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Qiu Y, Dai K, Zhong S, Chen S, Wang C, Chen H, Frydman L, Zhang Z. Spatiotemporal encoding MRI in a portable low-field system. Magn Reson Med 2024; 92:1011-1021. [PMID: 38623991 DOI: 10.1002/mrm.30104] [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: 12/05/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/17/2024]
Abstract
PURPOSE Demonstrate the potential of spatiotemporal encoding (SPEN) MRI to deliver largely undistorted 2D, 3D, and diffusion weighted images on a 110 mT portable system. METHODS SPEN's quadratic phase modulation was used to subsample the low-bandwidth dimension of echo planar acquisitions, delivering alias-free images with an enhanced immunity to image distortions in a laboratory-built, low-field, portable MRI system lacking multiple receivers. RESULTS Healthy brain images with different SPEN time-bandwidth products and subsampling factors were collected. These compared favorably to EPI acquisitions including topup corrections. Robust 3D and diffusion weighted SPEN images of diagnostic value were demonstrated, with 2.5 mm isotropic resolutions achieved in 3 min scans. This performance took advantage of the low specific absorption rate and relative long TEs associated with low-field MRI. CONCLUSION SPEN MRI provides a robust and advantageous fast acquisition approach to obtain faithful 3D images and DWI data in low-cost, portable, low-field systems without parallel acceleration.
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Affiliation(s)
- Yueqi Qiu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, People's Republic of China
- Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Ke Dai
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Sijie Zhong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, People's Republic of China
- Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Suen Chen
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, People's Republic of China
- Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Changyue Wang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Hao Chen
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, People's Republic of China
- Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Zhiyong Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, People's Republic of China
- Institute of Medical Robotics, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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Tayler MCD, Bodenstedt S. NMRduino: A modular, open-source, low-field magnetic resonance platform. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 362:107665. [PMID: 38598992 DOI: 10.1016/j.jmr.2024.107665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/06/2024] [Accepted: 03/20/2024] [Indexed: 04/12/2024]
Abstract
The NMRduino is a compact, cost-effective, sub-MHz NMR spectrometer that utilizes readily available open-source hardware and software components. One of its aims is to simplify the processes of instrument setup and data acquisition control to make experimental NMR spectroscopy accessible to a broader audience. In this introductory paper, the key features and potential applications of NMRduino are described to highlight its versatility both for research and education.
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Affiliation(s)
- Michael C D Tayler
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
| | - Sven Bodenstedt
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
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3
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Kawabata N, Asakawa N. Scanning ex situ solid-state magnetic resonance imaging on polymeric films using a static magnetic field gradient by an electromagnet. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:043701. [PMID: 38557881 DOI: 10.1063/5.0188529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
A new technique for ex situ solid-state nuclear magnetic resonance imaging of polymeric films has been developed. This method uses the static magnetic field gradient generated by a water-cooled copper electromagnet. The imaging process involves scanning the sample in the plane of the film under a static magnetic field gradient. Two-dimensional (2D) 19F MRI measurements are attempted, where the fast Fourier transform (FFT) spectra of the second half of a Hahn echo peak is used for the depth (X-axis) direction, and the sample film is mechanically moved for the Y-axis, which is in-plane with respect to the film surface and normal to the inter-magnetic-pole line (Z-axis). The sample is a poly(tetrafluoroethylene) [PTFE] film with carved stripes on its surface. Furthermore, three-dimensional (3D) measurements of the film surface and thickness orientations were also performed for an analogous PTFE film. For 2D profiling on the film surface, 2D sample-moving was used. For depth profiling, FFT spectrum analysis was undertaken for each voxel situated at a specific (Y, Z) coordinate within the film. As a result, a 3D image of the sample and its corresponding geometry were obtained, although the scanning area was restricted to a part of the sample. Finally, numerical simulations of the spatial distribution of the static magnetic field were performed to confirm the validity of the present method.
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Affiliation(s)
- Natsuki Kawabata
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjincho, Kiryu, Gunma 3768515, Japan
| | - Naoki Asakawa
- Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjincho, Kiryu, Gunma 3768515, Japan
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Berzins A, Grube H, Lazda R, Hannig MA, Smits J, Fescenko I. Tunable magnetic field source for magnetic field imaging microscopy. Ultramicroscopy 2022; 242:113624. [DOI: 10.1016/j.ultramic.2022.113624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 07/21/2022] [Accepted: 09/24/2022] [Indexed: 11/25/2022]
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Silva P, Jouda M, Korvink J. Magnetostatic reciprocity for MR magnet design. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2021; 2:607-617. [PMID: 37905211 PMCID: PMC10539805 DOI: 10.5194/mr-2-607-2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 06/29/2021] [Indexed: 11/02/2023]
Abstract
Electromagnetic reciprocity has long been a staple in magnetic resonance (MR) radio-frequency development, offering geometrical insights and a figure of merit for various resonator designs. In a similar manner, we use magnetostatic reciprocity to compute manufacturable solutions of complex magnet geometries, by establishing a quantitative metric for the placement and subsequent orientation of discrete pieces of permanent magnetic material. Based on magnetostatic theory and non-linear finite element modelling (FEM) simulations, it is shown how assembled permanent magnet setups perform in the embodiment of a variety of designs and how magnetostatic reciprocity is leveraged in the presence of difficulties associated with self-interactions, to fulfil various design objectives, including self-assembled micro-magnets, adjustable magnetic arrays, and an unbounded magnetic field intensity in a small volume, despite realistic saturation field strengths.
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Affiliation(s)
- Pedro Freire Silva
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, 76131 Karlsruhe, Germany
| | - Mazin Jouda
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, 76131 Karlsruhe, Germany
| | - Jan G. Korvink
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, 76131 Karlsruhe, Germany
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6
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Koolstra K, O'Reilly T, Börnert P, Webb A. Image distortion correction for MRI in low field permanent magnet systems with strong B 0 inhomogeneity and gradient field nonlinearities. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2021; 34:631-642. [PMID: 33502668 PMCID: PMC8338849 DOI: 10.1007/s10334-021-00907-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/14/2022]
Abstract
Objective To correct for image distortions produced by standard Fourier reconstruction techniques on low field permanent magnet MRI systems with strong \documentclass[12pt]{minimal}
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\begin{document}$${B}_{0}$$\end{document}B0 inhomogeneity and gradient field nonlinearities. Materials and methods Conventional image distortion correction algorithms require accurate \documentclass[12pt]{minimal}
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\begin{document}$${\Delta B}_{0}$$\end{document}ΔB0 maps which are not possible to acquire directly when the \documentclass[12pt]{minimal}
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\begin{document}$${B}_{0}$$\end{document}B0 inhomogeneities also produce significant image distortions. Here we use a readout gradient time-shift in a TSE sequence to encode the \documentclass[12pt]{minimal}
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\begin{document}$${B}_{0}$$\end{document}B0 field inhomogeneities in the k-space signals. Using a non-shifted and a shifted acquisition as input, \documentclass[12pt]{minimal}
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\begin{document}$$\Delta {B}_{0}$$\end{document}ΔB0 maps and images were reconstructed in an iterative manner. In each iteration, \documentclass[12pt]{minimal}
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\begin{document}$$\Delta {B}_{0}$$\end{document}ΔB0 maps were reconstructed from the phase difference using Tikhonov regularization, while images were reconstructed using either conjugate phase reconstruction (CPR) or model-based (MB) image reconstruction, taking the reconstructed field map into account. MB reconstructions were, furthermore, combined with compressed sensing (CS) to show the flexibility of this approach towards undersampling. These methods were compared to the standard fast Fourier transform (FFT) image reconstruction approach in simulations and measurements. Distortions due to gradient nonlinearities were corrected in CPR and MB using simulated gradient maps. Results Simulation results show that for moderate field inhomogeneities and gradient nonlinearities, \documentclass[12pt]{minimal}
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\begin{document}$$\Delta {B}_{0}$$\end{document}ΔB0 maps and images reconstructed using iterative CPR result in comparable quality to that for iterative MB reconstructions. However, for stronger inhomogeneities, iterative MB reconstruction outperforms iterative CPR in terms of signal intensity correction. Combining MB with CS, similar image and \documentclass[12pt]{minimal}
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\begin{document}$$\Delta {B}_{0}$$\end{document}ΔB0 map quality can be obtained without a scan time penalty. These findings were confirmed by experimental results. Discussion In case of \documentclass[12pt]{minimal}
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\begin{document}$${B}_{0}$$\end{document}B0 inhomogeneities in the order of kHz, iterative MB reconstructions can help to improve both image quality and \documentclass[12pt]{minimal}
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\begin{document}$$\Delta {B}_{0}$$\end{document}ΔB0 map estimation. Supplementary Information The online version contains supplementary material available at 10.1007/s10334-021-00907-2.
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Affiliation(s)
- Kirsten Koolstra
- Radiology, Division of Image Processing, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
| | - Thomas O'Reilly
- Radiology, C.J. Gorter Center for High-Field MRI, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Peter Börnert
- Radiology, C.J. Gorter Center for High-Field MRI, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.,Philips Research, Röntgenstraβe 24-26, 22335, Hamburg, Germany
| | - Andrew Webb
- Radiology, C.J. Gorter Center for High-Field MRI, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
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Alcicek S, Put P, Kontul V, Pustelny S. Zero-Field NMR J-Spectroscopy of Organophosphorus Compounds. J Phys Chem Lett 2021; 12:787-792. [PMID: 33411543 PMCID: PMC7877728 DOI: 10.1021/acs.jpclett.0c03532] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Organophosphorus compounds are a wide and diverse class of chemicals playing a crucial role in living organisms. This aspect has been often investigated using nuclear magnetic resonance (NMR), which provides information about molecular structure and function. In this paper, we report the results of theoretical and experimental studies on basic organophosphorus compounds using zero-field NMR, where spin dynamics are investigated in the absence of a magnetic field with the dominant heteronuclear J-coupling. We demonstrate that the zero-field NMR enables distinguishing the chemicals owing to their unique electronic environment even though their spin systems have the same alphabetic designation. Such information can be obtained just in a single measurement, while amplitudes and widths of observed low-field NMR resonances enable the study of processes affecting spin dynamics. An excellent agreement between simulations and measurements of the spectra, particularly in the largest frequency J-couplings range ever reported in zero-field NMR, is demonstrated.
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De Wever P, de Oliveira-Silva R, Marreiros J, Ameloot R, Sakellariou D, Fardim P. Topochemical Engineering of Cellulose-Carboxymethyl Cellulose Beads: A Low-Field NMR Relaxometry Study. Molecules 2020; 26:E14. [PMID: 33375128 PMCID: PMC7792948 DOI: 10.3390/molecules26010014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
The demand for more ecological, highly engineered hydrogel beads is driven by a multitude of applications such as enzyme immobilization, tissue engineering and superabsorbent materials. Despite great interest in hydrogel fabrication and utilization, the interaction of hydrogels with water is not fully understood. In this work, NMR relaxometry experiments were performed to study bead-water interactions, by probing the changes in bead morphology and surface energy resulting from the incorporation of carboxymethyl cellulose (CMC) into a cellulose matrix. The results show that CMC improves the swelling capacity of the beads, from 1.99 to 17.49, for pure cellulose beads and beads prepared with 30% CMC, respectively. Changes in water mobility and interaction energy were evaluated by NMR relaxometry. Our findings indicate a 2-fold effect arising from the CMC incorporation: bead/water interactions were enhanced by the addition of CMC, with minor additions having a greater effect on the surface energy parameter. At the same time, bead swelling was recorded, leading to a reduction in surface-bound water, enhancing water mobility inside the hydrogels. These findings suggest that topochemical engineering by adjusting the carboxymethyl cellulose content allows the tuning of water mobility and porosity in hybrid beads and potentially opens up new areas of application for this biomaterial.
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Affiliation(s)
- Pieter De Wever
- Bio- & Chemical Systems Technology, Reactor Engineering and Safety Section, Department of Chemical engineering, KU Leuven, Celestijnenlaan 200f, P.O. Box 2424, 3001 Leuven, Belgium;
| | - Rodrigo de Oliveira-Silva
- Centre for Membrane Separations, Adsorption, Catalysis, and Spectroscopy for Sustainable Solutions, Department of Microbial and Molecular Systems, Celestijnenlaan 200f, P.O. Box 2454, 3001 Leuven, Belgium; (R.d.O.-S.); (J.M.); (R.A.); (D.S.)
| | - João Marreiros
- Centre for Membrane Separations, Adsorption, Catalysis, and Spectroscopy for Sustainable Solutions, Department of Microbial and Molecular Systems, Celestijnenlaan 200f, P.O. Box 2454, 3001 Leuven, Belgium; (R.d.O.-S.); (J.M.); (R.A.); (D.S.)
| | - Rob Ameloot
- Centre for Membrane Separations, Adsorption, Catalysis, and Spectroscopy for Sustainable Solutions, Department of Microbial and Molecular Systems, Celestijnenlaan 200f, P.O. Box 2454, 3001 Leuven, Belgium; (R.d.O.-S.); (J.M.); (R.A.); (D.S.)
| | - Dimitrios Sakellariou
- Centre for Membrane Separations, Adsorption, Catalysis, and Spectroscopy for Sustainable Solutions, Department of Microbial and Molecular Systems, Celestijnenlaan 200f, P.O. Box 2454, 3001 Leuven, Belgium; (R.d.O.-S.); (J.M.); (R.A.); (D.S.)
| | - Pedro Fardim
- Bio- & Chemical Systems Technology, Reactor Engineering and Safety Section, Department of Chemical engineering, KU Leuven, Celestijnenlaan 200f, P.O. Box 2424, 3001 Leuven, Belgium;
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Bogaychuk A, Kuzmin V. Accounting for material imperfections in the design and optimization of low cost Halbach magnets. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:103904. [PMID: 33138559 DOI: 10.1063/5.0013274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate an experimental method for the improvement of the magnetic field homogeneity in Halbach magnets by taking magnet material imperfection into account. This method relies on the determination of the magnetization magnitude only for individual magnet blocks based on nuclear magnetic resonance field measurements in a simplified system, which, in our case, consists of four blocks. Then, a set of configurations with highest homogeneities can be found from simplified field map simulations of all possible configurations or by applying sophisticated optimum search algorithms if the number of blocks is large. Finally, the residual effect of angular magnetization deviations can be reduced by the experimental selection of the best configuration from the set found on the simulation step. This selection strategy is based on the conclusions made from statistical analysis of simulated field maps. By applying the described method to our eight-element magnet, we experimentally achieved tenfold field homogeneity improvement. Thus, in the best configuration, we obtained an average value of the magnetic field of 598.0 mT and a half-width of 226.9 ppm for a sample with a diameter of 4 mm and a height of 10 mm. These parameters along with the compact magnet size (40 × 40 × 102 mm3) and weight (0.6 kg) provide reasonable magnet quality compared with analogous systems having more complex magnet arrangements and significantly higher costs.
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Affiliation(s)
- A Bogaychuk
- Institute of Physics, Kazan Federal University, Kremlyovskaya Str. 18, Kazan 420008, Russia
| | - V Kuzmin
- Institute of Physics, Kazan Federal University, Kremlyovskaya Str. 18, Kazan 420008, Russia
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10
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O’Reilly T, Teeuwisse WM, de Gans D, Koolstra K, Webb AG. In vivo 3D brain and extremity MRI at 50 mT using a permanent magnet Halbach array. Magn Reson Med 2020; 85:495-505. [PMID: 32627235 PMCID: PMC7689769 DOI: 10.1002/mrm.28396] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/31/2020] [Accepted: 06/04/2020] [Indexed: 11/07/2022]
Abstract
Purpose To design a low‐cost, portable permanent magnet‐based MRI system capable of obtaining in vivo MR images within a reasonable scan time. Methods A discretized Halbach permanent magnet array with a clear bore diameter of 27 cm was designed for operation at 50 mT. Custom‐built gradient coils, RF coil, gradient amplifiers, and RF amplifier were integrated and tested on both phantoms and in vivo. Results Phantom results showed that the gradient nonlinearity in the y‐direction and z‐direction was less than 5% over a 15‐cm FOV and did not need correcting. For the x‐direction, it was significantly greater, but could be partially corrected in postprocessing. Three‐dimensional in vivo scans of the brain of a healthy volunteer using a turbo spin‐echo sequence were acquired at a spatial resolution of 4 × 4 × 4 mm in a time of about 2 minutes. The T1‐weighted and T2‐weighted scans showed a good degree of tissue contrast. In addition, in vivo scans of the knee of a healthy volunteer were acquired at a spatial resolution of about 3 × 2 × 2 mm within 12 minutes to show the applicability of the system to extremity imaging. Conclusion This work has shown that it is possible to construct a low‐field MRI unit with hardware components costing less than 10 000 Euros, which is able to acquire human images in vivo within a reasonable data‐acquisition time. The system has a high degree of portability with magnet weight of approximately 75 kg, gradient and RF amplifiers each 15 kg, gradient coils 10 kg, and spectrometer 5 kg.
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Affiliation(s)
- Thomas O’Reilly
- C.J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Wouter M. Teeuwisse
- C.J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | | | - Kirsten Koolstra
- C.J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Andrew G. Webb
- C.J. Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
- Technical University DelftDelftThe Netherlands
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11
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Kaseman DC, Magnelind PE, Widgeon Paisner S, Yoder JL, Alvarez M, Urbaitis AV, Janicke MT, Nath P, Espy MA, Williams RF. Design and implementation of a J-coupled spectrometer for multidimensional structure and relaxation detection at low magnetic fields. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:054103. [PMID: 32486714 DOI: 10.1063/1.5130391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
In recent years, it has been realized that low and ultra-low field (mT-nT magnetic field range) nuclear magnetic resonance spectroscopy can be used for molecular structural analysis. However, spectra are often hindered by lengthy acquisition times or require large sample volumes and high concentrations. Here, we report a low field (50 μT) instrument that employs a linear actuator to shuttle samples between a 1 T prepolarization field and a solenoid detector in a laboratory setting. The current experimental setup is benchmarked using water and 13C-methanol with a single scan detection limit of 2 × 1020 spins (3 µl, 55M H2O) and detection limit of 2.9 × 1019 (200 µl, 617 mM 13C-methanol) spins with signal averaging. The system has a dynamic range of >3 orders of magnitude. Investigations of room-temperature relaxation dynamics of 13C-methanol show that sample dilution can be used in lieu of sample heating to acquire spectra with linewidths comparable to high-temperature spectra. These results indicate that the T1 and T2 mechanisms are governed by both the proton exchange rate and the dissolved oxygen in the sample. Finally, a 2D correlation spectroscopy experiment is reported, performed in the strong coupling regime that resolves the multiple resonances associated with the heteronuclear J-coupling. The spectrum was collected using 10 times less sample and in less than half the time from previous reports in the strong coupling limit.
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Affiliation(s)
- Derrick C Kaseman
- Bioenergy and Biome Sciences Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Per E Magnelind
- Quantum Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Scarlett Widgeon Paisner
- Materials Science in Radiation and Dynamics Extremes Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Jacob L Yoder
- Bioenergy and Biome Sciences Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Marc Alvarez
- Bioenergy and Biome Sciences Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Algis V Urbaitis
- Quantum Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Michael T Janicke
- Inorganic, Isotope and Actinide Chemistry Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Pulak Nath
- Quantum Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Michelle A Espy
- Non-destructive Testing and Evaluation Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Robert F Williams
- Bioenergy and Biome Sciences Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Cooley CZ, Stockmann JP, Witzel T, LaPierre C, Mareyam A, Jia F, Zaitsev M, Wenhui Y, Zheng W, Stang P, Scott G, Adalsteinsson E, White JK, Wald LL. Design and implementation of a low-cost, tabletop MRI scanner for education and research prototyping. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 310:106625. [PMID: 31765969 DOI: 10.1016/j.jmr.2019.106625] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/19/2019] [Accepted: 10/20/2019] [Indexed: 06/10/2023]
Abstract
While access to a laboratory MRI system is ideal for teaching MR physics as well as many aspects of signal processing, providing multiple MRI scanners can be prohibitively expensive for educational settings. To address this need, we developed a small, low-cost, open-interface tabletop MRI scanner for academic use. We constructed and tested 20 of these scanners for parallel use by teams of 2-3 students in a teaching laboratory. With simplification and down-scaling to a 1 cm FOV, fully-functional scanners were achieved within a budget of $10,000 USD each. The design was successful for teaching MR principles and basic signal processing skills and serves as an accessible testbed for more advanced MR research projects. Customizable GUIs, pulse sequences, and reconstruction code accessible to the students facilitated tailoring the scanner to the needs of laboratory exercise. The scanners have been used by >800 students in 6 different courses and all designs, schematics, sequences, GUIs, and reconstruction code is open-source.
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Affiliation(s)
- Clarissa Zimmerman Cooley
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - Jason P Stockmann
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Thomas Witzel
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Cris LaPierre
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Azma Mareyam
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Feng Jia
- Dept. of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maxim Zaitsev
- Dept. of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Yang Wenhui
- Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
| | - Wang Zheng
- Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
| | - Pascal Stang
- Procyon Engineering, San Jose, CA, USA; Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Greig Scott
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Elfar Adalsteinsson
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, USA
| | - Jacob K White
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lawrence L Wald
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA; Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, USA
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13
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Tayler MCD, Gladden LF. Scalar relaxation of NMR transitions at ultralow magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 298:101-106. [PMID: 30544013 DOI: 10.1016/j.jmr.2018.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/24/2018] [Accepted: 11/27/2018] [Indexed: 05/27/2023]
Abstract
Nuclear magnetic resonance signals for 1H in simple chlorinated, brominated and deuterated liquids were detected at field strengths between 1 nT and a few μT to investigate the influence of scalar relaxation of the second kind (SR2K). SR2K describes the acceleration in magnetization decay rate for a spin-1/2 nucleus that is scalar coupled to a fast-relaxing quadrupolar nucleus. In agreement with simple theoretical models, the experimental data show that couplings to nuclei with small, nonzero quadrupole moments (2H) give rise to higher transverse relaxation rates at ultralow field than rapidly relaxing quadrupolar nuclei (Cl and Br). This behavior is opposite to the case normally encountered in high-field NMR, and demonstrates that certain nuclei in the spin system may be "weakly coupled" or even decoupled when the applied magnetic field is zero. The results show that the capability for precision determination of NMR frequencies and molecular structural information depends strongly on the composition and topology of the nuclear spin system.
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Affiliation(s)
- Michael C D Tayler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK.
| | - Lynn F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
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14
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Tayler MCD, Ward-Williams J, Gladden LF. NMR relaxation in porous materials at zero and ultralow magnetic fields. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:1-8. [PMID: 30316016 DOI: 10.1016/j.jmr.2018.09.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/28/2018] [Accepted: 09/29/2018] [Indexed: 06/08/2023]
Abstract
NMR detection in the ultralow-field regime (below 10 μT) was used to measure the nuclear spin relaxation rates of liquids imbibed into silica pellets with mean pore diameters in the 10-50 nm range. Heptane, formic acid and acetic acid were studied and relaxation rate data were compared with a conventional field-cycling NMR technique. Detection of 1H-13C spin coupling NMR signals at zero field (∼0.1 nT) allowed spectroscopic identification of molecules inside the porous material and unambiguous measurements of the chemistry-specific relaxation rates in liquid mixtures. In the case of molecules that contain 1H and 13C, spin-singlet state relaxation can provide additional information about the dynamics. Applications and future improvements to the methodology are discussed.
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Affiliation(s)
- Michael C D Tayler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK.
| | - Jordan Ward-Williams
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
| | - Lynn F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
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15
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Rossi L, Gerritsen JW, Nelemans L, Khajetoorians AA, Bryant B. An ultra-compact low temperature scanning probe microscope for magnetic fields above 30 T. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:113706. [PMID: 30501346 DOI: 10.1063/1.5046578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/18/2018] [Indexed: 06/09/2023]
Abstract
We present the design of a highly compact high field scanning probe microscope (HF-SPM) for operation at cryogenic temperatures in an extremely high magnetic field, provided by a water-cooled Bitter magnet able to reach 38 T. The HF-SPM is 14 mm in diameter: an Attocube nano-positioner controls the coarse approach of a piezoresistive atomic force microscopy cantilever to a scanned sample. The Bitter magnet constitutes an extreme environment for scanning probe microscopy (SPM) due to the high level of vibrational noise; the Bitter magnet noise at frequencies up to 300 kHz is characterized, and noise mitigation methods are described. The performance of the HF-SPM is demonstrated by topographic imaging and noise measurements at up to 30 T. Additionally, the use of the SPM as a three-dimensional dilatometer for magnetostriction measurements is demonstrated via measurements on a magnetically frustrated spinel sample.
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Affiliation(s)
- L Rossi
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Nijmegen, The Netherlands
| | - J W Gerritsen
- Institute of Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - L Nelemans
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Nijmegen, The Netherlands
| | - A A Khajetoorians
- Institute of Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - B Bryant
- High Field Magnet Laboratory (HFML-EMFL), Radboud University, Nijmegen, The Netherlands
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16
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Hibino Y, Sugahara K, Muro Y, Tanaka H, Sato T, Kondo Y. Simple and low-cost tabletop NMR system for chemical-shift-resolution spectra measurements. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 294:128-132. [PMID: 30036813 DOI: 10.1016/j.jmr.2018.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/08/2018] [Accepted: 07/06/2018] [Indexed: 05/03/2023]
Abstract
We have been working on developing a low-cost tabletop NMR system. We reported that a field homogeneity as high as 50 ppm was achieved with a simple NMR magnet by employing two facing ferrite magnets with iron disks in between (Chonlathep et al., 2017). In this paper, we report two improvements added to our previous system: (1) an FPGA based signal processing unit to improve the S/N ratio and (2) a simple shimming mechanism to improve the field homogeneity. We obtained as high as 1 ppm field homogeneity in the best case. The signals from hydrogen nuclear spins in a methyl and carboxy group in acetic acid were resolved in NMR spectra.
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Affiliation(s)
- Y Hibino
- Graduate School of Science and Engineering Research, Kindai University, 577-8502 Higashi-Osaka, Japan.
| | - K Sugahara
- Graduate School of Science and Engineering Research, Kindai University, 577-8502 Higashi-Osaka, Japan; Department of Electronics and Engineering, Kindai University, 577-8502 Higashi-Osaka, Japan.
| | - Y Muro
- THAMWAY Co., Ltd, 417-0001 Fuji, Japan
| | - H Tanaka
- THAMWAY Co., Ltd, 417-0001 Fuji, Japan
| | - T Sato
- THAMWAY Co., Ltd, 417-0001 Fuji, Japan
| | - Y Kondo
- Graduate School of Science and Engineering Research, Kindai University, 577-8502 Higashi-Osaka, Japan; Department of Physics, Kindai University, 577-8502 Higashi-Osaka, Japan.
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17
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Bashyam A, Li M, Cima MJ. Design and experimental validation of Unilateral Linear Halbach magnet arrays for single-sided magnetic resonance. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 292:36-43. [PMID: 29763794 DOI: 10.1016/j.jmr.2018.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 06/08/2023]
Abstract
Single-sided NMR has the potential for broad utility and has found applications in healthcare, materials analysis, food quality assurance, and the oil and gas industry. These sensors require a remote, strong, uniform magnetic field to perform high sensitivity measurements. We demonstrate a new permanent magnet geometry, the Unilateral Linear Halbach, that combines design principles from "sweet-spot" and linear Halbach magnets to achieve this goal through more efficient use of magnetic flux. We perform sensitivity analysis using numerical simulations to produce a framework for Unilateral Linear Halbach design and assess tradeoffs between design parameters. Additionally, the use of hundreds of small, discrete magnets within the assembly allows for a tunable design, improved robustness to variability in magnetization strength, and increased safety during construction. Experimental validation using a prototype magnet shows close agreement with the simulated magnetic field. The Unilateral Linear Halbach magnet increases the sensitivity, portability, and versatility of single-sided NMR.
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Affiliation(s)
- Ashvin Bashyam
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States; Electrical Engineering & Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States.
| | - Matthew Li
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States; Harvard-MIT Program of Health Sciences and Technology, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States.
| | - Michael J Cima
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States; Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, United States.
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