) spectroscopy for imaging metabolites. A standard chemical shift imaging (CSI) incorporated with 2D 1H-13C HMQC preparation was implemented in a tumor-bearing mouse after sacrifice at 30min post injection of [U-13C]glucose. The 4D data acquisition (two spectral and two spatial dimensions) allows the identification of multiple metabolites with 1H sensitivity and 13C spectral resolution, and the visualization of their distribution throughout the whole body. As the result, the increase of relative amount of lactate was observed in the brain, tumor, and inferior limb.
1963. | Clinical 3.0 T 13C MRS: Net Hepatic Glycogen Breakdown During 19 Hr Fast Paul Begovatz1, Sabine Kahl1, Bettina Nowotny1, Juergen Bunke2, Michael Roden1,3, and Jong-Hee Hwang1 1Institute of Clinical Diabetology, German Diabetes Center, Duesseldorf, Germany, 2Philips Healthcare, Hamburg, Germany, 3Department of Metabolic Diseases, University Clinics, Heinrich Heine University, Duesseldorf, Germany 13C-MRS is the only method to non-invasively measure changes in net hepatic glycogen concentrations which is of interest regarding the pathophysiology of type 2 diabetes. These measurements have traditionally been conducted on MR-systems designed for spectroscopy, however expansion to FDA approved scanners would play a vital role in clinical research. Proton decoupled C1-glycogen peaks were detected with SNRs ranging from 32:1 at 514mM, to 5:1 at 106mM, with a COV=12%. Rates of net hepatic glycogen breakdown in vivo were 5.53±0.22 µmol/kgBW/min, consistent with previous studies. This proves that the methods outlined here can be implemented for use in clinical trials.
1964. | Exercise Does Not Modulate Postprandial Lipid Uptake in Liver and Skeletal Muscle of Healthy and Diabetic Rats Richard AM Jonkers1, Sharon M. Janssens1, Klaas Nicolay1, Luc JC van Loon2, and Jeanine J. Prompers1 1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 2Department of Human Movement Sciences, Maastricht University Medical Centre+, Maastricht, Netherlands Insulin resistance has been associated with ectopic lipid accumulation. Physical activity improves insulin sensitivity, but the impact of exercise on lipid handling in insulin-resistant skeletal muscle and liver remains to be elucidated. The present study characterizes postprandial lipid handling in liver and muscle of healthy and diabetic rats after one hour of treadmill running using in vivo 13C-edited 1H-MRS in combination with 13C-labeled lipid administration. We showed that muscle but not liver lipid stores represent a viable substrate source during exercise in healthy and diabetic rats. However, postprandial lipid uptake in liver and muscle was not affected by prior exercise.
1965. | Kinetic Model-Based Analysis of Dynamic 31P MRS Data on ATP Metabolism in Rat Hindlimb Muscle Jeroen A. Jeneson1, Ranjan Dash2, Daniel A. Beard2, and Robert W. Wiseman3 1Center for Systems Biology of Energy Metabolism and Ageing, University Medical Center Groningen, Groningen, Netherlands, 2Physiology, Medical College of Wisconsin, Milwaukee, WI, United States, 3Physiology and Radiology, Michigan State University, East Lansing, MI, United States Dynamic 31P NMR spectroscopy has longtime been used to probe the homeostatic performance of the integrated biochemical networks involved in cellular energy balance in a variety of human diseases including heart failure and diabetes. Recent advances in computational modeling of these biochemical networks now offer a tool to link these macroscopic 31P MRS observations to the rich knowledge base on the molecular components interacting in these networks. Here, we explore the potential of such kinetic model-based analysis of dynamic 31P MRS recordings of ATP metabolism in muscle to extract information on the activity of a key mitochondrial enzyme, Pyruvate Dehydrogenase.
1966. | Neuronal and Astroglial Metabolism in APP-PS1 Mouse Model of Alzheimer's Disease with Progress of Age Vivek Tiwari1, Pandichelvam Veeraiah1, and Anant Bahadur Patel1 1NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, A.P., India Alzheimer's disease (AD) is associated with deficit and dysfunction of neurotransmitters and synapses. Cerebral metabolic fluxes were measured in APP-PS1 mouse model of AD with the progress of age by using 1H-[13C]-NMR spectroscopy in conjunction with infusion of 13C labeled glucose and acetate. APP-PS1 mice exhibit normal neurochemical profile and cerebral metabolism at very early age. At the preclinical age, neuronal metabolism is found to be impaired without any change in the level of neurometabolites. In addition to impaired neuronal metabolism and neurochemical profile, the APP-PS1 mice exhibit higher astroglial activity at the late age of the disease.
1967. | Nonlinear Laplacian Eigenmaps Dimension Reduction of in-vivo Magnetic Resonance Spectroscopic Imaging Analysis Guang Yang1, Felix Raschke1, Thomas Richard Barrick1, and Franklyn A. Howe1 1Division of Clinical Sciences, St. George’s University of London, London, United Kingdom MRSI has demonstrated great clinical potential as a supplement to standard imaging for non-invasive diagnosis of brain tumours. Pattern recognition(PR) techniques are used to assist MRSI tumour identification and characterisation, and they can be applied to MRSI data with suspected gliomas with an aim to segment regions relating to tumour core, tumour infiltration and normal brain. Dimensionality reduction(DR) is an important prerequisite in any real case of PR. In this work, we advocate the spectral manifold learning method of Laplacian eigenmaps as a DR technique suitable for MRSI datasets, with correlation to standard MRI to aid confirmation of our results.
1968. | Slow Training Effect on Intracellular Lipid in Skeletal Muscle Yoshikazu Okamoto1, Tomonori Isobe1, and Graham J. Kemp2 1University of Tsukuba Hospital, Tsukuba, Ibaraki, Japan, 2University of Liverpool, Liverpool, Liverpool, United Kingdom How slow training work to the fat metabolism in the muscle?
1969. | in vivo Investigation of Choline Compounds with 1H and 31P MRS in the Patients with Liver Disorders. Martin Gajdosik1, Ladislav Valkovic1, Marek Chmelik1, Stefan Traussnigg2, Michael Trauner2, Siegfried Trattnig1, and Martin Krssák1,3 1MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, 2Gastroenterology & Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria, 3Endocrinology & Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria The measurements of choline containing compounds in the liver lack the clean conclusion. In this study the link between 1H & 31P MR spectroscopy (MRS) regarding to choline containing compound and hepatic lipids in patients with liver disorders - non-alcoholic fatty liver disease and steatohepatitis was examined. The MRS measurements allowed to resolve the resonances of choline containing metabolites and we could find certain links between proton and phosphorus MRS derived measures of hepatic metabolism status.
1970. | 31P Magnetic Resonance Spectroscopic Imaging of the Breast; Influence of the Menstrual Cycle Bertine L. Stehouwer1, Wybe J.M. van der Kemp1, Peter R. Luijten1, Maurice A.A.J. van den Bosch1, Wouter B. Veldhuis1, Jannie P. Wijnen1, and Dennis W.J. Klomp1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands We investigated the phosphomonoester / phosphodiester ratio in the breast of healthy females, and the influence of the menstrual cycle on the ratio, using 31P magnetic resonance spectroscopy at 7.0 Tesla. Five premenopausal and five postmenopausal women were included. A variation in ratio’s was seen throughout the menstrual cycle, however no particular pattern could be objectified. The ratio always remained <1. When using 31P MRS in a clinical setting a variation between women and between moments in the menstrual cycle has to taken into account.
1971. | Signal-To-Noise Ratio Analysis of 31P MRS in Skeletal Muscle: Influence of Localization Schemes, RF Coils and Field Strength Georg Bernd Fiedler1,2, Albrecht Ingo Schmid1,2, Sigrun Goluch1,2, Ewald Moser1,2, and Martin Meyerspeer1,2 1Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Vienna, Austria, 2MR Centre of Excellence, Medical University of Vienna, Vienna, Vienna, Austria In this study the SNR of 31P MRS with FID, STEAM and semi-LASER acquisitions with single-loop and 3-channel coils were compared at 3 and 7T in human muscle in vivo. The PCr-peak's SNR from semi-LASER measurements in the gastrocnemius at 7T with an optimized three channel coil was similar to the SNR obtained with the well-established non-localized acquisition scheme at 3T using a single-loop coil. Localized 31P MRS at 7T, can therefore be used to acquire localized data with similar quality and temporal resolution, but with much higher specificity than standard pulse-acquire MRS used for dynamic studies of metabolism at 3T.
1972. | Cerebral Metabolic Response to Methylene Blue: A 31P Magnetization Transfer Study at 11.7T Andrew Bresnen1, Fang Du1, Geoffrey Clarke2, and Timothy O. Duong3 1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, 2Radiological Sciences, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States, 3UT Health Science Center at San Antonio, San Antonio, TX, United States Methylene blue (MB) has unique energy-enhancing and antioxidant properties. MB shows remarkable therapeutic effects in a number of neurological disorders, including Alzheimer's and Parkinson's diseases and traumatic and ischemic brain injury. In vitro studies have demonstrated that MB enhances mitochondrial ATP production via oxidative phoysphorylation, however the effects of MB on in vivo metabolites and metabolic rates remain unknown. In this study, we implemented 31P NMR based on the Four Angle Saturation Transfer method for rapid in vivo measurements of the effects of MB on relative concentrations of ATP, phosphocreatine and inorganic phosphorus and the forward creatine kinase (CK) rate.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
MRS of Animal Models
1973. | Effects of Cafeteria Diet and Voluntary Running on Brain Structure and Metabolism in Mice Markus Sack1,2, Johannes Fuss3, Claudia Falfán-Melgoza2, Sarah Biedermann1,2, Matthias Auer4, Jenny Lenz4, Gabriele Ende1, Alexander Sartorius2,5, Peter Gass3, and Wolfgang Weber-Fahr1,2 1Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim / Heidelberg University, Mannheim, Germany, 2RG Translational Imaging, Central Institute of Mental Health, Medical Faculty Mannheim / Heidelberg University, Mannheim, Germany, 3RG Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim / Heidelberg University, Mannheim, Germany, 4Endocrinology, Max Planck Institute of Psychiatry, Munich, Germany, 5Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim / Heidelberg University, Mannheim, Germany Obesity is one of the major health burdens of modern societies associated with a great variety of health-threatening sequela such as diabetes, cardiovascular diseases, cancer and even psychiatric disorders. We conducted a MR spectroscopy study investigating metabolic changes in a cafeteria-mouse model vs. control mice receiving standard chow in the right hippocampus and prefrontal cortex area in conjunction with VBM analyses. We found that physical exercise and cafeteria diet have opposite effects. While exercising mice show increased metabolite concentrations (NAA+NAAG and Glu+Gln) and increased volume within the hippocampal area, cafeteria diet counterparts the metabolic effect without impact on brain structure.
1974. | Spectroscopic Imaging of Brain Metabolism in a Mouse Model of Human Glioma-Initiating Cells: A Longitudinal Study at 14.1 T Mélanie Craveiro1, Cristina Cudalbu1, Denis Marino2, Ivan Radovanovic2, Virginie Clément-Schatlo2, and Rolf Gruetter3,4 1Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland, 3Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Departments of Radiology, Universities of Lausanne and Geneva, Lausanne and Geneva, Switzerland Mouse models of human gliomas have been developed by injection of fresh or cultured glioma-initiating cells (GIC), leading to slow infiltrative or fast developing and aggressive brain tumours. However, although brain tumours have been extensively studied, only a few studies have focused on the metabolic changes during their development. In this study, we imaged the metabolic changes occurring during tumour growth after an injection of cultured GIC using proton magnetic resonance spectroscopic imaging, which allowed for sensitive tumour detection prior to any visual signs on anatomical images, thus insuring an optimal evaluation of the first metabolite alterations.
1975. | In Vivo 13C MRS Investigation of Alterations in Cerebral Oxidative Metabolism in a Chronic Liver Disease Rat Model Bernard Lanz1,2, Cristina Cudalbu2, Valérie A. McLin3, Mario Lepore2, Olivier Braissant4, and Rolf Gruetter5,6 1Department of Radiology, University of Lausanne, Lausanne, Switzerland, 2Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Département de l'Enfant et de l'Adolescent, Unité de Gastroentérologie, Hépatologie et Nutrition, Hôpitaux Universitaires de Genčve (HUG), Geneva, Switzerland, 4Laboratoire de Chimie Clinique, Département de Pathologie et de Médecine de Laboratoire, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland, 5Laboratory for Functional and Metabolic Imaging (LIFMET), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland,6Departments of Radiology, Universities of Lausanne and Geneva, Lausanne and Geneva, Switzerland 13C MRS combined with the infusion of 13C-labeled glucose is a powerful tool to investigate brain energy metabolism in animal models. In the present study, we analyzed the effect of hepatic encephalopathy induced by chronic liver disease (CLD) on brain oxidative metabolism, using bile duct ligated rats as model for CLD.
1976. | Dietary Restriction Recovers Cerebral Activity in Pitx3 Knockout Mouse Model of Parkinson’s Disease Puneet Bagga1, Anup Nirmal Chugani1, M Suresh Kumar1, and Anant Bahadur Patel1 1NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India Pitx3 knockout (Pitx3-/-) mouse model is a well characterized genetic model of Parkinson’s disease (PD) due to malformation of substantia nigra leading to loss of dopamine innervations in striatum. Dietary restriction (DR) is linked with longevity and neuroprotection via many mechanisms. Regional cerebral metabolism was monitored by infusion of [1,6-13C2]glucose for 10 min in conjunction with 1H-[13C]-NMR spectroscopy of mice brain extracts. Glucose oxidation by Glutamatergic and GABAergic neurons was decreased, additionally thalamus-hypothalamic excitatory activity and neurotransmission was found to be reduced in Pitx3-/- mice which was observed to be recovered after 6 months of DR.
1977. | Effect of Maternal Exposure to High Fat Feeding on Cardiac Metabolism and Function in Offspring Petronella A. van Ewijk1,2, Sabina Paglialunga1, Anne Gemmink3, Jos M.G.M. Slenter2, Joachim E. Wildberger2, Jan F. Glatz4, Joris Hoeks1, Matthijs K.C. Hesselink3, Patrick Schrauwen1, Vera B. Schrauwen-Hinderling1,2, and Marianne Eline Kooi2 1Human Biology, Maastricht University Medical Centre, Maastricht, Limburg, Netherlands, 2Radiology, Maastricht University Medical Centre, Maastricht, Limburg, Netherlands,3Human Movement Sciences, Maastricht University Medical Centre, Maastricht, Limburg, Netherlands, 4Molecular Genetics, Maastricht University Medical Centre, Maastricht, Limburg, Netherlands We investigated in mice whether maternal exposure to a high fat (HF) diet increases susceptibility for cardiac lipotoxicity in male offspring on a HF-diet. Cardiac MR-spectroscopy showed initially higher cardiac lipid content in the HF/HF group (at 15 weeks) which decreased in this group with time and tended to be lower at 27 weeks compared to LF/HF. Cardiac CINE-MR imaging showed unchanged ejection fraction. Maximal mitochondrial respiration (determined ex vivo) tended to be lower the HF/HF group at 28 weeks. Maternal HF exposure lead to an initially elevated cardiac lipid content however, on the longer term, differences did not persist.
1978. | Impaired Pyruvate Carboxylase and Pentose Phosphate Pathway in APP-PS1 Mouse Model of Alzheimer’s Disease Anant Bahadur Patel1 and Vivek Tiwari1 1NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India Alzheimer’s Disease (AD) is one of the most common neurodegenerative disorders characterized by progressive memory impairment, disordered cognitive functions and perturbed synaptic transmission. The present study evaluates metabolic fluxes via pyruvate carboxylase (PC), pentose phosphate (PPP) and pyruvate dehydrogenase (PDH) pathways in 20 months old APP-PS1 mouse brain by using 1H-[13C]-NMR spectroscopy in conjunction with infusion of [2-13C]glucose. Our results indicate that fluxes through PC, PPP and PDH pathways are severely impaired in 20 months old APP-PS1 mice.
1979. | ex vivo Quantification of Regional Cerebral Metabolites in Chronic Alcohol Consumption-Induced Rats Do-Wan Lee1, Sang-Young Kim1, Taehyeong Lee2, Anes Ju3, Hwi-Yool Kim2, Dai-Jin Kim3,4, and Bo-Young Choe1 1Department of Biomedical Engineering, The Catholic University of Korea, College of Medicine, Seoul, Seoul, Korea, 2Department of Veterinary Surgery, Konkuk University of Korea, Seoul, Seoul, Korea, 3Department of Biomedical Science, The Catholic University of Korea, College of Medicine, Seoul, Seoul, Korea, 4Department of Psychiatry, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Seoul, Korea The aim of this study was to quantitatively investigate the chronic ethanol-induced cerebral metabolic changes in various regions of the rat brain, using the proton HR-MAS NMR spectroscopy technique. Our results showed that the levels of 2 to 7 metabolites were significantly altered in five brain regions of the ethanol-treated group, compared to the control group. Our key finding is that the Glu/tCr and Cho/tCr ratio levels showed the most significant differences in the thalamus of the rat brain. These increased metabolic ratio levels of the thalamus could be utilized as the key marker in the human chronic alcoholism.
1980. | 1H-[13C]-NMR Study to Evaluate the Efficacy of Levodopa Treatment in MPTP Mouse Model of Parkinson’s Disease Anant Bahadur Patel1, Anup Nirmal Chugani1, Rajeeva Voleti1, and Puneet Bagga1 1NMR Microimaging and Spectroscopy, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India MPTP is widely used chemical model to study the pathophysilogy of Parkinson’s disease. Levodopa is the most successful drug used for the treatment of Parkinson’s disease. Efficacy of levodopa for improving cerebral metabolism in MPTP treated mice was evaluated by 1H-[13C]-NMR spectroscopy in conjunction with infusion of [1,6-13C2]glucose. Cortical and striatal glucose oxidation by glutamatergic and GABAergic neurons, and total neurotransmission were found to be reduced in MPTP treated mice. Acute levodopa treatment improves the cerebral metabolism to the control level.
1981. | Hippocampal Neurochemical Changes in Neonatal Mouse Model of Phlebotomy-Induced Anemia Ivan Tkac1, Diana Wallin2, Tara Zamora2, Kathleen Ennis2, Ariel Stein2, Michael K. Georgieff2, and Raghavendra Rao2 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States In vivo 1H NMR spectroscopy was used to investigate changes in the neurochemical profile of the hippocampus of 14-day old anemic mice (Hct = 20 ± 2%). Anemia was induced by periodic blood draws during postnatal period P3 – P14. Small, but significant changes were observed in myo-inositol, lactate and phosphoethanolamine levels, which indicate myelination changes in the developing brain resulted from iron deficiency. These results suggest that uncompensated phlebotomy-induced blood loss is a risk factor, especially for preterm infants, and has implications on blood transfusion practices.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
ESR & Multinuclear
1982. | Combination of a Sodium Birdcage Coil with a Tunable Patch Antenna for B0 Shimming and Anatomical Localization at 9.4 T Christian C. Mirkes1,2, Jens Hoffmann1, Gunamony Shajan1, Rolf Pohmann1, and Klaus Scheffler1,2 1High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Department for Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany X-nucleus spectroscopy and imaging normally rely on proton imaging for anatomical localization and B0 shimming. A convenient way to perform these tasks, without having to make any changes to the X-nucleus coil, is presented here by the usage of the travelling wave concept and a two-channel proton patch antenna.
1983. | Adaptive Combination of Multichannel Data for Non-Proton MRI Stefan H. Hoffmann1, Florian M. Meise1,2, Armin Biller3, and Armin M. Nagel1 1Dpt. of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Siemens AG, Healthcare Sector, Magnetic Resonance, Erlangen, Germany, 3Dpt. of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany With the use of phased array receiver coils for non-proton MRI a large gain in SNR can be achieved. However, because of the intrinsically low SNR of the data the standard sum-of-squares (SoS) reconstruction is suboptimal and leads to a severe noise floor in the images. We showed that a multichannel reconstruction with the adaptive combination (AC) of the channels is highly beneficial in non-proton MRI. In vivo SNR maps of the AC multichannel reconstruction method of phased array data acquired with a 30-channel 23Na head coil at 3T are presented and a comparison with the standard SoS reconstruction is given.
1984. | A Measurement Setup for Combined Chlorine (35Cl) and Sodium (23Na) MRI of the Human Brain Armin M. Nagel1, Titus Lanz2, Dominik Berthel2, Frank Resmer2, Wolfhard Semmler1, and Reiner Umathum1 1Dpt. of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Rapid Biomedical, Rimpar, Germany A dual tuned head coil for combined 35Cl/ 23Na imaging is presented. For evaluating sensitivity optimization, two versions were built: one with a 23Na trap in the 35Cl resonator, one without. By including 23Na traps into the 35Cl resonator, the B1 efficiency of 35Cl versus 23Na can be controlled. The version with 23Na traps was evaluated in phantom and in vivo imaging. Both channels show good B1 efficiency and SNR performance. The presented setup allows for combined 23Na/ 35Cl MRI without repositioning of the patient.
1985. | In Vivo 17O-MRI at 3 Tesla Using a TxRx Surface Coil Jens Groebner1, Robert Borowiak1,2, Manuela Rösler3, Reiner Umathum3, Elmar Fischer1, John M. Pavlina1, and Michael Bock1 1Dept. of Radiology / Medical Physics, University Medical Center Freiburg, Freiburg, BW, Germany, 2Deutsches Konsortium für translationale Krebsforschung (DKTK), German Cancer Research Center (DKFZ), Heidelberg, BW, Germany, 3Dept. of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, BW, Germany Oxygen-17 (17O) MRI allows quantifying the metabolic turnover of oxygen in vivo. In this preliminary work a TxRx surface coil was constructed for direct 17O MRI at 3 Tesla. MR images of a phantom and a volunteer were acquired at 3T for the first time. An SNR of 45 in vitro and 50 in vivo could be achieved in clinically acceptable acquisition times of less than 15 min at in-plane resolutions between 5 and 12 mm.
1986. | Redox Map of Mouse Brain by Three-Dimensional EPR Imaging with Six-Membered Nitroxyl Radicals Miho C. Emoto1, Hideo Sato-Akaba2, Hiroshi Hirata3, and Hirotada G. Fujii1 1Center for Medical Education, Sapporo Medical University, Sapporo, Hokkaido, Japan, 2Department of Systems Innovation, Osaka Universivy, Toyonaka, Osaka, Japan,3Division of Bioengineering and Bioinformatics, Hokkaido University, Sapporo, Hokkaido, Japan Six-membered nitroxides such as TEMPOL and TEMPONE are redox-sensitive probes for redox research, but due to their short lifetime in vivo, they have not been fully examined in EPR imaging studies in living animals. In this study, an improved EPR imaging system with a rapid-field scanning capability was used, and three-dimensional EPR images of mouse heads were obtained after administration of TEMPOL and TEMPONE. Half-life maps of TEMPOL and TEMPONE in mouse heads were calculated from a series of EPR images recorded at an interval of 16 s. Obtained half-life maps clearly indicate the redox status of the mouse brain.
1987. | Brain Redox Mapping in Methamphetamine-Treated Mice Using Three-Dimensional EPR Imaging Hirotada G. Fujii1, Miho C. Emoto1, Mayumi Yamato2, and Ken-ichi Yamada2 1Center for Medical Education, Sapporo Medical University, Sapporo, Hokkiado, Japan, 2Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan Methamphetamine (METH)-induced neurotoxicity is associated with mitochondrial dysfunction and enhanced oxidative stress. The aims of the present study were to examine the redox status in the METH-treated mouse brain using the redox-sensitive imaging probe 3-methoxycarbonyl-2,2,5,5-tetramethyl-piperidine-1-oxyl (MCP), and to noninvasively visualize brain redox status with a three-dimensional electron paramagnetic resonance (EPR) imaging system. Half-life mapping of blood-brain-barrier-permeable MCP in METH-treated mice was obtained from a series of temporal EPR images of mouse heads at an interval of 20 s. The obtained half-life map of MCP clearly visualized the effect of METH treatment on the redox status in the mouse brain.
1988. | Electron Paramagnetic Resonance Spectrometry and Imaging in Melanomas: A Comparison Between Pigmented and Non-Pigmented Human Malignant Melanomas. Quentin Godechal1, Ghanem Ghanem2, Martin Cook3, and Bernard Gallez1 1Biomedical Magnetic Resonance, University of Louvain, Brussels, Belgium, 2Universite libre de Bruxelles, Brussels, Belgium, 3Department of Histopathology, Royal Surrey County Hospital, Guildford, United Kingdom In this study, we proposed to use EPR imaging as a tool to map the concentration of melanin inside ex-vivo human pigmented and non-pigmented melanomas and to correlate this cartography with anatomo-pathology. The importance of the pigmentation for EPR measurement was unambiguously demonstrated. Moreover, EPR images accurately reflected the distribution of melanin pigments within melanoma samples.
1989. | Principal Component Analysis Enhanced Dynamic Electron Paramagnetic Resonance Imaging of Cycling Hypoxia in vivo Gage Redler1, Boris Epel1, and Howard J. Halpern1 1Radiation and Cellular Oncology, University of Chicago, Chicago, IL, United States Hypoxia in tumors affects their malignant state and resistance to therapy. These effects may be more deleterious in regions undergoing cycling hypoxia. Electron paramagnetic resonance imaging (EPRI) has provided a non-invasive, quantitative imaging modality to investigate static pO2 in vivo. However, to image cycling hypoxia, better temporal resolution may be required. The tradeoff between temporal resolution and SNR results in lower SNR for EPRI images with higher temporal resolution. Principal component analysis is presented as a spatiotemporal filter via low-order approximation of EPRI projection data, allowing studies with SNR and temporal resolution necessary to study cycling hypoxia in vivo.
1990. | Sodium Triple-Quantum Coherence Characterization of Scaffolds Used in Cartilage Tissue Engineering Mrignayani Kotecha1, Allen Ye1, and Richard L. Magin1 1Bioengieering, University of Illinois at Chicago, Chicago, IL, United States Magnetic resonance characterization of engineered cartilage tissue using sodium triple quantum coherence spectroscopy (or imaging) is relatively new concept. Chondrocytes seeded in alginate beads, Scaffold free chondrocyte pellets and human mesenchymal stem cells seeded in ECM integrated collagen/chitosan based scaffolds were studied for four weeks post-cell seeding. We found that the sodium biexponential relaxation pathway of these tissue engineered constructs depends upon the scaffold properties, cell density and tissue microstructure. These finding suggests that sodium MRI can play an important role in understanding the tissue growth dynamics in cartilage tissue engineering.
1991. | Does Li Displace Intracellular Na in Brain?: An In Vivo 23Na MRI Study Richard A. Komoroski1, Diana M. Lindquist2, and John M. Pearce2 1Center for Imaging Research, University of Cincinnati, Cincinnati, OH, United States, 2Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States Elevated intracellular Na, possibly arising from abnormal Na,K-ATPase, has been proposed in bipolar disorder. Lithium is often an effective treatment for bipolar disorder. Sodium-23 MRI was used to follow the effect of an IP dose of Li on intracellular Na in normal rat brain in vivo. For brain parenchyma, 23Na MRI intensity increased by a maximum of 6.78% at 1.4 hrs after Li injection and then fell slightly over the next two hours. Sodium-23 T2s generally lengthened with time, consistent with intra- to extracellular movement of Na. The results are interpreted as displacement of intracellular Na by Li.
1992. | Biexponentially Weighted Sodium Imaging with Higher SNR Efficiency Nadia Benkhedah1, Peter Bachert1, and Armin M. Nagel1 1Dpt. Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany In this study a new method for generating biexponentially weighted sodium images is presented. Only two instead of three RF pulses are required for filtering the signal. Images show an up to 3 times improved SNR compared to conventional triple quantum filtered (TQF) images with the same measurement parameters. Measurement time can be shortened with the new sequence design by reducing the number of averages (only two instead of six are required) or by reducing TR (as SAR is only about 2/3 of that of TQF sequences) resulting in better SNR efficiency.
1993. | Triple-Quantum Filtered Chlorine Magnetic Resonance Imaging of the Human Brain Alina Gilles1, Nadia Benkhedah1, Peter Bachert1, Wolfhard Semmler1, and Armin M. Nagel1 1Dpt. of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany In this study we present the first in vivo TQF 35Cl images. MRI of TQF 35Cl suffers from low sensitivity due to low gyromagnetic ratio of 35Cl, fast relaxation and low intracellular concentration. However, for high fields (B0 = 7 T) acquisition of TQF 35Cl images is possible. Selective detection of 35Cl nuclei which are exposed to quadrupolar interaction, i.e. intracellular 35Cl, is thus feasible. Future monitoring of TQF 35Cl signal may prove worthwhile in understanding the pathophysiological changes of ion concentration in various diseases including those of the central nervous system (e.g. ischemia and tumors).
1994. | Evaluation of Lactate Detection Using Selective Multiple Quantum Coherence in Phantoms and Brain Tumours Lisa Maria Harris1, Nina Tunariu2, Toni Wallace1, Nandita M. deSouza1, Martin O. Leach1, and Geoffrey Payne1 1Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom, 2Institute of Cancer Research and Royal Marsden Hospital, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom A study using a selective homonuclear multiple quantum coherence transfer transfer (SelMQC) sequence to accurately quantify lactate by suppressing lipid signals is presented. Phantom studies are shown to verify both the lipid suppression and the lactate detection and the performance of the sequence was assessed in brain tumours where the presence of lactate and lipids are both expected.
1995. | Single Use Flexible Resonant Loops for L-Band Tooth EPR Selaka Bandara Bulumulla1, Daniel Lewek1, Christopher Kapusta1, David Davenport1, Joseph Iannotti1, Dmitriy Tipikin2, Benjamin Williams2, and Harold Swartz2 1GE Global Research, Niskayuna, NY, United States, 2Geisel School of Medicine, Hanover, NH, United States EPR can be used to estimate exposed radiation dose by measuring the amount of free radicals in the crystalline structure of the tooth enamel. In this work, we consider a potentially detachable, flexible resonant loop as a sensing probe. The flexible loop is conformal for a better fit to patient dependent variable incisor teeth geometries. Furthermore, this single use resonant loop eliminates the need for cleaning between subjects and increases the throughput by allowing the placement of the resonant loop prior to positioning the subject in the magnet. The loops can be fabricated using high volume, lower cost manufacturing methods.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
MRS & Relaxation
1996. | Measurement of Metabolite 1H Transverse Relaxation Times (T2) in the Human Visual Cortex Over an Extended Echo-Time Range During Visual Stimulation at 7T Francesca Branzoli1, Ece Ercan1, Andrew Webb1, and Itamar Ronen1 1C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands In this work we employed a method we recently developed for collection and analysis of multi-echo highly truncated MRS CPMG (Carr-Purrell Meiboom-Gill) spectroscopic data in order to achieve accurate proton transverse relaxation times (T2) measurements of total creatine (tCr), total NAA (tNAA) and choline compounds (tCho) in the primary visual cortex at 7T and to investigate possible T2 changes during visual stimulation. The large echo-time range employed allowed for evaluation of deviation of amplitude-TE curves from mono-exponential decay pattern, reflecting the presence of multi-components possessing different T2, as expected for the tCr signal at 3.0 ppm.
1997. | Measurement of Transverse Relaxation Times in Brain Tumors Akshay Madan1, Sandeep Ganji1, Elizabeth A. Maher2, and Changho Choi3 1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States, 2Harold C. Simmons Cancer Center, UT Southwestern Medical Center, Dallas, Texas, United States, 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States In this study we performed invivo T2 measurement of metabolites like N-acetylaspartate, Creatine, Choline and water in glioma patients for comparison with normal brain using single voxel point resolved spectroscopy at multiple echo times at 3T. We calculated T2 using monoexponential nonlinear fitting of metabolite signal estimates obtained from LCModel.
1998. | 129Xe-RBC T1 Dependence on Blood Oxygen Saturation Graham Norquay1, General Leung1, Jan Wolber2, Gillian M. Tozer1, and Jim M. Wild1 1University of Sheffield, Sheffield, South Yorkshire, United Kingdom, 2GE Healthcare, Amersham, Buckinghamshire, United Kingdom In this study, the T1 of hyperpolarised (HP) 129Xe in red blood cells (RBCs) was measured in vitro as a function of blood saturation (sO2) on a 1.5T scanner. 129Xe-RBC T1 was found to increase linearly with increasing sO2, where the mechanism believed to be responsible for the 129Xe-RBC T1 sO2 dependence is interactions of 129Xe nuclei with varying concentrations of paramagnetic deoxyhaemoglobin. The observed linearity between 129Xe-RBC T1 and sO2 has positive preclinical and clinical implications, as it may open up the possibility of using HP 129Xe in vivo as a non-invasive quantitative probe for blood oxygenation in tumours.
1999. | Measurement of the T1 Of 31P-Metabolites at 7 Tesla in the Human Heart Matthew D. Robson1, Stefan Neubauer1, and Christopher T. Rodgers1 1OCMR, Oxford University, Oxford, Oxfordshire, United Kingdom Measurement of high-energy metabolite concentrations in the heart offers insight and understanding of myocardial disease and may yield unique diagnostic information. A novel Look-Locker Inversion Recovery Chemical Shift Imaging sequence was developed for evaluation of 31P T1 in-vivo. Validation of this method on skeletal muscle agrees with previous work. In 5 healthy males, the measured cardiac T1s were: PCr=2.81±0.47s, -ATP=1.86±0.15s, -ATP=1.34±0.09s, and -ATP=0.98±0.15s. This reduction in T1compared to lower fields is consistent with work in skeletal muscle. CK flux has a significant influence over the apparent T1 of PCr and -ATP.
2000. | Preliminary 23Na Transverse Relaxation Time Investigation Using a Continuous Distribution Model Frank Riemer1, Bhavana S. Solanky1, Claudia Angela M. Wheeler-Kingshott1, and Xavier Golay2 1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, 2Department of Brain Repair & Rehabilitation, University College London, London, United Kingdom Preliminary results from using a continuous distribution model (regularized inverse Laplace transform) to analyse 23Na-T2* in the brain.
2001. | Spin-Lattice and Spin-Spin Relaxation of Water and Lipids in Human Vastus Lateralis M. Measured by 1H-MRS at 3T Sunil K. Valaparla1,2, Geoffrey D. Clarke2, and Timothy O. Duong2,3 1Research Imaging Institute, University of Texas Health Science Center San Antonio, San Antonio, Texas, United States, 2Radiology, University of Texas Health Science Center San Antonio, San Antonio, Texas, United States, 3Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, Texas, United States Quantitative evaluation of relaxation times can be used to measure metabolite concentrations accurately and for optimizing measurement protocols in single-voxel proton magnetic resonance spectroscopy (1H-MRS). This study reports spin-lattice and spin-spin relaxation times of water, intra and extra-myocellular lipids in the human vastus lateralis (VL) muscle obtained using a STEAM single voxel pulse sequence in normal healthy subjects at 3T. The results obtained are consistent with data reported for 1.5T in VL and other muscles at higher field strengths. These data can be applied to relaxation corrections for the absolute quantification of vastus lateralis m. lipid spectra in normal and diseased states.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
Methodology of Spectroscopic Localization & Imaging
2002. | Simultaneous In Vivo 1H and 31P MRS Acquisition in Ischemic Rat Brain at Ultrahigh Field Jennifer M. Taylor1,2, Xiao-Hong Zhu2, Yi Zhang2, and Wei Chen1,2 1Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States The information gained from a single MR spectroscopy (MRS) scan using conventional acquisition strategies is limited by the inability to acquire signal from multiple nuclei simultaneously. We propose a new MR acquisition configuration to allow for simultaneous acquisition of localized spin echo 1H and global single pulse 31P MRS. We show this technique’s feasibility for monitoring the alteration in cerebral metabolic and hemodynamic activities during an acute global forebrain ischemia in rat. This technique increases single measurement information and allows the exploration of the dynamic relationship among various metabolic and/or hemodynamic activities in animal or human under different physiopathological conditions.
2003. | in vivo Localized Correlated Spectroscopy Using Spectral Spatial Coherence Transfers Galen D. Reed1, Trey Jalbert1, Gerd Melkus1, Simon Hu1, Peder E.Z. Larson1, Sarah J. Nelson1, John Kurhanewicz1, and Daniel B. Vigneron1 1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States A localized correlated spectroscopy sequence using spectral spatial coeherence transfer / water suppression pulses is presented. High bandwidth and low peak power was achieved by phase modulation of the spectral filter and using phase-matched refocusing pulses. Insensitivity to transmitter power offsets is demonstrated in phantoms and compared to correlated spectroscopy acquired using selective presaturation. Preliminary data from vounteers indicate robust water suppression without cross peak degredation due to water contamination.
2004. | Accelerated 3D-Localized Echo Planar Correlated Spectroscopic Imaging of Calf Muscle Using Compressed Sensing Neil E. Wilson1, Brian L. Burns2, and M. Albert Thomas1 1University of California, Los Angeles, CA, United States, 2UCLA, Los Angeles, CA, United States In one dimensional (1D) spectroscopy, there is no information clearly linking J-coupled partners as there is with 2D localized correlated spectroscopy (L-COSY), which also produces much less crowded spectra. Recently, an echo planar spectroscopic imaging readout was added to L-COSY to collect a 4D data slice in (kx, ky, t2, t1) space (EP-COSI). Showing the potential for scan time reductions, NUS was retrospectively applied on the incrementally-acquired (ky, t1) plane. Here, we extend EP-COSI to a 3rd spatial dimension collecting data in (kx, ky, kz, t2, t1) and apply NUS prospectively on the (ky, kz, t1) volume.
2005. | Separation and Precise Estimation of Glutamate and Glutamine Using Spectroscopic Imaging in Human Brain at 3.0 T Sandeep Ganji1 and Changho Choi2 1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States, 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States We report in vivo spectroscopic imaging of glutamate and glutamine at 3T using an optimized echo-time PRESS-based localization method. Using our technique we achieved separation of Glu (2.35 ppm) and Gln (2.45 ppm) signals. The Gln concentration showed significant regional variation over the brain, with higher levels in gray matter dominant regions compared to white matter dominant regions. Higher concentrations of N-Acetylaspartylglutamic acid (NAAG) were well correlated with white matter dominant regions. Scan/rescan were performed in six healthy volunteers and reproducibility results are presented.
2006. | Sensitivity Decomposition of Water and Metabolites with Sensitivity Encoding for Reducing Scan Time Toru Shirai1, Satoshi Hirata1, Yo Taniguchi1, Yoshihisa Soutome1, and Yoshitaka Bito2 1Hitachi, Ltd., Central Research Laboratory, Kokubunji, Tokyo, Japan, 2Hitachi, Ltd., Kokubunji, Tokyo, Japan We propose a method that combines the sensitivity decomposition method with the sensitivity encoding method for simultaneously acquiring water and metabolites signals to reduce the scan time. This method consists of a measurement that shifts only the water signal on an image and undersamples in k-space, and a data process that separates each signal by using the coil sensitivities. The results of experiments with a healthy volunteer showed that the proposed method reduced the scan time to one-fourth of the fully sampled CSI, to which non-water-suppressed measurement was added.
2007. | Inherent Reduction of Residual Lipid Aliasing in SENSE-Accelerated 1H MRSI at 7T by Spatially Selective SRF Optimization Thomas Kirchner1, Lukas Eisenring1, Klaas P. Pruessmann1, and Anke Henning1,2 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Max Planck Institute for Biological Cybernetics, Tuebingen, Germany As a consequence of voxel bleeding and residual spatial aliasing in SENSE-accelerated in vivo 1H MRSI, lipid signal originating in the skull region is often found in spectroscopic imaging voxels in the brain. To a certain extent, those artifacts can be contained by target-driven overdiscretized reconstruction with direct optimization of the Spatial Response Function (SRF) compared to conventional SENSE with Hamming filtering. In this work, we demonstrate that an even better spectral quality can be achieved by exploiting spatial prior knowledge to specify spatially selective priority for SRF optimality.
2008. | Proton Observed Phosphor Editing (POPE) Brings Hope for in vivo Detection of Phospholipid Metabolites Dennis W. J. Klomp1, Robin A. de Graaf1,2, Christine Nabuurs3, Irene M.L. van Kalleveen1, Wybe J.M. van der Kemp1, Peter R. Luijten1, Hermien E. Kan4, Andrew Webb4, Jannie P. Wijnen1,4, and Vincent Oltman Boer5 1UMC Utrecht, Utrecht, Utrecht, Netherlands, 2Yale University, New Haven, CT, United States, 3Maastricht University, Maastricht, Limburg, Netherlands, 4Leiden UMC, Leiden, Holland, Netherlands, 5University Medical Center Utrecht, Utrecht, Utrecht, Netherlands Phospholipids are highly valuable biomarkers, but detection sensitivity requires substantial optimization. Although conventional in vivo 1H MRS cannot discriminate these phosphomono and diesters, 31P MRS can, but lacks sensitivity. Here we present that using 31P selective editing pulses in a 1H MRS experiment, sensitivity can be boosted by a factor of 2.8 compared to SNR optimized 31P MRS while still enabling distinct detection of phospho-choline (PC), -ethanolamine (PE) and their glycerol compounds (GPC and GPE). Validated in the human brain at 7T, these biomarkers can be explored in clinical studies.
2009. | The Effect of Compressed Sensing Reconstruction on the Spatial Resolution of Magnetic Resonance Spectroscopic Imaging. Lara Angharod Worthington1,2, Martin Wilson2,3, Theodoros N. Arvanitis2,4, Andrew C. Peet2,3, and Nigel Paul Davies3,5 1PSIBS, University of Birmingham, Birmingham, West Midlands, United Kingdom, 2Birmingham Children's Hospital NHS Foundation Trust, Birmingham, West Midlands, United Kingdom, 3Cancer Sciences, University of Birmingham, Birmingham, West Midlands, United Kingdom, 4School of Electronic, Electrical & Computer Engineering, University of Birmingham, Birmingham, West Midlands, United Kingdom, 5Imaging & Medical Physics, University Hospital Birmingham NHS Foundation Trust, Birmingham, West Midlands, United Kingdom Current clinical Magnetic Resonance Spectroscopic Imaging (MRSI) is limited by long acquisition times and poor spatial resolution. Compressed sensing has been suggested as a possible speed up technique, but the effect of this and other k-space under-sampling techniques on the quality of MRSI spatial resolution is so far unknown. This study developed a novel methodology to assess the spatial resolution in MRSI after reconstruction using compressed sensing and compared this to an equivalently sampled dataset at the center of k-space in phantom and volunteer datasets. This technique showed that compressed sensing maybe preferred in situations where acquisition speed and high spatial resolution is of importance.
2010. | Nonuniformly Undersampled 5D (3 Spatial + 2 Spectral) Echo Planar J-Resolved Spectroscopic Imaging of Brain Neil E. Wilson1, Brian L. Burns2, and M. Albert Thomas1 1University of California, Los Angeles, CA, United States, 2UCLA, Los Angeles, CA, United States J-resolved spectroscopy is a multidimensional technique to enhance spectral information by pushing multiplet splittings into a second dimension. EP-JRESI combines localized J-resolved spectroscopy with an echo planar readout for a single slice acquisition. Here, we extend EP-JRESI to include a 3D localization and use nonuniform sampling (NUS) and compressed sensing (CS) on the incrementally-acquired volume (ky, kz, t1) to achieve far greater accelerations in scan time.
2011. | 1H-MRS in the in Vivo Mouse Heart: A Comparison Between PRESS and STEAM Adrianus J. Bakermans1, Desiree Abdurrachim1, Klaas Nicolay1, and Jeanine J. Prompers1 1Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands Proton MR spectroscopy (1H-MRS) allows for the noninvasive detection of myocardial metabolites, but its application in preclinical studies has been limited. We assessed the suitability of PRESS and STEAM for 1H-MRS in the in vivo mouse heart. Both sequences were ECG-triggered and respiratory-gated. To maintain steady state of magnetization, dummy pulses were performed during respiratory gates. Water signal stability was slightly better for PRESS than for STEAM, and SNR for PRESS was two-fold higher compared to STEAM. Using PRESS-localized saturation recovery experiments, T1 values were determined for mouse myocardial water and triglyceride.
2012. | Application of Parallel Imaging and Compressed Sensing to Metabolic Imaging of the Brain Using H-1 MRSI at 7T and Using Hyperpolarized C-13 MRSI at 3T Maryam Vareth1,2, Yan Li1, Ilwoo Park1, and Sarah Nelson1,3 1Surbeck Laboratory of Advanced Imaging, Department of Radiology and Biomedical Imaging, Univ. of California, San Francisco, San Francisco, CA, United States,2UCSF/UCBerkeley Joint Graduate Group in Bioengineering, Univ. of California, Berkeley, Berkeley, CA, United States, 3Department of Bioengineering and Therapeutic Sciences, Univ. of California, San Francisco, San Francisco, CA, United States We developled and tested the feasibility of using parallel imaging (PI) and compressed sensing (CS) techniques to reconstruct phase-sensitive MRSI data for both hyperopoarzied 3T C-13 and 7T H-1 applications that require efficient and rapid k-space sampling. Self-calibrating techniques such as GRAPPA, SPIRiT were implemented for use in spectroscopy in addition to CS, to inintially investigate the most roubst and accurate estimation of fully sampled data. Results indicated that these methods effectively reconstructed the data.
2013. | 31P-Spectroscopy on Humans at 9.4 T in Combination with a Patch Antenna for Proton Imaging: Initial Results Morteza Bakhtiary1, Gunamony Shajan1, Jens Hoffmann1, Klaus Scheffler1,2, and Rolf Pohmann1 1Max Planck Institute for Biological Cybernetics, Tübingen, BW, Germany, 2Department for Biomedical Magnetic Resonance, University of Tübingen, Tübingen, BW, Germany Due to its low sensitivity, 31P spectroscopy can gain particularly from ultra high field strength. To demonstrate the potential of 31P in 9.4 T human applications, spectra from the calf and the brain of human subjects were acquired, using either a surface or a birdcage coil for phosphorus transmission and reception, combined with a proton traveling wave antenna for localization and shimming. First results show promising SNR and spectral quality.
2014. | Editing Magnetic Resonance Spectroscopy of Lactate at High Fields: Improved Efficiency by Inclusion of FOCI Pulses and Elimination of Co-Edited Macromolecules Jannie P. Wijnen1, Catalina S. Arteaga de Castro1, Vincent Oltman Boer2, Anna Andreychenko1, Peter R. Luijten1, Bas Neggers3, and Dennis W.J. Klomp1 1Radiology, University Medical Centre Utrecht, Utrecht, Utrecht, Netherlands, 2Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 3Psychiatry, University Medical Centre Utrecht, Utrecht, Utrecht, Netherlands The weakly coupled spin system of low concentrated lactate can be measured with MRS editing techniques. Obtaining this at the potentially high sensitivity of high field strength can be challenging due to the low available B1+ field resulting in narrow bandwidth refocusing pulses and therefore in large chemical shift displacement errors (CSDE). Frequency offset corrected inversion (FOCI) pulses substantially increase the bandwidth of adiabatic pulses and are used in this study in a MEGA-sLASER editing sequence for highly efficient measurements of lactate. Combined with nulling of co-edited macromolecules, we demonstrate that artefact free lactate signals can be detected in the human brain at 7T.
2015. | Magnetic Resonance Spectroscopy Based Temperature Calibration and in-vivo Brain Temperature Measurement of Traumatic Brain Injury Rats at 7 Tesla Sankar Seramani1, Bhanu Prakash K.N.1, Sanjay K. Verma1, Kian Chye Ng2, Enci Mary Kan2, Gopalan V.1, Michael N.1, Yaligar J1, Graham S.3, Jia Lu2, C. Childs4, and Sendhil S. Velan1,5 1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, 2Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore, 3Department of Psychology, National University of Singapore, Singapore, Singapore, 4Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore, 5Clinical Imaging Research Centre, Agency for Science, Technology and Research, Singapore, Singapore Magnetic resonance spectroscopy based non-invasive temperature measurement of an in-vivo brain is one of the most preferred ways of mapping the temperature of the brain. This is based on the relationship between water resonant frequency of the tissue and the actual temperature of the tissue. Hence, it is necessary to calibrate/derive the relationship between the chemical shift of the water and the temperature, by using the brain metabolites phantom for the given field strength of the magnet. Traumatic Brain Injuries (TBI) causes increase in brain temperature due to inflammation and other neuroprotective mechanism. Monitoring the region specific brain temperature in-vivo helps in predicting the prognosis of the treatment in the TBI subjects. We calibrated the in-house designed brain metabolite phantom at different temperatures on a 7 Tesla scanner and also explored the changes in brain temperature of TBI rats at different time-points. The water chemical shift showed a linear dependence on temperature in the phantom calibration and increased brain temperature was observed in TBI rats until Day-3, which decreased subsequently.
2016. | Improved Volume Localization for MRSI at 7T Using RF Shimming and RF Multiplexing Hoby P. Hetherington1, Nikolai I. Avdievich1, and Jullie Pan1 1Neurosurgery, Yale University, New Haven, CT, United States At 7T, increased spectral dispersion and decreased B1 results in increased spectral dispersion artifacts when using slice or slab selective pulses. Recent developments of RF shimming based localization using “ring” distributions generated solely by RF shimming eliminate spectral dispersion artifacts. However, with only 8 independent RF coils/RF channels, the ring distribution can reduce SNR for the neocortical periphery. In this work we describe an improved RF shimming based localization method using a 16 coil transceiver array and RF multiplexing to dramatically improve the selectivity of the ring distribution and preserve SNR for MRSI in the cortical periphery.
2017. | Accelerated Phosphorus MR Spectroscopic Imaging of Human Brain Using Compressed Sensing Gokce H. Hatay1, Cagil Gumus1, Bahattin Hakyemez2, and Esin Ozturk-Isik3 1Electrical and Electronics Engineering, Yeditepe University, Istanbul, Turkey, 2Department of Radiology, Uludag University, Bursa, Turkey, 3Biomedical Engineering, Yeditepe University, Istanbul, Turkey This study aims at assessing compressed sensing reconstruction for faster phosphorus MR spectroscopic imaging (31P MRSI) of human brain. A 31P MRSI dataset containing a tumor region and a healthy region was created based on the metabolite peak intensities of a volunteer dataset acquired at 3T. k-space data was randomly undersampled while preserving the cental portion for a reduction factor of 1.6, and reconstructed using compressed sensing. This study showed that compressed sensing reconstruction could be applied for faster 31P MR spectroscopic imaging, and its performance will be assessed in brain tumors.
2018. | 2D-GRAPPA Accelerated FID Based MRSI of the Brain at 7T Bernhard Strasser1, Gilbert Hangel1, Stephan Gruber1, Siegfried Trattnig1, and Wolfgang Bogner1,2 1Department of Radiology, Medical University of Vienna, Vienna, Vienna, Austria, 2Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, United States In this work the excess signal-to-noise ratio per unit time that was provided by the use of measuring with an FID based sequence at 7T, and performing an optimized coil combination was traded for a substantial reduction in scan time, thus, enabling high resolution MRSI measurements in clinical relevant times. This trade-off was achieved by using optimized 2D-GRAPPA acceleration. The acquisition times were reduced to below four minutes with a spectral quality that is comparable to that of a more than eight times longer measurement with a volume coil. Five volunteers were measured to prove the feasibility of the method.
2019. | MRS Sparse-FFT: Reducing Acquisition Time and Artifacts for in vivo 2D Correlation Spectroscopy Lixin Shi1, Ovidiu C. Andronesi2, Haitham Hassanieh1, Badih Ghazi1, Dina Katabi1, and Elfar Adalsteinsson1,3 1Electrical Engineering and Computer Science Department, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Martinos Center for Biomedical Imaging, Radiology Department, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, United States In-vivo localized 2D Correlation Spectroscopy (COSY) enables detection of new molecular biomarkers of disease. The challenges for this method are, however, long acquisition times and truncation artifacts along the f1 frequency dimension that may obscure the cross-diagonal peaks. We propose to address these challenges by adapting the recently developed sparse-FFT algorithms, which optimize reconstruction of sparse signals in the Fourier domain. Our preliminary results demonstrate that sparse-FFT can reduce measurement time of 2D COSY by almost a factor of three, eliminates t1 truncation artifacts resulting from the ringing tails of the diagonal peaks, and improves SNR and resolution of cross-peaks.
2020. | Implementation of GOIA-Wurst(16,4) Pulses in the Semi-LASER Sequence for SAR-Reduction in Prostate MRSI Isabell K. Steinseifer1, Marnix C. Maas1, Thiele Kobus1, Tom W.J. Scheenen1, and Arend Heerschap1 1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands We present 1H MRSI of the prostate achieved with the semi-LASER sequence and GOIA-WURST(16,4) refocusing pulses to reduce specific absorption rates. This can lead to reduced repetition times and improved k-space weighting to optimize SNR and acquisition times. In particular it may allow 1H MRSI with the use of an endorectal coil with increased spatial resolution within clinically acceptable scan times. The GOIA-W(16,4) pulses used in this work had a higher bandwidth than the standard higher order Hyperbolic Secant pulses (8.5kHz instead of 3.2 kHz) used in the semi-LASER sequence.
2021. | Group-Mean Template Modelling of NAA- And NAAG-Edited MR Spectra Nicolaas A. J. Puts1,2, Mona M. Mohamed1, Peter B. Barker1,2, and Richard Anthony Edward Edden1,2 1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, United States, 2FM Kirby Centre for functional neuroimaging, Kennedy Krieger Institute, Baltimore, Maryland, United States NAA and NAAG can be seperated in vivo using edited MRS. Our previous study used rough methods to analyse spectra, and the creation of basis sets is problematic. Here we shows that a template-based fitting model based on the group-mean of the data is suitable for fitting NAA and NAAG.
2022. | 3D Metabolic Mapping of the Brain at 7T by Pulse-Cascaded Hadamard Encoding with Short Acquisition Delay Gilbert Hangel1, Bernhard Strasser1, Stephan Gruber1, Marek Chmelik1, Siegfried Trattnig1, and Wolfgang Bogner1,2 1MR Centre of Excellence, Medical University of Vienna, Vienna, Vienna, Austria, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States This work compares metabolic maps of pulse-cascaded four-slice Hadamard Spectroscopic Imaging (HSI) with short acquisition delay to standard single slice 2D-CSI at 7T. HSI overcomes point-spread function problems in slice encoding direction and enables the measurement of few slices with high in-plane resolution in acceptable measurement time making full use of the high SNR at 7T. Pulse cascading reduces B1 requirements, specific absorption rates, and chemical shift displacement errors. The short acquisition delay maximizes SNR and avoids J-coupling effects. Measurements in eight volunteers show the good comparability of metabolic maps between HSI and CSI as well as the Hadamard-specific SNR-increase.
2023. | Metabolic Imaging with 3D Echo Planar Spectroscopic Imaging at 7 Tesla Sankar Seramani1, Yevgen Marchenko1, Sanjay K. Verma1, Bhanu Prakash K.N.1, Navin Michael1, Suresh Anand Sadananthan1, Andrew A. Maudsley2, and Sendhil S. Velan1,3 1Laborartory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, Singapore, 2Miller School of Medicine, University of Miami, Miami, Florida, United States, 3Clinical Imaging Research Centre, Agency for Science, Technology and Research, Singapore, Singapore 3D Echo Planar Spectroscopic Imaging (EPSI) is one of the promising fast spectroscopic imaging techniques to map the regional metabolite concentrations within clinically feasible time. Whole brain distributions of NAA, tCr, and tCho and its ratios can be measured using the 3D EPSI. We have implemented a 3D EPSI sequence on a 7T MRI/MRS scanner and demonstrated it in a phantom with a voxel resolution of 2mm3 and on a rat brain. Regional metabolite distributions of NAA, Creatine & Choline and its ratios were computed using MIDAS Software. The feasibiility of mapping whole brain NAA, Cr, Cho concentrations is demonstrated from the rat brain.
2024. | Automated Spectral Assessment of the BOLD Effect for Neurofeedback at 3 and 7 T. Yury Koush1,2, Mark A. Elliott3, Frank Scharnowski1,2, and Klaus Mathiak4,5 1Department of Radiology and Medical Informatics - CIBM, University of Geneva, Geneva, Switzerland, 2Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 4Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany, 5Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, JARA - Translational Brain Medicine, Aachen, Germany To date, conventional echo planar imaging (EPI) based fMRI is the only method capable of providing real-time neurofeedback from a spatially specific ROI. Our research provides evidence that localized functional single-voxel proton spectroscopy (fSVPS) can be used as an alternative approach. We automatized and evaluated this new approach by running real-time fSVPS experiments on high (3 T) and ultra-high (7 T) magnetic fields. Overall, real-time water SVPS neurofeedback is a promising tool for studying and manipulating brain activity, which holds great promise for important scientific and clinical applications.
2025. | Gradient Induced Sideband Artifacts in Non Water-Suppressed Proton CSI of the Human Brain at 9.4 T Grzegorz L. Chadzynski1,2, Rolf Pohmann2, Gunamony Shajan2, Rupert Kolb3, Uwe Klose3, and Klaus Scheffler1,2 1Dept. Biomedical Magnetic Resonance, University Hospital Tuebingen, Tuebingen, Germany, 2Dept. High-Field Magnetic Resonance, Max Planc Institute for Biological Cybernetics, Tuebingen, Germany, 3Dept. Neuroradiology, University Hospital Tuebingen, Tuebingen, Germany CSI without water suppression offers several advantages, like the possibility to use the water signal for absolute quantification. However, the unsuppressed spectra are hampered by gradient induced sidebands, which have to be removed before the quantification. Despite known difficulties (shorter T2 relaxation time, larger B0 and B1 inhomogeneities), previous studies demonstrated that CSI at ultra-high magnetic field is feasible. The aim of this study was to verify the feasibility of short TE proton CSI on the human brain without water suppression at the field strength of 9.4 T and to examine the influence of sidebands on the measured spectra.
2026. | MEGA-PRESSing Onward for More Metabolites: Aspartate, Lactate, and PE James B. Murdoch1, Andrew J. Wheaton1, and Robert Anderson1 1Toshiba Medical Research Institute USA, Mayfield Village, Ohio, United States With a change in the edit-ON selective inversion frequency to 3.89 ppm, the TE 80 MEGA-PRESS sequence favored for GABA editing can be used to highlight aspartate as well. Inverting the aspartate CH proton on half the acquisitions and taking the difference between edit-ON and edit-OFF shots yields a peak at 2.74 ppm from J-coupled aspartate CH2 spins. Other metabolites of interest with J-coupled resonances near 3.89 ppm are co-edited – including lactate and phosphorylethanolamine (PE). Posterior cingulate cortex (PCC) spectra from a normal volunteer were phase and frequency aligned on a shot-by-shot basis and processed with LCModel.
2027. | Slice Selective Adiabatic Pulse for Human 31P Cardiac Spectroscopy William T. Clarke1, Christopher T. Rodgers1, Stefan Neubauer1, and Matthew D. Robson1 1OCMR, University of Oxford, Oxford, United Kingdom 3D 31P chemical shift imaging (CSI) suffers from long scan times even at relatively low resolution. A slice selective adiabatic pulse (ASSESS) was implemented for 2D 31P CSI. The pulse is not affected by chemical shift, is B1 insensitive and produces an arbitrary flip angle. Simulations were used to choose optimal parameters and experimental setup. The pulse implementation was successfully demonstrated in phantoms. Short in vivo sequences were run on two volunteers at 3T. The spectra produced comparable SNR to the 3D method, all peaks expected were observed.
2028. | Real-Time Single-Voxel Water Proton Spectroscopy and Echo-Planar Imaging Sensitivity to the BOLD Effect at 3 and 7 T. Yury Koush1,2, Mark A. Elliott3, Frank Scharnowski1,2, and Klaus Mathiak4,5 1Department of Radiology and Medical Informatics - CIBM, University of Geneva, Geneva, Switzerland, 2Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 4Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany, 5Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, JARA - Translational Brain Medicine, Aachen, Germany It has been shown that spin-echo single-voxel proton spectroscopy (SVPS) can be used for spatially specific BOLD neurofeedback at 7 T. However, it is not clear how neurofeedback based on SVPS compares to the more commonly used gradient-echo echo-planar imaging (EPI) based neurofeedback. We showed that the data quality of real-time SVPS and EPI are comparable at 3 T. At 7 T, the real-time SVPS does not reach the quality of EPI and needs to be further improved. However, the 7 T spin-echo acquisition might target specifically microvascular contributions to the BOLD effect and benefit from increased spatial resolution.
2029. | Real-Time Motion Correction and B0 Shim Update for a Spectral Edited MEGA-LASER Sequence Ovidiu C. Andronesi1, Aaron T. Hess2, Matthew Dylan Tisdall1, Wolfgang Bogner1, André J. W. van der Kouwe1, and Bruce R. Rosen1 1Martinos Center, Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, United States, 2Centre for Clinical Magnetic Resonance, John Radcliffe Hospital, University of Oxford, Oxford, Oxford, United Kingdom J-difference spectral editing sequences such are necessary to detect important neurotransmitters and brain metabolites such as GABA, glutamate, 2-hydroxyglutarate, and glutathione which are otherwise obscured by more stronger signals. However, difference methods are susceptible to subtraction artifacts caused by subject movement, while the performance of narrow band MEGA pulses may be affected by drifts in the B0 field and shims. These challenges are likely to happen because editing requires long measurement times. Here we show that by acquiring in each TR an EPI volume navigator of the whole head prior to MEGA-LASER excitation we can perform real-time correction of motion in human subjects and update the shims and scanner frequency.
TRADITIONAL POSTER SESSION • MR SPECTROSCOPY Thursday, 25 April 2013 (10:30-12:30) Exhibition Hall
Methodology of Spectroscopic Quantitation
2030. | Enhancement of 2-Hydroxyglutarate Detectability by Triple-Refocusing Difference Editing at 3T in vivo Changho Choi1, Sandeep Ganji2, Akshay Madan1, Robert Bachoo1, Ralph DeBerardinis1, and Elizabeth A. Maher1 1University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2UT Southwestern Medical Center, Dallas, Texas, United States Given the great potential of 2HG as a biomarker in the diagnosis and management of glioma patients as well as the workup of an undiagnosed mass, the capability of precise detection of 2HG in vivo is extensively needed. In 1H-MRS, the 2HG signals are severely overlapped with other metabolite signals. Specifically, because of the close proximity of the 2HG 2.25 ppm resonance to the GABA 2.29 ppm resonance, when the 2HG levels are relatively low, 2HG estimation is elusive. Here we present 2HG measurements without considerable GABA contamination in patients in vivo, achieved by constant-TE triple-refocusing difference editing at 3T.
2031. | Accelerating 2D-JPRESS in the Human Brain with Compressed Sensing Trina Kok1, Navin Michael2, and Sendhil S. Velan1,3 1A*STAR-NUS Clinical Imaging Research Center, Singapore, Singapore, 2Singapore Institute for Clinical Sciences, Singapore, Singapore, 3Singapore Bioimaging Consortium, Singapore, Singapore Detection of metabolite signals are often hampered by spectral overlap arising from J-coupling effects. Existing techniques for improved separation include 2D spectroscopy methods such as 2DPRESS, which carries a penalty in scan-time and is often prohibitive when combined with spectroscopic imaging. In this work, we apply compressed sensing to a randomly under-sampled data set, collecting 30 t1 increments of the original 100 t1 increments. The reconstructed 2D spectrum is subsequently fitted with ProFit and we show that metabolites were recovered with reasonable CRLB values, with 30% of the original data.
2032. | Extraction of Glutamate from the GABA Edited Spectra Jan Willem C. van der Veen1, Ron de Beer2, Dirk van Ormondt2, and Jun Shen1 1Magnetic Resonance Spectroscopy Core, NIH, NIMH, Bethesda, Maryland, United States, 2Department of Applied Physics, TU Delft, Delft, Netherlands It is desirable to simultaneously measure glutamate and GABA in many clinical studies. Here we used full density matrix simulation to investigate the effects of GABA editing on the J evolution of glutamate, glutamine and NAA at 3 Tesla. It was found the editing pulse and spectra subtraction significantly reduced overlap of glutamate by glutamine and NAA, making it possible to extract glutamate using linear combination spectral fitting of the edited GABA spectra.
2033. | Partial Volume Correction Method for Improving Test-Retest Repeatability of In Vivo Human Brain 1H MRS and Quantification of Neurochemical Concentrations at 7T Byeong-Yeul Lee1, Xiao-Hong Zhu1, Wei Chen1, and Melissa Terpstra1 1Center for Magnetic Resonance Research (CMRR), Radiology Department, University of Minnesota, Minneapolis, MN, United States Human brain ultra-high field (7T) scanners are increasingly available in clinical settings and advantageous for sensitivity and specificity. Accurate quantification of metabolite concentrations from 1H MRS requires appropriate partial volume correction, especially when studying treatment effect or pathologies that alter brain morphometry. We developed a tissue segmentation method that remained reliable in the presence of inhomogeneous B1, which is typically encountered at ultra-high field. Utilization of T1/PD ratio images improved histogram based classification of tissue types. Using this approach to correct for partial volume effects, test-retest repeatability of metabolite concentrations quantified from single voxel in vivo 1H-MRS was improved.
2034. | Investigation of Techniques for Multi Element Coil Combination for 32 Channel 7T MRS Emma Louise Hall1, Mary C. Stephenson1, Darren Price1, and Peter G. Morris1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingam, Nottinghamshire, United Kingdom In magnetic resonance spectroscopy (MRS), the acquisition of data from multi-element receive coils is becoming common. As the number of coil elements increases the need arises for robust reconstruction methods. Here we compare three methods based on signal or signal and noise weighting. We demonstrate this on for proton MRS data acquired using a 32 channel receive coil at 7 Tesla acquired in different brain regions. We find that the visual cortex benefitted the most, whereas medial prefrontal cortex was relatively unaffected.
2035. | High-Resolution Localized 2D J-Resolved Spectroscopy Via Intermolecular Single-Quantum Coherences Yuqing Huang1, Zhiyong Zhang1, Shuhui Cai1, and Zhong Chen1 1Department of Electronic Science, Xiamen University, Xiamen, Fujian, China Localized 2D J-resolved spectroscopy can separate chemical shifts and J couplings into two different dimensions. It is widely used for the detection of metabolites in biological tissues, even in in vivo study. However, due to the intrinsic magnetic susceptibility in biological tissues, the localized 2D J-resolved spectrum is usually suffered from field inhomogeneity. In this report, a new pulse sequence based on intermolecular single-quantum coherences is presented to obtain localized 2D J-resolved spectrum in inhomogeneous fields, which is potentially useful for studying biological metabolites.
2036. | Removal of Lipid Nuisance Signals in MRSI Using a Spatial-Spectral Lipid Model Chao Ma1,2, Fan Lam1,2, Ryan Larsen2, Bradley P. Sutton2,3, and Zhi-Pei Liang1,2 1Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States Nuisance lipid signals from the subcutaneous lipid layer of the brain often cause significant difficulties for spectral quantification of the brain metabolites. Removal of the lipid signals in brain MRSI is desirable but challenging because they appear as multiple-peak, broad spectra that overlap with the spectra of important brain metabolites (e.g., lactate and NAA). In this work, we introduce a model-based post-processing method for effective removal of the lipid signals.
2037. | An Alternate Strategy for the Quantification of the in Vivo Glutamate/Glutamine (Glx) Peak at 2.35 Ppm Ravi Prakash Reddy Nanga1, Hari Hariharan1, and Ravinder Reddy1 1Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States Quantification of in vivo Glutamate/Glutamine (Glx) peak at 2.35 ppm from 1H MRS is contaminated with NAA, lipids, macromolecule and with Glx peak at 2.13 ppm. This contamination introduces a challenge in Glx quantification. Here, we propose and demonstrate an alternate strategy to quantify the Glx at 2.35 ppm with high reproducibility, in vivo.
2038. | Localization Profile Correction for ERETIC Based in Vivo 1H MRSI Quantification Niklaus Zoelch1, Alexander Fuchs1, and Anke Henning2,3 1Institue for Biomedical Engineering, UZH and ETH Zurich, Zurich, Switzerland, 2Institue for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 3Max Planck Institue for Biological Cybernetics, Tübingen, Germany ERETIC is a calibration method independent of the disease state, automatically compensates for changes in coil loading conditions and hence requires only a one time calibration against a high precision phantom. However, when ERETIC is used for the quantification of MRSI images, the combined effect of B1+ inhomogeneity across the volume of interest and slice profiles of the selective RF pulses used for localization need to be corrected for. In this work two approaches of this correction are presented and validated against internal water referencing.
2039. | in vivo Transverse Relaxation Time Measurements from Localized CT-COSY and JPRESS: A Validation Study Dimitri Martel1, Tangi Roussel1, Denis Friboulet1, Denis Grenier1, and Helene Ratiney1 1CREATIS ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Lyon 1, Villeurbanne, France Transverse relaxation time parameters (T2 and T2inh due to field inhomogeneity) of the three main singlets of NAA, Creatine and Choline in the rat hippocampus were measured at 7T using two 2D MRS sequences (Localized CT-COSY and JPRESS). Estimated T2inh with this approach compared with its direct measurements using a B0 field map show good agreement. T2 found by this method show lower values than expected. Diffusion loss due to the Hahn echo type of the sequences used is suspected.
2040. | Clinical MRS Data Processing Using KBDM Fernando Fernandes Paiva1, Alberto Tannus1, and Claudio Jose Magon1 1Institute of Physics of Sao Carlos, University of Sao Paulo, Sao Carlos, SP, Brazil KBDM is a parametric non-linear method that can be applied for fitting and spectral analysis of experimentally measured transient time signals and is a promising tool that can provide complimentary information to the well-established FT techniques. In the present study we investigate the feasibility of clinical MRS data processing using KBDM, with special attention to important issues such as signal-to-noise ratio and baseline distortions. The accuracy of the method for spectral analysis for both simulated and in vivo data is reported.
2041. | Gannet: GABA Analysis Toolkit for Edited MRS Richard Anthony Edward Edden1,2, Nicolaas A. J. Puts2,3, Peter B. Barker1,2, and C. John Evans4 1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 2F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States, 3Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom Gannet
2042. | Simultaneous Detection of 17 Brain Metabolites at 3T by JPRESS & ProFit Alexander Fuchs1, Peter Boesiger1, and Anke Henning1,2 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Zurich, Switzerland, 2Max Plank Institute for Biological Cybernetics, Tübingen, Germany In-vivo data acquired at 3T and simulated 2D JRPESS spectra were used to test and validate the new version of the ProFit fitting tool. The results indicate the potential to reliable fit up to 17 brain metabolites with CRLBs below 20%.
2043. | Maximum Entropy Reconstruction of Non-Uniformly Under-Sampled Multidimensional Spectroscopic Imaging in vivo Brian L. Burns1, Neil Wilson2, and M. Albert Thomas2,3 1Department of Biomedical Engineering, UCLA, Los Angeles, CA, United States, 2Biomedical Physics IDP, UCLA, Los Angeles, CA, United States, 3Radiology, UCLA, Los Angeles, CA, United States This work accelerates the acquisition of 4D MRSI data (2 spectral x 2 spatial) by under-sampling a spatial and a spectral dimension and reconstructing the missing data using Maximum Entropy (MaxEnt) non-linear reconstruction. Our results show that non-uniform under-sampling combined with MaxEnt is a viable way to reduce the scan times required of 4D MRSI to a clinically acceptable 6 minutes.