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Karabanov A, Kryukov E, Langlais D, Iuga D, Good J. Post-acquisition correction of NMR spectra distorted by dynamic and static field inhomogeneity of cryogen-free magnets. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 353:107494. [PMID: 37348258 DOI: 10.1016/j.jmr.2023.107494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/26/2023] [Accepted: 05/27/2023] [Indexed: 06/24/2023]
Abstract
Post-acquisition correction of NMR spectra is an important part of NMR spectroscopy that enables refined NMR spectra to be obtained, clean from undesirable out-phasing, broadening and noising. We describe analytical and numerical mathematical methods for post-acquisition correction of NMR spectra distorted by static and dynamic magnetic field inhomogeneity caused by imperfections of main superconducting coils and the cold head operation, typical for cryogen-free magnets. For the dynamic inhomogeneity, we apply a variant of the general reference deconvolution method, complemented with our mathematical analysis of spectral parameters. For the static inhomogeneity, we apply the method of a delayed Fourier transform, also supported with our analytical calculations. We verify our approach by correction processing of high-field experimental liquid-state 1H NMR spectra of water and ethanol as well as solid-state 13C MAS NMR spectra of adamantane and obtain good results for both static and dynamic field distortions. This work complements our previous work on instrumental suppression of dynamic distortions caused by the cold head operation. The results presented contribute well to the general field of processing NMR spectra and serve towards a more extensive use of cryogen-free magnets in high-resolution NMR spectroscopy.
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Affiliation(s)
| | | | | | - Dinu Iuga
- The University of Warwick, Coventry, UK
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Tseytlin O, Guggilapu P, Bobko AA, AlAhmad H, Xu X, Epel B, O'Connell R, Hoblitzell EH, Eubank TD, Khramtsov VV, Driesschaert B, Kazkaz E, Tseytlin M. Modular imaging system: Rapid scan EPR at 800 MHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 305:94-103. [PMID: 31238278 PMCID: PMC6656609 DOI: 10.1016/j.jmr.2019.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 06/05/2023]
Abstract
An electron paramagnetic resonance (EPR) imaging system has been custom built for use in pre-clinical and, potentially, clinical studies. Commercial standalone modules have been used in the design that are MATLAB-controlled. The imaging system combines digital and analog technologies. It was designed to achieve maximum flexibility and versatility and to perform standard and novel user-defined experiments. This design goal is achieved by frequency mixing of an arbitrary waveform generator (AWG) output at the intermediate frequency (IF) with a constant source frequency (SF). Low noise SF at 250, 750, and 1000 MHz are available in the system. A wide range of frequencies from near-baseband to L-band can be generated as a result. Two-stage downconversion at the signal detection side is implemented that enables multi-frequency EPR capability. In the first stage, the signal frequency is converted to IF. A novel AWG-enabled digital auto-frequency control method that operates at IF is described that is used for automatic resonator tuning. Quadrature baseband EPR signal is generated in the second downconversion step. The semi-digital approach of mixing low-noise frequency sources with an AWG permits generation of arbitrary excitation patterns that include but are not limited to frequency sweeps for resonator tuning and matching, continuous-wave, and pulse sequences. Presented in this paper is the demonstration of rapid scan (RS) EPR imaging implemented at 800 MHz. Generation of stable magnetic scan waveforms is critical for the RS method. A digital automatic scan control (DASC) system was developed for sinusoidal magnetic field scans. DASC permits tight control of both amplitude and phase of the scans. A surface loop resonator was developed using 3D printing technology. RS EPR imaging system was validated using sample phantoms. In vivo imaging of a breast cancer mouse model is demonstrated.
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Affiliation(s)
- Oxana Tseytlin
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Priyaankadevi Guggilapu
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Andrey A Bobko
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Hussien AlAhmad
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA; Department of Industrial & Management Systems Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Xuan Xu
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Boris Epel
- Center for EPR Imaging In Vivo Physiology, University of Chicago, IL 60637, USA
| | - Ryan O'Connell
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Emily H Hoblitzell
- In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA; Department of Microbiology, Immunology & Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Timothy D Eubank
- In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA; Department of Microbiology, Immunology & Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Valery V Khramtsov
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Benoit Driesschaert
- In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA; Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, USA
| | - Eiad Kazkaz
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA
| | - Mark Tseytlin
- Biochemistry Department, West Virginia University, Morgantown, WV 26506, USA; In Vivo Multifunctional Magnetic Resonance Center at Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA.
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Buntkowsky G, Ivanov K, Vieth HM. From Free Radicals and Spin-Chemistry Over Spin-Dynamics and Hyperpolarization to Biology and Materials Science. Z PHYS CHEM 2017. [DOI: 10.1515/zpch-2016-5006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Gerd Buntkowsky
- Technische Universität Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Alarich-Weiss-Straße 4, Darmstadt 64287, Germany
| | - Konstantin Ivanov
- International Tomography Center, Institutskaya 3A, Novosibirsk 630090, Russia
- Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia
| | - Hans-Martin Vieth
- International Tomography Center, Institutskaya 3A, Novosibirsk 630090, Russia
- Freie Universität Berlin, Institut für Experimentalphysik, Arnimallee 14, Berlin 14195, Germany
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