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Ma J, Chen J, Reed GD, Hackett EP, Harrison CE, Ratnakar J, Schulte RF, Zaha VG, Malloy CR, Park JM. Cardiac T 2 ∗ measurement of hyperpolarized 13 C metabolites using metabolite-selective multi-echo spiral imaging. Magn Reson Med 2021; 86:1494-1504. [PMID: 33821504 DOI: 10.1002/mrm.28796] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 01/01/2023]
Abstract
PURPOSE Noninvasive imaging with hyperpolarized (HP) pyruvate can capture in vivo cardiac metabolism. For proper quantification of the metabolites and optimization of imaging parameters, understanding MR characteristics such as T 2 ∗ s of the HP signals is critical. This study is to measure in vivo cardiac T 2 ∗ s of HP [1-13 C]pyruvate and the products in rodents and humans. METHODS A dynamic 13 C multi-echo spiral imaging sequence that acquires [13 C]bicarbonate, [1-13 C]lactate, and [1-13 C]pyruvate images in an interleaved manner was implemented for a clinical 3 Tesla system. T 2 ∗ of each metabolite was calculated from the multi-echo images by fitting the signal decay of each region of interest mono-exponentially. The performance of measuring T 2 ∗ using the sequence was first validated using a 13 C phantom and then with rodents following a bolus injection of HP [1-13 C]pyruvate. In humans, T 2 ∗ of each metabolite was calculated for left ventricle, right ventricle, and myocardium. RESULTS Cardiac T 2 ∗ s of HP [1-13 C]pyruvate, [1-13 C]lactate, and [13 C]bicarbonate in rodents were measured as 24.9 ± 5.0, 16.4 ± 4.7, and 16.9 ± 3.4 ms, respectively. In humans, T 2 ∗ of [1-13 C]pyruvate was 108.7 ± 22.6 ms in left ventricle and 129.4 ± 8.9 ms in right ventricle. T 2 ∗ of [1-13 C]lactate was 40.9 ± 8.3, 44.2 ± 5.5, and 43.7 ± 9.0 ms in left ventricle, right ventricle, and myocardium, respectively. T 2 ∗ of [13 C]bicarbonate in myocardium was 64.4 ± 2.5 ms. The measurements were reproducible and consistent over time after the pyruvate injection. CONCLUSION The proposed metabolite-selective multi-echo spiral imaging sequence reliably measures in vivo cardiac T 2 ∗ s of HP [1-13 C]pyruvate and products.
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Affiliation(s)
- Junjie Ma
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jun Chen
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Edward P Hackett
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Crystal E Harrison
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - James Ratnakar
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Vlad G Zaha
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Craig R Malloy
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jae Mo Park
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Electrical and Computer Engineering, The University of Texas at Dallas, Richardson, Texas, USA
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Riis-Vestergaard MJ, Breining P, Pedersen SB, Laustsen C, Stødkilde-Jørgensen H, Borghammer P, Jessen N, Richelsen B. Evaluation of Active Brown Adipose Tissue by the Use of Hyperpolarized [1- 13C]Pyruvate MRI in Mice. Int J Mol Sci 2018; 19:ijms19092597. [PMID: 30200469 PMCID: PMC6164296 DOI: 10.3390/ijms19092597] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/21/2018] [Accepted: 08/30/2018] [Indexed: 02/07/2023] Open
Abstract
The capacity to increase energy expenditure makes brown adipose tissue (BAT) a putative target for treatment of metabolic diseases such as obesity. Presently, investigation of BAT in vivo is mainly performed by fluoro-d-glucose positron emission tomography (FDG PET)/CT. However, non-radioactive methods that add information on, for example, substrate metabolism are warranted. Thus, the aim of this study was to evaluate the potential of hyperpolarized [1-13C]pyruvate Magnetic Resonance Imaging (HP-MRI) to determine BAT activity in mice following chronic cold exposure. Cold (6 °C) and thermo-neutral (30 °C) acclimated mice were scanned with HP-MRI for assessment of the interscapular BAT (iBAT) activity. Comparable mice were scanned with the conventional method FDG PET/MRI. Finally, iBAT was evaluated for gene expression and protein levels of the specific thermogenic marker, uncoupling protein 1 (UCP1). Cold exposure increased the thermogenic capacity 3–4 fold (p < 0.05) as measured by UCP1 gene and protein analysis. Furthermore, cold exposure as compared with thermo-neutrality increased iBAT pyruvate metabolism by 5.5-fold determined by HP-MRI which is in good agreement with the 5-fold increment in FDG uptake (p < 0.05) measured by FDG PET/MRI. iBAT activity is detectable in mice using HP-MRI in which potential changes in intracellular metabolism may add useful information to the conventional FDG PET studies. HP-MRI may also be a promising radiation-free tool for repetitive BAT studies in humans.
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Affiliation(s)
- Mette Ji Riis-Vestergaard
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, 8200 Aarhus N, Denmark.
- Institute of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark.
| | - Peter Breining
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, 8200 Aarhus N, Denmark.
- Institute of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark.
| | - Steen Bønløkke Pedersen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, 8200 Aarhus N, Denmark.
- Institute of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark.
| | - Christoffer Laustsen
- MR Research Center, Institute of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark.
| | | | - Per Borghammer
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, 8000 Aarhus C, Denmark.
| | - Niels Jessen
- Department of Clinical Pharmacology, Aarhus University Hospital, 8000 Aarhus C, Denmark.
| | - Bjørn Richelsen
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, 8200 Aarhus N, Denmark.
- Institute of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark.
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