1
|
Karasawa T, Saikawa J, Munaka T, Kobayashi T. Homogeneous B0 coil design method for open-access ultra-low field magnetic resonance imaging: A simulation study. Magn Reson Imaging 2024; 112:128-135. [PMID: 38986889 DOI: 10.1016/j.mri.2024.07.006] [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: 03/26/2024] [Revised: 06/10/2024] [Accepted: 07/03/2024] [Indexed: 07/12/2024]
Abstract
A multimodal brain function measurement system integrating functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) is expected to be a tool that will provide new insights into neuroscience. To integrate fMRI and MEG, an ultra-low-field MRI (ULF-MRI) scanner that can generate a static magnetic field (B0) with an electromagnetic coil and turn off the B0 during MEG measurements is desirable. While electromagnetic B0 coil has the above advantages, it also has a trade-off between size and the broadness of the magnetic field homogeneity. In this study, we proposed a method for designing a B0 multi-stage circular coil arrangement that determines the number of coils required to maximize magnetic field homogeneity and minimize the total wiring length of the coils. The optimized multi-stage coil arrangement had an external shape of 600 mm in diameter and a maximum height of 600 mm, with an aperture of 600 mm in diameter and 300 mm in height. The magnetic field homogeneity was <100 ppm over a 210 mm diameter spherical volume (DSV). Compared to a previous two coil pairs arrangement with the same magnetic field homogeneity, the diameter was 1/1.9 times smaller, indicating that the newly designed B0 coil arrangement realized a smaller size and wider magnetic field homogeneity.
Collapse
Affiliation(s)
- Tomohiro Karasawa
- Technology Research Laboratory, Shimadzu corporation, 3-9-4, Hikaridai, Seika-cho, Soraku-gun 619-0237, Japan
| | - Jiro Saikawa
- Technology Research Laboratory, Shimadzu corporation, 3-9-4, Hikaridai, Seika-cho, Soraku-gun 619-0237, Japan
| | - Tatsuya Munaka
- Technology Research Laboratory, Shimadzu corporation, 3-9-4, Hikaridai, Seika-cho, Soraku-gun 619-0237, Japan
| | - Tetsuo Kobayashi
- Office of Institutional Advancement and Communications, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
| |
Collapse
|
2
|
Kung HT, Cui SX, Kaplan JT, Joshi AA, Leahy RM, Nayak KS, Haldar JP. Diffusion tensor brain imaging at 0.55T: A feasibility study. Magn Reson Med 2024; 92:1649-1657. [PMID: 38725132 DOI: 10.1002/mrm.30156] [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: 11/06/2023] [Revised: 04/09/2024] [Accepted: 04/28/2024] [Indexed: 07/23/2024]
Abstract
PURPOSE To investigate the feasibility of diffusion tensor brain imaging at 0.55T with comparisons against 3T. METHODS Diffusion tensor imaging data with 2 mm isotropic resolution was acquired on a cohort of five healthy subjects using both 0.55T and 3T scanners. The signal-to-noise ratio (SNR) of the 0.55T data was improved using a previous SNR-enhancing joint reconstruction method that jointly reconstructs the entire set of diffusion weighted images from k-space using shared-edge constraints. Quantitative diffusion tensor parameters were estimated and compared across field strengths. We also performed a test-retest assessment of repeatability at each field strength. RESULTS After applying SNR-enhancing joint reconstruction, the diffusion tensor parameters obtained from 0.55T data were strongly correlated (R 2 ≥ 0 . 70 $$ {R}^2\ge 0.70 $$ ) with those obtained from 3T data. Test-retest analysis showed that SNR-enhancing reconstruction improved the repeatability of the 0.55T diffusion tensor parameters. CONCLUSION High-resolution in vivo diffusion MRI of the human brain is feasible at 0.55T when appropriate noise-mitigation strategies are applied.
Collapse
Affiliation(s)
- Hao-Ting Kung
- Signal and Image Processing Institute, Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California, USA
| | - Sophia X Cui
- Siemens Medical Solutions USA, Los Angeles, California, USA
| | - Jonas T Kaplan
- Brain and Creativity Institute, University of Southern California, Los Angeles, California, USA
| | - Anand A Joshi
- Signal and Image Processing Institute, Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California, USA
| | - Richard M Leahy
- Signal and Image Processing Institute, Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California, USA
| | - Krishna S Nayak
- Signal and Image Processing Institute, Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California, USA
| | - Justin P Haldar
- Signal and Image Processing Institute, Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California, USA
- Brain and Creativity Institute, University of Southern California, Los Angeles, California, USA
| |
Collapse
|
3
|
Sorby-Adams A, Guo J, de Havenon A, Payabvash S, Sze G, Pinter NK, Jaikumar V, Siddiqui A, Baldassano S, Garcia-Guarniz AL, Zabinska J, Lalwani D, Peasley E, Goldstein JN, Nelson OK, Schaefer PW, Wira CR, Pitts J, Lee V, Muir KW, Nimjee SM, Kirsch J, Eugenio Iglesias J, Rosen MS, Sheth KN, Kimberly WT. Diffusion-Weighted Imaging Fluid-Attenuated Inversion Recovery Mismatch on Portable, Low-Field Magnetic Resonance Imaging Among Acute Stroke Patients. Ann Neurol 2024; 96:321-331. [PMID: 38738750 PMCID: PMC11293843 DOI: 10.1002/ana.26954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/14/2024]
Abstract
OBJECTIVE For stroke patients with unknown time of onset, mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can guide thrombolytic intervention. However, access to MRI for hyperacute stroke is limited. Here, we sought to evaluate whether a portable, low-field (LF)-MRI scanner can identify DWI-FLAIR mismatch in acute ischemic stroke. METHODS Eligible patients with a diagnosis of acute ischemic stroke underwent LF-MRI acquisition on a 0.064-T scanner within 24 h of last known well. Qualitative and quantitative metrics were evaluated. Two trained assessors determined the visibility of stroke lesions on LF-FLAIR. An image coregistration pipeline was developed, and the LF-FLAIR signal intensity ratio (SIR) was derived. RESULTS The study included 71 patients aged 71 ± 14 years and a National Institutes of Health Stroke Scale of 6 (interquartile range 3-14). The interobserver agreement for identifying visible FLAIR hyperintensities was high (κ = 0.85, 95% CI 0.70-0.99). Visual DWI-FLAIR mismatch had a 60% sensitivity and 82% specificity for stroke patients <4.5 h, with a negative predictive value of 93%. LF-FLAIR SIR had a mean value of 1.18 ± 0.18 <4.5 h, 1.24 ± 0.39 4.5-6 h, and 1.40 ± 0.23 >6 h of stroke onset. The optimal cut-point for LF-FLAIR SIR was 1.15, with 85% sensitivity and 70% specificity. A cut-point of 6.6 h was established for a FLAIR SIR <1.15, with an 89% sensitivity and 62% specificity. INTERPRETATION A 0.064-T portable LF-MRI can identify DWI-FLAIR mismatch among patients with acute ischemic stroke. Future research is needed to prospectively validate thresholds and evaluate a role of LF-MRI in guiding thrombolysis among stroke patients with uncertain time of onset. ANN NEUROL 2024;96:321-331.
Collapse
Affiliation(s)
- Annabel Sorby-Adams
- Department of Neurology and the Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Jennifer Guo
- Department of Neurology and the Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Adam de Havenon
- Department of Neurology, Yale Center for Brain & Mind Health, Yale School of Medicine, New Haven, CT, USA
| | - Seyedmehdi Payabvash
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Gordon Sze
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Nandor K. Pinter
- Department of Radiology, Jacobs School of Medicine & Biomedical Sciences, University of Buffalo, Buffalo, New York, USA
- Department of Neurosurgery, Jacobs School of Medicine & Biomedical Sciences, University of Buffalo, Buffalo, New York, USA
| | - Vinay Jaikumar
- Department of Neurosurgery, Jacobs School of Medicine & Biomedical Sciences, University of Buffalo, Buffalo, New York, USA
| | - Adnan Siddiqui
- Department of Neurosurgery, Jacobs School of Medicine & Biomedical Sciences, University of Buffalo, Buffalo, New York, USA
| | - Steven Baldassano
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Ana-Lucia Garcia-Guarniz
- Department of Neurology and the Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Julia Zabinska
- Department of Neurology, Yale Center for Brain & Mind Health, Yale School of Medicine, New Haven, CT, USA
| | - Dheeraj Lalwani
- Department of Neurology, Yale Center for Brain & Mind Health, Yale School of Medicine, New Haven, CT, USA
| | - Emma Peasley
- Department of Neurology, Yale Center for Brain & Mind Health, Yale School of Medicine, New Haven, CT, USA
| | - Joshua N. Goldstein
- Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Olivia K. Nelson
- Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Pamela W. Schaefer
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Charles R. Wira
- Department of Emergency Medicine, Yale New Haven Hospital and Yale School of Medicine, New Haven, Connecticut, USA
| | - John Pitts
- Hyperfine Incorporated, Guilford, Connecticut, USA
| | - Vivien Lee
- Wexner Medical Center, Ohio State University, Columbus, Ohio, USA
| | - Keith W. Muir
- School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
| | - Shahid M. Nimjee
- Wexner Medical Center, Ohio State University, Columbus, Ohio, USA
| | - John Kirsch
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Juan Eugenio Iglesias
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Centre for Medical Image Computing, University College London, London, UK
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Matthew S. Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Kevin N. Sheth
- Department of Neurology, Yale Center for Brain & Mind Health, Yale School of Medicine, New Haven, CT, USA
| | - W. Taylor Kimberly
- Department of Neurology and the Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
4
|
Su S, Zhao Y, Ding Y, Lau V, Xiao L, Leung GKK, Lau GKK, Huang F, Vardhanabhuti V, Leong ATL, Wu EX. Ultra-low-field magnetization transfer imaging at 0.055T with low specific absorption rate. Magn Reson Med 2024. [PMID: 39044654 DOI: 10.1002/mrm.30231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 06/14/2024] [Accepted: 07/09/2024] [Indexed: 07/25/2024]
Abstract
PURPOSE To demonstrate magnetization transfer (MT) effects with low specific absorption rate (SAR) on ultra-low-field (ULF) MRI. METHODS MT imaging was implemented by using sinc-modulated RF pulse train (SPT) modules to provide bilateral off-resonance irradiation. They were incorporated into 3D gradient echo (GRE) and fast spin echo (FSE) protocols on a shielding-free 0.055T head scanner. MT effects were first verified using phantoms. Brain MT imaging was conducted in both healthy subjects and patients. RESULTS MT effects were clearly observed in phantoms using six SPT modules with total flip angle 3600° at central primary saturation bands of approximate offset ±786 Hz, even in the presence of large relative B0 inhomogeneity. For brain, strong MT effects were observed in gray matter, white matter, and muscle in 3D GRE and FSE imaging using six and sixteen SPT modules with total flip angle 3600° and 9600°, respectively. Fat, cerebrospinal fluid, and blood exhibited relatively weak MT effects. MT preparation enhanced tissue contrasts in T2-weighted and FLAIR-like images, and improved brain lesion delineation. The estimated MT SAR was 0.0024 and 0.0008 W/kg for two protocols, respectively, which is far below the US Food and Drug Administration (FDA) limit of 3.0 W/kg. CONCLUSION Robust MT effects can be readily obtained at ULF with extremely low SAR, despite poor relative B0 homogeneity in ppm. This unique advantage enables flexible MT pulse design and implementation on low-cost ULF MRI platforms to achieve strong MT effects in brain and beyond, potentially augmenting their clinical utility in the future.
Collapse
Affiliation(s)
- Shi Su
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Yujiao Zhao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Ye Ding
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Vick Lau
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Linfang Xiao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Gilberto K K Leung
- Department of Surgery, The University of Hong Kong, Hong Kong SAR, China
| | - Gary K K Lau
- Department of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Fan Huang
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong SAR, China
| | - Vince Vardhanabhuti
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong SAR, China
| | - Alex T L Leong
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| |
Collapse
|
5
|
Su S, Hu J, Ding Y, Zhang J, Lau V, Zhao Y, Wu EX. Ultra-low-field magnetic resonance angiography at 0.05 T: A preliminary study. NMR IN BIOMEDICINE 2024:e5213. [PMID: 39032076 DOI: 10.1002/nbm.5213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/24/2024] [Accepted: 06/18/2024] [Indexed: 07/22/2024]
Abstract
We aim to explore the feasibility of head and neck time-of-flight (TOF) magnetic resonance angiography (MRA) at ultra-low-field (ULF). TOF MRA was conducted on a highly simplified 0.05 T MRI scanner with no radiofrequency (RF) and magnetic shielding. A flow-compensated three-dimensional (3D) gradient echo (GRE) sequence with a tilt-optimized nonsaturated excitation RF pulse, and a flow-compensated multislice two-dimensional (2D) GRE sequence, were implemented for cerebral artery and vein imaging, respectively. For carotid artery and jugular vein imaging, flow-compensated 2D GRE sequences were utilized with venous and arterial blood presaturation, respectively. MRA was performed on young healthy subjects. Vessel-to-background contrast was experimentally observed with strong blood inflow effect and background tissue suppression. The large primary cerebral arteries and veins, carotid arteries, jugular veins, and artery bifurcations could be identified in both raw GRE images and maximum intensity projections. The primary brain and neck arteries were found to be reproducible among multiple examination sessions. These preliminary experimental results demonstrated the possibility of artery TOF MRA on low-cost 0.05 T scanners for the first time, despite the extremely low MR signal. We expect to improve the quality of ULF TOF MRA in the near future through sequence development and optimization, ongoing advances in ULF hardware and image formation, and the use of vascular T1 contrast agents.
Collapse
Affiliation(s)
- Shi Su
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Jiahao Hu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Ye Ding
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Junhao Zhang
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Vick Lau
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Yujiao Zhao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| |
Collapse
|
6
|
Han V, Reeder CP, Hernández-Morales M, Liu C. Any-nucleus distributed active programmable transmit coil. Magn Reson Med 2024; 92:389-405. [PMID: 38342981 DOI: 10.1002/mrm.30044] [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: 09/18/2023] [Revised: 12/23/2023] [Accepted: 01/22/2024] [Indexed: 02/13/2024]
Abstract
PURPOSE There are 118 known elements. Nearly all of them have NMR active isotopes and at least 39 different nuclei have biological relevance. Despite this, most of today's MRI is based on only one nucleus-1H. To facilitate imaging all potential nuclei, we present a single transmit coil able to excite arbitrary nuclei in human-scale MRI. THEORY AND METHODS We present a completely new type of RF coil, the Any-nucleus Distributed Active Programmable Transmit Coil (ADAPT Coil), with fast switches integrated into the structure of the coil to allow it to operate at any relevant frequency. This coil eliminates the need for the expensive traditional RF amplifier by directly converting direct current (DC) power into RF magnetic fields with frequencies chosen by digital control signals sent to the switches. Semiconductor switch imperfections are overcome by segmenting the coil. RESULTS Circuit simulations demonstrated the effectiveness of the ADAPT Coil approach, and a 9 cm diameter surface ADAPT Coil was implemented. Using the ADAPT Coil, 1H, 23Na, 2H, and 13C phantom images were acquired, and 1H and 23Na ex vivo images were acquired. To excite different nuclei, only digital control signals were changed, which can be programmed in real time. CONCLUSION The ADAPT Coil presents a low-cost, scalable, and efficient method for exciting arbitrary nuclei in human-scale MRI. This coil concept provides further opportunities for scaling, programmability, lowering coil costs, lowering dead-time, streamlining multinuclear MRI workflows, and enabling the study of dozens of biologically relevant nuclei.
Collapse
Affiliation(s)
- Victor Han
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
| | - Charlie P Reeder
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
| | - Miriam Hernández-Morales
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
| | - Chunlei Liu
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, USA
| |
Collapse
|
7
|
Murali S, Ding H, Adedeji F, Qin C, Obungoloch J, Asllani I, Anazodo U, Ntusi NAB, Mammen R, Niendorf T, Adeleke S. Bringing MRI to low- and middle-income countries: Directions, challenges and potential solutions. NMR IN BIOMEDICINE 2024; 37:e4992. [PMID: 37401341 DOI: 10.1002/nbm.4992] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 07/05/2023]
Abstract
The global disparity of magnetic resonance imaging (MRI) is a major challenge, with many low- and middle-income countries (LMICs) experiencing limited access to MRI. The reasons for limited access are technological, economic and social. With the advancement of MRI technology, we explore why these challenges still prevail, highlighting the importance of MRI as the epidemiology of disease changes in LMICs. In this paper, we establish a framework to develop MRI with these challenges in mind and discuss the different aspects of MRI development, including maximising image quality using cost-effective components, integrating local technology and infrastructure and implementing sustainable practices. We also highlight the current solutions-including teleradiology, artificial intelligence and doctor and patient education strategies-and how these might be further improved to achieve greater access to MRI.
Collapse
Affiliation(s)
- Sanjana Murali
- School of Medicine, Faculty of Medicine, Imperial College London, London, UK
| | - Hao Ding
- School of Medicine, Faculty of Medicine, Imperial College London, London, UK
| | - Fope Adedeji
- School of Medicine, Faculty of Medicine, University College London, London, UK
| | - Cathy Qin
- Department of Imaging, Imperial College Healthcare NHS Trust, London, UK
| | - Johnes Obungoloch
- Department of Biomedical Engineering, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Iris Asllani
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, New York, USA
| | - Udunna Anazodo
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- The Research Institute of London Health Sciences Centre and St. Joseph's Health Care, London, Ontario, Canada
| | - Ntobeko A B Ntusi
- Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
- South African Medical Research Council Extramural Unit on Intersection of Noncommunicable Diseases and Infectious Diseases, Cape Town, South Africa
| | - Regina Mammen
- Department of Cardiology, The Essex Cardiothoracic Centre, Basildon, UK
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (BUFF), Max-Delbrück Centre for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sola Adeleke
- School of Cancer & Pharmaceutical Sciences, King's College London, London, UK
- High Dimensional Neuro-oncology, University College London Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, UK
| |
Collapse
|
8
|
Samardzija A, Selvaganesan K, Zhang HZ, Sun H, Sun C, Ha Y, Galiana G, Constable RT. Low-Field, Low-Cost, Point-of-Care Magnetic Resonance Imaging. Annu Rev Biomed Eng 2024; 26:67-91. [PMID: 38211326 DOI: 10.1146/annurev-bioeng-110122-022903] [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] [Indexed: 01/13/2024]
Abstract
Low-field magnetic resonance imaging (MRI) has recently experienced a renaissance that is largely attributable to the numerous technological advancements made in MRI, including optimized pulse sequences, parallel receive and compressed sensing, improved calibrations and reconstruction algorithms, and the adoption of machine learning for image postprocessing. This new attention on low-field MRI originates from a lack of accessibility to traditional MRI and the need for affordable imaging. Low-field MRI provides a viable option due to its lack of reliance on radio-frequency shielding rooms, expensive liquid helium, and cryogen quench pipes. Moreover, its relatively small size and weight allow for easy and affordable installation in most settings. Rather than replacing conventional MRI, low-field MRI will provide new opportunities for imaging both in developing and developed countries. This article discusses the history of low-field MRI, low-field MRI hardware and software, current devices on the market, advantages and disadvantages, and low-field MRI's global potential.
Collapse
Affiliation(s)
- Anja Samardzija
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA;
| | - Kartiga Selvaganesan
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA;
| | - Horace Z Zhang
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA;
| | - Heng Sun
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA;
| | - Chenhao Sun
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Yonghyun Ha
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - Gigi Galiana
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA;
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| | - R Todd Constable
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA;
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
9
|
Zhao Y, Xiao L, Liu Y, Leong AT, Wu EX. Electromagnetic interference elimination via active sensing and deep learning prediction for radiofrequency shielding-free MRI. NMR IN BIOMEDICINE 2024; 37:e4956. [PMID: 37088894 DOI: 10.1002/nbm.4956] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/12/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023]
Abstract
At present, MRI scans are typically performed inside fully enclosed radiofrequency (RF) shielding rooms, posing stringent installation requirements and causing patient discomfort. We aim to eliminate electromagnetic interference (EMI) for MRI with no or incomplete RF shielding. In this study, a method of active sensing and deep learning EMI prediction is presented to model, predict, and remove EMI signal components from acquired MRI signals. Specifically, during each MRI scan, separate EMI-sensing coils placed in various locations are utilized to simultaneously sample external and internal EMI signals within two windows (for both conventional MRI signal acquisition and EMI characterization acquisition). A convolution neural network model is trained using the EMI characterization data to relate EMI signals detected by EMI-sensing coils to EMI signals in the MRI receive coil. This model is then used to retrospectively predict and remove EMI signal components detected by the MRI receive coil during the MRI signal acquisition window. This strategy was implemented on a low-cost ultralow-field 0.055 T permanent magnet MRI scanner without RF shielding. It produced final image signal-to-noise ratios that were comparable with those obtained using a fully enclosed RF shielding cage, and outperformed existing analytical EMI elimination methods (i.e., spectral domain transfer function and external dynamic interference estimation and removal [EDITER] methods). A preliminary experiment also demonstrated its applicability on a 1.5 T superconducting magnet MRI scanner with incomplete RF shielding. Altogether, the results demonstrated that the proposed method was highly effective in predicting and removing various EMI signals from both external environments and internal scanner electronics at both 0.055 T (2.3 MHz) and 1.5 T (63.9 MHz). The proposed strategy enables shielding-free MRI. The concept is relatively simple and is potentially applicable to other RF signal detection scenarios in the presence of external and/or internal EMI.
Collapse
Affiliation(s)
- Yujiao Zhao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, SAR, China
| | - Linfang Xiao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, SAR, China
| | - Yilong Liu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, SAR, China
| | - Alex T Leong
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, SAR, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, SAR, China
| |
Collapse
|
10
|
Abate F, Adu-Amankwah A, Ae-Ngibise KA, Agbokey F, Agyemang VA, Agyemang CT, Akgun C, Ametepe J, Arichi T, Asante KP, Balaji S, Baljer L, Basser PJ, Beauchemin J, Bennallick C, Berhane Y, Boateng-Mensah Y, Bourke NJ, Bradford L, Bruchhage M, Lorente RC, Cawley P, Cercignani M, D Sa V, Canha AD, Navarro ND, Dean DC, Delarosa J, Donald KA, Dvorak A, Edwards AD, Field D, Frail H, Freeman B, George T, Gholam J, Guerrero-Gonzalez J, Hajnal JV, Haque R, Hollander W, Hoodbhoy Z, Huentelman M, Jafri SK, Jones DK, Joubert F, Karaulanov T, Kasaro MP, Knackstedt S, Kolind S, Koshy B, Kravitz R, Lafayette SL, Lee AC, Lena B, Lepore N, Linguraru M, Ljungberg E, Lockart Z, Loth E, Mannam P, Masemola KM, Moran R, Murphy D, Nakwa FL, Nankabirwa V, Nelson CA, North K, Nyame S, O Halloran R, O'Muircheartaigh J, Oakley BF, Odendaal H, Ongeti CM, Onyango D, Oppong SA, Padormo F, Parvez D, Paus T, Pepper MS, Phiri KS, Poorman M, Ringshaw JE, Rogers J, Rutherford M, Sabir H, Sacolick L, Seal M, Sekoli ML, Shama T, Siddiqui K, Sindano N, Spelke MB, Springer PE, Suleman FE, Sundgren PC, Teixeira R, Terekegn W, Traughber M, Tuuli MG, Rensburg JV, Váša F, Velaphi S, Velasco P, Viljoen IM, Vokhiwa M, Webb A, Weiant C, Wiley N, Wintermark P, Yibetal K, Deoni S, Williams S. UNITY: A low-field magnetic resonance neuroimaging initiative to characterize neurodevelopment in low and middle-income settings. Dev Cogn Neurosci 2024; 69:101397. [PMID: 39029330 PMCID: PMC11315107 DOI: 10.1016/j.dcn.2024.101397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 05/28/2024] [Accepted: 05/30/2024] [Indexed: 07/21/2024] Open
Abstract
Measures of physical growth, such as weight and height have long been the predominant outcomes for monitoring child health and evaluating interventional outcomes in public health studies, including those that may impact neurodevelopment. While physical growth generally reflects overall health and nutritional status, it lacks sensitivity and specificity to brain growth and developing cognitive skills and abilities. Psychometric tools, e.g., the Bayley Scales of Infant and Toddler Development, may afford more direct assessment of cognitive development but they require language translation, cultural adaptation, and population norming. Further, they are not always reliable predictors of future outcomes when assessed within the first 12-18 months of a child's life. Neuroimaging may provide more objective, sensitive, and predictive measures of neurodevelopment but tools such as magnetic resonance (MR) imaging are not readily available in many low and middle-income countries (LMICs). MRI systems that operate at lower magnetic fields (< 100mT) may offer increased accessibility, but their use for global health studies remains nascent. The UNITY project is envisaged as a global partnership to advance neuroimaging in global health studies. Here we describe the UNITY project, its goals, methods, operating procedures, and expected outcomes in characterizing neurodevelopment in sub-Saharan Africa and South Asia.
Collapse
Affiliation(s)
- F Abate
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia; Waisman Research Center, Madison, WI, USA
| | - A Adu-Amankwah
- Korle-Bu Teaching Hospital, Accra, Ghana; Waisman Research Center, Madison, WI, USA
| | - K A Ae-Ngibise
- Kintampo Health Research Centre, Research and Development Division, Ghana Health Service, Kintampo North Municipality, Bono East Region, Ghana; Waisman Research Center, Madison, WI, USA
| | - F Agbokey
- Kintampo Health Research Centre, Research and Development Division, Ghana Health Service, Kintampo North Municipality, Bono East Region, Ghana; Waisman Research Center, Madison, WI, USA
| | - V A Agyemang
- Kintampo Health Research Centre, Research and Development Division, Ghana Health Service, Kintampo North Municipality, Bono East Region, Ghana; Waisman Research Center, Madison, WI, USA
| | - C T Agyemang
- Kintampo Health Research Centre, Research and Development Division, Ghana Health Service, Kintampo North Municipality, Bono East Region, Ghana; Waisman Research Center, Madison, WI, USA
| | - C Akgun
- flywheel.io Minneapolis, MN, USA; Waisman Research Center, Madison, WI, USA
| | - J Ametepe
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK; Waisman Research Center, Madison, WI, USA
| | - T Arichi
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - K P Asante
- Kintampo Health Research Centre, Research and Development Division, Ghana Health Service, Kintampo North Municipality, Bono East Region, Ghana; Waisman Research Center, Madison, WI, USA
| | - S Balaji
- Dept. of Neurology, University of British Columbia, Vancouver, BC, Canada; Waisman Research Center, Madison, WI, USA
| | - L Baljer
- Centre for Neuroimaging Sciences, King's College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - P J Basser
- National Institutes of Health, Washington, DC, USA; Waisman Research Center, Madison, WI, USA
| | - J Beauchemin
- Advanced Baby Imaging Lab, Providence, RI, USA; Waisman Research Center, Madison, WI, USA
| | - C Bennallick
- Centre for Neuroimaging Sciences, King's College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - Y Berhane
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia; Waisman Research Center, Madison, WI, USA
| | - Y Boateng-Mensah
- Korle-Bu Teaching Hospital, Accra, Ghana; Waisman Research Center, Madison, WI, USA
| | - N J Bourke
- Centre for Neuroimaging Sciences, King's College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - L Bradford
- Division of Developmental Paediatrics, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and the Neuroscience Institute, University of Cape Town, Cape Town, South Africa; Waisman Research Center, Madison, WI, USA
| | - Mmk Bruchhage
- Dept. of Psychology, Stavanger University, Norway; Waisman Research Center, Madison, WI, USA
| | - R Cano Lorente
- Advanced Baby Imaging Lab, Providence, RI, USA; Waisman Research Center, Madison, WI, USA
| | - P Cawley
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - M Cercignani
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK; Waisman Research Center, Madison, WI, USA
| | - V D Sa
- Advanced Baby Imaging Lab, Providence, RI, USA; Waisman Research Center, Madison, WI, USA
| | - A de Canha
- Institute for Cellular and Molecular Medicine, Department of Medical Immunology, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - N de Navarro
- Collective Minds Radiology, Sweden; Waisman Research Center, Madison, WI, USA
| | - D C Dean
- School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA; Waisman Research Center, Madison, WI, USA
| | - J Delarosa
- PATH, Seattle, WA, USA; Waisman Research Center, Madison, WI, USA
| | - K A Donald
- Division of Developmental Paediatrics, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and the Neuroscience Institute, University of Cape Town, Cape Town, South Africa; Waisman Research Center, Madison, WI, USA
| | - A Dvorak
- Dept. of Neurology, University of British Columbia, Vancouver, BC, Canada; Waisman Research Center, Madison, WI, USA
| | - A D Edwards
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - D Field
- Collective Minds Radiology, Sweden; Waisman Research Center, Madison, WI, USA
| | - H Frail
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - B Freeman
- University of North Carolina, Department of Obstetrics and Gynecology, Chapel Hill, USA; Waisman Research Center, Madison, WI, USA
| | - T George
- Department of Radiology, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University; Waisman Research Center, Madison, WI, USA
| | - J Gholam
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK; Waisman Research Center, Madison, WI, USA
| | - J Guerrero-Gonzalez
- School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA; Waisman Research Center, Madison, WI, USA
| | - J V Hajnal
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - R Haque
- International Centre for Diarrheal Disease Research, Bangladesh (Icddr,b), Dhaka, Bangladesh; Waisman Research Center, Madison, WI, USA
| | - W Hollander
- CaliberMRI, Boulder CO USA; Waisman Research Center, Madison, WI, USA
| | - Z Hoodbhoy
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan; Waisman Research Center, Madison, WI, USA
| | - M Huentelman
- TGen, Phoenix, AZ, USA; Waisman Research Center, Madison, WI, USA
| | - S K Jafri
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan; Waisman Research Center, Madison, WI, USA
| | - D K Jones
- Cardiff University Brain Research Imaging Center, Cardiff University, Cardiff, UK; Waisman Research Center, Madison, WI, USA
| | - F Joubert
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Microbiology and Genetics, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - T Karaulanov
- CaliberMRI, Boulder CO USA; Waisman Research Center, Madison, WI, USA
| | - M P Kasaro
- University of North Carolina - Global Projects Zambia, Lusaka, Zambia; Waisman Research Center, Madison, WI, USA
| | - S Knackstedt
- PATH, Seattle, WA, USA; Waisman Research Center, Madison, WI, USA
| | - S Kolind
- Dept. of Neurology, University of British Columbia, Vancouver, BC, Canada; Waisman Research Center, Madison, WI, USA
| | - B Koshy
- Developmental Paediatrics, Christian Medical College, Vellore, India; Waisman Research Center, Madison, WI, USA
| | - R Kravitz
- International Society for Magnetic Resonance in Medicine, San Fransisco, CA, USA; Waisman Research Center, Madison, WI, USA
| | - S Lecurieux Lafayette
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - A C Lee
- Brigham and Women's Hospital, Department of Pediatrics; Harvard Medical School; Boston, MA, USA; Waisman Research Center, Madison, WI, USA
| | - B Lena
- Dept. of Radiology, Leiden University, Leiden, the Netherlands; Waisman Research Center, Madison, WI, USA
| | - N Lepore
- Dept. of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Waisman Research Center, Madison, WI, USA
| | - M Linguraru
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, USA; Waisman Research Center, Madison, WI, USA
| | - E Ljungberg
- Medical Radiation Physics, Lund University, Lund, Sweden; Waisman Research Center, Madison, WI, USA
| | - Z Lockart
- Department of Radiology, Faculty of Health Sciences, Steve Biko Academic Hospital, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - E Loth
- Department of Forensic and Neurodevelopemental Science, Institute of Psychatry, Psychology and Neuroscience, King's College London, London, United Kingdom; Waisman Research Center, Madison, WI, USA
| | - P Mannam
- Developmental Paediatrics, Christian Medical College, Vellore, India; Waisman Research Center, Madison, WI, USA
| | - K M Masemola
- Department of Paediatrics and Child Health, Kalafong Hospital and Faculty of Health Sciences, University of Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - R Moran
- Centre for Neuroimaging Sciences, King's College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - D Murphy
- Department of Forensic and Neurodevelopemental Science, Institute of Psychatry, Psychology and Neuroscience, King's College London, London, United Kingdom; Waisman Research Center, Madison, WI, USA
| | - F L Nakwa
- Department of Paediatrics and Child Health, Chris Hani Baragwanath Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Waisman Research Center, Madison, WI, USA
| | - V Nankabirwa
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University. Kampala, Uganda; Waisman Research Center, Madison, WI, USA
| | - C A Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, USA; Waisman Research Center, Madison, WI, USA
| | - K North
- Brigham and Women's Hospital, Department of Pediatrics; Harvard Medical School; Boston, MA, USA; Waisman Research Center, Madison, WI, USA
| | - S Nyame
- Kintampo Health Research Centre, Research and Development Division, Ghana Health Service, Kintampo North Municipality, Bono East Region, Ghana; Waisman Research Center, Madison, WI, USA
| | - R O Halloran
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - J O'Muircheartaigh
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - B F Oakley
- Department of Forensic and Neurodevelopemental Science, Institute of Psychatry, Psychology and Neuroscience, King's College London, London, United Kingdom; Waisman Research Center, Madison, WI, USA
| | - H Odendaal
- Dept Obstet Gynaecol, Stellenbosch University, South Africa; Waisman Research Center, Madison, WI, USA
| | - C M Ongeti
- Jaramogi Oginga Odinga Teaching and Referral Hospital, Kisumu, Kenya; Waisman Research Center, Madison, WI, USA
| | - D Onyango
- Jaramogi Oginga Odinga Teaching and Referral Hospital, Kisumu, Kenya; Waisman Research Center, Madison, WI, USA
| | - S A Oppong
- Korle-Bu Teaching Hospital, Accra, Ghana; Waisman Research Center, Madison, WI, USA
| | - F Padormo
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - D Parvez
- Collective Minds Radiology, Sweden; Waisman Research Center, Madison, WI, USA
| | - T Paus
- Departments of Psychiatry and Neuroscience, Faculty of Medicine and Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Montreal, Quebec, Canada; Waisman Research Center, Madison, WI, USA
| | - M S Pepper
- Institute for Cellular and Molecular Medicine, Department of Medical Immunology, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - K S Phiri
- Training and Research Unit of Excellence (TRUE), Zomba Malawi; Waisman Research Center, Madison, WI, USA
| | - M Poorman
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - J E Ringshaw
- Division of Developmental Paediatrics, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and the Neuroscience Institute, University of Cape Town, Cape Town, South Africa; Waisman Research Center, Madison, WI, USA
| | - J Rogers
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - M Rutherford
- Centre for the Developing Brain, Kings College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - H Sabir
- Experimental Neonatology, University Hospitals Bonn, Bonn, Germany; Waisman Research Center, Madison, WI, USA
| | - L Sacolick
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - M Seal
- Murdoch Children's Research Institute, Melbourne, AUS; Waisman Research Center, Madison, WI, USA
| | - M L Sekoli
- Institute for Cellular and Molecular Medicine, Department of Medical Immunology, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - T Shama
- International Centre for Diarrheal Disease Research, Bangladesh (Icddr,b), Dhaka, Bangladesh; Waisman Research Center, Madison, WI, USA
| | - K Siddiqui
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - N Sindano
- University of North Carolina - Global Projects Zambia, Lusaka, Zambia; Waisman Research Center, Madison, WI, USA
| | - M B Spelke
- University of North Carolina, Department of Obstetrics and Gynecology, Chapel Hill, USA; Waisman Research Center, Madison, WI, USA
| | - P E Springer
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa; Waisman Research Center, Madison, WI, USA
| | - F E Suleman
- Department of Radiology, Faculty of Health Sciences, Kalafong Hospital, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - P C Sundgren
- Section of Diagnostic Radiology,Department of Clinical Sciences Lund, Lund University, Lund, Sweden; Waisman Research Center, Madison, WI, USA
| | - R Teixeira
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - W Terekegn
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia; Waisman Research Center, Madison, WI, USA
| | - M Traughber
- Hyperfine.io, Guilford, CT, USA; Waisman Research Center, Madison, WI, USA
| | - M G Tuuli
- Jaramogi Oginga Odinga Teaching and Referral Hospital, Kisumu, Kenya; Waisman Research Center, Madison, WI, USA
| | - J van Rensburg
- Institute for Cellular and Molecular Medicine, Department of Medical Immunology, University of Pretoria, Pretoria, South Africa; Waisman Research Center, Madison, WI, USA
| | - F Váša
- Centre for Neuroimaging Sciences, King's College London, London, UK; Waisman Research Center, Madison, WI, USA
| | - S Velaphi
- Department of Paediatrics and Child Health, Chris Hani Baragwanath Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Waisman Research Center, Madison, WI, USA
| | - P Velasco
- flywheel.io Minneapolis, MN, USA; Waisman Research Center, Madison, WI, USA
| | - I M Viljoen
- Department of Radiology, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University; Waisman Research Center, Madison, WI, USA
| | - M Vokhiwa
- Training and Research Unit of Excellence (TRUE), Zomba Malawi; Waisman Research Center, Madison, WI, USA
| | - A Webb
- Dept. of Radiology, Leiden University, Leiden, the Netherlands; Waisman Research Center, Madison, WI, USA
| | - C Weiant
- CaliberMRI, Boulder CO USA; Waisman Research Center, Madison, WI, USA
| | - N Wiley
- Dept. of Neurology, University of British Columbia, Vancouver, BC, Canada; Waisman Research Center, Madison, WI, USA
| | - P Wintermark
- Division of Newborn Medicine, Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, QC, Canada; Waisman Research Center, Madison, WI, USA
| | - K Yibetal
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia; Waisman Research Center, Madison, WI, USA
| | - Scl Deoni
- Bill & Melinda Gates Foundation, MNCH D&T, Seattle, WA, USA; Waisman Research Center, Madison, WI, USA
| | - Scr Williams
- Centre for Neuroimaging Sciences, King's College London, London, UK; Waisman Research Center, Madison, WI, USA.
| |
Collapse
|
11
|
Capuani S, Maiuro A, Giampà E, Montuori M, Varrucciu V, Hagberg GE, Vinicola V, Colonna S. Assessment of Calcaneal Spongy Bone Magnetic Resonance Characteristics in Women: A Comparison between Measures Obtained at 0.3 T, 1.5 T, and 3.0 T. Diagnostics (Basel) 2024; 14:1050. [PMID: 38786348 PMCID: PMC11119204 DOI: 10.3390/diagnostics14101050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND There is a growing interest in bone tissue MRI and an even greater interest in using low-cost MR scanners. However, the characteristics of bone MRI remain to be fully defined, especially at low field strength. This study aimed to characterize the signal-to-noise ratio (SNR), T2, and T2* in spongy bone at 0.3 T, 1.5 T, and 3.0 T. Furthermore, relaxation times were characterized as a function of bone-marrow lipid/water ratio content and trabecular bone density. METHODS Thirty-two women in total underwent an MR-imaging investigation of the calcaneus at 0.3 T, 1.5 T, and 3.0 T. MR-spectroscopy was performed at 3.0 T to assess the fat/water ratio. SNR, T2, and T2* were quantified in distinct calcaneal regions (ST, TC, and CC). ANOVA and Pearson correlation statistics were used. RESULTS SNR increase depends on the magnetic field strength, acquisition sequence, and calcaneal location. T2* was different at 3.0 T and 1.5 T in ST, TC, and CC. Relaxation times decrease as much as the magnetic field strength increases. The significant linear correlation between relaxation times and fat/water found in healthy young is lost in osteoporotic subjects. CONCLUSION The results have implications for the possible use of relaxation vs. lipid/water marrow content for bone quality assessment and the development of quantitative MRI diagnostics at low field strength.
Collapse
Affiliation(s)
- Silvia Capuani
- CNR-ISC c/o Physics Department, “Sapienza” University of Rome, P.zle Aldo Moro 5, 00185 Rome, Italy; (A.M.); (M.M.)
- Neuroimaging Laboratory, Santa Lucia Foundation, IRCCS Rome, Via Ardeatina 309, 00179 Rome, Italy
| | - Alessandra Maiuro
- CNR-ISC c/o Physics Department, “Sapienza” University of Rome, P.zle Aldo Moro 5, 00185 Rome, Italy; (A.M.); (M.M.)
- Physics Department, “Sapienza” University of Rome, P.zle Aldo Moro 5, 00185 Rome, Italy
| | - Emiliano Giampà
- Rehabilitation Hospital, Santa Lucia Foundation, IRCCS Rome, Via Ardeatina 309, 00179 Rome, Italy; (E.G.); (V.V.)
| | - Marco Montuori
- CNR-ISC c/o Physics Department, “Sapienza” University of Rome, P.zle Aldo Moro 5, 00185 Rome, Italy; (A.M.); (M.M.)
| | - Viviana Varrucciu
- Radiology Department, Santa Lucia Foundation, IRCCS Rome, Via Ardeatina 309, 00179 Rome, Italy; (V.V.); (S.C.)
| | - Gisela E. Hagberg
- High Field Magnetic Resonance, Max-Planck-Institute for Biological Cybernetics, 72076 Tübingen, Germany;
| | - Vincenzo Vinicola
- Rehabilitation Hospital, Santa Lucia Foundation, IRCCS Rome, Via Ardeatina 309, 00179 Rome, Italy; (E.G.); (V.V.)
| | - Sergio Colonna
- Radiology Department, Santa Lucia Foundation, IRCCS Rome, Via Ardeatina 309, 00179 Rome, Italy; (V.V.); (S.C.)
| |
Collapse
|
12
|
Wan C, He W, Xu Z. Water-Fat Separation for the Knee on a 50 mT Portable MRI Scanner. IEEE Trans Biomed Eng 2024; 71:1687-1696. [PMID: 38150336 DOI: 10.1109/tbme.2023.3347441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
OBJECTIVE The Dixon method is frequently employed in clinical and scientific research for fat suppression, because it has lower sensitivity to static magnetic field inhomogeneity compared to chemical shift selective saturation or its variants and maintains image signal-to-noise ratio (SNR). Recently, research on very-low-field (VLF < 100 mT) magnetic resonance imaging (MRI) has regained popularity. However, there is limited literature on water-fat separation in VLF MRI. Here, we present a modified two-point Dixon method specifically designed for VLF MRI. METHODS Most experiments were performed on a homemade 50 mT portable MRI scanner. The receiving coil adopted a homemade quadrature receiving coil. The data were acquired using spin-echo and gradient-echo sequences. We considered the T2* effect, and added priori information to existing two-point Dixon method. Then, the method used regional iterative phasor extraction (RIPE) to extract the error phasor. Finally, least squares solutions for water and fat were obtained and fat signal fraction was calculated. RESULTS For phantom evaluation, water-only and fat-only images were obtained and the local fat signal fractions were calculated, with two samples being 0.94 and 0.93, respectively. For knee imaging, cartilage, muscle and fat could be clearly distinguished. The water-only images were able to highlight areas such as cartilage that could not be easily distinguished without separation. CONCLUSION This work has demonstrated the feasibility of using a 50 mT MRI scanner for water-fat separation. SIGNIFICANCE To the best of our knowledge, this is the first reported result of water-fat separation at a 50 mT portable MRI scanner.
Collapse
|
13
|
Tyndall DA, Price JB, Gaalaas L, Spin-Neto R. Surveying the landscape of diagnostic imaging in dentistry's future: Four emerging technologies with promise. J Am Dent Assoc 2024; 155:364-378. [PMID: 38520421 DOI: 10.1016/j.adaj.2024.01.005] [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: 05/24/2023] [Revised: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND Advances in digital radiography for both intraoral and panoramic imaging and cone-beam computed tomography have led the way to an increase in diagnostic capabilities for the dental care profession. In this article, the authors provide information on 4 emerging technologies with promise. TYPES OF STUDIES REVIEWED The authors feature the following: artificial intelligence in the form of deep learning using convolutional neural networks, dental magnetic resonance imaging, stationary intraoral tomosynthesis, and second-generation cone-beam computed tomography sources based on carbon nanotube technology and multispectral imaging. The authors review and summarize articles featuring these technologies. RESULTS The history and background of these emerging technologies are previewed along with their development and potential impact on the practice of dental diagnostic imaging. The authors conclude that these emerging technologies have the potential to have a substantial influence on the practice of dentistry as these systems mature. The degree of influence most likely will vary, with artificial intelligence being the most influential of the 4. CONCLUSIONS AND PRACTICAL IMPLICATIONS The readers are informed about these emerging technologies and the potential effects on their practice going forward, giving them information on which to base decisions on adopting 1 or more of these technologies. The 4 technologies reviewed in this article have the potential to improve imaging diagnostics in dentistry thereby leading to better patient care and heightened professional satisfaction.
Collapse
|
14
|
Shen S, Koonjoo N, Longarino FK, Lamb LR, Villa Camacho JC, Hornung TPP, Ogier SE, Yan S, Bortfeld TR, Saksena MA, Keenan KE, Rosen MS. Breast imaging with an ultra-low field MRI scanner: a pilot study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.04.01.24305081. [PMID: 38633799 PMCID: PMC11023648 DOI: 10.1101/2024.04.01.24305081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Breast cancer screening is necessary to reduce mortality due to undetected breast cancer. Current methods have limitations, and as a result many women forego regular screening. Magnetic resonance imaging (MRI) can overcome most of these limitations, but access to conventional MRI is not widely available for routine annual screening. Here, we used an MRI scanner operating at ultra-low field (ULF) to image the left breasts of 11 women (mean age, 35 years ±13 years) in the prone position. Three breast radiologists reviewed the imaging and were able to discern the breast outline and distinguish fibroglandular tissue (FGT) from intramammary adipose tissue. Additionally, the expert readers agreed on their assessment of the breast tissue pattern including fatty, scattered FGT, heterogeneous FGT, and extreme FGT. This preliminary work demonstrates that ULF breast MRI is feasible and may be a potential option for comfortable, widely deployable, and low-cost breast cancer diagnosis and screening.
Collapse
|
15
|
Lavrova A, Seiberlich N, Kelsey L, Richardson J, Comer J, Masotti M, Itriago-Leon P, Wright K, Mishra S. Comparison of image quality and diagnostic efficacy of routine clinical lumbar spine imaging at 0.55T and 1.5/3T. Eur J Radiol 2024; 175:111406. [PMID: 38490129 DOI: 10.1016/j.ejrad.2024.111406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/19/2024] [Accepted: 03/03/2024] [Indexed: 03/17/2024]
Abstract
PURPOSE To compare image quality, assess inter-reader variability, and evaluate the diagnostic efficacy of routine clinical lumbar spine sequences at 0.55T compared with those collected at 1.5/3T to assess common spine pathology. METHODS 665 image series across 70 studies, collected at 0.55T and 1.5/3T, were assessed by two neuroradiology fellows for overall imaging quality (OIQ), artifacts, and accurate visualization of anatomical features (intervertebral discs, neural foramina, spinal cord, bone marrow, and conus / cauda equina nerve roots) using a 4-point Likert scale (1 = non-diagnostic to 4 = excellent). For the 0.55T scans, the most appropriate diagnosis(es) from a picklist of common spine pathologies was selected. The mean ± SD of all scores for all features for each sequence and reader at 0.55T and 1.5/3T were calculated. Paired t-tests (p ≤ 0.05) were used to compare ratings between field strengths. The inter-reader agreement was calculated using linear-weighted Cohen's Kappa coefficient (p ≤ 0.05). Unpaired VCG analysis for OIQ was additionally employed to represent differences between 0.55T and 1.5/3T (95 % CI). RESULTS All sequences at 0.55T were rated as acceptable (≥2) for diagnostic use by both readers despite significantly lower scores for some compared to those at 1.5/3T. While there was low inter-reader agreement on individual scores, the agreement on the diagnosis was high, demonstrating the potential of this system for detecting routine spine pathology. CONCLUSIONS Clinical lumbar spine imaging at 0.55T produces diagnostic-quality images demonstrating the feasibility of its use in diagnosing spinal pathology, including osteomyelitis/discitis, post-surgical changes with complications, and metastatic disease.
Collapse
Affiliation(s)
- Anna Lavrova
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States; Department of Neurology, Mayo Clinic, Rochester, MN, United States
| | - Nicole Seiberlich
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
| | - Lauren Kelsey
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
| | - Jacob Richardson
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
| | - John Comer
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
| | - Maria Masotti
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, United States
| | | | - Katherine Wright
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
| | - Shruti Mishra
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States.
| |
Collapse
|
16
|
Meng F, Guo Y, Wei H, Xu Z. Development of a Helmet-Shape Dual-Channel RF coil for brain imaging at 54 mT using inverse boundary element method. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 360:107636. [PMID: 38377783 DOI: 10.1016/j.jmr.2024.107636] [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: 08/17/2023] [Revised: 02/04/2024] [Accepted: 02/08/2024] [Indexed: 02/22/2024]
Abstract
Very-low field (VLF) magnetic resonance imaging (MRI) offers advantages in term of size, weight, cost, and the absence of robust shielding requirements. However, it encounters challenges in maintaining a high signal-to-noise ratio (SNR) due to low magnetic fields (below 100 mT). Developing a close-fitting radio frequency (RF) receive coil is crucial to improve the SNR. In this study, we devised and optimized a helmet-shaped dual-channel RF receive coil tailored for brain imaging at a magnetic field strength of 54 mT (2.32 MHz). The methodology integrates the inverse boundary element method (IBEM) to formulate initial coil structures and wiring patterns, followed by optimization through introducing regularization terms. This approach frames the design process as an inverse problem, ensuring a close fit to the head contour. Combining theoretical optimization with physical measurements of the coil's AC resistance, we identified the optimal loop count for both axial and radial coils as nine and eight loops, respectively. The effectiveness of the designed dual-channel coil was verified through the imaging of a CuSO4 phantom and a healthy volunteer's brain. Notably, the in-vivo images exhibited an approximate 16-25 % increase in SNR with poorer B1 homogeneity compared to those obtained using single-channel coils. The high-quality images achieved by T1, T2-weighted, and fluid-attenuated inversion-recovery (FLAIR) protocols enhance the diagnostic potential of VLF MRI, particularly in cases of cerebral stroke and trauma patients. This study underscores the adaptability of the design methodology for the customization of RF coil structures in alignment with individual imaging requirements.
Collapse
Affiliation(s)
- Fanqin Meng
- School of Electrical Engineering, Chongqing University, Chongqing 400044, China
| | - Yi Guo
- Central Hospital, Chongqing University, Chongqing 400014, China
| | - He Wei
- School of Electrical Engineering, Chongqing University, Chongqing 400044, China
| | - Zheng Xu
- School of Electrical Engineering, Chongqing University, Chongqing 400044, China.
| |
Collapse
|
17
|
Kempf N, Körber R, Plaumann M, Pravdivtsev AN, Engelmann J, Boldt J, Scheffler K, Theis T, Buckenmaier K. 13C MRI of hyperpolarized pyruvate at 120 µT. Sci Rep 2024; 14:4468. [PMID: 38396023 PMCID: PMC10891046 DOI: 10.1038/s41598-024-54770-x] [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: 11/28/2023] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
Nuclear spin hyperpolarization increases the sensitivity of magnetic resonance dramatically, enabling many new applications, including real-time metabolic imaging. Parahydrogen-based signal amplification by reversible exchange (SABRE) was employed to hyperpolarize [1-13C]pyruvate and demonstrate 13C imaging in situ at 120 µT, about twice Earth's magnetic field, with two different signal amplification by reversible exchange variants: SABRE in shield enables alignment transfer to heteronuclei (SABRE-SHEATH), where hyperpolarization is transferred from parahydrogen to [1-13C]pyruvate at a magnetic field below 1 µT, and low-irradiation generates high tesla (LIGHT-SABRE), where hyperpolarization was prepared at 120 µT, avoiding magnetic field cycling. The 3-dimensional images of a phantom were obtained using a superconducting quantum interference device (SQUID) based magnetic field detector with submillimeter resolution. These 13C images demonstrate the feasibility of low-field 13C metabolic magnetic resonance imaging (MRI) of 50 mM [1-13C]pyruvate hyperpolarized by parahydrogen in reversible exchange imaged at about twice Earth's magnetic field. Using thermal 13C polarization available at 120 µT, the same experiment would have taken about 300 billion years.
Collapse
Affiliation(s)
- Nicolas Kempf
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
| | - Rainer Körber
- Physikalisch-Technische Bundesanstalt, 10587, Berlin, Germany
| | - Markus Plaumann
- Institute for Molecular Biology and Medicinal Chemistry, Medical Faculty, Otto-von-Guericke University, 39120, Magdeburg, Germany
| | - Andrey N Pravdivtsev
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center, Kiel University, 24118, Kiel, Germany
| | - Jörn Engelmann
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
| | - Johannes Boldt
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
| | - Klaus Scheffler
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
- Departement of Biomedical Magnetic Resonance, Eberhard-Karls University, 72076, Tübingen, Germany
| | - Thomas Theis
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany
- Departement of Chemistry and Physics, NC State University, Raleigh, 27695, USA
| | - Kai Buckenmaier
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tübingen, Germany.
| |
Collapse
|
18
|
McGrath C, Bieri O, Kozerke S, Bauman G. Self-gated cine phase-contrast balanced SSFP flow quantification at 0.55 T. Magn Reson Med 2024; 91:174-189. [PMID: 37668108 DOI: 10.1002/mrm.29837] [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: 03/23/2023] [Revised: 07/13/2023] [Accepted: 08/02/2023] [Indexed: 09/06/2023]
Abstract
PURPOSE To implement cine phase-contrast balanced SSFP (PC-bSSFP) for low-field 0.55T cardiac MRI by exploiting the intrinsic flow sensitivity of the bSSFP slice-select gradient and the in-plane phase-cancelation properties of radial trajectories, enabling self-gated and referenceless PC-bSSFP flow quantification at 0.55 T. METHODS A free-running, tiny golden-angle radial PC-bSSFP approach was implemented on 0.55T and 1.5T systems. Cardiac and respiratory self-gating was incorporated to enable electrocardiogram-free scanning during breath-hold and free-breathing. By exploiting the intrinsic in-plane phase-cancelation properties of radial acquisitions and background phase fitting, referenceless single-point PC-bSSFP was realized. In vivo data were acquired in the ascending aorta of healthy subjects at 0.55 T and 1.5 T during breath-hold and free-breathing. Flow data, SNR, and velocity-to-noise ratio were compared relative to data obtained with phase-contrast spoiled gradient-echo variants. RESULTS Velocities acquired with PC-bSSFP compared well with data from phase-contrast spoiled gradient-echo (RMSEv = 5.8 cm/s). PC-bSSFP at 0.55 T resulted in high-quality cine magnitude images and phase maps with sufficient SNR and velocity-to-noise ratio. Breath-hold and free-breathing PC-bSSFP performed very similarly, with comparable flow quantification (RMSEv = 5.7 cm/s). Referenceless single-point PC-bSSFP results agreed well with two-point PC-bSSFP (-1.8 ± 5.2 cm/s) while reducing scan times 2-fold. CONCLUSION PC-bSSFP is feasible on low-field 0.55T systems, producing high-quality cine images while permitting simultaneous aortic flow measurements during breath-hold and free-breathing and without the need for electrocardiogram gating.
Collapse
Affiliation(s)
- Charles McGrath
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Oliver Bieri
- Division of Radiological Physics, Department of Radiology, University Hospital Basel, Basel, Switzerland
- Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Grzegorz Bauman
- Division of Radiological Physics, Department of Radiology, University Hospital Basel, Basel, Switzerland
- Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| |
Collapse
|
19
|
Jalloul M, Miranda-Schaeubinger M, Noor AM, Stein JM, Amiruddin R, Derbew HM, Mango VL, Akinola A, Hart K, Weygand J, Pollack E, Mohammed S, Scheel JR, Shell J, Dako F, Mhatre P, Kulinski L, Otero HJ, Mollura DJ. MRI scarcity in low- and middle-income countries. NMR IN BIOMEDICINE 2023; 36:e5022. [PMID: 37574441 DOI: 10.1002/nbm.5022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/19/2023] [Accepted: 07/21/2023] [Indexed: 08/15/2023]
Abstract
Since the introduction of MRI as a sustainable diagnostic modality, global accessibility to its services has revealed a wide discrepancy between populations-leaving most of the population in LMICs without access to this important imaging modality. Several factors lead to the scarcity of MRI in LMICs; for example, inadequate infrastructure and the absence of a dedicated workforce are key factors in the scarcity observed. RAD-AID has contributed to the advancement of radiology globally by collaborating with our partners to make radiology more accessible for medically underserved communities. However, progress is slow and further investment is needed to ensure improved global access to MRI.
Collapse
Affiliation(s)
- Mohammad Jalloul
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | - Abass M Noor
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- RAD-AID International, Chevy Chase, Maryland, USA
- Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joel M Stein
- Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Raisa Amiruddin
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Hermon Miliard Derbew
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- College of Health Science, Addis Ababa University, Addis Ababa, Ethiopia
| | - Victoria L Mango
- RAD-AID International, Chevy Chase, Maryland, USA
- Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | | | - Kelly Hart
- Tufts Medical Center, Boston, Massachusetts, USA
| | | | - Erica Pollack
- RAD-AID International, Chevy Chase, Maryland, USA
- University of Colorado Anschutz Medical Center, Aurora, Colorado, USA
| | - Sharon Mohammed
- RAD-AID International, Chevy Chase, Maryland, USA
- Bellevue Hospital Center NYCHHC, New York, New York, USA
| | - John R Scheel
- RAD-AID International, Chevy Chase, Maryland, USA
- Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jessica Shell
- RAD-AID International, Chevy Chase, Maryland, USA
- Siemens Medical Solutions USA, Inc., Cary, North Carolina, USA
| | - Farouk Dako
- RAD-AID International, Chevy Chase, Maryland, USA
- Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Pradnya Mhatre
- RAD-AID International, Chevy Chase, Maryland, USA
- Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Hansel J Otero
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | |
Collapse
|
20
|
MacCulloch K, Browning A, Bedoya DOG, McBride SJ, Abdulmojeed MB, Dedesma C, Goodson BM, Rosen MS, Chekmenev EY, Yen YF, TomHon P, Theis T. Facile hyperpolarization chemistry for molecular imaging and metabolic tracking of [1- 13C]pyruvate in vivo. JOURNAL OF MAGNETIC RESONANCE OPEN 2023; 16-17:100129. [PMID: 38090022 PMCID: PMC10715622 DOI: 10.1016/j.jmro.2023.100129] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Hyperpolarization chemistry based on reversible exchange of parahydrogen, also known as Signal Amplification By Reversible Exchange (SABRE), is a particularly simple approach to attain high levels of nuclear spin hyperpolarization, which can enhance NMR and MRI signals by many orders of magnitude. SABRE has received significant attention in the scientific community since its inception because of its relative experimental simplicity and its broad applicability to a wide range of molecules, however in vivo detection of molecular probes hyperpolarized by SABRE has remained elusive. Here we describe a first demonstration of SABRE-hyperpolarized contrast detected in vivo, specifically using hyperpolarized [1-13C]pyruvate. Biocompatible formulations of hyperpolarized [1-13C]pyruvate in, both, methanol-water mixtures, and ethanol-water mixtures followed by dilution with saline and catalyst filtration were prepared and injected into healthy Sprague Dawley and Wistar rats. Effective hyperpolarization-catalyst removal was performed with silica filters without major losses in hyperpolarization. Metabolic conversion of pyruvate to lactate, alanine, and bicarbonate was detected in vivo. Pyruvate-hydrate was also observed as minor byproduct. Measurements were performed on the liver and kidney at 4.7 T via time-resolved spectroscopy and chemical-shift-resolved MRI. In addition, whole-body metabolic measurements were obtained using a cryogen-free 1.5 T MRI system, illustrating the utility of combining lower-cost MRI systems with simple, low-cost hyperpolarization chemistry to develop safe, and scalable molecular imaging.
Collapse
Affiliation(s)
- Keilian MacCulloch
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695,USA
| | - Austin Browning
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695,USA
| | - David O. Guarin Bedoya
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Stephen J. McBride
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695,USA
| | | | - Carlos Dedesma
- Vizma Life Sciences Inc., Chapel Hill, NC, 27514, United States
| | - Boyd M. Goodson
- School of Chemical & Biomolecular Sciences and Materials Technology Center, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Matthew S. Rosen
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Eduard Y. Chekmenev
- Department of Chemistry, Integrative Bio-sciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit, MI 48202, USA
- Russian Academy of Sciences, 119991 Moscow, Russia
| | - Yi-Fen Yen
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Patrick TomHon
- Vizma Life Sciences Inc., Chapel Hill, NC, 27514, United States
| | - Thomas Theis
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695,USA
- Department of Physics, North Carolina State University, Raleigh, NC 27606, USA
- Joint UNC & NC State Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27606, USA
| |
Collapse
|
21
|
Cawley P, Padormo F, Cromb D, Almalbis J, Marenzana M, Teixeira R, Uus A, O’Muircheartaigh J, Williams SC, Counsell SJ, Arichi T, Rutherford MA, Hajnal JV, Edwards AD. Development of neonatal-specific sequences for portable ultralow field magnetic resonance brain imaging: a prospective, single-centre, cohort study. EClinicalMedicine 2023; 65:102253. [PMID: 38106560 PMCID: PMC10725077 DOI: 10.1016/j.eclinm.2023.102253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 12/19/2023] Open
Abstract
Background Magnetic Resonance (MR) imaging is key for investigation of suspected newborn brain abnormalities. Access is limited in low-resource settings and challenging in infants needing intensive care. Portable ultralow field (ULF) MRI is showing promise in bedside adult brain imaging. Use in infants and children has been limited as brain-tissue composition differences necessitate sequence modification. The aim of this study was to develop neonatal-specific ULF structural sequences and test these across a range of gestational maturities and pathologies to inform future validation studies. Methods Prospective cohort study within a UK neonatal specialist referral centre. Infants undergoing 3T MRI were recruited for paired ULF (64mT) portable MRI by convenience sampling from the neonatal unit and post-natal ward. Key inclusion criteria: 1) Infants with risk or suspicion of brain abnormality, or 2) preterm and term infants without suspicion of major genetic, chromosomal or neurological abnormality. Exclusions: presence of contra-indication for MR scanning. ULF sequence parameters were optimised for neonatal brain-tissues by iterative and explorative design. Neuroanatomic and pathologic features were compared by unblinded review, informing optimisation of subsequent sequence generations in a step-wise manner. Main outcome: visual identification of healthy and abnormal brain tissues/structures. ULF MR spectroscopy, diffusion, susceptibility weighted imaging, arteriography, and venography require pre-clinical technical development and have not been tested. Findings Between September 23, 2021 and October 25, 2022, 102 paired scans were acquired in 87 infants; 1.17 paired scans per infant. Median age 9 days, median postmenstrual age 40+2 weeks (range: 31+3-53+4). Infants had a range of intensive care requirements. No adverse events observed. Optimised ULF sequences can visualise key neuroanatomy and brain abnormalities. In finalised neonatal sequences: T2w imaging distinguished grey and white matter (7/7 infants), ventricles (7/7), pituitary tissue (5/7), corpus callosum (7/7) and optic nerves (7/7). Signal congruence was seen within the posterior limb of the internal capsule in 10/11 infants on finalised T1w scans. In addition, brain abnormalities visualised on ULF optimised sequences have similar MR signal patterns to 3T imaging, including injury secondary to infarction (6/6 infants on T2w scans), hypoxia-ischaemia (abnormal signal in basal ganglia, thalami and white matter 2/2 infants on T2w scans, cortical highlighting 1/1 infant on T1w scan), and congenital malformations: polymicrogyria 3/3, absent corpus callosum 2/2, and vermian hypoplasia 3/3 infants on T2w scans. Sequences are susceptible to motion corruption, noise, and ULF artefact. Non-identified pathologies were small or subtle. Interpretation On unblinded review, optimised portable MR can provide sufficient contrast, signal, and resolution for neuroanatomical identification and detection of a range of clinically important abnormalities. Blinded validation studies are now warranted. Funding The Bill and Melinda Gates Foundation, the MRC, the Wellcome/EPSRC Centre for Medical Engineering, the MRC Centre for Neurodevelopmental Disorders, and the National Institute for Health Research (NIHR) Biomedical Research Centres based at Guy's and St Thomas' and South London & Maudsley NHS Foundation Trusts and King's College London.
Collapse
Affiliation(s)
- Paul Cawley
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- Neonatal Intensive Care Unit, Evelina Children’s Hospital London, St Thomas’ Hospital, 6th Floor North Wing, Westminster Bridge Road, London SE1 7EH, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | - Francesco Padormo
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- Medical Physics, Guy’s & St. Thomas' NHS Foundation Trust, London, UK
- Hyperfine, Inc., 351 New Whitfield St., Guilford, Connecticut 06437, USA
| | - Daniel Cromb
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- Neonatal Intensive Care Unit, Evelina Children’s Hospital London, St Thomas’ Hospital, 6th Floor North Wing, Westminster Bridge Road, London SE1 7EH, UK
| | - Jennifer Almalbis
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- Neonatal Intensive Care Unit, Evelina Children’s Hospital London, St Thomas’ Hospital, 6th Floor North Wing, Westminster Bridge Road, London SE1 7EH, UK
| | - Massimo Marenzana
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - Rui Teixeira
- Hyperfine, Inc., 351 New Whitfield St., Guilford, Connecticut 06437, USA
| | - Alena Uus
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - Jonathan O’Muircheartaigh
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
- Department of Forensic and Neurodevelopmental Science, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Steven C.R. Williams
- Centre for Neuroimaging Sciences, King’s College London, De Crespigny Park, London SE5 8AF, UK
| | - Serena J. Counsell
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - Tomoki Arichi
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
- Paediatric Neurosciences, Evelina London Children’s Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK
| | - Mary A. Rutherford
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | - Joseph V. Hajnal
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - A. David Edwards
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London SE1 7EH, UK
- Neonatal Intensive Care Unit, Evelina Children’s Hospital London, St Thomas’ Hospital, 6th Floor North Wing, Westminster Bridge Road, London SE1 7EH, UK
- MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| |
Collapse
|
22
|
Mazurek MH, Parasuram NR, Peng TJ, Beekman R, Yadlapalli V, Sorby-Adams AJ, Lalwani D, Zabinska J, Gilmore EJ, Petersen NH, Falcone GJ, Sujijantarat N, Matouk C, Payabvash S, Sze G, Schiff SJ, Iglesias JE, Rosen MS, de Havenon A, Kimberly WT, Sheth KN. Detection of Intracerebral Hemorrhage Using Low-Field, Portable Magnetic Resonance Imaging in Patients With Stroke. Stroke 2023; 54:2832-2841. [PMID: 37795593 PMCID: PMC11103256 DOI: 10.1161/strokeaha.123.043146] [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: 03/20/2023] [Accepted: 09/13/2023] [Indexed: 10/06/2023]
Abstract
BACKGROUND Neuroimaging is essential for detecting spontaneous, nontraumatic intracerebral hemorrhage (ICH). Recent data suggest ICH can be characterized using low-field magnetic resonance imaging (MRI). Our primary objective was to investigate the sensitivity and specificity of ICH on a 0.064T portable MRI (pMRI) scanner using a methodology that provided clinical information to inform rater interpretations. As a secondary aim, we investigated whether the incorporation of a deep learning (DL) reconstruction algorithm affected ICH detection. METHODS The pMRI device was deployed at Yale New Haven Hospital to examine patients presenting with stroke symptoms from October 26, 2020 to February 21, 2022. Three raters independently evaluated pMRI examinations. Raters were provided the images alongside the patient's clinical information to simulate real-world context of use. Ground truth was the closest conventional computed tomography or 1.5/3T MRI. Sensitivity and specificity results were grouped by DL and non-DL software to investigate the effects of software advances. RESULTS A total of 189 exams (38 ICH, 89 acute ischemic stroke, 8 subarachnoid hemorrhage, 3 primary intraventricular hemorrhage, 51 no intracranial abnormality) were evaluated. Exams were correctly classified as positive or negative for ICH in 185 of 189 cases (97.9% overall accuracy). ICH was correctly detected in 35 of 38 cases (92.1% sensitivity). Ischemic stroke and no intracranial abnormality cases were correctly identified as blood-negative in 139 of 140 cases (99.3% specificity). Non-DL scans had a sensitivity and specificity for ICH of 77.8% and 97.1%, respectively. DL scans had a sensitivity and specificity for ICH of 96.6% and 99.3%, respectively. CONCLUSIONS These results demonstrate improvements in ICH detection accuracy on pMRI that may be attributed to the integration of clinical information in rater review and the incorporation of a DL-based algorithm. The use of pMRI holds promise in providing diagnostic neuroimaging for patients with ICH.
Collapse
Affiliation(s)
- Mercy H. Mazurek
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | | | - Teng J. Peng
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Rachel Beekman
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | | | - Annabel J. Sorby-Adams
- Department of Neurology, Division of Neurocritical Care, Massachusetts General Hospital, Boston, MA, USA
| | - Dheeraj Lalwani
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Julia Zabinska
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Emily J. Gilmore
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Nils H. Petersen
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Guido J. Falcone
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | | | - Charles Matouk
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
| | - Sam Payabvash
- Department of Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Gordon Sze
- Department of Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Steven J. Schiff
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
- Yale Center for Brain & Mind Heath, Yale School of Medicine, New Haven, CT, USA
| | - Juan Eugenio Iglesias
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Centre for Medical Image Computing, University College London, London, UK
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew S. Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Adam de Havenon
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - W. Taylor Kimberly
- Department of Neurology, Division of Neurocritical Care, Massachusetts General Hospital, Boston, MA, USA
| | - Kevin N. Sheth
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Yale Center for Brain & Mind Heath, Yale School of Medicine, New Haven, CT, USA
| |
Collapse
|
23
|
张 宇, 何 为, 杨 磊, 贺 玉, 吴 嘉, 徐 征. [Research on a portable shielding-free ultra-low field magnetic resonance imaging system]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2023; 40:829-836. [PMID: 37879910 PMCID: PMC10600425 DOI: 10.7507/1001-5515.202303060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/30/2023] [Indexed: 10/27/2023]
Abstract
The portable light-weight magnetic resonance imaging system can be deployed in special occasions such as Intensive Care Unit (ICU) and ambulances, making it possible to implement bedside monitoring imaging systems, mobile stroke units and magnetic resonance platforms in remote areas. Compared with medium and high field imaging systems, ultra-low-field magnetic resonance imaging equipment utilizes light-weight permanent magnets, which are compact and easy to move. However, the image quality is highly susceptible to external electromagnetic interference without a shielded room and there are still many key technical problems in hardware design to be solved. In this paper, the system hardware design and environmental electromagnetic interference elimination algorithm were studied. Consequently, some research results were obtained and a prototype of portable shielding-free 50 mT magnetic resonance imaging system was built. The light-weight magnet and its uniformity, coil system and noise elimination algorithm and human brain imaging were verified. Finally, high-quality images of the healthy human brain were obtained. The results of this study would provide reference for the development and application of ultra-low-field magnetic resonance imaging technology.
Collapse
Affiliation(s)
- 宇翔 张
- 重庆大学 电气工程学院(重庆 400044)School of Electrical Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - 为 何
- 重庆大学 电气工程学院(重庆 400044)School of Electrical Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - 磊 杨
- 重庆大学 电气工程学院(重庆 400044)School of Electrical Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - 玉成 贺
- 重庆大学 电气工程学院(重庆 400044)School of Electrical Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - 嘉敏 吴
- 重庆大学 电气工程学院(重庆 400044)School of Electrical Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - 征 徐
- 重庆大学 电气工程学院(重庆 400044)School of Electrical Engineering, Chongqing University, Chongqing 400044, P. R. China
| |
Collapse
|
24
|
Yang X, Yu B, Xi C, Song C, Yang R, Wang W, Wang X, Zhang X, Feng C, Wang X, Cheng G, Chen Y, Zhu Y. A safety study on ultra‑high or moderate static magnetic fields combined with platycodin D against lung cancer. Oncol Lett 2023; 26:453. [PMID: 37720665 PMCID: PMC10502950 DOI: 10.3892/ol.2023.14040] [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] [Received: 05/02/2023] [Accepted: 07/25/2023] [Indexed: 09/19/2023] Open
Abstract
Due to the serious side effects of chemotherapy drugs against lung cancer, and the antitumor properties and high safety of magnetic fields, the present study combined moderate or ultra-high intensity statics magnetic fields (SMFs) with platycodin D (PD) to explore the antitumor efficiency and biosafety. The antitumor effects of PD with or without moderate and ultra-high SMFs on A549 cells bearing mice were compared. Mouse body weight, food/water intake, hematology routine, blood biochemistry, tumor weight and tissues hematoxylin and eosin (H&E) staining were examined. Behavior was measured using the elevated plus maze, open field and vital signs tests. The combined targets of PD and SMFs were detected using RNA-sequencing (RNA-seq). The results showed that the antitumor effect of 22 Tesla (T) SMF group was 3.6-fold higher compared with that of the 2 mg/kg PD group (tumor growth inhibition=10.08%), while the antitumor effect of 150 mT SMF was only 1.56-fold higher compared with that of PD. Although PD reduced the food intake, there was no significant difference in body weight, water intake or food consumption among PD and SMF groups. Behavioral results indicated that PD ameliorated dysphoria in mice, but SMFs reduced this effect. However, no significant abnormalities were found in routine blood, blood biochemistry test, H&E staining or organ index, except renal index which was reduced by PD with or without SMFs. RNA-sequencing (RNA-seq) demonstrated that SMFs and PD synergistically targeted the expression of genes associated with tumor growth, inflammation and neurological disease. The present study showed the antitumor efficacy and biosafety of moderate or ultra-high SMF combined with PD, which exhibited only few side effects in the treatment of lung cancer, thus supporting further research for the clinical application of magnetic fields.
Collapse
Affiliation(s)
- Xingxing Yang
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| | - Biao Yu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China
| | - Chuanying Xi
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China
| | - Chao Song
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China
| | - Rui Yang
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| | - Wei Wang
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| | - Xin Wang
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| | - Xuhan Zhang
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| | - Chuanlin Feng
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China
| | - Xinyu Wang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China
| | - Guofeng Cheng
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, P.R. China
| | - Yansong Chen
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| | - Yong Zhu
- School of Biological and Food Engineering, Hefei Normal University, Hefei, Anhui 230601, P.R. China
| |
Collapse
|
25
|
Campbell-Washburn AE, Keenan KE, Hu P, Mugler JP, Nayak KS, Webb AG, Obungoloch J, Sheth KN, Hennig J, Rosen MS, Salameh N, Sodickson DK, Stein JM, Marques JP, Simonetti OP. Low-field MRI: A report on the 2022 ISMRM workshop. Magn Reson Med 2023; 90:1682-1694. [PMID: 37345725 PMCID: PMC10683532 DOI: 10.1002/mrm.29743] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/21/2023] [Accepted: 05/17/2023] [Indexed: 06/23/2023]
Abstract
In March 2022, the first ISMRM Workshop on Low-Field MRI was held virtually. The goals of this workshop were to discuss recent low field MRI technology including hardware and software developments, novel methodology, new contrast mechanisms, as well as the clinical translation and dissemination of these systems. The virtual Workshop was attended by 368 registrants from 24 countries, and included 34 invited talks, 100 abstract presentations, 2 panel discussions, and 2 live scanner demonstrations. Here, we report on the scientific content of the Workshop and identify the key themes that emerged. The subject matter of the Workshop reflected the ongoing developments of low-field MRI as an accessible imaging modality that may expand the usage of MRI through cost reduction, portability, and ease of installation. Many talks in this Workshop addressed the use of computational power, efficient acquisitions, and contemporary hardware to overcome the SNR limitations associated with low field strength. Participants discussed the selection of appropriate clinical applications that leverage the unique capabilities of low-field MRI within traditional radiology practices, other point-of-care settings, and the broader community. The notion of "image quality" versus "information content" was also discussed, as images from low-field portable systems that are purpose-built for clinical decision-making may not replicate the current standard of clinical imaging. Speakers also described technical challenges and infrastructure challenges related to portability and widespread dissemination, and speculated about future directions for the field to improve the technology and establish clinical value.
Collapse
Affiliation(s)
- Adrienne E Campbell-Washburn
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Kathryn E Keenan
- Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado, USA
| | - Peng Hu
- School of Biomedical Engineering, ShanghaiTech University, Shanghai, China
| | - John P Mugler
- Department of Radiology & Medical Imaging, Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Krishna S Nayak
- Ming Hsieh Department of Electrical and Computer Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
| | - Andrew G Webb
- Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Kevin N Sheth
- Division of Neurocritical Care and Emergency Neurology, Departments of Neurology and Neurosurgery, and the Yale Center for Brain and Mind Health, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jürgen Hennig
- Dept.of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthew S Rosen
- Massachusetts General Hospital, A. A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts, USA
| | - Najat Salameh
- Center for Adaptable MRI Technology (AMT Center), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Daniel K Sodickson
- Department of Radiology, NYU Langone Health, New York, New York, USA
- Center for Advanced Imaging Innovation and Research, NYU Langone Health, New York, New York, USA
| | - Joel M Stein
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - José P Marques
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Orlando P Simonetti
- Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio, USA
- Department of Radiology, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
26
|
Shoghli A, Chow D, Kuoy E, Yaghmai V. Current role of portable MRI in diagnosis of acute neurological conditions. Front Neurol 2023; 14:1255858. [PMID: 37840918 PMCID: PMC10576557 DOI: 10.3389/fneur.2023.1255858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/06/2023] [Indexed: 10/17/2023] Open
Abstract
Neuroimaging is an inevitable component of the assessment of neurological emergencies. Magnetic resonance imaging (MRI) is the preferred imaging modality for detecting neurological pathologies and provides higher sensitivity than other modalities. However, difficulties such as intra-hospital transport, long exam times, and availability in strict access-controlled suites limit its utility in emergency departments and intensive care units (ICUs). The evolution of novel imaging technologies over the past decades has led to the development of portable MRI (pMRI) machines that can be deployed at point-of-care. This article reviews pMRI technologies and their clinical implications in acute neurological conditions. Benefits of pMRI include timely and accurate detection of major acute neurological pathologies such as stroke and intracranial hemorrhage. Additionally, pMRI can be potentially used to monitor the progression of neurological complications by facilitating serial measurements at the bedside.
Collapse
Affiliation(s)
| | | | | | - Vahid Yaghmai
- Department of Radiological Sciences, School of Medicine, University of California, Irvine, Irvine, CA, United States
| |
Collapse
|
27
|
Kimberly WT, Sorby-Adams AJ, Webb AG, Wu EX, Beekman R, Bowry R, Schiff SJ, de Havenon A, Shen FX, Sze G, Schaefer P, Iglesias JE, Rosen MS, Sheth KN. Brain imaging with portable low-field MRI. NATURE REVIEWS BIOENGINEERING 2023; 1:617-630. [PMID: 37705717 PMCID: PMC10497072 DOI: 10.1038/s44222-023-00086-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/06/2023] [Indexed: 09/15/2023]
Abstract
The advent of portable, low-field MRI (LF-MRI) heralds new opportunities in neuroimaging. Low power requirements and transportability have enabled scanning outside the controlled environment of a conventional MRI suite, enhancing access to neuroimaging for indications that are not well suited to existing technologies. Maximizing the information extracted from the reduced signal-to-noise ratio of LF-MRI is crucial to developing clinically useful diagnostic images. Progress in electromagnetic noise cancellation and machine learning reconstruction algorithms from sparse k-space data as well as new approaches to image enhancement have now enabled these advancements. Coupling technological innovation with bedside imaging creates new prospects in visualizing the healthy brain and detecting acute and chronic pathological changes. Ongoing development of hardware, improvements in pulse sequences and image reconstruction, and validation of clinical utility will continue to accelerate this field. As further innovation occurs, portable LF-MRI will facilitate the democratization of MRI and create new applications not previously feasible with conventional systems.
Collapse
Affiliation(s)
- W Taylor Kimberly
- Department of Neurology and the Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Annabel J Sorby-Adams
- Department of Neurology and the Center for Genomic Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew G Webb
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Rachel Beekman
- Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale New Haven Hospital and Yale School of Medicine, Yale Center for Brain & Mind Health, New Haven, CT, USA
| | - Ritvij Bowry
- Departments of Neurosurgery and Neurology, McGovern Medical School, University of Texas Health Neurosciences, Houston, TX, USA
| | - Steven J Schiff
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
| | - Adam de Havenon
- Division of Vascular Neurology, Department of Neurology, Yale New Haven Hospital and Yale School of Medicine, New Haven, CT, USA
| | - Francis X Shen
- Harvard Medical School Center for Bioethics, Harvard law School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - Gordon Sze
- Department of Radiology, Yale New Haven Hospital and Yale School of Medicine, New Haven, CT, USA
| | - Pamela Schaefer
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Juan Eugenio Iglesias
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Centre for Medical Image Computing, University College London, London, UK
- Computer Science and AI Laboratory, Massachusetts Institute of Technology, Boston, MA, USA
| | - Matthew S Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kevin N Sheth
- Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Yale New Haven Hospital and Yale School of Medicine, Yale Center for Brain & Mind Health, New Haven, CT, USA
| |
Collapse
|
28
|
Theilenberg S, Shang Y, Ghazouani J, Kumaragamage C, Nixon TW, McIntyre S, Vaughan JT, Parkinson B, Garwood M, de Graaf RA, Juchem C. Design and realization of a multi-coil array for B 0 field control in a compact 1.5T head-only MRI scanner. Magn Reson Med 2023; 90:1228-1241. [PMID: 37145035 PMCID: PMC10330274 DOI: 10.1002/mrm.29692] [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: 12/17/2022] [Revised: 03/27/2023] [Accepted: 04/14/2023] [Indexed: 05/06/2023]
Abstract
PURPOSE To design and implement a multi-coil (MC) array for B0 field generation for image encoding and simultaneous advanced shimming in a novel 1.5T head-only MRI scanner. METHODS A 31-channel MC array was designed following the unique constraints of this scanner design: The vertically oriented magnet is very short, stopping shortly above the shoulders of a sitting subject, and includes a window for the subject to see through. Key characteristics of the MC hardware, the B0 field generation capabilities, and thermal behavior, were optimized in simulations prior to its construction. The unit was characterized via bench testing. B0 field generation capabilities were validated on a human 4T MR scanner by analysis of experimental B0 fields and by comparing images for several MRI sequences acquired with the MC array to those acquired with the system's linear gradients. RESULTS The MC system was designed to produce a multitude of linear and nonlinear magnetic fields including linear gradients of up to 10 kHz/cm (23.5 mT/m) with MC currents of 5 A per channel. With water cooling it can be driven with a duty cycle of up to 74% and ramp times of 500 μs. MR imaging experiments encoded with the developed multi-coil hardware were largely artifact-free; residual imperfections were predictable, and correctable. CONCLUSION The presented compact multi-coil array is capable of generating image encoding fields with amplitudes and quality comparable to clinical systems at very high duty cycles, while additionally enabling high-order B0 shimming capabilities and the potential for nonlinear encoding fields.
Collapse
Affiliation(s)
- Sebastian Theilenberg
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - Yun Shang
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - Jalal Ghazouani
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
| | - Chathura Kumaragamage
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT, United States
| | - Terence W. Nixon
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT, United States
| | - Scott McIntyre
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT, United States
| | - J. Thomas Vaughan
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
- Department of Radiology, Columbia University Medical Center, New York, NY, United States
| | - Ben Parkinson
- Robinson Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Mike Garwood
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States
| | - Robin A. de Graaf
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, CT, United States
| | - Christoph Juchem
- Department of Biomedical Engineering, Columbia University, New York, NY, United States
- Department of Radiology, Columbia University Medical Center, New York, NY, United States
| |
Collapse
|
29
|
Thankarajan E, Oz S, Saady A, Kulbitski K, Kompanets MO, Eisen MS, Berlin S. SNAP-Tag-Targeted MRI-Fluorescent Multimodal Probes. Chembiochem 2023; 24:e202300172. [PMID: 37092744 DOI: 10.1002/cbic.202300172] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/02/2023] [Accepted: 04/24/2023] [Indexed: 04/25/2023]
Abstract
Magnetic resonance imaging (MRI) is a powerful imaging modality, widely employed in research and clinical settings. However, MRI images suffer from low signals and a lack of target specificity. We aimed to develop a multimodal imaging probe to detect targeted cells by MRI and fluorescence microscopy. We synthesized a trifunctional imaging probe consisting of a SNAP-tag substrate for irreversible and specific labelling of cells, cyanine dyes for bright fluorescence, and a chelated GdIII molecule for enhancing MRI contrast. Our probes exhibit specific and efficient labelling of genetically defined cells (expressing SNAP-tag at their membrane), bright fluorescence and MRI signal. Our synthetic approach provides a versatile platform for the production of multimodal imaging probes, particularly for light microscopy and MRI.
Collapse
Affiliation(s)
- Ebaston Thankarajan
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3525422, Israel
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Shimrit Oz
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3525422, Israel
| | - Abed Saady
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3525422, Israel
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
- Present address: School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - Kseniya Kulbitski
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Mykhail O Kompanets
- L.M. Litvinenko Institute of Physico-Organic Chemistry and Coal Chemistry, National Academy of Sciences of Ukraine, Kyiv, 02660, Ukraine
| | - Moris S Eisen
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa, 3200003, Israel
| | - Shai Berlin
- Department of Neuroscience, Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3525422, Israel
| |
Collapse
|
30
|
Oberdick SD, Jordanova KV, Lundstrom JT, Parigi G, Poorman ME, Zabow G, Keenan KE. Iron oxide nanoparticles as positive T 1 contrast agents for low-field magnetic resonance imaging at 64 mT. Sci Rep 2023; 13:11520. [PMID: 37460669 DOI: 10.1038/s41598-023-38222-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 07/05/2023] [Indexed: 07/20/2023] Open
Abstract
We have investigated the efficacy of superparamagnetic iron oxide nanoparticles (SPIONs) as positive T1 contrast agents for low-field magnetic resonance imaging (MRI) at 64 millitesla (mT). Iron oxide-based agents, such as the FDA-approved ferumoxytol, were measured using a variety of techniques to evaluate T1 contrast at 64 mT. Additionally, we characterized monodispersed carboxylic acid-coated SPIONs with a range of diameters (4.9-15.7 nm) in order to understand size-dependent properties of T1 contrast at low-field. MRI contrast properties were measured using 64 mT MRI, magnetometry, and nuclear magnetic resonance dispersion (NMRD). We also measured MRI contrast at 3 T to provide comparison to a standard clinical field strength. SPIONs have the capacity to perform well as T1 contrast agents at 64 mT, with measured longitudinal relaxivity (r1) values of up to 67 L mmol-1 s-1, more than an order of magnitude higher than corresponding r1 values at 3 T. The particles exhibit size-dependent longitudinal relaxivities and outperform a commercial Gd-based agent (gadobenate dimeglumine) by more than eight-fold at physiological temperatures. Additionally, we characterize the ratio of transverse to longitudinal relaxivity, r2/r1 and find that it is ~ 1 for the SPION based agents at 64 mT, indicating a favorable balance of relaxivities for T1-weighted contrast imaging. We also correlate the magnetic and structural properties of the particles with models of nanoparticle relaxivity to understand generation of T1 contrast. These experiments show that SPIONs, at low fields being targeted for point-of-care low-field MRI systems, have a unique combination of magnetic and structural properties that produce large T1 relaxivities.
Collapse
Affiliation(s)
- Samuel D Oberdick
- Department of Physics, University of Colorado, Boulder, CO, 80309, USA.
- National Institute of Standards and Technology, Boulder, CO, 80305, USA.
| | | | - John T Lundstrom
- Department of Physics, University of Colorado, Boulder, CO, 80309, USA
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
- Department of Chemistry "Ugo Schiff", University of Florence, Via Della Lastruccia 3, 50019, Sesto Fiorentino, Italy
- Consorzio Interuniversitario Risonanze Magnetiche Metallo Proteine (CIRMMP), Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Italy
| | | | - Gary Zabow
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - Kathryn E Keenan
- National Institute of Standards and Technology, Boulder, CO, 80305, USA
| |
Collapse
|
31
|
Bryden N, Atalla SW, Kelley M, Holmes LR, Branca RT. Enhanced 129 Xe T 1 relaxation in whole blood and in the presence of SPIONs at low magnetic field strengths. Magn Reson Med 2023; 90:21-33. [PMID: 36797796 PMCID: PMC10963042 DOI: 10.1002/mrm.29619] [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: 11/29/2022] [Revised: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 02/18/2023]
Abstract
PURPOSE To compare the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on the T1 of 129 Xe and 1 H and to measure the relaxation of 129 Xe in blood at low and high magnetic field strengths. METHODS 129 Xe and 1 H T1 relaxometry was performed at low- and high-field strengths in samples containing different SPION concentrations, while imaging was used to compare the contrast obtainable in these two field regimes. In vivo experiments at variable field strengths were performed to determine the depolarization of 129 Xe in blood and the feasibility of in vivo dissolved-phase spectroscopy and imaging at low field. RESULTS The SPION relaxivity was substantially greater at low field for 1 H, increasing from 0.92 ± 0.06 mM s-1 at 11.7T to 31.5 ± 1.8 mM s-1 at 0.6 mT, and for 129 Xe, which increased from 0.13 ± 0.03 mM s-1 at 11.7T to 7.32 ± 0.71 mM s-1 at 2.1 mT. The additional MR signal loss increased from 0.7% at 9.4T to 20.6 ± 4.2% at 0.6 mT for 1 H and from -0.7 ± 3.4% at 9.4T to 12.7 ± 3.5% at 2.1 mT for 129 Xe. Blood was found to depolarize 129 Xe below 3T in a manner inversely proportional to the field strength. In vitro studies at 2.1 mT suggest 129 Xe relaxation times below 5 s in blood dilutions as low as 0.4% volume. CONCLUSION SPIONs longitudinal relaxivity increases at low field both for 1 H and 129 Xe. The depolarization of xenon in blood, which is found to increase below 3T, effectively prevents in vivo dissolved-phase spectroscopy and imaging at low-field strengths.
Collapse
Affiliation(s)
- Nicholas Bryden
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sebastian W Atalla
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Michele Kelley
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Leah R Holmes
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rosa T Branca
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
32
|
Hennig J. An evolution of low-field strength MRI. MAGMA (NEW YORK, N.Y.) 2023; 36:335-346. [PMID: 37289275 PMCID: PMC10386941 DOI: 10.1007/s10334-023-01104-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 05/05/2023] [Accepted: 05/17/2023] [Indexed: 06/09/2023]
Abstract
The paper describes the evolution of low-field MRI from the very early pioneering days in the late 70 s until today. It is not meant to give a comprehensive historical account of the development of MRI, but rather to highlight the different research environments then and now. In the early 90 s, when low-field systems below 1.5 T essentially vanished, there were just no reasonable means available to make up for the factor of roughly three in signal-to-noise-ratio (SNR) between 0.5 and 1.5 T. This has drastically changed. Improvements in hardware-closed Helium-free magnets, RF receiver systems and especially much faster gradients, much more flexible sampling schemes including parallel imaging and compressed sensing and especially the use of AI at all stages of the imaging process have made low-field MRI a clinically viable supplement to conventional MRI. Ultralow-field MRI with magnets around 0.05 T are also back and constitute a bold and courageous endeavor to bring MRI to communities, which have neither the means nor the infrastructure to sustain a current standard of care MRI.
Collapse
Affiliation(s)
- Juergen Hennig
- Department of Radiology, Medical Physics, Faculty of Medicine, University of Freiburg, Killianstr.5a, 79106, Freiburg, Germany.
| |
Collapse
|
33
|
Salameh N, Lurie DJ, Ipek Ö, Cooley CZ, Campbell-Washburn AE. Exploring the foothills: benefits below 1 Tesla? MAGMA (NEW YORK, N.Y.) 2023; 36:329-333. [PMID: 37482583 DOI: 10.1007/s10334-023-01106-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/02/2023] [Indexed: 07/25/2023]
Affiliation(s)
- Najat Salameh
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - David J Lurie
- Biomedical Physics, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Özlem Ipek
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Clarissa Zimmerman Cooley
- Department of Radiology, Massachusetts General Hospital, Athinoula A Martinos Center for Biomedical Imaging, Boston, MA, USA
| | - Adrienne E Campbell-Washburn
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
34
|
Ramasawmy R, Mugler JP, Javed A, Wang Z, Herzka DA, Meyer CH, Campbell-Washburn AE. Concomitant field compensation of spiral turbo spin-echo at 0.55 T. MAGMA (NEW YORK, N.Y.) 2023; 36:465-475. [PMID: 37306784 PMCID: PMC10771127 DOI: 10.1007/s10334-023-01103-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/26/2023] [Accepted: 05/15/2023] [Indexed: 06/13/2023]
Abstract
OBJECTIVE Diagnostic-quality neuroimaging methods are vital for widespread clinical adoption of low field MRI. Spiral imaging is an efficient acquisition method that can mitigate the reduced signal-to-noise ratio at lower field strengths. As concomitant field artifacts are worse at lower field, we propose a generalizable quadratic gradient-field nulling as an echo-to-echo compensation and apply it to spiral TSE at 0.55 T. MATERIALS AND METHODS A spiral in-out TSE acquisition was developed with a compensation for concomitant field variation between spiral interleaves, by adding bipolar gradients around each readout to minimize phase differences at each refocusing pulse. Simulations were performed to characterize concomitant field compensation approaches. We demonstrate our proposed compensation method in phantoms and (n = 8) healthy volunteers at 0.55 T. RESULTS Spiral read-outs with integrated spoiling demonstrated strong concomitant field artifacts but were mitigated using the echo-to-echo compensation. Simulations predicted a decrease of concomitant field phase RMSE between echoes of 42% using the proposed compensation. Spiral TSE improved SNR by 17.2 ± 2.3% compared to reference Cartesian acquisition. DISCUSSION We demonstrated a generalizable approach to mitigate concomitant field artifacts for spiral TSE acquisitions via the addition of quadratic-nulling gradients, which can potentially improve neuroimaging at low-field through increased acquisition efficiency.
Collapse
Affiliation(s)
- Rajiv Ramasawmy
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - John P Mugler
- Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Ahsan Javed
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zhixing Wang
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Daniel A Herzka
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Craig H Meyer
- Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, VA, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Adrienne E Campbell-Washburn
- Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
35
|
Selvaganesan K, Wan Y, Ha Y, Wu B, Hancock K, Galiana G, Constable RT. Magnetic resonance imaging using a nonuniform Bo (NuBo) field-cycling magnet. PLoS One 2023; 18:e0287344. [PMID: 37319289 PMCID: PMC10270621 DOI: 10.1371/journal.pone.0287344] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 06/02/2023] [Indexed: 06/17/2023] Open
Abstract
Magnetic resonance imaging (MRI) is a powerful noninvasive diagnostic tool with superior soft tissue contrast. However, access to MRI is limited since current systems depend on homogeneous, high field strength main magnets (B0-fields), with strong switchable gradients which are expensive to install and maintain. In this work we propose a new approach to MRI where imaging is performed in an inhomogeneous field using radiofrequency spatial encoding, thereby eliminating the need for uniform B0-fields and conventional cylindrical gradient coils. The proposed technology uses an innovative data acquisition and reconstruction approach by integrating developments in field cycling, parallel imaging and non-Fourier based algebraic reconstruction. The scanner uses field cycling to image in an inhomogeneous B0-field; in this way magnetization is maximized during the high field polarization phase, and B0 inhomogeneity effects are minimized by using a low field during image acquisition. In addition to presenting the concept, this work provides experimental verification of a long-lived spin echo signal, spatially varying resolution, as well as both simulated and experimental 2D images. Our initial design creates an open MR system that can be installed in a patient examination table for body imaging (e.g., breast or liver) or built into a wall for weighted-spine imaging. The proposed system introduces a new class of inexpensive, open, silent MRIs that could be housed in doctor's offices much like ultrasound is today, making MRI more widely accessible.
Collapse
Affiliation(s)
- Kartiga Selvaganesan
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States of America
| | - Yuqing Wan
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States of America
| | - Yonghyun Ha
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States of America
| | - Baosong Wu
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States of America
| | - Kasey Hancock
- Department of Electrical Engineering, Yale University, New Haven, CT, United States of America
| | - Gigi Galiana
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States of America
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States of America
| | - R. Todd Constable
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States of America
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States of America
| |
Collapse
|
36
|
Parasuram NR, Crawford AL, Mazurek MH, Chavva IR, Beekman R, Gilmore EJ, Petersen NH, Payabvash S, Sze G, Eugenio Iglesias J, Omay SB, Matouk C, Longbrake EE, de Havenon A, Schiff SJ, Rosen MS, Kimberly WT, Sheth KN. Future of Neurology & Technology: Neuroimaging Made Accessible Using Low-Field, Portable MRI. Neurology 2023; 100:1067-1071. [PMID: 36720639 PMCID: PMC10259275 DOI: 10.1212/wnl.0000000000207074] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 01/04/2023] [Indexed: 02/02/2023] Open
Abstract
In the 20th century, the advent of neuroimaging dramatically altered the field of neurologic care. However, despite iterative advances since the invention of CT and MRI, little progress has been made to bring MR neuroimaging to the point of care. Recently, the emergence of a low-field (<1 T) portable MRI (pMRI) is setting the stage to revolutionize the landscape of accessible neuroimaging. Users can transport the pMRI into a variety of locations, using a standard 110-220 V wall outlet. In this article, we discuss current applications for pMRI, including in the acute and critical care settings, the barriers to broad implementation, and future opportunities.
Collapse
Affiliation(s)
- Nethra R Parasuram
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Anna L Crawford
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Mercy H Mazurek
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Isha R Chavva
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Rachel Beekman
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Emily J Gilmore
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Nils H Petersen
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Seyedmehdi Payabvash
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Gordon Sze
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Juan Eugenio Iglesias
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Sacit B Omay
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Charles Matouk
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Erin E Longbrake
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Adam de Havenon
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Steven J Schiff
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Matthew S Rosen
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - W Taylor Kimberly
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston
| | - Kevin N Sheth
- From the Department of Neurology (N.R.P., A.L.C., M.H.M., I.R.C., R.B., E.J.G., N.H.P., E.E.L., A.d.H., K.N.S.), and Department of Radiology (S.P., G.S.), Yale University School of Medicine, New Haven, CT; Computer Science and Artificial Intelligence Laboratory (CSAIL) (J.E.I.), Massachusetts Institute of Technology, Cambridge; Athinoula A. Martinos Center for Biomedical Imaging (J.E.I., M.S.R.), Massachusetts General Hospital, Charlestown; Department of Neurosurgery (S.B.O., C.M.), Yale University School of Medicine, New Haven, CT; Department of Neurosurgery (S.J.S.), Engineering Science and Mechanics, and Physics, The Pennsylvania State University, University Park; and Division of Neurocritical Care (W.T.K.), Department of Neurology, Massachusetts General Hospital, Boston.
| |
Collapse
|
37
|
Jordanova KV, Martin MN, Ogier SE, Poorman ME, Keenan KE. In vivo quantitative MRI: T 1 and T 2 measurements of the human brain at 0.064 T. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01095-x. [PMID: 37208553 PMCID: PMC10386946 DOI: 10.1007/s10334-023-01095-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 04/03/2023] [Accepted: 04/19/2023] [Indexed: 05/21/2023]
Abstract
OBJECTIVE To measure healthy brain [Formula: see text] and [Formula: see text] relaxation times at 0.064 T. MATERIALS AND METHODS [Formula: see text] and [Formula: see text] relaxation times were measured in vivo for 10 healthy volunteers using a 0.064 T magnetic resonance imaging (MRI) system and for 10 test samples on both the MRI and a separate 0.064 T nuclear magnetic resonance (NMR) system. In vivo [Formula: see text] and [Formula: see text] values are reported for white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) for automatic segmentation regions and manual regions of interest (ROIs). RESULTS [Formula: see text] sample measurements on the MRI system were within 10% of the NMR measurement for 9 samples, and one sample was within 11%. Eight [Formula: see text] sample MRI measurements were within 25% of the NMR measurement, and the two longest [Formula: see text] samples had more than 25% variation. Automatic segmentations generally resulted in larger [Formula: see text] and [Formula: see text] estimates than manual ROIs. DISCUSSION [Formula: see text] and [Formula: see text] times for brain tissue were measured at 0.064 T. Test samples demonstrated accuracy in WM and GM ranges of values but underestimated long [Formula: see text] in the CSF range. This work contributes to measuring quantitative MRI properties of the human body at a range of field strengths.
Collapse
Affiliation(s)
- Kalina V Jordanova
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, Boulder, CO, USA.
| | - Michele N Martin
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, Boulder, CO, USA
| | - Stephen E Ogier
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, Boulder, CO, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO, USA
| | | | - Kathryn E Keenan
- Physical Measurement Laboratory, National Institute of Standards and Technology, NIST, Boulder, CO, USA
| |
Collapse
|
38
|
Martin MN, Jordanova KV, Kos AB, Russek SE, Keenan KE, Stupic KF. Relaxation measurements of an MRI system phantom at low magnetic field strengths. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01086-y. [PMID: 37209233 PMCID: PMC10386925 DOI: 10.1007/s10334-023-01086-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/23/2023] [Accepted: 03/29/2023] [Indexed: 05/22/2023]
Abstract
OBJECTIVE Temperature controlled T1 and T2 relaxation times are measured on NiCl2 and MnCl2 solutions from the ISMRM/NIST system phantom at low magnetic field strengths of 6.5 mT, 64 mT and 550 mT. MATERIALS AND METHODS The T1 and T2 were measured of five samples with increasing concentrations of NiCl2 and five samples with increasing concentrations of MnCl2. All samples were scanned at 6.5 mT, 64 mT and 550 mT, at sample temperatures ranging from 10 °C to 37 °C. RESULTS The NiCl2 solutions showed little change in T1 and T2 with magnetic field strength, and both relaxation times decreased with increasing temperature. The MnCl2 solutions showed an increase in T1 and a decrease in T2 with increasing magnetic field strength, and both T1 and T2 increased with increasing temperature. DISCUSSION The low field relaxation rates of the NiCl2 and MnCl2 arrays in the ISMRM/NIST system phantom are investigated and compared to results from clinical field strengths of 1.5 T and 3.0 T. The measurements can be used as a benchmark for MRI system functionality and stability, especially when MRI systems are taken out of the radiology suite or laboratory and into less traditional environments.
Collapse
Affiliation(s)
- Michele N Martin
- U.S. Department of Commerce, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA.
| | - Kalina V Jordanova
- U.S. Department of Commerce, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA
| | - Anthony B Kos
- U.S. Department of Commerce, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA
| | - Stephen E Russek
- U.S. Department of Commerce, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA
| | - Kathryn E Keenan
- U.S. Department of Commerce, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA
| | - Karl F Stupic
- U.S. Department of Commerce, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA
| |
Collapse
|
39
|
Webb A, O'Reilly T. Tackling SNR at low-field: a review of hardware approaches for point-of-care systems. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01100-3. [PMID: 37202656 PMCID: PMC10386948 DOI: 10.1007/s10334-023-01100-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 05/03/2023] [Accepted: 05/09/2023] [Indexed: 05/20/2023]
Abstract
OBJECTIVE To review the major hardware components of low-field point-of-care MRI systems which affect the overall sensitivity. METHODS Designs for the following components are reviewed and analyzed: magnet, RF coils, transmit/receive switches, preamplifiers, data acquisition system, and methods for grounding and mitigating electromagnetic interference. RESULTS High homogeneity magnets can be produced in a variety of different designs including C- and H-shaped as well as Halbach arrays. Using Litz wire for RF coil designs enables unloaded Q values of ~ 400 to be reached, with body loss representing about 35% of the total system resistance. There are a number of different schemes to tackle issues arising from the low coil bandwidth with respect to the imaging bandwidth. Finally, the effects of good RF shielding, proper electrical grounding, and effective electromagnetic interference reduction can lead to substantial increases in image signal-to-noise ratio. DISCUSSION There are many different magnet and RF coil designs in the literature, and to enable meaningful comparisons and optimizations to be performed it would be very helpful to determine a standardized set of sensitivity measures, irrespective of design.
Collapse
Affiliation(s)
- Andrew Webb
- Department of Radiology, C.J. Gorter MRI Center, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands.
| | - Thomas O'Reilly
- Department of Radiology, C.J. Gorter MRI Center, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| |
Collapse
|
40
|
Ellermann F, Saul P, Hövener JB, Pravdivtsev AN. Modern Manufacturing Enables Magnetic Field Cycling Experiments and Parahydrogen-Induced Hyperpolarization with a Benchtop NMR. Anal Chem 2023; 95:6244-6252. [PMID: 37018544 DOI: 10.1021/acs.analchem.2c03682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Benchtop NMR (btNMR) spectrometers are revolutionizing the way we use NMR and lowering the cost drastically. Magnetic field cycling (MFC) experiments with precise timing and control over the magnetic field, however, were hitherto not available on btNMRs, although some systems exist for high-field, high-resolution NMR spectrometers. Still, the need and potential for btNMR MFC is great─e.g., to perform and analyze parahydrogen-induced hyperpolarization, another method that has affected analytical chemistry and NMR beyond expectations. Here, we describe a setup that enables MFC on btNMRs for chemical analysis and hyperpolarization. Taking full advantage of the power of modern manufacturing, including computer-aided design, three-dimensional printing, and microcontrollers, the setup is easy to reproduce, highly reliable, and easy to adjust and operate. Within 380 ms, the NMR tube was shuttled reliably from the electromagnet to the NMR isocenter (using a stepper motor and gear rod). We demonstrated the power of this setup by hyperpolarizing nicotinamide using signal amplification by reversible exchange (SABRE), a versatile method to hyperpolarize a broad variety of molecules including metabolites and drugs. Here, the standard deviation of SABRE hyperpolarization was between 0.2 and 3.3%. The setup also allowed us to investigate the field dependency of the polarization and the effect of different sample preparation protocols. We found that redissolution of the activated and dried Ir catalyst always reduced the polarization. We anticipate that this design will greatly accelerate the ascension of MFC experiments for chemical analysis with btNMR─adding yet another application to this rapidly developing field.
Collapse
Affiliation(s)
- Frowin Ellermann
- Section for Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel 24118, Germany
| | - Philip Saul
- Section for Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel 24118, Germany
| | - Jan-Bernd Hövener
- Section for Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel 24118, Germany
| | - Andrey N Pravdivtsev
- Section for Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel 24118, Germany
| |
Collapse
|
41
|
Yin Q, Kichari JR, Alebeek AHV, Korteweg MA, Teunissen BP, Ritt MJ. Using a Dedicated Extremity MRI Scanner for Depicting Anatomic Structures of Common Wrist Pathologies: A Pilot Comparison with a 3-Tesla MRI Scanner. J Wrist Surg 2023; 12:147-154. [PMID: 36926212 PMCID: PMC10010896 DOI: 10.1055/s-0042-1744366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/31/2022] [Indexed: 10/18/2022]
Abstract
Background This pilot study explored the value of a dedicated extremity magnetic resonance imaging (MRI) scanner by focusing on the qualitative depiction of important wrist structures in common wrist pathologies, the overall image quality, artifacts, and participant experience in undergoing the examinations. Methods Images of the right wrist of 10 healthy adult volunteers were acquired with a 0.31-Tesla (T) dedicated extremity MRI and a 3-T MRI system, using a dedicated wrist coil. Images were separately evaluated by three radiologists. Paired images were randomized and graded for the visibility of anatomical details, including the triangular fibrocartilage complex (TFCC; central disc, meniscus homolog, and ulnar attachment), carpal ligaments (scapholunate [SL] and lunotriquetral [LT] ligaments), intercarpal cartilage, and median and ulnar nerves. Mean values and standard deviations of evaluation results were calculated for each sequence. Participants' experience in undergoing the examination in both MRI scanners was explored using a questionnaire. Results The mean values of anatomic structures and overall image quality were significantly in favor of the 3-T MRI scanner, compared with the dedicated extremity MRI scanner. With respect to patient satisfaction in undergoing the examination, the overall trend suggested that patients were more in favor of the dedicated extremity MRI scanner. Conclusion For defining the real clinical value of the dedicated MRI scanner in the treatment of hand and wrist pathology, studies focused on pathologies are needed, which is certainly warranted, considering the important benefits of these devices including lower costs and higher accessibility for both patients and health care providers.
Collapse
Affiliation(s)
- Qi Yin
- Department of Plastic, Reconstructive and Hand Surgery, Amsterdam UMC, The Netherlands
| | - Jayant R. Kichari
- Department of Radiology, St. Jansdal hospital, Harderwijk, The Netherlands
| | | | | | | | - Marco J.P.F. Ritt
- Department of Plastic, Reconstructive and Hand Surgery, Amsterdam UMC, The Netherlands
- The Hand Clinic, Amsterdam, The Netherlands
| |
Collapse
|
42
|
Parsa J, Webb A. Specific absorption rate (SAR) simulations for low-field (< 0.1 T) MRI systems. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01073-3. [PMID: 36933091 PMCID: PMC10386976 DOI: 10.1007/s10334-023-01073-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 01/19/2023] [Accepted: 02/23/2023] [Indexed: 03/19/2023]
Abstract
OBJECTIVE To simulate the magnetic and electric fields produced by RF coil geometries commonly used at low field. Based on these simulations, the specific absorption rate (SAR) efficiency can be derived to ensure safe operation even when using short RF pulses and high duty cycles. METHODS Electromagnetic simulations were performed at four different field strengths between 0.05 and 0.1 T, corresponding to the lower and upper limits of current point-of-care (POC) neuroimaging systems. Transmit magnetic and electric fields, as well as transmit efficiency and SAR efficiency were simulated. The effects of a close-fitting shield on the EM fields were also assessed. SAR calculations were performed as a function of RF pulse length in turbo-spin echo (TSE) sequences. RESULTS Simulations of RF coil characteristics and B1+ transmit efficiencies agreed well with corresponding experimentally determined parameters. Overall, the SAR efficiency was, as expected, higher at the lower frequencies studied, and many orders of magnitude greater than at conventional clinical field strengths. The tight-fitting transmit coil results in the highest SAR in the nose and skull, which are not thermally sensitive tissues. The calculated SAR efficiencies showed that only when 180° refocusing pulses of duration ~ 10 ms are used for TSE sequences does SAR need to be carefully considered. CONCLUSION This work presents a comprehensive overview of the transmit and SAR efficiencies for RF coils used for POC MRI neuroimaging. While SAR is not a problem for conventional sequences, the values derived here should be useful for RF intensive sequences such as T1ρ, and also demonstrate that if very short RF pulses are required then SAR calculations should be performed.
Collapse
Affiliation(s)
- Javad Parsa
- C.J. Gorter MRI Centre, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.,Percuros B.V., Leiden, The Netherlands
| | - Andrew Webb
- C.J. Gorter MRI Centre, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
| |
Collapse
|
43
|
Manso Jimeno M, Vaughan JT, Geethanath S. Superconducting magnet designs and MRI accessibility: A review. NMR IN BIOMEDICINE 2023:e4921. [PMID: 36914280 DOI: 10.1002/nbm.4921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 02/13/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Presently, magnetic resonance imaging (MRI) magnets must deliver excellent magnetic field (B0 ) uniformity to achieve optimum image quality. Long magnets can satisfy the homogeneity requirements but require considerable superconducting material. These designs result in large, heavy, and costly systems that aggravate as field strength increases. Furthermore, the tight temperature tolerance of niobium titanium magnets adds instability to the system and requires operation at liquid helium temperature. These issues are crucial factors in the disparity of MR density and field strength use across the globe. Low-income settings show reduced access to MRI, especially to high field strengths. This article summarizes the proposed modifications to MRI superconducting magnet design and their impact on accessibility, including compact, reduced liquid helium, and specialty systems. Reducing the amount of superconductor inevitably entails shrinking the magnet size, resulting in higher field inhomogeneity. This work also reviews the state-of-the-art imaging and reconstruction methods to overcome this issue. Finally, we summarize the current and future challenges and opportunities in the design of accessible MRI.
Collapse
Affiliation(s)
- Marina Manso Jimeno
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, New York, USA
- Columbia Magnetic Resonance Research Center, Columbia University in the City of New York, New York, New York, USA
| | - John Thomas Vaughan
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, New York, USA
- Columbia Magnetic Resonance Research Center, Columbia University in the City of New York, New York, New York, USA
| | - Sairam Geethanath
- Columbia Magnetic Resonance Research Center, Columbia University in the City of New York, New York, New York, USA
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, The Biomedical Engineering and Imaging Institute, New York, New York, USA
| |
Collapse
|
44
|
Perron S, Ouriadov A. Hyperpolarized 129Xe MRI at low field: Current status and future directions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 348:107387. [PMID: 36731353 DOI: 10.1016/j.jmr.2023.107387] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/07/2022] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Magnetic Resonance Imaging (MRI) is dictated by the magnetization of the sample, and is thus a low-sensitivity imaging method. Inhalation of hyperpolarized (HP) noble gases, such as helium-3 and xenon-129, is a non-invasive, radiation-risk free imaging technique permitting high resolution imaging of the lungs and pulmonary functions, such as the lung microstructure, diffusion, perfusion, gas exchange, and dynamic ventilation. Instead of increasing the magnetic field strength, the higher spin polarization achievable from this method results in significantly higher net MR signal independent of tissue/water concentration. Moreover, the significantly longer apparent transverse relaxation time T2* of these HP gases at low magnetic field strengths results in fewer necessary radiofrequency (RF) pulses, permitting larger flip angles; this allows for high-sensitivity imaging of in vivo animal and human lungs at conventionally low (<0.5 T) field strengths and suggests that the low field regime is optimal for pulmonary MRI using hyperpolarized gases. In this review, theory on the common spin-exchange optical-pumping method of hyperpolarization and the field dependence of the MR signal of HP gases are presented, in the context of human lung imaging. The current state-of-the-art is explored, with emphasis on both MRI hardware (low field scanners, RF coils, and polarizers) and image acquisition techniques (pulse sequences) advancements. Common challenges surrounding imaging of HP gases and possible solutions are discussed, and the future of low field hyperpolarized gas MRI is posed as being a clinically-accessible and versatile imaging method, circumventing the siting restrictions of conventional high field scanners and bringing point-of-care pulmonary imaging to global facilities.
Collapse
Affiliation(s)
- Samuel Perron
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada.
| | - Alexei Ouriadov
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; School of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
45
|
Varghese J, Jin N, Giese D, Chen C, Liu Y, Pan Y, Nair N, Shalaan MT, Khan M, Tong MS, Ahmad R, Han Y, Simonetti OP. Building a comprehensive cardiovascular magnetic resonance exam on a commercial 0.55 T system: A pictorial essay on potential applications. Front Cardiovasc Med 2023; 10:1120982. [PMID: 36937932 PMCID: PMC10014600 DOI: 10.3389/fcvm.2023.1120982] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 02/06/2023] [Indexed: 03/05/2023] Open
Abstract
Background Contemporary advances in low-field magnetic resonance imaging systems can potentially widen access to cardiovascular magnetic resonance (CMR) imaging. We present our initial experience in building a comprehensive CMR protocol on a commercial 0.55 T system with a gradient performance of 26 mT/m amplitude and 45 T/m/s slew rate. To achieve sufficient image quality, we adapted standard imaging techniques when possible, and implemented compressed-sensing (CS) based techniques when needed in an effort to compensate for the inherently low signal-to-noise ratio at lower field strength. Methods A prototype CMR exam was built on an 80 cm, ultra-wide bore commercial 0.55 T MR system. Implementation of all components aimed to overcome the inherently lower signal of low-field and the relatively longer echo and repetition times owing to the slower gradients. CS-based breath-held and real-time cine imaging was built utilizing high acceleration rates to meet nominal spatial and temporal resolution recommendations. Similarly, CS 2D phase-contrast cine was implemented for flow. Dark-blood turbo spin echo sequences with deep learning based denoising were implemented for morphology assessment. Magnetization-prepared single-shot myocardial mapping techniques incorporated additional source images. CS-based dynamic contrast-enhanced imaging was implemented for myocardial perfusion and 3D MR angiography. Non-contrast 3D MR angiography was built with electrocardiogram-triggered, navigator-gated magnetization-prepared methods. Late gadolinium enhanced (LGE) tissue characterization methods included breath-held segmented and free-breathing single-shot imaging with motion correction and averaging using an increased number of source images. Proof-of-concept was demonstrated through porcine infarct model, healthy volunteer, and patient scans. Results Reasonable image quality was demonstrated for cardiovascular structure, function, flow, and LGE assessment. Low-field afforded utilization of higher flip angles for cine and MR angiography. CS-based techniques were able to overcome gradient speed limitations and meet spatial and temporal resolution recommendations with imaging times comparable to higher performance scanners. Tissue mapping and perfusion imaging require further development. Conclusion We implemented cardiac applications demonstrating the potential for comprehensive CMR on a novel commercial 0.55 T system. Further development and validation studies are needed before this technology can be applied clinically.
Collapse
Affiliation(s)
- Juliet Varghese
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Ning Jin
- Cardiovascular MR R&D, Siemens Medical Solutions USA, Malvern, PA, United States
| | - Daniel Giese
- Magnetic Resonance, Siemens Healthcare, Erlangen, Germany
- Institute of Radiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Chong Chen
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Yingmin Liu
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Yue Pan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Nikita Nair
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Mahmoud T. Shalaan
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Mahmood Khan
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
- Department of Emergency Medicine, The Ohio State University, Columbus, OH, United States
| | - Matthew S. Tong
- Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH, United States
| | - Rizwan Ahmad
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Yuchi Han
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
- Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH, United States
| | - Orlando P. Simonetti
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
- Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH, United States
- Department of Radiology, The Ohio State University, Columbus, OH, United States
| |
Collapse
|
46
|
Fiorito M, Yushchenko M, Cicolari D, Sarracanie M, Salameh N. Fast, interleaved, Look-Locker-based T 1 mapping with a variable averaging approach: Towards temperature mapping at low magnetic field. NMR IN BIOMEDICINE 2023; 36:e4826. [PMID: 36057925 PMCID: PMC10078420 DOI: 10.1002/nbm.4826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 08/18/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Proton resonance frequency shift (PRFS) is currently the gold standard method for magnetic resonance thermometry. However, the linearity between the temperature-dependent phase accumulation and the static magnetic field B0 confines its use to rather high-field scanners. Applications such as thermal therapies could naturally benefit from lower field MRI settings through leveraging increased accessibility, a lower physical and economical footprint, and further consideration of the technical challenges associated with the integration of heating systems into conventional clinical scanners. T 1 -based thermometry has been proposed as an alternative to the gold standard; however, because of longer acquisition times, it has found clinical use solely with adipose tissue where PRFS fails. At low field, the enhanced T 1 dispersion, combined with reduced relaxation times, make T 1 mapping an appealing candidate. Here, an interleaved Look-Locker-based T 1 mapping sequence was proposed for temperature quantification at 0.1 T. A variable averaging scheme was introduced, to maximize the signal-to-noise ratio throughout T 1 recovery. In calibrated samples, an average T 1 accuracy of 85% ± 4% was achieved in 10 min, compared with the 77% ± 7% obtained using a standard averaging scheme. Temperature maps between 29.0 and 41.7°C were eventually reconstructed, with a precision of 3.0 ± 1.1°C and an accuracy of 1.5 ± 1.0°C. Accounting for longer thermal treatments and less strict temperature constraints, applications such as MR-guided mild hyperthermia treatments at low field could be envisioned.
Collapse
Affiliation(s)
- Marco Fiorito
- Department of Biomedical EngineeringCenter for Adaptable MRI Technology, University of BaselAllschwilSwitzerland
| | - Maksym Yushchenko
- Department of Biomedical EngineeringCenter for Adaptable MRI Technology, University of BaselAllschwilSwitzerland
| | | | - Mathieu Sarracanie
- Department of Biomedical EngineeringCenter for Adaptable MRI Technology, University of BaselAllschwilSwitzerland
| | - Najat Salameh
- Department of Biomedical EngineeringCenter for Adaptable MRI Technology, University of BaselAllschwilSwitzerland
| |
Collapse
|
47
|
Guallart‐Naval T, O'Reilly T, Algarín JM, Pellicer‐Guridi R, Vives‐Gilabert Y, Craven‐Brightman L, Negnevitsky V, Menküc B, Galve F, Stockmann JP, Webb A, Alonso J. Benchmarking the performance of a low-cost magnetic resonance control system at multiple sites in the open MaRCoS community. NMR IN BIOMEDICINE 2023; 36:e4825. [PMID: 36097704 PMCID: PMC10078257 DOI: 10.1002/nbm.4825] [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: 03/22/2022] [Revised: 08/15/2022] [Accepted: 08/26/2022] [Indexed: 05/15/2023]
Abstract
PURPOSE To describe the current properties and capabilities of an open-source hardware and software package that is being developed by many sites internationally with the aim of providing an inexpensive yet flexible platform for low-cost MRI. METHODS This article describes three different setups from 50 to 360 mT in different settings, all of which used the MaRCoS console for acquiring data, and different types of software interface (custom-built GUI or Pulseq overlay) to acquire it. RESULTS Images are presented both from phantoms and in vivo from healthy volunteers to demonstrate the image quality that can be obtained from the MaRCoS hardware/software interfaced to different low-field magnets. CONCLUSIONS The results presented here show that a number of different sequences commonly used in the clinic can be programmed into an open-source system relatively quickly and easily, and can produce good quality images even at this early stage of development. Both the hardware and software will continue to develop, and it is an aim of this article to encourage other groups to join this international consortium.
Collapse
Affiliation(s)
- Teresa Guallart‐Naval
- MRILab, Institute for Molecular Imaging and Instrumentation (i3M)Spanish National Research Council (CSIC) and Universitat Politècnica de València (UPV)ValenciaSpain
- Tesoro Imaging S.L.ValenciaSpain
| | - Thomas O'Reilly
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - José M. Algarín
- MRILab, Institute for Molecular Imaging and Instrumentation (i3M)Spanish National Research Council (CSIC) and Universitat Politècnica de València (UPV)ValenciaSpain
| | | | - Yolanda Vives‐Gilabert
- Intelligent Data Analysis Laboratory, Department of Electronic EngineeringUniversitat de ValènciaValenciaSpain
| | | | | | - Benjamin Menküc
- University of Applied Sciences and Arts DortmundDortmundGermany
| | - Fernando Galve
- MRILab, Institute for Molecular Imaging and Instrumentation (i3M)Spanish National Research Council (CSIC) and Universitat Politècnica de València (UPV)ValenciaSpain
| | - Jason P. Stockmann
- Massachusetts General Hospital, A. A. Martinos Center for Biomedical ImagingCharlestownMAUSA
| | - Andrew Webb
- Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Joseba Alonso
- MRILab, Institute for Molecular Imaging and Instrumentation (i3M)Spanish National Research Council (CSIC) and Universitat Politècnica de València (UPV)ValenciaSpain
| |
Collapse
|
48
|
Gudino N, Littin S. Advancements in Gradient System Performance for Clinical and Research MRI. J Magn Reson Imaging 2023; 57:57-70. [PMID: 36073722 DOI: 10.1002/jmri.28421] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/18/2022] [Accepted: 08/18/2022] [Indexed: 02/03/2023] Open
Abstract
In magnetic resonance imaging (MRI), spatial field gradients are applied along each axis to encode the location of the nuclear spin in the frequency domain. During recent years, the development of new gradient technologies has been focused on the generation of stronger and faster gradient fields for imaging with higher spatial and temporal resolution. This benefits imaging methods, such as brain diffusion and functional MRI, and enables human imaging at ultra-high field MRI. In addition to improving gradient performance, new technologies have been presented to minimize peripheral nerve stimulation and gradient-related acoustic noise, both generated by the rapid switching of strong gradient fields. This review will provide a general background on the gradient system and update on the state-of-the-art gradient technology. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 1.
Collapse
Affiliation(s)
- Natalia Gudino
- MRI Engineering Core, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Sebastian Littin
- Medical Physics, Department of Radiology, Faculty of Medicine, University Freiburg, Freiburg, Germany
| |
Collapse
|
49
|
Arnold TC, Freeman CW, Litt B, Stein JM. Low-field MRI: Clinical promise and challenges. J Magn Reson Imaging 2023; 57:25-44. [PMID: 36120962 PMCID: PMC9771987 DOI: 10.1002/jmri.28408] [Citation(s) in RCA: 62] [Impact Index Per Article: 62.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 02/03/2023] Open
Abstract
Modern MRI scanners have trended toward higher field strengths to maximize signal and resolution while minimizing scan time. However, high-field devices remain expensive to install and operate, making them scarce outside of high-income countries and major population centers. Low-field strength scanners have drawn renewed academic, industry, and philanthropic interest due to advantages that could dramatically increase imaging access, including lower cost and portability. Nevertheless, low-field MRI still faces inherent limitations in image quality that come with decreased signal. In this article, we review advantages and disadvantages of low-field MRI scanners, describe hardware and software innovations that accentuate advantages and mitigate disadvantages, and consider clinical applications for a new generation of low-field devices. In our review, we explore how these devices are being or could be used for high acuity brain imaging, outpatient neuroimaging, MRI-guided procedures, pediatric imaging, and musculoskeletal imaging. Challenges for their successful clinical translation include selecting and validating appropriate use cases, integrating with standards of care in high resource settings, expanding options with actionable information in low resource settings, and facilitating health care providers and clinical practice in new ways. By embracing both the promise and challenges of low-field MRI, clinicians and researchers have an opportunity to transform medical care for patients around the world. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 6.
Collapse
Affiliation(s)
- Thomas Campbell Arnold
- Department of Bioengineering, School of Engineering & Applied ScienceUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Center for Neuroengineering and TherapeuticsUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Colbey W. Freeman
- Department of Radiology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Brian Litt
- Center for Neuroengineering and TherapeuticsUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Joel M. Stein
- Center for Neuroengineering and TherapeuticsUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
- Department of Radiology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| |
Collapse
|
50
|
Smith L, Kuncic Z, Byrne HL, Waddington D. Nanoparticles for MRI-guided radiation therapy: a review. Cancer Nanotechnol 2022. [DOI: 10.1186/s12645-022-00145-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AbstractThe development of nanoparticle agents for MRI-guided radiotherapy is growing at an increasing pace, with clinical trials now underway and many pre-clinical evaluation studies ongoing. Gadolinium and iron-oxide-based nanoparticles remain the most clinically advanced nanoparticles to date, although several promising candidates are currently under varying stages of development. Goals of current and future generation nanoparticle-based contrast agents for MRI-guided radiotherapy include achieving positive signal contrast on T1-weighted MRI scans, local radiation enhancement at clinically relevant concentrations and, where applicable, avoidance of uptake by the reticuloendothelial system. Exploiting the enhanced permeability and retention effect or the use of active targeting ligands on nanoparticle surfaces is utilised to promote tumour uptake. This review outlines the current status of promising nanoparticle agents for MRI-guided radiation therapy, including several platforms currently undergoing clinical evaluation or at various stages of the pre-clinical development process. Challenges facing nanoparticle agents and possible avenues for current and future development are discussed.
Collapse
|