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Rama E, Mohapatra SR, Sugimura Y, Suzuki T, Siebert S, Barmin R, Hermann J, Baier J, Rix A, Lemainque T, Koletnik S, Elshafei AS, Pallares RM, Dadfar SM, Tolba RH, Schulz V, Jankowski J, Apel C, Akhyari P, Jockenhoevel S, Kiessling F. In vitro and in vivo evaluation of biohybrid tissue-engineered vascular grafts with transformative 1H/ 19F MRI traceable scaffolds. Biomaterials 2024; 311:122669. [PMID: 38906013 DOI: 10.1016/j.biomaterials.2024.122669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 06/09/2024] [Accepted: 06/14/2024] [Indexed: 06/23/2024]
Abstract
Biohybrid tissue-engineered vascular grafts (TEVGs) promise long-term durability due to their ability to adapt to hosts' needs. However, the latter calls for sensitive non-invasive imaging approaches to longitudinally monitor their functionality, integrity, and positioning. Here, we present an imaging approach comprising the labeling of non-degradable and degradable TEVGs' components for their in vitro and in vivo monitoring by hybrid 1H/19F MRI. TEVGs (inner diameter 1.5 mm) consisted of biodegradable poly(lactic-co-glycolic acid) (PLGA) fibers passively incorporating superparamagnetic iron oxide nanoparticles (SPIONs), non-degradable polyvinylidene fluoride scaffolds labeled with highly fluorinated thermoplastic polyurethane (19F-TPU) fibers, a smooth muscle cells containing fibrin blend, and endothelial cells. 1H/19F MRI of TEVGs in bioreactors, and after subcutaneous and infrarenal implantation in rats, revealed that PLGA degradation could be faithfully monitored by the decreasing SPIONs signal. The 19F signal of 19F-TPU remained constant over weeks. PLGA degradation was compensated by cells' collagen and α-smooth-muscle-actin deposition. Interestingly, only TEVGs implanted on the abdominal aorta contained elastin. XTT and histology proved that our imaging markers did not influence extracellular matrix deposition and host immune reaction. This concept of non-invasive longitudinal assessment of cardiovascular implants using 1H/19F MRI might be applicable to various biohybrid tissue-engineered implants, facilitating their clinical translation.
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Affiliation(s)
- Elena Rama
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Saurav Ranjan Mohapatra
- Department of Biohybrid & Medical Textiles, AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Yukiharu Sugimura
- Department of Cardiac Surgery, Medical Faculty and RWTH University Hospital Aachen, RWTH Aachen University, Aachen, Germany
| | - Tomoyuki Suzuki
- Department of Cardiac Surgery, Medical Faculty and RWTH University Hospital Aachen, RWTH Aachen University, Aachen, Germany
| | - Stefan Siebert
- Department of Biohybrid & Medical Textiles, AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Roman Barmin
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Juliane Hermann
- Institute for Molecular Cardiovascular Research (IMCAR), University Hospital RWTH Aachen, Aachen, Germany
| | - Jasmin Baier
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Anne Rix
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Teresa Lemainque
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany; Department of Diagnostic and Interventional Radiology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany
| | - Susanne Koletnik
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Asmaa Said Elshafei
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Roger Molto Pallares
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Seyed Mohammadali Dadfar
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany; Ardena Oss, 5349 AB Oss, the Netherlands
| | - René H Tolba
- Institute for Laboratory Animal Science and Experimental Surgery, Medical Faculty, RWTH Aachen International University, Aachen, Germany
| | - Volkmar Schulz
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Joachim Jankowski
- Institute for Molecular Cardiovascular Research (IMCAR), University Hospital RWTH Aachen, Aachen, Germany; Aachen-Maastricht Institute for CardioRenal Disease (AMICARE), University Hospital RWTH Aachen, Aachen, Germany; Department of Pathology, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, the Netherlands
| | - Christian Apel
- Department of Biohybrid & Medical Textiles, AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Payam Akhyari
- Department of Cardiac Surgery, Medical Faculty and RWTH University Hospital Aachen, RWTH Aachen University, Aachen, Germany
| | - Stefan Jockenhoevel
- Department of Biohybrid & Medical Textiles, AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074 Aachen, Germany.
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Zhang B, Lowrance D, Sarma MK, Bartlett M, Zaha D, Nelson MD, Henning A. 3T 31P/ 1H calf muscle coil for 1H and 31P MRI/MRS integrated with NIRS data acquisition. Magn Reson Med 2024; 91:2638-2651. [PMID: 38263948 DOI: 10.1002/mrm.30025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 01/25/2024]
Abstract
PURPOSE Our aim was to design and build a 3T 31P/1H calf coil that is capable of providing both good 31P and 1H transmit and receive performance, as well as being capable of accommodating a near-infrared spectroscopy (NIRS) device for simultaneous NIRS data and MRI/MRS acquisition. METHOD In this work, we propose a new 3T 31P/1H birdcage combination design consisting of two co-centrically positioned birdcages on the same surface to maximize transmit efficiency and sensitivity for both nuclei. The 31P birdcage is a high-pass birdcage, whereas the 1H birdcage is a low-pass one to minimize coupling. The diameter of the 31P/1H birdcage combination was designed to be large enough to accommodate a NIRS device for simultaneous NIRS data and MRI/MRS acquisition. RESULTS The one-layer coil structure of the birdcage combination significantly streamlines the mechanical design and coil assembly process. Full-wave simulation results show that the 31P and 1H are very well decoupled with each other, and the 1H and 31P SNR surpasses that of their standalone counterparts in the central area. Experiment results show that the inclusion of a NIRS device does not significantly affect the performance of the coil, thus enabling simultaneous NIRS and MRI readouts during exercise. CONCLUSION Our findings demonstrate the feasibility and effectiveness of this dual-tuned coil design for combined NIRS and MRS measurements, offering potential benefits for studying metabolic and functional changes in the skeletal muscle in vivo.
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Affiliation(s)
- Bei Zhang
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Daniel Lowrance
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Manoj Kumar Sarma
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - David Zaha
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Anke Henning
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Karkouri J, Rodgers CT. Sequence building block for magnetic resonance spectroscopy on Siemens VE-series scanners. NMR IN BIOMEDICINE 2024:e5165. [PMID: 38807311 DOI: 10.1002/nbm.5165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 05/30/2024]
Abstract
We present a sequence building block (SBB) that embeds magnetic resonance spectroscopy (MRS) into another sequence on the Siemens VE platform without any custom hardware. This enables dynamic studies such as functional MRS (fMRS), dynamic shimming and frequency correction, and acquisition of navigator images for motion correction. The SBB supports nonlocalised spectroscopy (free induction decay), STimulated Echo Acquisition Mode single voxel spectroscopy, and 1D, 2D and 3D phase-encoded chemical shift imaging. It can embed 1H or X-nuclear MRS into a 1H sequence; and 1H-MRS into an X-nuclear sequence. We demonstrate integration into the vendor's gradient-recalled echo sequence. We acquire test data in phantoms with three coils (31P/1H, 13C/1H and 2H/1H) and in two volunteers on a 7-T Terra MRI scanner. Fifteen lines of code are required to insert the SBB into a sequence. Spectra and images are acquired successfully in all cases in phantoms, and in human abdomen and calf muscle. Phantom comparison of signal-to-noise ratio and linewidth showed that the SBB has negligible effects on image and spectral quality, except that it sometimes produces a nuclear Overhauser effect (NOE) signal enhancement for multinuclear applications in line with conventional 1H NOE pulses. Our new SBB embeds MRS into a host imaging or spectroscopy sequence in 15 lines of code. It allows homonuclear and heteronuclear interleaving. The package is available through the standard C2P procedure. We hope this will lower the barrier for entry to studies applying dynamic fMRS and for online motion correction and B0-shim updating.
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Affiliation(s)
- Jabrane Karkouri
- Wolfson Brain Imaging Center, University of Cambridge, Cambridge, UK
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Cap V, Rocha dos Santos VR, Repnin K, Červený D, Laistler E, Meyerspeer M, Frass-Kriegl R. Combining Dipole and Loop Coil Elements for 7 T Magnetic Resonance Studies of the Human Calf Muscle. SENSORS (BASEL, SWITZERLAND) 2024; 24:3309. [PMID: 38894105 PMCID: PMC11174775 DOI: 10.3390/s24113309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/26/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024]
Abstract
Combining proton and phosphorus magnetic resonance spectroscopy offers a unique opportunity to study the oxidative and glycolytic components of metabolism in working muscle. This paper presents a 7 T proton calf coil design that combines dipole and loop elements to achieve the high performance necessary for detecting metabolites with low abundance and restricted visibility, specifically lactate, while including the option of adding a phosphorus array. We investigated the transmit, receive, and parallel imaging performance of three transceiver dipoles with six pair-wise overlap-decoupled standard or twisted pair receive-only coils. With a higher SNR and more efficient transmission decoupling, standard loops outperformed twisted pair coils. The dipoles with standard loops provided a four-fold-higher image SNR than a multinuclear reference coil comprising two proton channels and 32% more than a commercially available 28-channel proton knee coil. The setup enabled up to three-fold acceleration in the right-left direction, with acceptable g-factors and no visible aliasing artefacts. Spectroscopic phantom measurements revealed a higher spectral SNR for lactate with the developed setup than with either reference coil and fewer restrictions in voxel placement due to improved transmit homogeneity. This paper presents a new use case for dipoles and highlights their advantages for the integration in multinuclear calf coils.
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Affiliation(s)
- Veronika Cap
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Vasco Rafael Rocha dos Santos
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Kostiantyn Repnin
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - David Červený
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
- Institute for Clinical and Experimental Medicine, 140 21 Prague, Czech Republic
- Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University, 121 08 Prague, Czech Republic
| | - Elmar Laistler
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin Meyerspeer
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| | - Roberta Frass-Kriegl
- High Field MR Center, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
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Paška J, Wang B, Chen AM, Madelin G, Brown R. Triple-tuned birdcage and single-tuned dipole array for quadri-nuclear head MRI at 7 T. Magn Reson Med 2024; 91:2188-2199. [PMID: 38116692 PMCID: PMC10950522 DOI: 10.1002/mrm.29977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/31/2023] [Accepted: 11/28/2023] [Indexed: 12/21/2023]
Abstract
PURPOSE The purpose of this work was to design and build a coil for quadri-nuclear MRI of the human brain at 7 T. METHODS We built a transmit/receive triple-tuned (45.6 MHz for 2 $$ {}^2 $$ H, 78.6 MHz for 23 $$ {}^{23} $$ Na, and 120.3 MHz for 31 $$ {}^{31} $$ P) quadrature four-rod birdcage that was geometrically interleaved with a transmit/receive four-channel dipole array (297.2 MHz for 1 $$ {}^1 $$ H). The birdcage rods contained passive, two-pole resonant circuits that emulated capacitors required for single-tuning at three frequencies. The birdcage assembly also included triple-tuned matching networks, baluns, and transmit/receive switches. We assessed the performance of the coil with quality factor (Q) and signal-to-noise ratio (SNR) measurements, and performed in vivo multinuclear MRI and MR spectroscopic imaging (MRSI). RESULTS Q measurements showed that the triple-tuned birdcage efficiency was within 33% of that of single-tuned baseline birdcages at all three frequencies. The quadri-tuned coil SNR was 78%, 59%, 44%, and 48% lower than that of single or dual-tuned reference coils for 1 $$ {}^1 $$ H, 2 $$ {}^2 $$ H, 23 $$ {}^{23} $$ Na, and 31 $$ {}^{31} $$ P, respectively. Quadri-nuclear MRI and MRSI was demonstrated in brain in vivo in about 30 min. CONCLUSION While the SNR of the quadruple tuned coil was significantly lower than dual- and single-tuned reference coils, it represents a step toward truly simultaneous quadri-nuclear measurements.
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Affiliation(s)
- Jan Paška
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Bili Wang
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Anna M. Chen
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Guillaume Madelin
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Ryan Brown
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
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Liu J, Wang M, Sun Z, Wang Y, Yang G, Wang W, Wang Q. Method for determining matching capacitances for floating cable traps in magnetic resonance imaging up to 14 T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 358:107612. [PMID: 38118321 DOI: 10.1016/j.jmr.2023.107612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 12/22/2023]
Abstract
Floating cable traps (FCTs) enhance coil tuning, improve the signal-to-noise ratio of magnetic resonance imaging (MRI), and reduce the risks to patients. As MRI technology continues to advance, it becomes crucial to design efficient FCTs that are tailored to different magnetic fields and nuclei. Here, a method is proposed for determining and correcting the appropriate capacitances for FCTs in MRI systems. To validate the effectiveness of this approach, FCTs were designed and manufactured for hydrogen nuclei in magnetic fields of 1.5-14 T. The results of bench testing show that the attenuation of common-mode currents was more than -20 dB, and the maximum frequency deviation in all the FCTs was 0.345%. Furthermore, the results of magnetic resonance spin-echo imaging show that the signal-to-noise ratio was improved significantly by using the FCTs. Overall, this study shows the effectiveness of the designed FCTs in improving signal-to-noise ratio, and it provides valuable insights for designing efficient FCTs tailored to different magnetic fields and nuclei in MRI applications.
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Affiliation(s)
- Jinhao Liu
- School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Miutian Wang
- School of Electronics, Peking University, Beijing, 100871, China.
| | - Zhen Sun
- School of Electronics, Peking University, Beijing, 100871, China.
| | - Yaohui Wang
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100190, China; Division of Superconducting Magnet Science and Technology, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Gang Yang
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
| | - Weimin Wang
- School of Electronics, Peking University, Beijing, 100871, China; Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, 518055, China; Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, 518132, China.
| | - Qiuliang Wang
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100190, China; Division of Superconducting Magnet Science and Technology, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
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Gast LV, Platt T, Nagel AM, Gerhalter T. Recent technical developments and clinical research applications of sodium ( 23Na) MRI. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2023; 138-139:1-51. [PMID: 38065665 DOI: 10.1016/j.pnmrs.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 12/18/2023]
Abstract
Sodium is an essential ion that plays a central role in many physiological processes including the transmembrane electrochemical gradient and the maintenance of the body's homeostasis. Due to the crucial role of sodium in the human body, the sodium nucleus is a promising candidate for non-invasively assessing (patho-)physiological changes. Almost 10 years ago, Madelin et al. provided a comprehensive review of methods and applications of sodium (23Na) MRI (Madelin et al., 2014) [1]. More recent review articles have focused mainly on specific applications of 23Na MRI. For example, several articles covered 23Na MRI applications for diseases such as osteoarthritis (Zbyn et al., 2016, Zaric et al., 2020) [2,3], multiple sclerosis (Petracca et al., 2016, Huhn et al., 2019) [4,5] and brain tumors (Schepkin, 2016) [6], or for imaging certain organs such as the kidneys (Zollner et al., 2016) [7], the brain (Shah et al., 2016, Thulborn et al., 2018) [8,9], and the heart (Bottomley, 2016) [10]. Other articles have reviewed technical developments such as radiofrequency (RF) coils for 23Na MRI (Wiggins et al., 2016, Bangerter et al., 2016) [11,12], pulse sequences (Konstandin et al., 2014) [13], image reconstruction methods (Chen et al., 2021) [14], and interleaved/simultaneous imaging techniques (Lopez Kolkovsky et al., 2022) [15]. In addition, 23Na MRI topics have been covered in review articles with broader topics such as multinuclear MRI or ultra-high-field MRI (Niesporek et al., 2019, Hu et al., 2019, Ladd et al., 2018) [16-18]. During the past decade, various research groups have continued working on technical improvements to sodium MRI and have investigated its potential to serve as a diagnostic and prognostic tool. Clinical research applications of 23Na MRI have covered a broad spectrum of diseases, mainly focusing on the brain, cartilage, and skeletal muscle (see Fig. 1). In this article, we aim to provide a comprehensive summary of methodological and hardware developments, as well as a review of various clinical research applications of sodium (23Na) MRI in the last decade (i.e., published from the beginning of 2013 to the end of 2022).
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Affiliation(s)
- Lena V Gast
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Tanja Platt
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Armin M Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Teresa Gerhalter
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
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Hou J, Bauer CC, Sun C, Malone B, Griffin J, Wright SM. A Four-Channel Broadband MRI Receive Array Coil. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082622 DOI: 10.1109/embc40787.2023.10340396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Low-impedance preamplifier decoupling is commonly used in RF coil array construction to minimize coupling between elements through mutual impedance. The trap circuit is an essential component in preamp decoupling techniques, but becomes a limiting factor in constructing multi-tuned, multi-nuclear coil arrays. In principle, it is possible to double-tune or multi-tune the trap circuits, but will add complexity and loss. We present a broadband decoupling approach using high impedance preamplifiers. A dual-tuned prototype four-channel array using this approach which targets 2H and 23 Na at 4.7T, has been previously constructed, evaluated and reported. Without any retuning of the array, the same setup is tested at the 23Na and 31P frequencies for 3T. Initial bench measurements and Chemical Shift Imaging (CSI) results are acquired and presented in this study.Clinical Relevance- This study could reduce the complexity of multi-nuclear array coil design.
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Touchet-Valle E, Tasmim S, Ware TH, McDougall MP. Evaluation of Low-Loss Polymer Switches for Multinuclear MRI/S . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38083302 DOI: 10.1109/embc40787.2023.10340712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Implementation of multinuclear MRI/S as a diagnostic tool in clinical settings faces many challenges. One of those challenges is the development of highly sensitive multinuclear RF coils. Current multi-tuning techniques incorporate lossy components that impact the highest achievable SNR for at least one of the coil frequencies. As a result, optimization of multinuclear coil designs continues to be a priority for RF hardware engineers. To address this challenge, a new frequency switching technology that incorporates stimuli-responsive polymer materials was explored. Q measurements were used as a comparison metric between single-tuned, a standard switching network, and the proposed switching technology. The Q losses measured in the new switching method remained below 38% when compared to single-tuned coils. These results are consistent with low loss values reported using traditional switching networks. Furthermore, preliminary testing indicates that there is potential for improvement. These results establish the new technology as a promising alternative to traditional switching techniques.Clinical Relevance- A low loss multi-tuning technique for MRI radiofrequency coils has the potential of improving the study and diagnosis of disease.
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Dai J, Gosselink M, van der Velden TA, Meliadò EF, Raaijmakers AJE, Klomp DWJ. An RF coil design to enable quintuple nuclear whole-brain MRI. Magn Reson Med 2023; 89:2131-2141. [PMID: 36740899 DOI: 10.1002/mrm.29577] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 12/02/2022] [Accepted: 12/21/2022] [Indexed: 02/07/2023]
Abstract
PURPOSE To bring metabolic imaging based on multi-NMR toward practical use from the RF hardware perspective. METHODS A highly integrated RF coil is designed for whole-brain MRI and MRS targeted to five nuclear species: 1 H, 19 F, 31 P, 23 Na, and 13 C. Dipole antennas and closely loaded local receiver loops are combined in this setup. RESULTS High-quality in vivo scan results of 1 H, 31 P, 23 Na, and 13 C on healthy volunteers have been achieved. For 1 H, the transmit efficiency is 77% of a single-tuned commercial head coil (NOVA 8-transmit [Tx]/32-receive [Rx]; NOVA Medical, Wilmington, MA, USA). For 31 P, 110% SNR of a dual-tuned close-fit head-birdcage was achieved at the center of the subject, based on MR experiments on a phantom. For 31 P, 23 Na, and 13 C, bench measurements indicate SNR loss of 15%, 27%, and 30% compared with single-tuned conditions. 19 F performance has been proven to be similar to that of 1 H through bench tests and electromagnetic simulations. CONCLUSION With this device, 1 H-based anatomic images that are expected to meet clinical requirements, as well as high-quality multi-NMR images and spectra, can be acquired within one scan session without hardware replacement or patient repositioning, enabling morphologic and metabolic MRI within acceptable scan time.
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Affiliation(s)
- Jiying Dai
- University Medical Center Utrecht, Utrecht, The Netherlands.,Tesla Dynamic Coils B.V., Zaltbommel, The Netherlands
| | - Mark Gosselink
- University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Ettore Flavio Meliadò
- University Medical Center Utrecht, Utrecht, The Netherlands.,Tesla Dynamic Coils B.V., Zaltbommel, The Netherlands
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Hong SM, Choi CH, Shah NJ, Felder J. Design of a Folded, Double-Tuned Loop Coil for ¹H/X-Nuclei MRI Applications. IEEE TRANSACTIONS ON MEDICAL IMAGING 2023; 42:1424-1430. [PMID: 37015697 DOI: 10.1109/tmi.2022.3228305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
MR measurement using a combination of X-nuclei and proton MRI is of great interest as the information provided by the two nuclei is highly complementary, with the X-nuclei signal giving metabolic data relating to potential biomarkers and the proton signal affording anatomical details. Due to the relatively weak signal obtained from X-nuclei, combining an X-nuclei coil with a proton coil is also advantageous for [Formula: see text] shimming and scout images. One approach to building a double-resonant coil is to modify the coil geometry. Here, to achieve double-resonance, a 2× 1 ladder network was designed and tuned at both proton and X-nuclei frequencies successfully. Due to coupling between closed wires, the double-tuned coil generates a shifted transmit efficiency pattern compared to that of the single-tuned loop at the 7T MRI proton frequency. To compensate for the shifted pattern, one part of the 2× 1 ladder network was folded, and the tuning and performance of the folded double-tuned coil were evaluated in simulations and MR measurements. The proposed structure was further evaluated with overlapped decoupling in a receive-only array. The results show that our proposed folded double-tuned coil moderated the shifted pattern of a straight double-tuned loop coil and provided minimum losses at both proton and X-nuclei frequencies. The proposed folded double-tuned loop coil has also been further extended to a receive-only array.
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Li Z, Bao Q, Liu C, Li Y, Yang Y, Liu M. Recent advances in microfluidics-based bioNMR analysis. LAB ON A CHIP 2023; 23:1213-1225. [PMID: 36651305 DOI: 10.1039/d2lc00876a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Nuclear magnetic resonance (NMR) has been used in a variety of fields due to its powerful analytical capability. To facilitate biochemical NMR (bioNMR) analysis for samples with a limited mass, a number of integrated systems have been developed by coupling microfluidics and NMR. However, there are few review papers that summarize the recent advances in the development of microfluidics-based NMR (μNMR) systems. Herein, we review the advancements in μNMR systems built on high-field commercial instruments and low-field compact platforms. Specifically, μNMR platforms with three types of typical microcoils settled in the high-field NMR instruments will be discussed, followed by summarizing compact NMR systems and their applications in biomedical point-of-care testing. Finally, a conclusion and future prospects in the field of μNMR were given.
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Affiliation(s)
- Zheyu Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology-Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Qingjia Bao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology-Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Chaoyang Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology-Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Ying Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology-Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Yunhuang Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology-Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Maili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology-Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan 430071, China.
- University of Chinese Academy of Sciences, Beijing 10049, China
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Özen AC, Spreter F, Schimpf W, Fischer J, Ilbey S, Reiss S, Maier A, von Elverfeldt D, Heidt T, von Zur Mühlen C, Bock M. Scalable and modular 8-channel transmit and 8-channel flexible receive coil array for 19 F MRI of large animals. Magn Reson Med 2023; 89:1237-1250. [PMID: 36226654 DOI: 10.1002/mrm.29490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/23/2022] [Accepted: 09/24/2022] [Indexed: 02/02/2023]
Abstract
PURPOSE To introduce an RF coil system consisting of an 8-channel transmit (Tx) and 8-channel receive (Rx) coil arrays for 19 F MRI of large animals. METHODS The Tx efficiency and homogeneity of the 8-element loop coil array (loop size: 6 × 15 cm2 ) were simulated for two different pig models rendered from MR images. An 8-channel Rx coil array consisting of a flexible 6-channel posterior and a 2-channel planar anterior array was designed to fit on the abdomen of an average-sized pig in supine position. Measurements were performed in a grid phantom and ex vivo on a pig model with perfluoroctylbromide (PFOB)-filled tubes inserted in the thorax. RESULTS Measured and simulated Tx efficiency and homogeneity for the 8-channel and 5-channel arrays were in good agreement: 1.87 ± 0.22μT/√kW versus 1.96 ± 0.29μT/√kW, and 2.29 ± 0.39μT/√kW versus 2.41 ± 0.37μT/√kW. An isolation of 38 ± 8 dB is achieved between the 19 F Tx and Rx elements, and over 30 dB between the 1 H and 19 F elements. The PFOB-filled vials could be clearly identified within the cadaver abdomen with an SNR of 275 ± 51 for a 3D gradient-echo sequence with 2-mm isotropic resolution and 12 averages, acquired in 9:52 min:s. Performance of the Tx array was robust against phase and amplitude mismatches at the input ports. CONCLUSIONS A modular and scalable Tx array offers improved Tx efficiency in 19 F MRI of large animals with various sizes. Although conventional birdcage coils have superior Tx efficiency within the target region of interest, scalability of the Tx array to animal size is a major benefit. The described 19 F coil provides homogeneous excitation and high sensitivity detection in large pig models.
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Affiliation(s)
- Ali Caglar Özen
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Felix Spreter
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Waldemar Schimpf
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Johannes Fischer
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Serhat Ilbey
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Simon Reiss
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Alexander Maier
- Department of Cardiology and Angiology I, University Heart Center, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Dominik von Elverfeldt
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Timo Heidt
- Department of Cardiology and Angiology I, University Heart Center, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Constantin von Zur Mühlen
- Department of Cardiology and Angiology I, University Heart Center, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Michael Bock
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
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Sun P, Wu Z, Lin L, Hu G, Zhang X, Wang J. MR-Nucleomics: The study of pathological cellular processes with multinuclear magnetic resonance spectroscopy and imaging in vivo. NMR IN BIOMEDICINE 2023; 36:e4845. [PMID: 36259659 DOI: 10.1002/nbm.4845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 09/28/2022] [Accepted: 10/08/2022] [Indexed: 06/16/2023]
Abstract
Clinical medicine has experienced a rapid development in recent decades, during which therapies targeting specific cellular signaling pathways, or specific cell surface receptors, have been increasingly adopted. While these developments in clinical medicine call for improved precision in diagnosis and treatment monitoring, modern medical imaging methods are restricted mainly to anatomical imaging, lagging behind the requirements of precision medicine. Although positron emission tomography and single photon emission computed tomography have been used clinically for studies of metabolism, their applications have been limited by the exposure risk to ionizing radiation, the subsequent limitation in repeated and longitudinal studies, and the incapability in assessing downstream metabolism. Magnetic resonance spectroscopy (MRS) or spectroscopic imaging (MRSI) are, in theory, capable of assessing molecular activities in vivo, although they are often limited by sensitivity. Here, we review some recent developments in MRS and MRSI of multiple nuclei that have potential as molecular imaging tools in the clinic.
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Affiliation(s)
- Peng Sun
- Clinical & Technical Support, Philips Healthcare, China
| | - Zhigang Wu
- Clinical & Technical Support, Philips Healthcare, China
| | - Liangjie Lin
- Clinical & Technical Support, Philips Healthcare, China
| | - Geli Hu
- Clinical & Technical Support, Philips Healthcare, China
| | | | - Jiazheng Wang
- Clinical & Technical Support, Philips Healthcare, China
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Lopez Kolkovsky AL, Carlier PG, Marty B, Meyerspeer M. Interleaved and simultaneous multi-nuclear magnetic resonance in vivo. Review of principles, applications and potential. NMR IN BIOMEDICINE 2022; 35:e4735. [PMID: 35352440 PMCID: PMC9542607 DOI: 10.1002/nbm.4735] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/03/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Magnetic resonance signals from different nuclei can be excited or received at the same time,rendering simultaneous or rapidly interleaved multi-nuclear acquisitions feasible. The advan-tages are a reduction of total scan time compared to sequential multi-nuclear acquisitions or that additional information from heteronuclear data is obtained at thesame time and anatomical position. Information content can be qualitatively increased by delivering a more comprehensive MR-based picture of a transient state (such as an exercise bout). Also, combiningnon-proton MR acquisitions with 1 Hinformation (e.g., dynamic shim updates and motion correction) can be used to improve data quality during long scans and benefits image coregistration. This work reviews the literature on interleaved and simultaneous multi-nuclear MRI and MRS in vivo. Prominent use cases for this methodology in clinical and research applications are brain and muscle, but studies have also been carried out in other targets, including the lung, knee, breast and heart. Simultaneous multi-nuclear measurements in the liver and kidney have also been performed, but exclusively in rodents. In this review, a consistent nomenclature is proposed, to help clarify the terminology used for this principle throughout the literature on in-vivo MR. An overview covers the basic principles, the technical requirements on the MR scanner and the implementations realised either by MR system vendors or research groups, from the early days until today. Considerations regarding the multi-tuned RF coils required and heteronuclear polarisation interactions are briefly discussed, and fields for future in-vivo applications for interleaved multi-nuclear MR pulse sequences are identified.
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Affiliation(s)
- Alfredo L. Lopez Kolkovsky
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of MyologyParisFrance
- NMR laboratoryCEA, DRF, IBFJParisFrance
| | - Pierre G. Carlier
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of MyologyParisFrance
- NMR laboratoryCEA, DRF, IBFJParisFrance
| | - Benjamin Marty
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of MyologyParisFrance
- NMR laboratoryCEA, DRF, IBFJParisFrance
| | - Martin Meyerspeer
- High‐Field MR Center, Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
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Puchnin V, Ivanov V, Gulyaev M, Pirogov Y, Zubkov M. Imaging Capabilities of the ¹H-X-Nucleus Metamaterial-Inspired Multinuclear RF-Coil. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:1587-1595. [PMID: 35030077 DOI: 10.1109/tmi.2022.3143693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this paper, we present the initial experimental investigation of a two-coil receive/transmit design for small animals imaging at 7T MRI. The system uses a butterfly-type coil tuned to 300 MHz for scanning the 1H nuclei and a non-resonant loop antenna with a metamaterial-inspired resonator with the ability to tune over a wide frequency range for X-nuclei. 1H, 31P, 23Na and 13C, which are of particular interest in biomedical MRI, were selected as test nuclei in this work. Coil simulations show the two parts of the radiofrequency (RF) assembly to be decoupled and operating independently due to the orthogonality of the excited RF transverse magnetic fields. Simulations and phantom experimental imaging show sufficiently homogeneous transverse transmit RF fields and tuning capabilities for the pilot multiheteronuclear experiments.
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Choi CH, Hong SM, Felder J, Tellmann L, Scheins J, Kops ER, Lerche C, Shah NJ. A Novel J-Shape Antenna Array for Simultaneous MR-PET or MR-SPECT Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:1104-1113. [PMID: 34860648 DOI: 10.1109/tmi.2021.3132576] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Simultaneous MR-PET/-SPECT is an emerging technology that capitalises on the invaluable advantages of both modalities, allowing access to numerous sensitive tracers and superior soft-tissue contrast alongside versatile functional imaging capabilities. However, to optimise these capabilities, concurrent acquisitions require the MRI antenna located inside the PET/SPECT field-of-view to be operated without compromising any aspects of system performance or image quality compared to the stand-alone instrumentation. Here, we report a novel gamma-radiation-transparent antenna concept. The end-fed J-shape antenna is particularly adept for hybrid ultra-high field MR-PET/-SPECT applications as it enables all highly attenuating materials to be placed outside the imaging field-of-view. Furthermore, this unique configuration also provides advantages in stand-alone MR applications by reducing the amount of coupling between the cables and the antenna elements, and by lowering the potential specific absorption rate burden. The use of this new design was experimentally verified according to the important features for both ultra-high field MRI and the 511 keV transmission scan. The reconstructed attenuation maps evidently showed much lower attenuation ( ∼ 15 %) for the proposed array when compared to the conventional dipole antenna array since there were no high-density components. In MR, it was observed that the signal-to-noise ratio from the whole volume obtained using the proposed array was comparable to that acquired by the conventional array which was also in agreement with the simulation results. The unique feature, J-shape array, would enable simultaneous MR-PET/-SPECT experiments to be conducted without unduly compromising any aspects of system performance and image quality compared to the stand-alone instrumentation.
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Kajiwara M, Haishi T, Prananto D, Sasaki S, Kaseda R, Narita I, Terada Y. Development of an Add-on 23Na-MRI Radiofrequency Platform for a 1H-MRI System Using a Crossband Repeater: Proof-of-concept. Magn Reson Med Sci 2021; 22:103-115. [PMID: 34897148 PMCID: PMC9849411 DOI: 10.2463/mrms.tn.2021-0094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
23Na-MRI provides information on Na+ content, and its application in the medical field has been highly anticipated. However, for existing clinical 1H-MRI systems, its implementation requires an additional broadband RF transmitter, dedicated transceivers, and RF coils for Na+ imaging. However, a standard medical MRI system cannot often be modified to perform 23Na imaging. We have developed an add-on crossband RF repeater system that enables 23Na-MRI simply by inserting it into the magnet bore of an existing 1H MRI. The three axis gradient fields controlled by the 1H-MRI system were directly used for 23Na imaging without any deformation. A crossband repeater is a common technique used for amateur radio. This concept was proven by a saline solution phantom and in vivo mouse experiments. This add-on RF platform is applicable to medical 1H MRI systems and can enhance the application of 23Na-MRI in clinical usage.
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Affiliation(s)
- Michiru Kajiwara
- Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tomoyuki Haishi
- Department of Radiological Sciences, School of Health Sciences at Narita, International University of Health and Welfare, Narita, Chiba, Japan,MRTechnology Inc., Tsukuba, Ibaraki, Japan,Japan Agency for Medical Research and Development, AMED SENTAN, Tokyo, Japan
| | - Dwi Prananto
- Japan Agency for Medical Research and Development, AMED SENTAN, Tokyo, Japan,Faculty of Engineering, Niigata University, Niigata, Niigata, Japan
| | - Susumu Sasaki
- Japan Agency for Medical Research and Development, AMED SENTAN, Tokyo, Japan,Faculty of Engineering, Niigata University, Niigata, Niigata, Japan
| | - Ryohei Kaseda
- Japan Agency for Medical Research and Development, AMED SENTAN, Tokyo, Japan,Division of Clinical Nephrology and Rheumatology, Niigata University, Niigata, Niigata, Japan
| | - Ichiei Narita
- Japan Agency for Medical Research and Development, AMED SENTAN, Tokyo, Japan,Division of Clinical Nephrology and Rheumatology, Niigata University, Niigata, Niigata, Japan
| | - Yasuhiko Terada
- Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan,Corresponding author: Institute of Applied Physics, University of Tsukuba, 1-1-1, Tennodai, Ibaraki 305-8573, Japan. Phone: +81-29-853-5214, Fax: +81-29-853-5769,
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Celik AA, Choi CH, Tellmann L, Rick C, Shah NJ, Felder J. Design and Construction of a PET-Compatible Double-Tuned 1H/ 31P MR Head Coil. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:2015-2022. [PMID: 33798075 DOI: 10.1109/tmi.2021.3070626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Simultaneous MR-PET is an increasingly popular multimodal imaging technique that is able to combine metabolic information obtained from PET with anatomical/functional information from MRI. One of the key technological challenges of the technique is the integration of a PET-transparent MR coil system, a solution to which is demonstrated here for a double-tuned 1H/31P head coil at 3 T. Two single-resonant birdcage coils tuned to the 1H and 31P resonances were arranged in an interleaved fashion and electrically decoupled with the use of trap circuits. All high 511 keV quanta absorbing components were arranged outside the PET field-of-view in order to minimize count rate reduction. The materials inside the PET field-of-view were carefully evaluated and chosen for minimum impact on the PET image quality. As far as possible, the coil case was geometrically optimized to avoid sharp transitions in attenuation, which may potentially result in streaking artefacts during PET image reconstruction. The coil caused a count rate loss of just above 5% when inserted into the PET detector ring. Except for the anterior region, which was designed to maintain free openings for increased patient comfort, an almost uniform distribution of 511 keV attenuation was maintained around the circumference of the coil. MR-related performance for both nuclei was similar or slightly better than that of a commercial double-tuned coil, despite the MR-PET coil having a close-fitting RF screen to shield the PET and MR electronics from possible electromagnetic interferences.
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Modo M. 19F Magnetic Resonance Imaging and Spectroscopy in Neuroscience. Neuroscience 2021; 474:37-50. [PMID: 33766776 DOI: 10.1016/j.neuroscience.2021.03.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 12/23/2022]
Abstract
1H magnetic resonance imaging (MRI) has established itself as a key diagnostic technique, affording the visualization of brain anatomy, blood flow, activity and connectivity. The detection of other atoms (e.g. 19F, 23Na, 31P), so called hetero-nuclear MRI and spectroscopy (MRS), provides investigative avenues that complement and extend the richness of information that can be gained from 1H MRI. Especially 19F MRI is increasingly emerging as a multi-nuclear (1H/19F) technique that can be exploited to visualize cell migration and trafficking. The lack of a 19F background signal in the brain affords an unequivocal detection suitable for quantification. Fluorine-based contrast material can be engineered as nanoemulsions, nanocapsules, or nanoparticles to label cells in vitro or in vivo. Fluorinated blood substitutes, typically nanoemulsions, can also carry oxygen and serve as a theranostic in poorly perfused brain regions. Brain tissue concentrations of fluorinated pharmaceuticals, including inhalation anesthetics (e.g. isoflurane) and anti-depressants (e.g. fluoxetine), can also be measured using MRS. However, the low signal from these compounds provides a challenge for imaging. Further methodological advances that accelerate signal acquisition (e.g. compressed sensing, cryogenic coils) are required to expand the applications of 19F MR imaging to, for instance, determine the regional pharmacokinetics of novel fluorine-based drugs. Improvements in 19F signal detection and localization, combined with the development of novel sensitive probes, will increase the utility of these multi-nuclear studies. These advances will provide new insights into cellular and molecular processes involved in neurodegenerative disease, as well as the mode of action of pharmaceutical compounds.
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Affiliation(s)
- Michel Modo
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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Wilcox M, Wright SM, McDougall M. A Review of Non- 1H RF Receive Arrays in Magnetic Resonance Imaging and Spectroscopy. IEEE OPEN JOURNAL OF ENGINEERING IN MEDICINE AND BIOLOGY 2020; 1:290-300. [PMID: 35402958 PMCID: PMC8975242 DOI: 10.1109/ojemb.2020.3030531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/15/2020] [Accepted: 09/25/2020] [Indexed: 11/16/2022] Open
Abstract
It is now common practice to use radiofrequency (RF) coils to increase the signal-to-noise ratio (SNR) in 1H magnetic resonance imaging and spectroscopy experiments. Use of array coils for non-1H experiments, however, has been historically more limited despite the fact that these nuclei suffer inherently lower sensitivity and could benefit greatly from an increased SNR. Recent advancements in receiver technology and increased support from scanner manufacturers have now opened greater options for the use of array coils for non-1H magnetic resonance experiments. This paper reviews the research in adopting array coil technology with an emphasis on studies of the most commonly studied non-1H nuclei including 31P, 13C, 23Na, and 19F. These nuclei offer complementary information to 1H imaging and spectroscopy and have proven themselves important in the study of numerous disease processes. While recent work with non-1H array coils has shown promising results, the technology is not yet widely utilized and should see substantial developments in the coming years.
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