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Zhu M, Jhajharia A, Josan S, Park JM, Yen YF, Pfefferbaum A, Hurd RE, Spielman DM, Mayer D. Investigating the origin of the 13 C lactate signal in the anesthetized healthy rat brain in vivo after hyperpolarized [1- 13 C]pyruvate injection. NMR Biomed 2024; 37:e5073. [PMID: 37990800 DOI: 10.1002/nbm.5073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 11/23/2023]
Abstract
The goal of this study was to investigate the origin of brain lactate (Lac) signal in the healthy anesthetized rat after injection of hyperpolarized (HP) [1-13 C]pyruvate (Pyr). Dynamic two-dimensional spiral chemical shift imaging with flow-sensitizing gradients revealed reduction in both vascular and brain Pyr, while no significant dependence on the level of flow suppression was detected for Lac. These results support the hypothesis that the HP metabolites predominantly reside in different compartments in the brain (i.e., Pyr in the blood and Lac in the parenchyma). Data from high-resolution metabolic imaging of [1-13 C]Pyr further demonstrated that Lac detected in the brain was not from contributions of vascular signal attributable to partial volume effects. Additionally, metabolite distributions and kinetics measured with dynamic imaging after injection of HP [1-13 C]Lac were similar to Pyr data when Pyr was used as the substrate. These data do not support the hypothesis that Lac observed in the brain after Pyr injection was generated in other organs and then transported across the blood-brain barrier (BBB). Together, the presented results provide further evidence that even in healthy anesthetized rats, the transport of HP Pyr across the BBB is sufficiently fast to permit detection of its metabolic conversion to Lac within the brain.
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Affiliation(s)
- Minjie Zhu
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Aditya Jhajharia
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sonal Josan
- Digital Health, Siemens Healthineers, Erlangen, Germany
| | - Jae Mo Park
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Biomedical Engineering, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yi-Fen Yen
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Adolf Pfefferbaum
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Ralph E Hurd
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Dirk Mayer
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
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2
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Adamson PM, Datta K, Watkins R, Recht LD, Hurd RE, Spielman DM. Deuterium metabolic imaging for 3D mapping of glucose metabolism in humans with central nervous system lesions at 3T. Magn Reson Med 2024; 91:39-50. [PMID: 37796151 PMCID: PMC10841984 DOI: 10.1002/mrm.29830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/19/2023] [Accepted: 07/28/2023] [Indexed: 10/06/2023]
Abstract
PURPOSE To explore the potential of 3T deuterium metabolic imaging (DMI) using a birdcage 2 H radiofrequency (RF) coil in both healthy volunteers and patients with central nervous system (CNS) lesions. METHODS A modified gradient filter, home-built 2 H volume RF coil, and spherical k-space sampling were employed in a three-dimensional chemical shift imaging acquisition to obtain high-quality whole-brain metabolic images of 2 H-labeled water and glucose metabolic products. These images were acquired in a healthy volunteer and three subjects with CNS lesions of varying pathologies. Hardware and pulse sequence experiments were also conducted to improve the signal-to-noise ratio of DMI at 3T. RESULTS The ability to quantify local glucose metabolism in correspondence to anatomical landmarks across patients with varying CNS lesions is demonstrated, and increased lactate is observed in one patient with the most active disease. CONCLUSION DMI offers the potential to examine metabolic activity in human subjects with CNS lesions with DMI at 3T, promising for the potential of the future clinical translation of this metabolic imaging technique.
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Affiliation(s)
- Philip M. Adamson
- Department of Electrical Engineering, Stanford University, Stanford, California USA
| | - Keshav Datta
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Ron Watkins
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Lawrence D. Recht
- Department of Neurology, Stanford University, Stanford, California, USA
| | - Ralph E. Hurd
- Department of Radiology, Stanford University, Stanford, California, USA
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Spielman DM, Gu M, Hurd RE, Riemer RK, Okamura K, Hanley FL. Proton magnetic resonance spectroscopy assessment of neonatal brain metabolism during cardiopulmonary bypass surgery. NMR Biomed 2022; 35:e4752. [PMID: 35483967 PMCID: PMC9484292 DOI: 10.1002/nbm.4752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
Here, we report on the development and performance of a robust 3-T single-voxel proton magnetic resonance spectroscopy (1 H MRS) experimental protocol and data analysis pipeline for quantifying brain metabolism during cardiopulmonary bypass (CPB) surgery in a neonatal porcine model, with the overall goal of elucidating primary mechanisms of brain injury associated with these procedures. The specific aims were to assess which metabolic processes can be reliably interrogated by 1 H MRS on a 3-T clinical scanner and to provide an initial assessment of brain metabolism during deep hypothermia cardiac arrest (DHCA) surgery and recovery. Fourteen neonatal pigs underwent CPB surgery while placed in a 3-T MRI scanner for 18, 28, and 37°C DHCA studies under hyperglycemic, euglycemic, and hypoglycemic conditions. Total imaging times, including baseline measurements, circulatory arrest (CA), and recovery averaged 3 h/animal, during which 30-40 single-voxel 1 H MRS spectra (sLASER pulse sequence, TR/TE = 2000/30 ms, 64 or 128 averages) were acquired from a 2.2-cc right midbrain voxel. 1 H MRS at 3 T was able to reliably quantify (1) anaerobic metabolism via depletion of brain glucose and the associated build-up of lactate during CA, (2) phosphocreatine (PCr) to creatine (Cr) conversion during CA and subsequent recovery upon reperfusion, (3) a robust increase in the glutamine-to-glutamate (Gln/Glu) ratio during the post-CA recovery period, and (4) a broadening of the water peak during CA. In vivo 1 H MRS at 3 T can reliably quantify subtle metabolic brain changes previously deemed challenging to interrogate, including brain glucose concentrations even under hypoglycemic conditions, ATP usage via the conversion of PCr to Cr, and differential changes in Glu and Gln. Observed metabolic changes during CPB surgery of a neonatal porcine model provide new insights into possible mechanisms for prevention of neuronal injury.
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Affiliation(s)
- Daniel M. Spielman
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Meng Gu
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - Ralph E. Hurd
- Department of Radiology, Stanford University School of Medicine, Stanford, California, USA
| | - R. Kirk Riemer
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Kenichi Okamura
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Frank L. Hanley
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA
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4
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Park JM, Josan S, Hurd RE, Graham J, Havel PJ, Bendahan D, Mayer D, Chung Y, Spielman DM, Jue T. Hyperpolarized NMR study of the impact of pyruvate dehydrogenase kinase inhibition on the pyruvate dehydrogenase and TCA flux in type 2 diabetic rat muscle. Pflugers Arch 2021; 473:1761-1773. [PMID: 34415396 DOI: 10.1007/s00424-021-02613-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 01/06/2023]
Abstract
The role of pyruvate dehydrogenase in mediating lipid-induced insulin resistance stands as a central question in the pathogenesis of type 2 diabetes mellitus. Many researchers have invoked the Randle hypothesis to explain the reduced glucose disposal in skeletal muscle by envisioning an elevated acetyl CoA pool arising from increased oxidation of fatty acids. Over the years, in vivo NMR studies have challenged that monolithic view. The advent of the dissolution dynamic nuclear polarization NMR technique and a unique type 2 diabetic rat model provides an opportunity to clarify. Dynamic nuclear polarization enhances dramatically the NMR signal sensitivity and allows the measurement of metabolic kinetics in vivo. Diabetic muscle has much lower pyruvate dehydrogenase activity than control muscle, as evidenced in the conversion of [1-13C]lactate and [2-13C]pyruvate to HCO3- and acetyl carnitine. The pyruvate dehydrogenase kinase inhibitor, dichloroacetate, restores rapidly the diabetic pyruvate dehydrogenase activity to control level. However, diabetic muscle has a much larger dynamic change in pyruvate dehydrogenase flux than control. The dichloroacetate-induced surge in pyruvate dehydrogenase activity produces a differential amount of acetyl carnitine but does not affect the tricarboxylic acid flux. Further studies can now proceed with the dynamic nuclear polarization approach and a unique rat model to interrogate closely the biochemical mechanism interfacing oxidative metabolism with insulin resistance and metabolic inflexibility.
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Affiliation(s)
- Jae Mo Park
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.,Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, CA, 94305, USA
| | - Sonal Josan
- Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, CA, 94305, USA.,Neuroscience Program, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - Ralph E Hurd
- Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, CA, 94305, USA.,Applied Science Laboratory, GE Healthcare, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA
| | - James Graham
- Department of Molecular Biosciences, University of California Davis, 3426 Meyer Hall, Davis, CA, 95616, USA
| | - Peter J Havel
- Department of Molecular Biosciences, University of California Davis, 3426 Meyer Hall, Davis, CA, 95616, USA
| | - David Bendahan
- CNRS, Aix-Marseille University, CRMBM, 13385, Marseille, France
| | - Dirk Mayer
- Neuroscience Program, SRI International, 333 Ravenswood Ave., Menlo Park, CA, 94025, USA.,Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, 22 S. Green St., Baltimore, MD, 21201, USA
| | - Youngran Chung
- Department of Biochemistry and Molecular Medicine, University of California-Davis, 4323 Tupper Hall, Davis, CA, 95616, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, CA, 94305, USA
| | - Thomas Jue
- Department of Biochemistry and Molecular Medicine, University of California-Davis, 4323 Tupper Hall, Davis, CA, 95616, USA.
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Tkáč I, Deelchand D, Dreher W, Hetherington H, Kreis R, Kumaragamage C, Považan M, Spielman DM, Strasser B, de Graaf RA. Water and lipid suppression techniques for advanced 1 H MRS and MRSI of the human brain: Experts' consensus recommendations. NMR Biomed 2021; 34:e4459. [PMID: 33327042 PMCID: PMC8569948 DOI: 10.1002/nbm.4459] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 11/23/2020] [Indexed: 05/09/2023]
Abstract
The neurochemical information provided by proton magnetic resonance spectroscopy (MRS) or MR spectroscopic imaging (MRSI) can be severely compromised if strong signals originating from brain water and extracranial lipids are not properly suppressed. The authors of this paper present an overview of advanced water/lipid-suppression techniques and describe their advantages and disadvantages. Moreover, they provide recommendations for choosing the most appropriate techniques for proper use. Methods of water signal handling are primarily focused on the VAPOR technique and on MRS without water suppression (metabolite cycling). The section on lipid-suppression methods in MRSI is divided into three parts. First, lipid-suppression techniques that can be implemented on most clinical MR scanners (volume preselection, outer-volume suppression, selective lipid suppression) are described. Second, lipid-suppression techniques utilizing the combination of k-space filtering, high spatial resolutions and lipid regularization are presented. Finally, three promising new lipid-suppression techniques, which require special hardware (a multi-channel transmit system for dynamic B1+ shimming, a dedicated second-order gradient system or an outer volume crusher coil) are introduced.
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Affiliation(s)
- Ivan Tkáč
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Dinesh Deelchand
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - Wolfgang Dreher
- Department of Chemistry, In vivo-MR Group, University Bremen, Bremen, Germany
| | - Hoby Hetherington
- Department of Radiology Magnetic Resonance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Roland Kreis
- Departments of Radiology and Biomedical Research, University Bern, Bern, Switzerland
| | - Chathura Kumaragamage
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT, USA
| | - Michal Považan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel M. Spielman
- Department of Radiology, Stanford University, Stanford, California, CA, USA
| | - Bernhard Strasser
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Boston, MA, USA
| | - Robin A. de Graaf
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT, USA
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6
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Ho TC, Teresi GI, Segarra JR, Ojha A, Walker JC, Gu M, Spielman DM, Sacchet MD, Jiang F, Rosenberg-Hasson Y, Maecker H, Gotlib IH. Higher Levels of Pro-inflammatory Cytokines Are Associated With Higher Levels of Glutamate in the Anterior Cingulate Cortex in Depressed Adolescents. Front Psychiatry 2021; 12:642976. [PMID: 33935833 PMCID: PMC8081972 DOI: 10.3389/fpsyt.2021.642976] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/26/2021] [Indexed: 12/14/2022] Open
Abstract
Animal models of stress and related conditions, including depression, have shown that elevated peripheral levels of inflammatory cytokines have downstream consequences on glutamate (Glu) in the brain. Although studies in human adults with depression have reported evidence of higher inflammation but lower Glu in the anterior cingulate cortex (ACC), the extent to which peripheral inflammation contributes to glutamatergic abnormalities in adolescents with depression is not well-understood. It is also unclear whether antioxidants, such as ascorbate (Asc), may buffer against the effects of inflammation on Glu metabolism. Fifty-five depressed adolescents were recruited in the present cross-sectional study and provided blood samples, from which we assayed pro-inflammatory cytokines, and underwent a short-TE proton magnetic spectroscopy scan at 3T, from which we estimated Glu and Asc in the dorsal ACC. In the 31 adolescents with usable cytokine and Glu data, we found that IL-6 was significantly positively associated with dorsal ACC Glu (β = 0.466 ± 0.199, p = 0.029). Of the 16 participants who had usable Asc data, we found that at higher levels of dorsal ACC Asc, there was a negative association between IL-6 and Glu (interaction effect: β = -0.906 ± 0.433, p = 0.034). Importantly, these results remained significant when controlling for age, gender, percentage of gray matter in the dorsal ACC voxel, BMI, and medication (antidepressant and anti-inflammatory) usage. While preliminary, our results underscore the importance of examining both immune and neural contributors to depression and highlight the potential role of anti-inflammatory compounds in mitigating the adverse effects of inflammation (e.g., glutamatergic neuroexcitotoxicity). Future studies that experimentally manipulate levels of inflammation, and of ascorbate, and that characterize these effects on cortical glutamate concentrations and subsequent behavior in animals and in humans are needed.
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Affiliation(s)
- Tiffany C Ho
- Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
| | - Giana I Teresi
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Jillian R Segarra
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Amar Ojha
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
| | - Johanna C Walker
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Meng Gu
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Daniel M Spielman
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Matthew D Sacchet
- Center for Depression, Anxiety, and Stress Research, McLean Hospital and Harvard Medical School, Belmont, MA, United States
| | - Fei Jiang
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States
| | - Yael Rosenberg-Hasson
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Holden Maecker
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Ian H Gotlib
- Department of Psychology, Stanford University, Stanford, CA, United States
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7
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Reyes ST, Mohajeri S, Krasinska K, Guo SG, Gu M, Pisani L, Rosenberg J, Spielman DM, Chin FT. GABA Measurement in a Neonatal Fragile X Syndrome Mouse Model Using 1H-Magnetic Resonance Spectroscopy and Mass Spectrometry. Front Mol Neurosci 2020; 13:612685. [PMID: 33390902 PMCID: PMC7775297 DOI: 10.3389/fnmol.2020.612685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/20/2020] [Indexed: 11/20/2022] Open
Abstract
Fragile X syndrome (FXS) is the leading monogenetic cause of autism spectrum disorder and inherited cause of intellectual disability that affects approximately one in 7,000 males and one in 11,000 females. In FXS, the Fmr1 gene is silenced and prevents the expression of the fragile X mental retardation protein (FMRP) that directly targets mRNA transcripts of multiple GABAA subunits. Therefore, FMRP loss adversely impacts the neuronal firing of the GABAergic system which creates an imbalance in the excitatory/inhibitory ratio within the brain. Current FXS treatment strategies focus on curing symptoms, such as anxiety or decreased social function. While treating symptoms can be helpful, incorporating non-invasive imaging to evaluate how treatments change the brain's biology may explain what molecular aberrations are associated with disease pathology. Thus, the GABAergic system is suitable to explore developing novel therapeutic strategies for FXS. To understand how the GABAergic system may be affected by this loss-of-function mutation, GABA concentrations were examined within the frontal cortex and thalamus of 5-day-old wild type and Fmr1 knockout mice using both 1H magnetic resonance imaging (1H-MRS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Our objective was to develop a reliable scanning method for neonatal mice in vivo and evaluate whether 1H-MRS is suitable to capture regional GABA concentration differences at the front end of the critical cortical period where abnormal neurodevelopment occurs due to FMRP loss is first detected. 1H-MRS quantified GABA concentrations in both frontal cortex and thalamus of wild type and Fmr1 knockout mice. To substantiate the results of our 1H-MRS studies, in vitro LC-MS/MS was also performed on brain homogenates from age-matched mice. We found significant changes in GABA concentration between the frontal cortex and thalamus within each mouse from both wild type and Fmr1 knockout mice using 1H-MRS and LC-MS/MS. Significant GABA levels were also detected in these same regions between wild type and Fmr1 knockout mice by LC-MS/MS, validating that FMRP loss directly affects the GABAergic system. Thus, these new findings support the need to develop an effective non-invasive imaging method to monitor novel GABAergic strategies aimed at treating patients with FXS.
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Affiliation(s)
- Samantha T. Reyes
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Sanaz Mohajeri
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Karolina Krasinska
- Stanford University Mass Spectrometry Laboratory, Stanford University, Stanford, CA, United States
| | - Scarlett G. Guo
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Meng Gu
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Laura Pisani
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Jarrett Rosenberg
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Daniel M. Spielman
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Frederick T. Chin
- Department of Radiology, Stanford University, Stanford, CA, United States
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8
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Walker JC, Teresi GI, Weisenburger RL, Segarra JR, Ojha A, Kulla A, Sisk L, Gu M, Spielman DM, Rosenberg-Hasson Y, Maecker HT, Singh MK, Gotlib IH, Ho TC. Study Protocol for Teen Inflammation Glutamate Emotion Research (TIGER). Front Hum Neurosci 2020; 14:585512. [PMID: 33192421 PMCID: PMC7604389 DOI: 10.3389/fnhum.2020.585512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/03/2020] [Indexed: 12/19/2022] Open
Abstract
This article provides an overview of the study protocol for the Teen Inflammation Glutamate Emotion Research (TIGER) project, a longitudinal study in which we plan to recruit 60 depressed adolescents (ages 13–18 years) and 30 psychiatrically healthy controls in order to examine the inflammatory and glutamatergic pathways that contribute to the recurrence of depression in adolescents. TIGER is the first study to examine the effects of peripheral inflammation on neurodevelopmental trajectories by assessing changes in cortical glutamate in depressed adolescents. Here, we describe the scientific rationale, design, and methods for the TIGER project. This article is intended to serve as an introduction to this project and to provide details for investigators who may be seeking to replicate or extend these methods for other related research endeavors.
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Affiliation(s)
- Johanna C Walker
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Giana I Teresi
- Department of Psychology, Stanford University, Stanford, CA, United States
| | | | - Jillian R Segarra
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Amar Ojha
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
| | - Artenisa Kulla
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Lucinda Sisk
- Department of Psychology, Yale University, New Haven, CT, United States
| | - Meng Gu
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Daniel M Spielman
- Department of Radiology, Stanford University, Stanford, CA, United States.,Department of Electrical Engineering, Stanford University, Stanford, CA, United States
| | - Yael Rosenberg-Hasson
- Human Immune Monitoring Center, Stanford University, Stanford, CA, United States.,Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Holden T Maecker
- Human Immune Monitoring Center, Stanford University, Stanford, CA, United States.,Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Manpreet K Singh
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Ian H Gotlib
- Department of Psychology, Stanford University, Stanford, CA, United States
| | - Tiffany C Ho
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States.,Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA, United States
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9
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Datta K, Lauritzen MH, Merchant M, Jang T, Liu SC, Hurd R, Recht L, Spielman DM. Reversed metabolic reprogramming as a measure of cancer treatment efficacy in rat C6 glioma model. PLoS One 2019; 14:e0225313. [PMID: 31830049 PMCID: PMC6907781 DOI: 10.1371/journal.pone.0225313] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 11/01/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Metabolism in tumor shifts from oxidative phosphorylation to inefficient glycolysis resulting in overproduction of lactate (Warburg effect), and cancers may be effectively treated if this imbalance were corrected. The aim of this longitudinal study of glioblastoma in a rat model was to determine whether the ratio of lactate (surrogate marker for glycolysis) to bicarbonate (for oxidative phosphorylation), as measured via in vivo magnetic resonance imaging of hyperpolarized 13C-labeled pyruvate accurately predicts survival. METHODS C6 Glioma implanted male Wistar rats (N = 26) were treated with an anti-vascular endothelial growth factor antibody B20.4.1.1 in a preliminary study to assess the efficacy of the drug. In a subsequent longitudinal survival study, magnetic resonance spectroscopic imaging (MRSI) was used to estimate [1-13C]Lactate and [1-13C]Bicarbonate in tumor and contralateral normal appearing brain of glioma implanted rats (N = 13) after injection of hyperpolarized [1-13C]Pyruvate at baseline and 48 hours post-treatment with B20.4.1.1. RESULTS A survival of ~25% of B20.4.1.1 treated rats was noted in the preliminary study. In the longitudinal imaging experiment, changes in 13C Lactate, 13C Bicarbonate and tumor size measured at baseline and 48 hours post-treatment did not correlate with survival. 13C Lactate to 13C Bicarbonate ratio increased in all the 6 animals that succumbed to the tumor whereas the ratio decreased in 6 of the 7 animals that survived past the 70-day observation period. CONCLUSIONS 13C Lactate to 13C Bicarbonate ratio (Lac/Bic) at 48 hours post-treatment is highly predictive of survival (p = 0.003). These results suggest a potential role for the 13C Lac/Bic ratio serving as a valuable measure of tumor metabolism and predicting therapeutic response.
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Affiliation(s)
- Keshav Datta
- Department of Electrical Engineering, Stanford University, Stanford, California, United States of America
- Department of Radiology, Stanford University, Stanford, California, United States of America
- * E-mail:
| | - Mette H. Lauritzen
- Department of Radiology, Stanford University, Stanford, California, United States of America
| | - Milton Merchant
- Department of Neurology, Stanford University, Stanford, California, United States of America
| | - Taichang Jang
- Department of Neurology, Stanford University, Stanford, California, United States of America
| | - Shie-Chau Liu
- Department of Radiology, Stanford University, Stanford, California, United States of America
| | - Ralph Hurd
- Department of Radiology, Stanford University, Stanford, California, United States of America
| | - Lawrence Recht
- Department of Neurology, Stanford University, Stanford, California, United States of America
| | - Daniel M. Spielman
- Department of Electrical Engineering, Stanford University, Stanford, California, United States of America
- Department of Radiology, Stanford University, Stanford, California, United States of America
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10
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Girgis RR, Baker S, Mao X, Gil R, Javitt DC, Kantrowitz JT, Gu M, Spielman DM, Ojeil N, Xu X, Abi-Dargham A, Shungu DC, Kegeles LS. Effects of acute N-acetylcysteine challenge on cortical glutathione and glutamate in schizophrenia: A pilot in vivo proton magnetic resonance spectroscopy study. Psychiatry Res 2019; 275:78-85. [PMID: 30884334 PMCID: PMC6515541 DOI: 10.1016/j.psychres.2019.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/11/2019] [Accepted: 03/11/2019] [Indexed: 12/11/2022]
Abstract
Findings from in vivo brain proton magnetic resonance spectroscopy (1H MRS) and preclinical studies have suggested region- and medication status-dependent increases in glutamate (Glu) levels and deficiencies in glutathione (GSH) levels in schizophrenia. N-acetylcysteine (NAC), a GSH synthesis precursor, has demonstrated modest clinical benefit in schizophrenia. The objective of this study was to examine the effects of acute administration of NAC on GSH and Glu levels measured with 1H MRS in 19 patients with schizophrenia and 20 healthy control subjects. Levels of GSH were acquired in dorsal anterior cingulate cortex (dACC), and those of Glu in dACC and medial prefrontal cortex (mPFC), at baseline and 60 min following acute oral administration of 2400 mg of NAC. No differences in the levels of GSH or Glu were found at baseline or following NAC administration between patients with schizophrenia and control subjects in either of the targeted brain regions. Future studies measuring GSH levels in brain regions previously found to exhibit glutamatergic abnormalities or using genetic polymorphisms, while controlling for the age and medication status of the cohorts, are warranted to better identify groups of patients more likely to respond to NAC and its mode of action and mechanisms.
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Affiliation(s)
- Ragy R Girgis
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA.
| | - Seth Baker
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA
| | - Xiangling Mao
- Department of Radiology, Weill Cornell Medical College, New York, USA
| | - Roberto Gil
- Department of Psychiatry, Stony Brook University School of Medicine, Stony Brook, USA
| | - Daniel C Javitt
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA
| | - Joshua T Kantrowitz
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA
| | - Meng Gu
- Department of Radiology, Stanford University, Stanford, CA, USA
| | | | - Najate Ojeil
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA
| | - Xiaoyan Xu
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA
| | - Anissa Abi-Dargham
- Department of Psychiatry, Stony Brook University School of Medicine, Stony Brook, USA
| | - Dikoma C Shungu
- Department of Radiology, Weill Cornell Medical College, New York, USA
| | - Lawrence S Kegeles
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York State Psychiatric Institute, 1051 Riverside Drive, Unit 31, New York, NY 10032, USA
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11
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Bachawal SV, Park JM, Valluru KS, Loft MD, Felt SA, Vilches-Moure JG, Saenz YF, Daniel B, Iagaru A, Sonn G, Cheng Z, Spielman DM, Willmann JK. Multimodality Hyperpolarized C-13 MRS/PET/Multiparametric MR Imaging for Detection and Image-Guided Biopsy of Prostate Cancer: First Experience in a Canine Prostate Cancer Model. Mol Imaging Biol 2019; 21:861-870. [DOI: 10.1007/s11307-018-1235-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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12
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Kurhanewicz J, Vigneron DB, Ardenkjaer-Larsen JH, Bankson JA, Brindle K, Cunningham CH, Gallagher FA, Keshari KR, Kjaer A, Laustsen C, Mankoff DA, Merritt ME, Nelson SJ, Pauly JM, Lee P, Ronen S, Tyler DJ, Rajan SS, Spielman DM, Wald L, Zhang X, Malloy CR, Rizi R. Hyperpolarized 13C MRI: Path to Clinical Translation in Oncology. Neoplasia 2019; 21:1-16. [PMID: 30472500 PMCID: PMC6260457 DOI: 10.1016/j.neo.2018.09.006] [Citation(s) in RCA: 276] [Impact Index Per Article: 55.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/27/2018] [Accepted: 09/27/2018] [Indexed: 12/22/2022]
Abstract
This white paper discusses prospects for advancing hyperpolarization technology to better understand cancer metabolism, identify current obstacles to HP (hyperpolarized) 13C magnetic resonance imaging's (MRI's) widespread clinical use, and provide recommendations for overcoming them. Since the publication of the first NIH white paper on hyperpolarized 13C MRI in 2011, preclinical studies involving [1-13C]pyruvate as well a number of other 13C labeled metabolic substrates have demonstrated this technology's capacity to provide unique metabolic information. A dose-ranging study of HP [1-13C]pyruvate in patients with prostate cancer established safety and feasibility of this technique. Additional studies are ongoing in prostate, brain, breast, liver, cervical, and ovarian cancer. Technology for generating and delivering hyperpolarized agents has evolved, and new MR data acquisition sequences and improved MRI hardware have been developed. It will be important to continue investigation and development of existing and new probes in animal models. Improved polarization technology, efficient radiofrequency coils, and reliable pulse sequences are all important objectives to enable exploration of the technology in healthy control subjects and patient populations. It will be critical to determine how HP 13C MRI might fill existing needs in current clinical research and practice, and complement existing metabolic imaging modalities. Financial sponsorship and integration of academia, industry, and government efforts will be important factors in translating the technology for clinical research in oncology. This white paper is intended to provide recommendations with this goal in mind.
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Affiliation(s)
- John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | | | - James A Bankson
- Department of Imaging Physics, MD Anderson Medical Center, Houston, TX, USA
| | - Kevin Brindle
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | | | - Kayvan R Keshari
- Department of Radiology, Memorial Sloan Kettering Cancer Center, NY, New York, USA
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Denmark
| | | | - David A Mankoff
- Department of Radiology, University of Pennsylvania, PA, USA
| | - Matthew E Merritt
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Sarah J Nelson
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - John M Pauly
- Department of Electric Engineering, Stanford University, USA
| | - Philips Lee
- Functional Metabolism Group, Singapore Biomedical Consortium, Agency for Science, Technology and Research, Singapore
| | - Sabrina Ronen
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - Damian J Tyler
- Department of Biomedical Science, University of Oxford, Oxford, UK
| | - Sunder S Rajan
- Center for Devices and Radiological Health (CDRH), FDA, White Oak, MD, USA
| | - Daniel M Spielman
- Departments of Radiology and Electric Engineering, Stanford University, USA
| | - Lawrence Wald
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Xiaoliang Zhang
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - Craig R Malloy
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rahim Rizi
- Department of Radiology, University of Pennsylvania, PA, USA
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13
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Hegarty JP, Gu M, Spielman DM, Cleveland SC, Hallmayer JF, Lazzeroni LC, Raman MM, Frazier TW, Phillips JM, Reiss AL, Hardan AY. A proton MR spectroscopy study of the thalamus in twins with autism spectrum disorder. Prog Neuropsychopharmacol Biol Psychiatry 2018; 81:153-160. [PMID: 28941767 PMCID: PMC5731458 DOI: 10.1016/j.pnpbp.2017.09.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/17/2017] [Accepted: 09/18/2017] [Indexed: 01/16/2023]
Abstract
Multiple lines of research have reported thalamic abnormalities in individuals with autism spectrum disorder (ASD) that are associated with social communication impairments (SCI), restricted and repetitive behaviors (RRB), or sensory processing abnormalities (SPA). Thus, the thalamus may represent a common neurobiological structure that is shared across symptom domains in ASD. Same-sex monozygotic (MZ) and dizygotic (DZ) twin pairs with and without ASD underwent cognitive/behavioral evaluation and magnetic resonance imaging to assess the thalamus. Neurometabolites were measured with 1H magnetic resonance spectroscopy (MRS) utilizing a multi-voxel PRESS sequence and were referenced to creatine+phosphocreatine (tCr). N-acetyl aspartate (NAA), a marker of neuronal integrity, was reduced in twins with ASD (n=47) compared to typically-developing (TD) controls (n=33), and this finding was confirmed in a sub-sample of co-twins discordant for ASD (n=11). NAA in the thalamus was correlated to a similar extent with SCI, RRB, and SPA, such that reduced neuronal integrity was associated with greater symptom severity. Glutamate+glutamine (Glx) was also reduced in affected versus unaffected co-twins. Additionally, NAA and Glx appeared to be primarily genetically-mediated, based on comparisons between MZ and DZ twin pairs. Thus, thalamic abnormalities may be influenced by genetic susceptibility for ASD but are likely not domain-specific.
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Affiliation(s)
- John P Hegarty
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA.
| | - Meng Gu
- Department of Radiology, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA
| | - Sue C Cleveland
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
| | - Joachim F Hallmayer
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
| | - Laura C Lazzeroni
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
| | - Mira M Raman
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
| | - Thomas W Frazier
- Autism Speaks, 29600 Fairmount Blvd, Pepper Pike, OH 44124, USA; Cleveland Clinic Children's, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Jennifer M Phillips
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
| | - Allan L Reiss
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
| | - Antonio Y Hardan
- Department of Psychiatry and Behavioral Sciences, Stanford University, 401 Quarry Road, Stanford, CA 94305, USA
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14
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Corbin ZA, Zaharchuk G, Spielman DM, Recht LD. NIMG-72. CEREBRAL BLOW FLOW AND SUV TRENDS IN PET/MRI FOLLOWING BEVACIZUMAB ADMINISTRATION IN GLIOBLASTOMA. Neuro Oncol 2017. [DOI: 10.1093/neuonc/nox168.644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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15
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Tee SS, Park JM, Hurd RE, Brimacombe KR, Boxer MB, Massoud TF, Rutt BK, Spielman DM. PKM2 activation sensitizes cancer cells to growth inhibition by 2-deoxy-D-glucose. Oncotarget 2017; 8:90959-90968. [PMID: 29207616 PMCID: PMC5710897 DOI: 10.18632/oncotarget.19630] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 07/06/2017] [Indexed: 12/18/2022] Open
Abstract
Cancer metabolism has emerged as an increasingly attractive target for interfering with tumor growth. Small molecule activators of pyruvate kinase isozyme M2 (PKM2) suppress tumor formation but have an unknown effect on established tumors. We demonstrate that TEPP-46, a PKM2 activator, results in increased glucose consumption, providing the rationale for combining PKM2 activators with the toxic glucose analog, 2-deoxy-D-glucose (2-DG). Combination treatment resulted in reduced viability of a range of cell lines in standard cell culture conditions at concentrations of drugs that had no effect when used alone. This effect was replicated in vivo on established subcutaneous tumors. We further demonstrated the ability to detect acute metabolic differences in combination treatment using hyperpolarized magnetic resonance spectroscopy (MRS). Combination treated tumors displayed a higher pyruvate to lactate 13C-label exchange 2 hr post-treatment. This ability to assess the effect of drugs non-invasively may accelerate the implementation and clinical translation of drugs that target cancer metabolism.
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Affiliation(s)
- Sui Seng Tee
- Department of Radiology, Stanford University, Stanford, CA, USA.,Current/Present address: Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jae Mo Park
- Department of Radiology, Stanford University, Stanford, CA, USA.,Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ralph E Hurd
- Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, USA
| | - Kyle R Brimacombe
- National Center for Advancing Translational Sciences, NIH, Bethesda, MD, USA.,NIH Chemical Genomics Center, Bethesda, MD, USA
| | - Matthew B Boxer
- National Center for Advancing Translational Sciences, NIH, Bethesda, MD, USA
| | - Tarik F Massoud
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Brian K Rutt
- Department of Radiology, Stanford University, Stanford, CA, USA
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16
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Abstract
Reactive oxygen species (ROS) are essential cellular metabolites widely implicated in many diseases including cancer, inflammation, and cardiovascular and neurodegenerative disorders. Yet, ROS signaling remains poorly understood, and their measurements are a challenge due to high reactivity and instability. Here, we report the development of 13C-thiourea as a probe to detect and measure H2O2 dynamics with high sensitivity and spatiotemporal resolution using hyperpolarized 13C magnetic resonance spectroscopic imaging. In particular, we show 13C-thiourea to be highly polarizable and to possess a long spin-lattice relaxation time (T1), which enables real-time monitoring of ROS-mediated transformation. We also demonstrate that 13C-thiourea reacts readily with H2O2 to give chemically distinguishable products in vitro and validate their detection in vivo in a mouse liver. This study suggests that 13C-thiourea is a promising agent for noninvasive detection of H2O2 in vivo. More broadly, our findings outline a viable clinical application for H2O2 detection in patients with a range of diseases.
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Affiliation(s)
- Arif Wibowo
- Department
of Biochemistry, Stanford University, Stanford, California 94305, United States
| | - Jae Mo Park
- Advanced
Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department
of Radiology, Stanford University, Stanford, California 94305, United States
| | - Shie-Chau Liu
- Department
of Radiology, Stanford University, Stanford, California 94305, United States
| | - Chaitan Khosla
- Department
of Biochemistry, Stanford University, Stanford, California 94305, United States
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford
ChEM-H, Stanford University, Stanford, California 94305, United States
| | - Daniel M. Spielman
- Department
of Radiology, Stanford University, Stanford, California 94305, United States
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17
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Park JM, Wu M, Datta K, Liu SC, Castillo A, Lough H, Spielman DM, Billingsley KL. Hyperpolarized Sodium [1- 13C]-Glycerate as a Probe for Assessing Glycolysis In Vivo. J Am Chem Soc 2017; 139:6629-6634. [PMID: 28467066 DOI: 10.1021/jacs.7b00708] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hyperpolarized 13C magnetic resonance spectroscopy (MRS) provides unprecedented opportunities to obtain clinical diagnostic information through in vivo monitoring of metabolic pathways. The continuing advancement of this field relies on the identification of molecular probes that can effectively interrogate pathways critical to disease. In this report, we describe the synthesis, development, and in vivo application of sodium [1-13C]-glycerate ([13C]-Glyc) as a novel probe for evaluating glycolysis using hyperpolarized 13C MRS. This agent was prepared by a concise synthetic route and formulated for dynamic nuclear polarization. [13C]-Glyc displayed a high level of polarization and long spin-lattice relaxation time-both of which are necessary for future clinical investigations. In vivo spectroscopic studies with hyperpolarized [13C]-Glyc in rat liver furnished metabolic products, [13C]-labeled pyruvate and lactate, originating from glycolysis. The levels of production and relative intensities of these metabolites were directly correlated with the induced glycolytic state (fasted versus fed groups). This work establishes hyperpolarized [13C]-Glyc as a novel agent for clinically relevant 13C MRS studies of energy metabolism and further provides opportunities for evaluating intracellular redox states in biochemical investigations.
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Affiliation(s)
- Jae Mo Park
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center , Dallas, Texas 75390, United States
| | - Marvin Wu
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States
| | | | | | - Andrew Castillo
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States
| | - Heather Lough
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States
| | | | - Kelvin L Billingsley
- Department of Chemistry and Biochemistry, San Francisco State University , San Francisco, California 94132, United States.,Department of Chemistry and Biochemistry, California State University, Fullerton , Fullerton, California 92834, United States
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18
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Gu M, Hurd R, Noeske R, Baltusis L, Hancock R, Sacchet MD, Gotlib IH, Chin FT, Spielman DM. GABA editing with macromolecule suppression using an improved MEGA-SPECIAL sequence. Magn Reson Med 2017; 79:41-47. [PMID: 28370458 DOI: 10.1002/mrm.26691] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 02/15/2017] [Accepted: 03/05/2017] [Indexed: 01/08/2023]
Abstract
PURPOSE The most common γ-aminobutyric-acid (GABA) editing approach, MEGA-PRESS, uses J-editing to measure GABA distinct from larger overlapping metabolites, but suffers contamination from coedited macromolecules (MMs) comprising 40 to 60% of the observed signal. MEGA-SPECIAL is an alternative method with better MM suppression, but is not widely used primarily because of its relatively poor spatial localization. Our goal was to develop an improved MM-suppressed GABA editing sequence at 3 Tesla. METHODS We modified a single-voxel MEGA-SPECIAL sequence with an oscillating readout gradient for improved spatial localization, and used very selective 30-ms editing pulses for improved suppression of coedited MMs. RESULTS Simulation and in vivo experiments confirmed excellent MM suppression, insensitive to the range of B0 frequency drifts typically encountered in vivo. Both intersubject and intrasubject studies showed that MMs, when suppressed by the improved MEGA-SPECIAL method, contributed approximately 40% to the corresponding MEGA-PRESS measurements. From the intersubject study, the coefficient of variation for GABA+/Cre (MEGA-PRESS) was 11.2% versus 7% for GABA/Cre (improved MEGA-SPECIAL), demonstrating significantly reduced variance (P = 0.005), likely coming from coedited MMs. CONCLUSIONS This improved MEGA-SPECIAL sequence provides unbiased GABA measurements with reduced variance as compared with conventional MEGA-PRESS. This approach is also relatively insensitive to the range of B0 drifts typically observed in in vivo human studies. Magn Reson Med 79:41-47, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Meng Gu
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Ralph Hurd
- GE Healthcare, Menlo Park, California, USA
| | | | - Laima Baltusis
- Center for Cognitive and Neurobiological Imaging, Stanford University, Stanford, California, USA
| | - Roeland Hancock
- Department of Psychiatry, University of California, San Francisco, California, USA
| | - Matthew D Sacchet
- Neurosciences Program and Psychology, Stanford University, Stanford, California, USA
| | - Ian H Gotlib
- Neurosciences Program and Psychology, Stanford University, Stanford, California, USA
| | - Frederick T Chin
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University, Stanford, California, USA
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19
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Park JM, Khemtong C, Liu SC, Hurd RE, Spielman DM. In vivo assessment of intracellular redox state in rat liver using hyperpolarized [1- 13 C]Alanine. Magn Reson Med 2017; 77:1741-1748. [PMID: 28261868 DOI: 10.1002/mrm.26662] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/10/2017] [Accepted: 02/08/2017] [Indexed: 12/14/2022]
Abstract
PURPOSE The intracellular lactate to pyruvate concentration ratio is a commonly used tissue assay biomarker of redox, being proportional to free cytosolic [NADH]/[NAD+ ]. In this study, we assessed the use of hyperpolarized [1-13 C]alanine and the subsequent detection of the intracellular products of [1-13 C]pyruvate and [1-13 C]lactate as a useful substrate for assessing redox levels in the liver in vivo. METHODS Animal experiments were conducted to measure in vivo metabolism at baseline and after ethanol infusion. A solution of 80-mM hyperpolarized [1-13 C]alanine was injected intravenously at baseline (n = 8) and 45 min after ethanol infusion (n = 4), immediately followed by the dynamic acquisition of 13 C MRS spectra. RESULTS In vivo rat liver spectra showed peaks from [1-13 C] alanine and the products of [1-13 C]lactate, [1-13 C]pyruvate, and 13 C-bicarbonate. A significantly increased 13 C-lactate/13 C-pyruvate ratio was observed after ethanol infusion (8.46 ± 0.58 at baseline versus 13.58 ± 0.69 after ethanol infusion; P < 0.001) consistent with the increased NADH produced by liver metabolism of ethanol to acetaldehyde and then acetate. A decrease in 13 C-bicarbonate production was also noted, potentially reflecting ethanol-induced mitochondrial redox changes. CONCLUSION A method to measure in vivo tissue redox using hyperpolarized [1-13 C]alanine is presented, with the validity of the proposed 13 C-pyruvate/13 C-lactate metric tested using an ethanol challenge to alter liver redox state. Magn Reson Med 77:1741-1748, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Jae Mo Park
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, Stanford University, Stanford, California, USA
| | - Chalermchai Khemtong
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Shie-Chau Liu
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Ralph E Hurd
- Applied Science Laboratory, GE Healthcare, Menlo Park, California, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University, Stanford, California, USA
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20
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Datta K, Spielman DM. Doublet asymmetry for estimating polarization in hyperpolarized 13 C-pyruvate studies. NMR Biomed 2017; 30:10.1002/nbm.3670. [PMID: 28004867 PMCID: PMC5330392 DOI: 10.1002/nbm.3670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 10/12/2016] [Accepted: 10/14/2016] [Indexed: 06/06/2023]
Abstract
Hyperpolarized 13 C MRS allows in vivo interrogation of key metabolic pathways, with pyruvate (Pyr) the substrate of choice for current clinical studies. Knowledge of the liquid-state polarization is needed for full quantitation, and asymmetry of the C2 doublet, arising from 1% naturally abundant [1,2-13 C]Pyr in any hyperpolarized [1-13 C]Pyr sample, has been suggested as a direct measure of in vivo C1 polarization via the use of an in vitro calibration curve. Here we show that different polarization levels can yield the same C2 -doublet asymmetry, thus limiting the utility of this metric for quantitation. Furthermore, although the time evolution of doublet asymmetry is poorly modeled using the expected dominant relaxation mechanisms of carbon-proton dipolar coupling and chemical shift anisotropy, the inclusion of a C-C dipolar coupling term can explain the observed initial evolution of the C2 doublet asymmetry beyond its expected thermal equilibrium value.
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Affiliation(s)
- Keshav Datta
- Department of Electrical Engineering, Stanford University, Stanford,
CA, USA
- Department of Radiology, Stanford University, Stanford, CA,
USA
| | - Daniel M. Spielman
- Department of Electrical Engineering, Stanford University, Stanford,
CA, USA
- Department of Radiology, Stanford University, Stanford, CA,
USA
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21
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Park JM, Spielman DM, Josan S, Jang T, Merchant M, Hurd RE, Mayer D, Recht LD. Hyperpolarized (13)C-lactate to (13)C-bicarbonate ratio as a biomarker for monitoring the acute response of anti-vascular endothelial growth factor (anti-VEGF) treatment. NMR Biomed 2016; 29:650-9. [PMID: 26990457 PMCID: PMC4833516 DOI: 10.1002/nbm.3509] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 01/14/2016] [Accepted: 02/03/2016] [Indexed: 05/25/2023]
Abstract
Hyperpolarized [1-(13)C]pyruvate MRS provides a unique imaging opportunity to study the reaction kinetics and enzyme activities of in vivo metabolism because of its favorable imaging characteristics and critical position in the cellular metabolic pathway, where it can either be reduced to lactate (reflecting glycolysis) or converted to acetyl-coenzyme A and bicarbonate (reflecting oxidative phosphorylation). Cancer tissue metabolism is altered in such a way as to result in a relative preponderance of glycolysis relative to oxidative phosphorylation (i.e. Warburg effect). Although there is a strong theoretical basis for presuming that readjustment of the metabolic balance towards normal could alter tumor growth, a robust noninvasive in vivo tool with which to measure the balance between these two metabolic processes has yet to be developed. Until recently, hyperpolarized (13)C-pyruvate imaging studies had focused solely on [1-(13)C]lactate production because of its strong signal. However, without a concomitant measure of pyruvate entry into the mitochondria, the lactate signal provides no information on the balance between the glycolytic and oxidative metabolic pathways. Consistent measurement of (13)C-bicarbonate in cancer tissue, which does provide such information, has proven difficult, however. In this study, we report the reliable measurement of (13)C-bicarbonate production in both the healthy brain and a highly glycolytic experimental glioblastoma model using an optimized (13)C MRS imaging protocol. With the capacity to obtain signal in all tumors, we also confirm for the first time that the ratio of (13)C-lactate to (13)C-bicarbonate provides a more robust metric relative to (13)C-lactate for the assessment of the metabolic effects of anti-angiogenic therapy. Our data suggest a potential application of this ratio as an early biomarker to assess therapeutic effectiveness. Furthermore, although further study is needed, the results suggest that anti-angiogenic treatment results in a rapid normalization in the relative tissue utilization of glycolytic and oxidative phosphorylation by tumor tissue.
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Affiliation(s)
- Jae Mo Park
- Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, California 94305, U.S.A
| | - Daniel M. Spielman
- Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, California 94305, U.S.A
| | - Sonal Josan
- Department of Radiology, Stanford University, 1201 Welch Rd., Stanford, California 94305, U.S.A
- Biosciences Division, SRI International, 333 Ravenswood Ave.., Menlo Park, California 94025, U.S.A
| | - Taichang Jang
- Department of Neurology and Neurological Sciences, Stanford University, 875 Blake Wilbur Dr., Palo Alto, California 94304, U.S.A
| | - Milton Merchant
- Department of Neurology and Neurological Sciences, Stanford University, 875 Blake Wilbur Dr., Palo Alto, California 94304, U.S.A
| | - Ralph E. Hurd
- Applied Science Laboratory West, GE Healthcare, 333 Ravenswood Ave., Menlo Park, California 94025, U.S.A
| | - Dirk Mayer
- Biosciences Division, SRI International, 333 Ravenswood Ave.., Menlo Park, California 94025, U.S.A
- Department of Diagnostic Radiology and Nuclear Medicine, , University of Maryland, 22 S. Greene St., Baltimore, Maryland 21201, U.S.A
| | - Lawrence D. Recht
- Department of Neurology and Neurological Sciences, Stanford University, 875 Blake Wilbur Dr., Palo Alto, California 94304, U.S.A
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Park JM, Josan S, Mayer D, Hurd RE, Chung Y, Bendahan D, Spielman DM, Jue T. Hyperpolarized 13C NMR observation of lactate kinetics in skeletal muscle. ACTA ACUST UNITED AC 2015; 218:3308-18. [PMID: 26347554 DOI: 10.1242/jeb.123141] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 08/21/2015] [Indexed: 01/02/2023]
Abstract
The production of glycolytic end products, such as lactate, usually evokes a cellular shift from aerobic to anaerobic ATP generation and O2 insufficiency. In the classical view, muscle lactate must be exported to the liver for clearance. However, lactate also forms under well-oxygenated conditions, and this has led investigators to postulate lactate shuttling from non-oxidative to oxidative muscle fiber, where it can serve as a precursor. Indeed, the intracellular lactate shuttle and the glycogen shunt hypotheses expand the vision to include a dynamic mobilization and utilization of lactate during a muscle contraction cycle. Testing the tenability of these provocative ideas during a rapid contraction cycle has posed a technical challenge. The present study reports the use of hyperpolarized [1-(13)C]lactate and [2-(13)C]pyruvate in dynamic nuclear polarization (DNP) NMR experiments to measure the rapid pyruvate and lactate kinetics in rat muscle. With a 3 s temporal resolution, (13)C DNP NMR detects both [1-(13)C]lactate and [2-(13)C]pyruvate kinetics in muscle. Infusion of dichloroacetate stimulates pyruvate dehydrogenase activity and shifts the kinetics toward oxidative metabolism. Bicarbonate formation from [1-(13)C]lactate increases sharply and acetyl-l-carnitine, acetoacetate and glutamate levels also rise. Such a quick mobilization of pyruvate and lactate toward oxidative metabolism supports the postulated role of lactate in the glycogen shunt and the intracellular lactate shuttle models. The study thus introduces an innovative DNP approach to measure metabolite transients, which will help delineate the cellular and physiological role of lactate and glycolytic end products.
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Affiliation(s)
- Jae Mo Park
- Radiology, Stanford University, Stanford, CA 94305, USA
| | - Sonal Josan
- Radiology, Stanford University, Stanford, CA 94305, USA Neuroscience Program, SRI International, Menlo Park, CA 94025, USA
| | - Dirk Mayer
- Neuroscience Program, SRI International, Menlo Park, CA 94025, USA Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, MD 21201, USA
| | | | - Youngran Chung
- Biochemistry and Molecular Medicine, University of California Davis, Davis, CA 95616, USA
| | - David Bendahan
- Centre de Resonance Magnetique Biologique et Medicale, Aix-Marseille University, Marseille 13385, France
| | | | - Thomas Jue
- Biochemistry and Molecular Medicine, University of California Davis, Davis, CA 95616, USA
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Park JM, Josan S, Jang T, Merchant M, Watkins R, Hurd RE, Recht LD, Mayer D, Spielman DM. Volumetric spiral chemical shift imaging of hyperpolarized [2-(13) c]pyruvate in a rat c6 glioma model. Magn Reson Med 2015; 75:973-84. [PMID: 25946547 DOI: 10.1002/mrm.25766] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/01/2015] [Accepted: 04/16/2015] [Indexed: 01/17/2023]
Abstract
PURPOSE MRS of hyperpolarized [2-(13)C]pyruvate can be used to assess multiple metabolic pathways within mitochondria as the (13)C label is not lost with the conversion of pyruvate to acetyl-CoA. This study presents the first MR spectroscopic imaging of hyperpolarized [2-(13)C]pyruvate in glioma-bearing brain. METHODS Spiral chemical shift imaging with spectrally undersampling scheme (1042 Hz) and a hard-pulse excitation was exploited to simultaneously image [2-(13)C]pyruvate, [2-(13)C]lactate, and [5-(13)C]glutamate, the metabolites known to be produced in brain after an injection of hyperpolarized [2-(13)C]pyruvate, without chemical shift displacement artifacts. A separate undersampling scheme (890 Hz) was also used to image [1-(13)C]acetyl-carnitine. Healthy and C6 glioma-implanted rat brains were imaged at baseline and after dichloroacetate administration, a drug that modulates pyruvate dehydrogenase kinase activity. RESULTS The baseline metabolite maps showed higher lactate and lower glutamate in tumor as compared to normal-appearing brain. Dichloroacetate led to an increase in glutamate in both tumor and normal-appearing brain. Dichloroacetate-induced %-decrease of lactate/glutamate was comparable to the lactate/bicarbonate decrease from hyperpolarized [1-(13)C]pyruvate studies. Acetyl-carnitine was observed in the muscle/fat tissue surrounding the brain. CONCLUSION Robust volumetric imaging with hyperpolarized [2-(13)C]pyruvate and downstream products was performed in glioma-bearing rat brains, demonstrating changes in mitochondrial metabolism with dichloroacetate.
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Affiliation(s)
- Jae Mo Park
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Sonal Josan
- Department of Radiology, Stanford University, Stanford, California, USA.,SRI International, Menlo Park, California, USA
| | - Taichang Jang
- Department of Neurology and Neurological Sciences, Stanford, California, USA
| | - Milton Merchant
- Department of Neurology and Neurological Sciences, Stanford, California, USA
| | - Ron Watkins
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Ralph E Hurd
- Applied Science Laboratory, GE Healthcare, Menlo Park, California, USA
| | - Lawrence D Recht
- Department of Neurology and Neurological Sciences, Stanford, California, USA
| | - Dirk Mayer
- SRI International, Menlo Park, California, USA.,Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University, Stanford, California, USA
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24
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Sabati M, Sheriff S, Gu M, Wei J, Zhu H, Barker PB, Spielman DM, Alger JR, Maudsley AA. Multivendor implementation and comparison of volumetric whole-brain echo-planar MR spectroscopic imaging. Magn Reson Med 2014; 74:1209-20. [PMID: 25354190 DOI: 10.1002/mrm.25510] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 12/14/2022]
Abstract
PURPOSE To assess volumetric proton MR spectroscopic imaging (MRSI) of the human brain on multivendor MRI instruments. METHODS Echo-planar spectroscopic imaging was developed on instruments from three manufacturers, with matched specifications and acquisition protocols that accounted for differences in sampling performance, radiofrequency (RF) power, and data formats. Intersite reproducibility was evaluated for signal-normalized maps of N-acetylaspartate (NAA), creatine (Cre), and choline using phantom and human subject measurements. Comparative analyses included metrics for spectral quality, spatial coverage, and mean values in atlas-registered brain regions. RESULTS Intersite differences for phantom measurements were less than 1.7% for individual metabolites and less than 0.2% for ratio measurements. Spatial uniformity ranged from 79% to 91%. The human studies found differences of mean values in the temporal lobe, but good agreement in other white matter regions, with maximum differences relative to their mean of under 3.2%. For NAA/Cre, the maximum difference was 1.8%. In gray matter, a significant difference was observed for frontal lobe NAA. Primary causes of intersite differences were attributed to shim quality, B0 drift, and accuracy of RF excitation. Correlation coefficients for measurements at each site were over 0.60, indicating good reliability. CONCLUSION A volumetric intensity-normalized MRSI acquisition can be implemented in a comparable manner across multivendor MR instruments.
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Affiliation(s)
- Mohammad Sabati
- Department of Radiology, University of Miami, Miami, Florida, USA.,Department of Radiology, University of Calgary, Calgary, Canada
| | - Sulaiman Sheriff
- Department of Radiology, University of Miami, Miami, Florida, USA
| | - Meng Gu
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Juan Wei
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, and the F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Henry Zhu
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, and the F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Peter B Barker
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, and the F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Daniel M Spielman
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Jeffry R Alger
- Neurology and Radiological Sciences, University of California, Los Angeles, California, USA
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Maudsley AA, Roy B, Gupta RK, Sheriff S, Awasthi R, Gu M, Husain N, Mohakud S, Behari S, Spielman DM. Association of metabolite concentrations and water diffusivity in normal appearing brain tissue with glioma grade. J Neuroimaging 2013; 24:585-589. [PMID: 24251857 DOI: 10.1111/jon.12063] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/09/2013] [Accepted: 08/03/2013] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Studies of brain tumors have identified altered tissue metabolism and water diffusion in MRI normal appearing tissue regions. In this retrospective study the relationship of these imaging measures with tumor grade in gliomas was investigated. METHODS MR spectroscopic imaging of whole brain and mean diffusivity (MD) measurements were obtained in subjects with untreated glioma and from normal control subjects. Mean metabolite values for N-acetylaspartate (NAA), total creatine (Cre), and total choline (Cho) were obtained in gray- and white-matter regions for the hemisphere contralateral to the tumor location, and MD values were obtained from contralateral normal-appearing white matter. Analyses tested for differences in mean values between subject groups while accounting for age. RESULTS Analysis demonstrated increased NAA/Cre and MD, and decreased Cho/NAA for all tumor grades relative to control values. Differences between tumor grades were also observed for NAA, NAA/Cre, and Cho/NAA. Abnormal values of water diffusion were also observed, but with only a weak association between alterations in diffusion and tissue metabolites. CONCLUSIONS This study supports previous observations of altered tissue metabolism and water diffusion in normal-appearing white matter while additionally finding differences of metabolite values in gray matter and an association with tumor grade.
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Affiliation(s)
| | - Bhaswati Roy
- Departments of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Rakesh K Gupta
- Departments of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | | | - Rishi Awasthi
- Departments of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Meng Gu
- Department of Radiology, Stanford University, California
| | - Nuzhat Husain
- Department of Pathology, Ram Manohar Lohia, Institute of Medical Sciences, Lucknow, India
| | - Sudipa Mohakud
- Departments of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Sanjay Behari
- Departments of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Park JM, Josan S, Grafendorfer T, Yen YF, Hurd RE, Spielman DM, Mayer D. Measuring mitochondrial metabolism in rat brain in vivo using MR Spectroscopy of hyperpolarized [2-¹³C]pyruvate. NMR Biomed 2013; 26:1197-203. [PMID: 23553852 PMCID: PMC3726546 DOI: 10.1002/nbm.2935] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 12/27/2012] [Accepted: 01/30/2013] [Indexed: 05/12/2023]
Abstract
Hyperpolarized [1-(13) C]pyruvate ([1-(13) C]Pyr) has been used to assess metabolism in healthy and diseased states, focusing on the downstream labeling of lactate (Lac), bicarbonate and alanine. Although hyperpolarized [2-(13) C]Pyr, which retains the labeled carbon when Pyr is converted to acetyl-coenzyme A, has been used successfully to assess mitochondrial metabolism in the heart, the application of [2-(13) C]Pyr in the study of brain metabolism has been limited to date, with Lac being the only downstream metabolic product reported previously. In this study, single-time-point chemical shift imaging data were acquired from rat brain in vivo. [5-(13) C]Glutamate, [1-(13) C]acetylcarnitine and [1-(13) C]citrate were detected in addition to resonances from [2-(13) C]Pyr and [2-(13) C]Lac. Brain metabolism was further investigated by infusing dichloroacetate, which upregulates Pyr flux to acetyl-coenzyme A. After dichloroacetate administration, a 40% increase in [5-(13) C]glutamate from 0.014 ± 0.004 to 0.020 ± 0.006 (p = 0.02), primarily from brain, and a trend to higher citrate (0.002 ± 0.001 to 0.004 ± 0.002) were detected, whereas [1-(13) C]acetylcarnitine was increased in peripheral tissues. This study demonstrates, for the first time, that hyperpolarized [2-(13) C]Pyr can be used for the in vivo investigation of mitochondrial function and tricarboxylic acid cycle metabolism in brain.
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Affiliation(s)
- Jae Mo Park
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Sonal Josan
- Department of Radiology, Stanford University, Stanford, CA, USA
- Neuroscience Program, SRI International, Menlo Park, CA, USA
| | | | - Yi-Fen Yen
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Ralph E. Hurd
- Applied Science Lab, GE Healthcare, Menlo Park, CA, USA
| | - Daniel M. Spielman
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Dirk Mayer
- Department of Radiology, Stanford University, Stanford, CA, USA
- Neuroscience Program, SRI International, Menlo Park, CA, USA
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Roy B, Gupta RK, Maudsley AA, Awasthi R, Sheriff S, Gu M, Husain N, Mohakud S, Behari S, Pandey CM, Rathore RKS, Spielman DM, Alger JR. Utility of multiparametric 3-T MRI for glioma characterization. Neuroradiology 2013; 55:603-13. [PMID: 23377234 PMCID: PMC4209475 DOI: 10.1007/s00234-013-1145-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 01/21/2013] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Accurate grading of cerebral glioma using conventional structural imaging techniques remains challenging due to the relatively poor sensitivity and specificity of these methods. The purpose of this study was to evaluate the relative sensitivity and specificity of structural magnetic resonance imaging and MR measurements of perfusion, diffusion, and whole-brain spectroscopic parameters for glioma grading. METHODS Fifty-six patients with radiologically suspected untreated glioma were studied with T1- and T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, diffusion tensor imaging, and volumetric whole-brain MR spectroscopic imaging. Receiver-operating characteristic analysis was performed using the relative cerebral blood volume (rCBV), apparent diffusion coefficient, fractional anisotropy, and multiple spectroscopic parameters to determine optimum thresholds for tumor grading and to obtain the sensitivity, specificity, and positive and negative predictive values for identifying high-grade gliomas. Logistic regression was performed to analyze all the parameters together. RESULTS The rCBV individually classified glioma as low and high grade with a sensitivity and specificity of 100 and 88 %, respectively, based on a threshold value of 3.34. On combining all parameters under consideration, the classification was achieved with 2 % error and sensitivity and specificity of 100 and 96 %, respectively. CONCLUSION Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters.
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Affiliation(s)
- Bhaswati Roy
- Department of Radiology & Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana, India 122002
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Gu M, Zahr NM, Spielman DM, Sullivan EV, Pfefferbaum A, Mayer D. Quantification of glutamate and glutamine using constant-time point-resolved spectroscopy at 3 T. NMR Biomed 2013; 26:164-172. [PMID: 22761057 PMCID: PMC3742105 DOI: 10.1002/nbm.2831] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 05/30/2012] [Accepted: 05/30/2012] [Indexed: 05/30/2023]
Abstract
Separate quantification of glutamate (Glu) and glutamine (Gln) using conventional MRS on clinical scanners is challenging. In previous work, constant-time point-resolved spectroscopy (CT-PRESS) was optimized at 3 T to detect Glu, but did not resolve Gln. To quantify Glu and Gln, a time-domain basis set was constructed taking into account metabolite T(2) relaxation times and dephasing from B(0) inhomogeneity. Metabolite concentrations were estimated by fitting the basis one-dimensional CT-PRESS diagonal magnitude spectra to the measured spectrum. This method was first validated using seven custom-built phantoms containing variable metabolite concentrations, and then applied to in vivo data acquired in rats exposed to vaporized ethanol and controls. Separate metabolite quantification revealed increased Gln after 16 weeks and increased Glu after 24 weeks of vaporized ethanol exposure in ethanol-treated compared with control rats. Without separate quantification, the signal from the combined resonances of Glu and Gln (Glx) showed an increase at both 16 and 24 weeks in ethanol-exposed rats, precluding the determination of the independent and differential contribution of each metabolite at each time.
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Affiliation(s)
- Meng Gu
- Department of Radiology, Stanford University, Stanford, CA 94305, USA.
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29
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Park JM, Recht LD, Josan S, Merchant M, Jang T, Yen YF, Hurd RE, Spielman DM, Mayer D. Metabolic response of glioma to dichloroacetate measured in vivo by hyperpolarized (13)C magnetic resonance spectroscopic imaging. Neuro Oncol 2013; 15:433-41. [PMID: 23328814 DOI: 10.1093/neuonc/nos319] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The metabolic phenotype that derives disproportionate energy via glycolysis in solid tumors, including glioma, leads to elevated lactate labeling in metabolic imaging using hyperpolarized [1-(13)C]pyruvate. Although the pyruvate dehydrogenase (PDH)-mediated flux from pyruvate to acetyl coenzyme A can be indirectly measured through the detection of carbon-13 ((13)C)-labeled bicarbonate, it has proven difficult to visualize (13)C-bicarbonate at high enough levels from injected [1-(13)C]pyruvate for quantitative analysis in brain. The aim of this study is to improve the detection of (13)C-labeled metabolites, in particular bicarbonate, in glioma and normal brain in vivo and to measure the metabolic response to dichloroacetate, which upregulates PDH activity. METHODS An optimized protocol for chemical shift imaging and high concentration of hyperpolarized [1-(13)C]pyruvate were used to improve measurements of lactate and bicarbonate in C6 glioma-transplanted rat brains. Hyperpolarized [1-(13)C]pyruvate was injected before and 45 min after dichloroacetate infusion. Metabolite ratios of lactate to bicarbonate were calculated to provide improved metrics for characterizing tumor metabolism. RESULTS Glioma and normal brain were well differentiated by lactate-to-bicarbonate ratio (P = .002, n = 5) as well as bicarbonate (P = .0002) and lactate (P = .001), and a stronger response to dichloroacetate was observed in glioma than in normal brain. CONCLUSION Our results clearly demonstrate for the first time the feasibility of quantitatively detecting (13)C-bicarbonate in tumor-bearing rat brain in vivo, permitting the measurement of dichloroacetate-modulated changes in PDH flux. The simultaneous detection of lactate and bicarbonate provides a tool for a more comprehensive analysis of glioma metabolism and the assessment of metabolic agents as anti-brain cancer drugs.
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Affiliation(s)
- Jae Mo Park
- Stanford University, Department of Radiology, The Lucas Center for Imaging, 1201 Welch Road, Stanford, CA, 94305, USA.
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30
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Mayer D, Yen YF, Josan S, Park JM, Pfefferbaum A, Hurd RE, Spielman DM. Application of hyperpolarized [1-¹³C]lactate for the in vivo investigation of cardiac metabolism. NMR Biomed 2012; 25:1119-24. [PMID: 22278751 PMCID: PMC3357452 DOI: 10.1002/nbm.2778] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 12/09/2011] [Accepted: 12/16/2011] [Indexed: 05/08/2023]
Abstract
In addition to cancer imaging, (13) C-MRS of hyperpolarized pyruvate has also demonstrated utility for the investigation of cardiac metabolism and ischemic heart disease. Although no adverse effects have yet been reported for doses commonly used in vivo, high substrate concentrations have lead to supraphysiological pyruvate levels that can affect the underlying metabolism and should be considered when interpreting results. With lactate serving as an important energy source for the heart and physiological lactate levels one to two orders of magnitude higher than for pyruvate, hyperpolarized lactate could potentially be used as an alternative to pyruvate for probing cardiac metabolism. In this study, hyperpolarized [1-(13) C]lactate was used to acquire time-resolved spectra from the healthy rat heart in vivo and to measure dichloroacetate (DCA)-modulated changes in flux through pyruvate dehydrogenase (PDH). Both primary oxidation of lactate to pyruvate and subsequent conversion of pyruvate to alanine and bicarbonate could reliably be detected. Since DCA stimulates the activity of PDH through inhibition of PDH kinase, a more than 2.5-fold increase in bicarbonate-to-substrate ratio was found after administration of DCA, similar to the effect when using [1-(13) C]pyruvate as the substrate.
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Affiliation(s)
- Dirk Mayer
- SRI International, Neuroscience Program, 333 Ravenswood Ave, Menlo Park, CA 94025, USA.
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31
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Park JM, Josan S, Jang T, Merchant M, Yen YF, Hurd RE, Recht L, Spielman DM, Mayer D. Metabolite kinetics in C6 rat glioma model using magnetic resonance spectroscopic imaging of hyperpolarized [1-(13)C]pyruvate. Magn Reson Med 2012; 68:1886-93. [PMID: 22334279 DOI: 10.1002/mrm.24181] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 11/25/2011] [Accepted: 01/03/2012] [Indexed: 12/25/2022]
Abstract
In addition to an increased lactate-to-pyruvate ratio, altered metabolism of a malignant glioma can be further characterized by its kinetics. Spatially resolved dynamic data of pyruvate and lactate from C6-implanted female Sprague-Dawley rat brain were acquired using a spiral chemical shift imaging sequence after a bolus injection of a hyperpolarized [1-(13)C]pyruvate. Apparent rate constants for the conversion of pyruvate to lactate in three different regions (glioma, normal appearing brain, and vasculature) were estimated based on a two-site exchange model. The apparent conversion rate constant was 0.018 ± 0.004 s(-1) (mean ± standard deviation, n = 6) for glioma, 0.009 ± 0.003 s(-1) for normal brain, and 0.005 ± 0.001 s(-1) for vasculature, whereas the lactate-to-pyruvate ratio, the metabolic marker used to date to identify tumor regions, was 0.36 ± 0.07 (mean ± SD), 0.24 ± 0.07, and 0.12 ± 0.02 for glioma, normal brain, and vasculature, respectively. The data suggest that the apparent conversion rate better differentiate glioma from normal brain (P = 0.001, n = 6) than the lactate-to-pyruvate ratio (P = 0.02).
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Affiliation(s)
- Jae Mo Park
- Department of Electrical Engineering, Stanford University, Stanford, California, USA.
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32
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Darpolor MM, Yen YF, Chua MS, Xing L, Clarke-Katzenberg RH, Shi W, Mayer D, Josan S, Hurd RE, Pfefferbaum A, Senadheera L, So S, Hofmann LV, Glazer GM, Spielman DM. In vivo MRSI of hyperpolarized [1-(13)C]pyruvate metabolism in rat hepatocellular carcinoma. NMR Biomed 2011; 24:506-13. [PMID: 21674652 PMCID: PMC3073155 DOI: 10.1002/nbm.1616] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 07/24/2010] [Accepted: 08/10/2010] [Indexed: 05/22/2023]
Abstract
Hepatocellular carcinoma (HCC), the primary form of human adult liver malignancy, is a highly aggressive tumor with average survival rates that are currently less than 1 year following diagnosis. Most patients with HCC are diagnosed at an advanced stage, and no efficient marker exists for the prediction of prognosis and/or response(s) to therapy. We have reported previously a high level of [1-(13)C]alanine in an orthotopic HCC using single-voxel hyperpolarized [1-(13)C]pyruvate MRS. In the present study, we implemented a three-dimensional MRSI sequence to investigate this potential hallmark of cellular metabolism in rat livers bearing HCC (n = 7 buffalo rats). In addition, quantitative real-time polymerase chain reaction was used to determine the mRNA levels of lactate dehydrogenase A, nicotinamide adenine (phosphate) dinucleotide dehydrogenase quinone 1 and alanine transaminase. The enzyme levels were significantly higher in tumor than in normal liver tissues within each rat, and were associated with the in vivo MRSI signal of [1-(13)C]alanine and [1-(13)C]lactate after a bolus intravenous injection of [1-(13)C]pyruvate. Histopathological analysis of these tumors confirmed the successful growth of HCC as a nodule in buffalo rat livers, revealing malignancy and hypervascular architecture. More importantly, the results demonstrated that the metabolic fate of [1-(13)C]pyruvate conversion to [1-(13)C]alanine significantly superseded that of [1-(13)C]pyruvate conversion to [1-(13)C]lactate, potentially serving as a marker of HCC tumors.
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Affiliation(s)
- Moses M Darpolor
- Department of Radiology, Stanford University, Stanford, CA 94305-5488, USA.
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Mayer D, Yen YF, Takahashi A, Josan S, Tropp J, Rutt BK, Hurd RE, Spielman DM, Pfefferbaum A. Dynamic and high-resolution metabolic imaging of hyperpolarized [1-13C]-pyruvate in the rat brain using a high-performance gradient insert. Magn Reson Med 2011; 65:1228-33. [PMID: 21500253 PMCID: PMC3126907 DOI: 10.1002/mrm.22707] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 10/04/2010] [Accepted: 10/08/2010] [Indexed: 12/25/2022]
Abstract
Fast chemical shift imaging (CSI) techniques are advantageous in metabolic imaging of hyperpolarized compounds due to the limited duration of the signal amplification. At the same time, reducing the acquisition time in hyperpolarized imaging does not necessarily lead to the conventional penalty in signal-to-noise ratio that occurs in imaging at thermal equilibrium polarization levels. Here a high-performance gradient insert was used in combination with undersampled spiral CSI to increase either the imaging speed or the spatial resolution of hyperpolarized (13)C metabolic imaging on a clinical 3T MR scanner. Both a single-shot sequence with a total acquisition time of 125 ms and a three-shot sequence with a nominal in-plane resolution of 1.5 mm were implemented. The k-space trajectories were measured and then used during image reconstruction. The technique was applied to metabolic imaging of the rat brain in vivo after the injection of hyperpolarized [1-(13)C]-pyruvate. Dynamic imaging afforded the measurement of region-of-interest-specific time courses of pyruvate and its metabolic products, while imaging at high spatial resolution was used to better characterize the spatial distribution of the metabolite signals.
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Affiliation(s)
- Dirk Mayer
- SRI International, Neuroscience Program, Menlo Park, California 94025, USA.
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MacKenzie JD, Yen YF, Mayer D, Tropp JS, Hurd RE, Spielman DM. Detection of inflammatory arthritis by using hyperpolarized 13C-pyruvate with MR imaging and spectroscopy. Radiology 2011; 259:414-20. [PMID: 21406626 DOI: 10.1148/radiol.10101921] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To examine the feasibility of using magnetic resonance (MR) spectroscopy with hyperpolarized carbon 13 ((13)C)-labeled pyruvate to detect inflammation. MATERIALS AND METHODS The animal care and use committee approved all work with animals. Arthritis was induced in the right hind paw of six rats; the left hind paw served as an internal control. The lactate dehydrogenase-catalyzed conversion of pyruvate to lactate was measured in inflamed and control paws by using (13)C MR spectroscopy. Clinical and histologic data were obtained to confirm the presence and severity of arthritis. Hyperpolarized (13)C-pyruvate was intravenously injected into the rats before simultaneous imaging of both paws with (13)C MR spectroscopy. The Wilcoxon signed rank test was used to test for differences in metabolites between the control and arthritic paws. RESULTS All animals showed findings of inflammation in the affected paws and no signs of arthritis in the control paws at both visible inspection (clinical index of 3 for arthritic paws and 0 for control paws) and histologic examination (histologic score of 3-5 for arthritic paws and 0 for control paws). Analysis of the spectroscopic profiles of (13)C-pyruvate and converted (13)C-lactate showed an increase in the amount of (13)C-lactate in inflamed paws (median lactate-to-pyruvate ratio, 0.50; mean lactate-to-pyruvate ratio ± standard deviation, 0.52 ± 0.16) versus control paws (median lactate-to-pyruvate ratio, 0.27; mean lactate-to-pyruvate ratio, 0.32 ± 0.11) (P < .03). The ratio of (13)C-lactate to total (13)C was also significantly increased in inflamed paws compared with control paws (P < .03). CONCLUSION These results suggest that alterations in the conversion of pyruvate to lactate as detected with (13)C-MR spectroscopy may be indicative of the presence of inflammatory arthritis.
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Affiliation(s)
- John D MacKenzie
- Department of Radiology, Stanford University, Stanford, Calif, USA
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Abstract
PURPOSE To compare generalized autocalibrating partially parallel acquisitions (GRAPPA), modified sensitivity encoding (mSENSE), and SENSE in phase-contrast magnetic resonance imaging (PC-MRI) applications. MATERIALS AND METHODS Aliasing of the torso can occur in PC-MRI applications. If the data are further undersampled for parallel imaging, SENSE can be problematic in correctly unaliasing signals due to coil sensitivity maps that do not match that of the aliased volume. Here, a method for estimating coil sensitivities in flow applications is described. Normal volunteers (n = 5) were scanned on a 1.5 T MRI scanner and underwent PC-MRI scans using GRAPPA, mSENSE, SENSE, and conventional PC-MRI acquisitions. Peak velocity and flow through the aorta and pulmonary artery were evaluated. RESULTS Bland-Altman statistics for flow in the aorta and pulmonary artery acquired with mSENSE and GRAPPA methods (R = 2 and R = 3 cases) have comparable mean differences to flow acquired with conventional PC-MRI. GRAPPA and mSENSE PC-MRI have more robust measurements than SENSE when there is aliasing artifact caused by insufficient coil sensitivity maps. For peak velocity, there are no considerable differences among the mSENSE, GRAPPA, and SENSE reconstructions and are comparable to conventional PC-MRI. CONCLUSION Flow measurements of images reconstructed with autocalibration techniques have comparable agreement with conventional PC-MRI and provide robust measurements in the presence of wraparound.
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Affiliation(s)
- Calvin Lew
- Department of Radiology, Stanford University, Stanford, California 94305, USA.
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Hurd RE, Yen YF, Tropp J, Pfefferbaum A, Spielman DM, Mayer D. Cerebral dynamics and metabolism of hyperpolarized [1-(13)C]pyruvate using time-resolved MR spectroscopic imaging. J Cereb Blood Flow Metab 2010; 30:1734-41. [PMID: 20588318 PMCID: PMC2975615 DOI: 10.1038/jcbfm.2010.93] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 04/28/2010] [Accepted: 06/02/2010] [Indexed: 01/17/2023]
Abstract
Dynamic hyperpolarized [1-(13)C]pyruvate metabolic imaging in the normal anesthetized rat brain is demonstrated on a clinical 3-T magnetic resonance imaging scanner. A 12-second bolus injection of hyperpolarized [1-(13)C]pyruvate is imaged at a 3-second temporal resolution. The observed dynamics are evaluated with regard to cerebral blood volume (CBV), flow, transport, and metabolic exchange with the cerebral lactate pool. A model for brain [1-(13)C]lactate, based on blood-brain transport kinetics, CBV, and the observed pyruvate dynamics is described.
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Affiliation(s)
- Ralph E Hurd
- Global Applied Science Laboratory, GE Healthcare, Menlo Park, California 94025, USA.
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Mayer D, Yen YF, Levin YS, Tropp J, Pfefferbaum A, Hurd RE, Spielman DM. In vivo application of sub-second spiral chemical shift imaging (CSI) to hyperpolarized 13C metabolic imaging: comparison with phase-encoded CSI. J Magn Reson 2010; 204:340-5. [PMID: 20346717 PMCID: PMC2893149 DOI: 10.1016/j.jmr.2010.03.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 03/04/2010] [Accepted: 03/04/2010] [Indexed: 05/15/2023]
Abstract
A fast spiral chemical shift imaging (CSI) has been developed to address the challenge of the limited acquisition window in hyperpolarized (13)C metabolic imaging. The sequence exploits the sparsity of the spectra and prior knowledge of resonance frequencies to reduce the measurement time by undersampling the data in the spectral domain. As a consequence, multiple reconstructions are necessary for any given data set as only frequency components within a selected bandwidth are reconstructed "in-focus" while components outside that band are severely blurred ("spectral tomosynthesis"). A variable-flip-angle scheme was used for optimal use of the longitudinal magnetization. The sequence was applied to sub-second metabolic imaging of the rat in vivo after injection of hyperpolarized [1-(13)C]-pyruvate on a clinical 3T MR scanner. The comparison with conventional CSI based on phase encoding showed similar signal-to-noise ratio (SNR) and spatial resolution in metabolic maps for the substrate and its metabolic products lactate, alanine, and bicarbonate, despite a 50-fold reduction in scan time for the spiral CSI acquisition. The presented results demonstrate that dramatic reductions in scan time are feasible in hyperpolarized (13)C metabolic imaging without a penalty in SNR or spatial resolution.
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Affiliation(s)
- Dirk Mayer
- Stanford University, Department of Radiology, Richard M. Lucas Center for Imaging, 1201 Welch Rd., Stanford, CA 94305, USA.
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Spielman DM, Mayer D, Yen YF, Tropp J, Hurd RE, Pfefferbaum A. In vivo measurement of ethanol metabolism in the rat liver using magnetic resonance spectroscopy of hyperpolarized [1-13C]pyruvate. Magn Reson Med 2009; 62:307-13. [PMID: 19526498 DOI: 10.1002/mrm.21998] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
[1-(13)C]pyruvate is a readily polarizable substrate that has been the subject of numerous magnetic resonance spectroscopy (MRS) studies of in vivo metabolism. In this work (13)C-MRS of hyperpolarized [1-(13)C]pyruvate was used to interrogate a metabolic pathway involved in neither aerobic nor anaerobic metabolism. In particular, ethanol consumption leads to altered liver metabolism, which when excessive is associated with adverse medical conditions including fatty liver disease, hepatitis, cirrhosis, and cancer. Here we present a method for noninvasively monitoring this important process in vivo. Following the bolus injection of hyperpolarized [1-(13)C]pyruvate, we demonstrate a significantly increased rat liver lactate production rate with the coadministration of ethanol (P = 0.0016 unpaired t-test). The affect is attributable to increased liver nicotinamide adenine dinucleotide (NADH) associated with ethanol metabolism in combination with NADH's role as a coenzyme in pyruvate-to-lactate conversion. Beyond studies of liver metabolism, this novel in vivo assay of changes in NADH levels makes hyperpolarized [1-(13)C]pyruvate a potentially viable substrate for studying the multiple in vivo metabolic pathways that use NADH (or NAD(+)) as a coenzyme, thus broadening the range of applications that have been discussed in the literature to date.
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Affiliation(s)
- Daniel M Spielman
- Stanford University Department of Radiology, Lucas Center for Medical Imaging, Stanford, CA 94305, USA.
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Mayer D, Yen YF, Tropp J, Pfefferbaum A, Hurd RE, Spielman DM. Application of subsecond spiral chemical shift imaging to real-time multislice metabolic imaging of the rat in vivo after injection of hyperpolarized 13C1-pyruvate. Magn Reson Med 2009; 62:557-64. [PMID: 19585607 PMCID: PMC2782691 DOI: 10.1002/mrm.22041] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 03/15/2009] [Indexed: 11/06/2022]
Abstract
Dynamic nuclear polarization can create hyperpolarized compounds with MR signal-to-noise ratio enhancements on the order of 10,000-fold. Both exogenous and normally occurring endogenous compounds can be polarized, and their initial concentration and downstream metabolic products can be assessed using MR spectroscopy. Given the transient nature of the hyperpolarized signal enhancement, fast imaging techniques are a critical requirement for real-time metabolic imaging. We report on the development of an ultrafast, multislice, spiral chemical shift imaging sequence, with subsecond acquisition time, achieved on a clinical MR scanner. The technique was used for dynamic metabolic imaging in rats, with measurement of time-resolved spatial distributions of hyperpolarized (13)C(1)-pyruvate and metabolic products (13)C(1)-lactate and (13)C(1)-alanine, with a temporal resolution of as fast as 1 s. Metabolic imaging revealed different signal time courses in liver from kidney. These results demonstrate the feasibility of real-time, hyperpolarized metabolic imaging and highlight its potential in assessing organ-specific kinetic parameters.
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Affiliation(s)
- Dirk Mayer
- Department of Radiology, Stanford University, Richard M Lucas Center for Imaging, Stanford, California 94305-5488, USA.
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Benoit MR, Mayer D, Barak Y, Chen IY, Hu W, Cheng Z, Wang SX, Spielman DM, Gambhir SS, Matin A. Visualizing implanted tumors in mice with magnetic resonance imaging using magnetotactic bacteria. Clin Cancer Res 2009; 15:5170-7. [PMID: 19671860 DOI: 10.1158/1078-0432.ccr-08-3206] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE To determine if magnetotactic bacteria can target tumors in mice and provide positive contrast for visualization using magnetic resonance imaging. EXPERIMENTAL DESIGN The ability of the magnetotactic bacterium, Magnetospirillum magneticum AMB-1 (referred to from here as AMB-1), to confer positive magnetic resonance imaging contrast was determined in vitro and in vivo. For the latter studies, AMB-1 were injected either i.t. or i.v. Bacterial growth conditions were manipulated to produce small (approximately 25-nm diameter) magnetite particles, which were observed using transmission electron microscopy. Tumor targeting was confirmed using 64Cu-labeled bacteria and positron emission tomography and by determination of viable cell counts recovered from different organs and the tumor. RESULTS We show that AMB-1 bacteria with small magnetite particles generate T1-weighted positive contrast, enhancing in vivo visualization by magnetic resonance imaging. Following i.v. injection of 64Cu-labeled AMB-1, positron emission tomography imaging revealed increasing colonization of tumors and decreasing infection of organs after 4 hours. Viable cell counts showed that, by day 6, the bacteria had colonized tumors but were cleared completely from other organs. Magnetic resonance imaging showed a 1.22-fold (P = 0.003) increased positive contrast in tumors on day 2 and a 1.39-fold increase (P = 0.0007) on day 6. CONCLUSION Magnetotactic bacteria can produce positive magnetic resonance imaging contrast and colonize mouse tumor xenografts, providing a potential tool for improved magnetic resonance imaging visualization in preclinical and translational studies to track cancer.
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Affiliation(s)
- Michael R Benoit
- Department of Microbiology and Immunology, Stanford University, Stanford, California 94305-5124, USA
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Gu M, Spielman DM. B1 and T1 insensitive water and lipid suppression using optimized multiple frequency-selective preparation pulses for whole-brain 1H spectroscopic imaging at 3T. Magn Reson Med 2009; 61:462-6. [PMID: 19161165 DOI: 10.1002/mrm.21843] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A new method for the simultaneous suppression of water and lipid resonances using a series of dual-band frequency-selective radiofrequency (RF) pulses with associated dephasing gradients is presented. By optimizing the nutation angles of the individual pulses, the water and lipid suppression is made insensitive to a range of both T1-relaxation times and B1 inhomogeneities. The method consists only of preparatory RF pulses and thus can be combined with a wide variety of MRSI schemes including both long and short TE studies. Simulations yield suppression factors, in the presence of +/-20% B1 inhomogeneity, on the order of 100 for lipid peaks with three different T1s (300 ms, 310 ms, and 360 ms), and water peaks with T1s ranging from 0.8 s to 4 s. Excellent in vivo study performance is demonstrated using a 3 Tesla volumetric proton spectroscopic imaging (1H-MRSI) sequence for measuring the primary brain metabolites peaks of choline (Cho), creatine (Cr), and N-acetyl aspartate (NAA).
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Affiliation(s)
- Meng Gu
- Department of Electrical Engineering, Stanford University, Stanford, California 94305-5488, USA.
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Abstract
Spectroscopic imaging applications outside of the brain can suffer from artifacts due to inherent long scan times and susceptibility to motion. A fast spectroscopic imaging sequence has been devised with reduced sensitivity to motion. The sequence uses oscillating readout gradients and acquires k-space data in a spiral out-in fashion, which allows fast k-space coverage. We show that a spiral out-in readout acquisition is characterized by small gradient moments, reducing sensitivity to motion-induced artifacts. Data are acquired comparing the sequence to normal phase encoded spectroscopic imaging and conventional spiral spectroscopic imaging protocols. In addition, in vivo data are acquired from the liver, demonstrating potential usage as a multivoxel fat/water spectroscopic imaging tool. Results indicate that in the presence of motion, ghosting effects are reduced while metabolite signal increases of approximately 10% can be achieved.
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Affiliation(s)
- Dong-Hyun Kim
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea.
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Gu M, Liu C, Spielman DM. Parallel spectroscopic imaging reconstruction with arbitrary trajectories using k-space sparse matrices. Magn Reson Med 2009; 61:267-72. [PMID: 19165883 DOI: 10.1002/mrm.21838] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Parallel imaging reconstruction has been successfully applied to magnetic resonance spectroscopic imaging (MRSI) to reduce scan times. For undersampled k-space data on a Cartesian grid, the reconstruction can be achieved in image domain using a sensitivity encoding (SENSE) algorithm for each spectral data point. Alternative methods for reconstruction with undersampled Cartesian k-space data are the SMASH and GRAPPA algorithms that do the reconstruction in the k-space domain. To reconstruct undersampled MRSI data with arbitrary k-space trajectories, image-domain-based iterative SENSE algorithm has been applied at the cost of long computing times. In this paper, a new k-space domain-based parallel spectroscopic imaging reconstruction with arbitrary k-space trajectories using k-space sparse matrices is applied to MRSI with spiral k-space trajectories. The algorithm achieves MRSI reconstruction with reduced memory requirements and computing times. The results are demonstrated in both phantom and in vivo studies. Spectroscopic images very similar to that reconstructed with fully sampled spiral k-space data are obtained at different reduction factors.
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Affiliation(s)
- Meng Gu
- Lucas Center for MR Spectroscopy and Imaging, Department of Radiology, Stanford University, Stanford, California 94305-5488, USA.
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Gu M, Kim DH, Mayer D, Sullivan EV, Pfefferbaum A, Spielman DM. Reproducibility study of whole-brain 1H spectroscopic imaging with automated quantification. Magn Reson Med 2009; 60:542-7. [PMID: 18727040 DOI: 10.1002/mrm.21713] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A reproducibility study of proton MR spectroscopic imaging ((1)H-MRSI) of the human brain was conducted to evaluate the reliability of an automated 3D in vivo spectroscopic imaging acquisition and associated quantification algorithm. A PRESS-based pulse sequence was implemented using dualband spectral-spatial RF pulses designed to fully excite the singlet resonances of choline (Cho), creatine (Cre), and N-acetyl aspartate (NAA) while simultaneously suppressing water and lipids; 1% of the water signal was left to be used as a reference signal for robust data processing, and additional lipid suppression was obtained using adiabatic inversion recovery. Spiral k-space trajectories were used for fast spectral and spatial encoding yielding high-quality spectra from 1 cc voxels throughout the brain with a 13-min acquisition time. Data were acquired with an 8-channel phased-array coil and optimal signal-to-noise ratio (SNR) for the combined signals was achieved using a weighting based on the residual water signal. Automated quantification of the spectrum of each voxel was performed using LCModel. The complete study consisted of eight healthy adult subjects to assess intersubject variations and two subjects scanned six times each to assess intrasubject variations. The results demonstrate that reproducible whole-brain (1)H-MRSI data can be robustly obtained with the proposed methods.
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Affiliation(s)
- Meng Gu
- Department of Electrical Engineering, Stanford University, Stanford, California 94305-5488, USA.
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Geraghty PR, van den Bosch MAAJ, Spielman DM, Hunjan S, Birdwell RL, Fong KJ, Stables LA, Zakhour M, Herfkens RJ, Ikeda DM. MRI and (1)H MRS of the breast: presence of a choline peak as malignancy marker is related to K21 value of the tumor in patients with invasive ductal carcinoma. Breast J 2008; 14:574-80. [PMID: 19000051 DOI: 10.1111/j.1524-4741.2008.00650.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To assess which specific morphologic features, enhancement patterns, or pharmacokinetic parameters on breast Magnetic Resonance Imaging (MRI) could predict a false-negative outcome of Proton MR Spectroscopy ((1)H MRS) exam in patients with invasive breast cancer. Sixteen patients with invasive ductal carcinoma of the breast were prospectively included and underwent both, contrast-enhanced breast MRI and (1)H MRS examination of the breast. The MR images were reviewed and the lesions morphologic features, enhancement patterns and pharmacokinetic parameters (k21-value) were scored according to the ACR BI-RADS-MRI lexicon criteria. For the in vivo MRS studies, each spectrum was evaluated for the presence of choline based on consensus reading. Breast MRI and (1)H MRS data were compared to histopathologic findings. In vivo (1)H MRS detected a choline peak in 14/16 (88%) cancers. A false-negative (1)H MRS study occurred in 2/16 (14%) cancer patients. K21 values differed between both groups: the 14 choline positive cancers had k21 values ranging from 0.01 to 0.20/second (mean 0.083/second), whereas the two choline-negative cancers showed k21 values of 0.03 and 0.05/second, respectively (mean 0.040/second). Also enhancement kinetics did differ between both groups; typically both cancers that were choline-negative showed a late phase plateau (100%), whereas this was only shown in 5/14 (36%) of the choline positive cases. There was no difference between both groups with regard to morphologic features on MRI. This study showed that false-negative (1)H MRS examinations do occur in breast cancer patients, and that the presence of a choline peak on (1)H MRS as malignancy marker is related to the k21 value of the invasive tumor being imaged.
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Affiliation(s)
- Patricia R Geraghty
- Department of Radiology, Stanford University School of Medicine, Stanford, CA 94305-5488, USA
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Abstract
Spiral chemical shift imaging (CSI) is a fast CSI technique that simultaneously encodes 1D spectral and 2D spatial information. Therefore, it potentially allows one to perform a 2D-CSI experiment in a single shot. However, for most applications, limitations on maximum gradient strength and slew rate make multiple excitations necessary in order to achieve a desired spectral bandwidth. In this work we reduce the number of spatial interleaves and, hence, the minimum total measurement time of spiral CSI by using an iterative sensitivity encoding reconstruction algorithm which utilizes complementary spatial encoding afforded by the spatially inhomogeneous sensitivity profiles of individual receiver coils. The performance of the new method was evaluated in phantom and in vivo experiments. Parallel spiral CSI produced maps of brain metabolites similar to those obtained using conventional gridding reconstruction of the fully sampled data with only a small decrease in time-normalized signal-to-noise ratio and a small increase in noise for higher acceleration factors.
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Affiliation(s)
- Dirk Mayer
- Stanford University, Richard M. Lucas Center for Magnetic Resonance Spectroscopy and Imaging, Department of Radiology, Stanford, California 94305-5488, USA.
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Levin YS, Mayer D, Yen YF, Hurd RE, Spielman DM. Optimization of fast spiral chemical shift imaging using least squares reconstruction: application for hyperpolarized (13)C metabolic imaging. Magn Reson Med 2007; 58:245-52. [PMID: 17654596 DOI: 10.1002/mrm.21327] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A least-squares-based optimization and reconstruction algorithm has been developed for rapid metabolic imaging in the context of hyperpolarized (13)C. The algorithm uses a priori knowledge of resonance frequencies, J-coupling constants, and T(2)* values to enable acquisition of high-quality metabolic images with imaging times of approximately 100 ms for an 8-cm field of view (FOV) and 0.5 cm isotropic resolution. A root-mean-square error (rMSE) analysis is introduced to optimize metabolic image quality by appropriate choice of pulse sequence parameters, echo times, and signal model. By performing the reconstruction in k-space, the algorithm also allows the inclusion of the effect of chemical shift evolution during the readout period. Single-interleaf multiecho spiral chemical shift imaging (spCSI) is analyzed in detail as an illustrative example for the use of the new reconstruction and optimization algorithm. Simulation of the in vivo spectrum following the bolus injection of hyperpolarized (13)C(1) pyruvate shows that single-interleaf spiral spectroscopic imaging can achieve image quality in 100 ms, comparable to the performance of a 13-s phase-encoded chemical shift imaging (FIDCSI) experiment. Single-interleaf spCSI was also tested at a 3-T MR scanner using a phantom containing approximately 0.5-M solutions of alanine, lactate, and a pyruvate-pyruvate hydrate C(1)-C(2) ester at thermal equilibrium polarization, all enriched to 99% (13)C in the C(1) carbonyl positions. Upon reconstruction using the k-space-based least-squares technique, metabolite ratios obtained using the spCSI method were comparable to those obtained using a reference FIDCSI acquisition.
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Affiliation(s)
- Y S Levin
- Stanford University School of Medicine, Department of Radiology, Stanford, California 94305, USA.
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Abstract
A numerical simulation tool was developed to calculate the echo amplitudes of J-coupled resonances within a series of radiofrequency (RF) refocused echoes. The signal modulation due to J-coupling in rapid acquisition with relaxation enhancement (RARE) is suppressed only when the inverse of the pulse interval (tau) is large compared to both the chemical shift (CS) difference (Deltadelta) of the coupled spins and the coupling constant. In contrast, the echo amplitudes in ultrafast low-flip-angle RARE (U-FLARE) oscillate around a quasi-steady-state value that is greater than zero (neglecting relaxation and diffusion) even when Deltadelta > 1/tau. The flip-angle distribution over the measured slice caused by the use of Gaussian-shape slice-selective refocusing pulses further reduces the echo oscillations. When the pulse interval falls short of the fast pulse rate regime, spectroscopic U-FLARE provides an improved spatial impulse response in the phase-encoding (PE) direction compared to spectroscopic RARE.
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Affiliation(s)
- Dirk Mayer
- Lucas MRS Imaging Center, Department of Radiology, Stanford University, Stanford, California 94305-5488, USA.
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Kim DH, Henry R, Spielman DM. Fast multivoxel two-dimensional spectroscopic imaging at 3 T. Magn Reson Imaging 2007; 25:1155-61. [PMID: 17418519 PMCID: PMC2128753 DOI: 10.1016/j.mri.2007.01.118] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 01/24/2007] [Accepted: 01/28/2007] [Indexed: 10/23/2022]
Abstract
The utility of multivoxel two-dimensional chemical shift imaging in the clinical environment will ultimately be determined by the imaging time and the metabolite peaks that can be detected. Different k-space sampling schemes can be characterized by their minimum required imaging time. The use of spiral-based readout gradients effectively reduces the minimum scan time required due to simultaneous data acquisition in three k-space dimensions (k(x), k(y) and k(f(2))). A 3-T spiral-based multivoxel two-dimensional spectroscopic imaging sequence using the PRESS excitation scheme was implemented. Good performance was demonstrated by acquiring preliminary in vivo data for applications, including brain glutamate imaging, metabolite T(2) quantification and high-spatial-resolution prostate spectroscopic imaging. All protocols were designed to acquire data within a 17-min scan time at a field strength of 3 T.
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Affiliation(s)
- Dong-Hyun Kim
- Department of Radiology, University of California-San Francisco, San Francisco, CA, USA.
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Lew CD, Alley MT, Bammer R, Spielman DM, Chan FP. Peak velocity and flow quantification validation for sensitivity-encoded phase-contrast MR imaging. Acad Radiol 2007; 14:258-69. [PMID: 17307658 PMCID: PMC1993829 DOI: 10.1016/j.acra.2006.11.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 11/17/2006] [Accepted: 11/17/2006] [Indexed: 11/22/2022]
Abstract
RATIONALE AND OBJECTIVES Phase-contrast (PC) magnetic resonance imaging (MRI) technique has important clinical applications in blood flow quantification and pressure gradient estimation by velocity measurement. Parallel imaging using sensitivity encoding (SENSE) may substantially reduce scan time. We demonstrate the utility of PC-MRI measurements accelerated by SENSE under clinical conditions. MATERIALS AND METHODS Accuracy and repeatability of a SENSE-PC implementation was evaluated by comparison with a commercial PC sequence with five normal volunteers. Twenty-six patients were then scanned with SENSE-PC at reduction factors (R = 1, 2, and 3). Blood flow and peak velocity were measured in the aorta and pulmonary trunk in 16 patients and peak velocity was measured at the coarctation of 10 patients. Quantitative flow, shunt ratio, and peak velocity measurements obtained with different reduction factors were compared using correlation, linear regression, and Bland-Altman statistics. All studies were approved by an Institutional Review Board, and informed consent was acquired from all subjects. RESULTS The correlation coefficients for all comparisons were >0.962 and with high statistical significance (P < .01). Linear regression slopes ranged between 0.96 and 1.11 for flow and 0.88 to 1.05 for peak velocity. For flow, the Bland-Altman statistics yielded a total mean difference ranging from -0.02 to 0.05) L/minute with 2 standard of deviation limits ranging from -0.52 to 0.75 L/minute. For peak velocity, the total mean difference ranged from -0.10 to -0.004) milliseconds with 2-SD limits ranging from -0.062 to 0.46 milliseconds. R = 3 to R = 1 comparisons had greater 2-SD limits than R = 2 to R = 1 comparisons. CONCLUSION SENSE PC-MRI measurements for flow and pressure gradient estimation were comparable to conventional PC-MRI.
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Affiliation(s)
- Calvin D Lew
- Lucas MRS/I Center, Stanford University, 1201 Welch Road, Stanford, CA 94305.
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