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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.
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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
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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.
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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
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He J, Jiang X, Zhang C, Li Y, Liu C, Liu X, Li B, Peng H, Ta D. Stretchable Ultrasound Metalens for Biomedical Zoom Imaging and Bone Quality Assessment with Subwavelength Resolution. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2312221. [PMID: 39007285 DOI: 10.1002/smll.202312221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 06/25/2024] [Indexed: 07/16/2024]
Abstract
Ultrasound imaging is extensively used in biomedical science and clinical practice. Imaging resolution and tunability of imaging plane are key performance indicators, but both remain challenging to be improved due to the longer wavelength compared with light and the lack of zoom lens for ultrasound. Here, the ultrasound zoom imaging based on a stretchable planar metalens that simultaneously achieves the subwavelength imaging resolution and dynamic control of the imaging plane is reported. The proposed zoom imaging ultrasonography enables precise bone fracture diagnosis and comprehensive osteoporosis assessment. Millimeter-scale microarchitectures of the cortical bones at different depths can be selectively imaged with a 0.6-wavelength resolution. The morphological features of bone fractures, including the shape, size and position, are accurately detected. Based on the extracted ultrasound information of cancellous bones with healthy matrix, osteopenia and osteoporosis, a multi-index osteoporosis evaluation method is developed. Furthermore, it provides additional biological information in aspects of bone elasticity and attenuation to access the comprehensive osteoporosis assessment. The soft metalens also features flexibility and biocompatibility for preferable applications on wearable devices. This work provides a strategy for the development of high-resolution ultrasound biomedical zoom imaging and comprehensive bone quality diagnosis system.
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Affiliation(s)
- Jiajie He
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Xue Jiang
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
- State Key Laboratory of Integrated Chips and System, Fudan University, Shanghai, 200433, China
| | - Chuanxin Zhang
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Ying Li
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Chengcheng Liu
- Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Xin Liu
- Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Boyi Li
- Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Huisheng Peng
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Laboratory of Advanced Materials, Fudan University, Shanghai, 200438, China
| | - Dean Ta
- Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai, 200433, China
- State Key Laboratory of Integrated Chips and System, Fudan University, Shanghai, 200433, China
- Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
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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.
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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
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5
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Zhao Y, Xiao L, Hu J, Wu EX. Robust EMI elimination for RF shielding-free MRI through deep learning direct MR signal prediction. Magn Reson Med 2024; 92:112-127. [PMID: 38376455 DOI: 10.1002/mrm.30046] [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: 05/08/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 02/21/2024]
Abstract
PURPOSE To develop a new electromagnetic interference (EMI) elimination strategy for RF shielding-free MRI via active EMI sensing and deep learning direct MR signal prediction (Deep-DSP). METHODS Deep-DSP is proposed to directly predict EMI-free MR signals. During scanning, MRI receive coil and EMI sensing coils simultaneously sample data within two windows (i.e., for MR data and EMI characterization data acquisition, respectively). Afterward, a residual U-Net model is trained using synthetic MRI receive coil data and EMI sensing coil data acquired during EMI signal characterization window, to predict EMI-free MR signals from signals acquired by MRI receive and EMI sensing coils. The trained model is then used to directly predict EMI-free MR signals from data acquired by MRI receive and sensing coils during the MR signal-acquisition window. This strategy was evaluated on an ultralow-field 0.055T brain MRI scanner without any RF shielding and a 1.5T whole-body scanner with incomplete RF shielding. RESULTS Deep-DSP accurately predicted EMI-free MR signals in presence of strong EMI. It outperformed recently developed EDITER and convolutional neural network methods, yielding better EMI elimination and enabling use of few EMI sensing coils. Furthermore, it could work well without dedicated EMI characterization data. CONCLUSION Deep-DSP presents an effective EMI elimination strategy that outperforms existing methods, advancing toward truly portable and patient-friendly MRI. It exploits electromagnetic coupling between MRI receive and EMI sensing coils as well as typical MR signal characteristics. Despite its deep learning nature, Deep-DSP framework is computationally simple and efficient.
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Affiliation(s)
- Yujiao Zhao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Linfang Xiao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Jiahao Hu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, People's Republic of China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
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Padarthi S, Prabakar A, Deshpande SR, Udupa SM, Arunachalam A. Affordable, state-of-the-art, magnetic resonance imaging scanners: Design and manufacturing insights. NMR IN BIOMEDICINE 2024; 37:e5024. [PMID: 37582549 DOI: 10.1002/nbm.5024] [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: 06/14/2022] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/17/2023]
Abstract
In the current study, design and manufacturing insights into the development of affordable, state-of-the-art, magnetic resonance imaging (MRI) scanners are provided, and imaging results to demonstrate their viability are presented. Perspectives on affordability and accessibility are given, followed by a set of scanner specifications that, if met, can satisfy these criteria. Next, the architecture of a concept scanner that can satisfy some of these requirements is outlined and explained in detail. Specific insights into the design modifications that can enable reductions in power consumption, weight, and form factors are provided. Scanner performance benchmarking via large American College of Radiology phantom imaging tests is reported. Human volunteer imaging results are shown for the most common clinical contrasts to establish viability and demonstrate body coverage. In summary, a ground-up approach for designing state-of-the-art, yet affordable, MRI scanners is described, along with insights into the future steps that must be taken to ensure genuine accessibility and affordability.
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Affiliation(s)
| | - Akash Prabakar
- Voxelgrids Innovations Private Limited, Bengaluru, India
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7
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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: 0] [Impact Index Per Article: 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.
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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
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Altaf A, Shakir M, Irshad HA, Atif S, Kumari U, Islam O, Kimberly WT, Knopp E, Truwit C, Siddiqui K, Enam SA. Applications, limitations and advancements of ultra-low-field magnetic resonance imaging: A scoping review. Surg Neurol Int 2024; 15:218. [PMID: 38974534 PMCID: PMC11225429 DOI: 10.25259/sni_162_2024] [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: 03/04/2024] [Accepted: 05/17/2024] [Indexed: 07/09/2024] Open
Abstract
Background Ultra-low-field magnetic resonance imaging (ULF-MRI) has emerged as an alternative with several portable clinical applications. This review aims to comprehensively explore its applications, potential limitations, technological advancements, and expert recommendations. Methods A review of the literature was conducted across medical databases to identify relevant studies. Articles on clinical usage of ULF-MRI were included, and data regarding applications, limitations, and advancements were extracted. A total of 25 articles were included for qualitative analysis. Results The review reveals ULF-MRI efficacy in intensive care settings and intraoperatively. Technological strides are evident through innovative reconstruction techniques and integration with machine learning approaches. Additional advantages include features such as portability, cost-effectiveness, reduced power requirements, and improved patient comfort. However, alongside these strengths, certain limitations of ULF-MRI were identified, including low signal-to-noise ratio, limited resolution and length of scanning sequences, as well as variety and absence of regulatory-approved contrast-enhanced imaging. Recommendations from experts emphasize optimizing imaging quality, including addressing signal-to-noise ratio (SNR) and resolution, decreasing the length of scan time, and expanding point-of-care magnetic resonance imaging availability. Conclusion This review summarizes the potential of ULF-MRI. The technology's adaptability in intensive care unit settings and its diverse clinical and surgical applications, while accounting for SNR and resolution limitations, highlight its significance, especially in resource-limited settings. Technological advancements, alongside expert recommendations, pave the way for refining and expanding ULF-MRI's utility. However, adequate training is crucial for widespread utilization.
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Affiliation(s)
- Ahmed Altaf
- Department of Surgery, Section of Neurosurgery, Aga Khan University Hospital, Karachi, Sindh, Pakistan
| | - Muhammad Shakir
- Department of Surgery, Section of Neurosurgery, Aga Khan University Hospital, Karachi, Sindh, Pakistan
| | | | - Shiza Atif
- Medical College, Aga Khan University Hospital, Karachi, Sindh, Pakistan
| | - Usha Kumari
- Medical College, Peoples University of Medical and Health Sciences for Women, Karachi, Sindh, Pakistan
| | - Omar Islam
- Department of Diagnostic Radiology, Queen’s University, Kingston General Hospital, Kingston, Canada
| | - W. Taylor Kimberly
- Department of Neurology, Massachusetts General Hospital, Boston, United States
| | | | | | | | - S. Ather Enam
- Department of Surgery, Section of Neurosurgery, Aga Khan University Hospital, Karachi, Sindh, Pakistan
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Poojar P, Oiye IE, Aggarwal K, Jimeno MM, Vaughan JT, Geethanath S. Repeatability of image quality in very low-field MRI. NMR IN BIOMEDICINE 2024:e5198. [PMID: 38840502 DOI: 10.1002/nbm.5198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 04/12/2024] [Accepted: 05/13/2024] [Indexed: 06/07/2024]
Abstract
BACKGROUND Very low-field MR has emerged as a promising complementary device to high-field MRI scanners, offering several advantages. One of the key benefits is that very low-field scanners are generally more portable and affordable to purchase and maintain, making them an attractive option for medical facilities looking to reduce costs. Very low-field MRI systems also have lower RF power deposition, making them safer and less likely to cause tissue heating or other safety concerns. They are also simpler to maintain, as they do not require cooling agents such as liquid helium. However, these portable MR scanners are impacted by temperature, lower magnetic field strength, and inhomogeneity, resulting in images with lower signal-to-noise ratio (SNR) and higher geometric distortions. It is essential to investigate and tabulate the variations in these parameters to establish bounds so that subsequent in vivo studies and deployment of these portable systems can be well informed. PURPOSE The aim of this work is to investigate the repeatability of image quality metrics such as SNR and geometrical distortion at 0.05 T over 10 days and three sessions per day. METHODS We acquired repeatability data over 10 days with three sessions per day. The measurements included temperature, humidity, transmit frequency, off-resonance maps, and 3D turbo spin echo (TSE) images of an in vitro phantom. This resulted in a protocol with 11 sequences. We also acquired a 3 T data set for reference. The image quality metrics included computing SNR and eccentricity (to assess geometrical distortion) to investigate the repeatability of 0.05 T image quality. The image reconstruction included drift correction, k-space filtering, and off-resonance correction. We computed the experimental parameters' coefficient of variation (CV) and the resulting image quality metrics to assess repeatability. We have explored the impact of electromagnetic interference (EMI) on image quality in very low-field MRI. The investigation involved varying both the distance and amplitude of the EMI-producing coil from the signal generator to analyze their effects on image quality. RESULTS The range of temperature measured during the study was within 1.5 °C. The off-resonance maps acquired before and after the 3D TSE showed similar hotspots and were changed mainly by a global constant. The SNR measurements were highly repeatable across sessions and over the 10 days, quantified by a CV of 6.7%. The magnetic field inhomogeneity effects quantified by eccentricity showed a CV of 13.7%, but less than 5.1% in two of the three sessions over 10 days. The use of conjugate phase reconstruction mitigated geometrical distortion artifacts. Temperature and humidity did not significantly affect SNR or mean frequency drift within the ranges of these environmental factors investigated. The EMI experiment showed that as the amplitude increased the SNR decreased, and concurrently the root mean square of the background increased with a rise in EMI amplitude or a reduction in distance. CONCLUSIONS We found that humidity and temperature in the range investigated did not impact SNR or frequency. Based on the CV values computed session-wise and for the overall study, our findings indicate high repeatability for SNR and magnetic field homogeneity.
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Affiliation(s)
- Pavan Poojar
- Addiction Institute of Mount Sinai, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Ivan Etoku Oiye
- Accessible Magnetic Resonance Laboratory, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Kunal Aggarwal
- Biomedical Imaging and Engineering Institute, Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Marina Manso Jimeno
- Columbia Magnetic Resonance Research Center, Columbia University, New York, New York, USA
| | - John Thomas Vaughan
- Columbia Magnetic Resonance Research Center, Columbia University, New York, New York, USA
| | - Sairam Geethanath
- Accessible Magnetic Resonance Laboratory, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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10
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Ma C, Liu Y. Neural Similarity and Synchrony among Friends. Brain Sci 2024; 14:562. [PMID: 38928562 PMCID: PMC11202270 DOI: 10.3390/brainsci14060562] [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: 04/30/2024] [Revised: 05/24/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024] Open
Abstract
Researchers have long recognized that friends tend to exhibit behaviors that are more similar to each other than to those of non-friends. In recent years, the concept of neural similarity or neural synchrony among friends has garnered significant attention. This body of research bifurcates into two primary areas of focus: the specificity of neural similarity among friends (vs. non-friends) and the situational factors that influence neural synchrony among friends. This review synthesizes the complex findings to date, highlighting consistencies and identifying gaps in the current understanding. It aims to provide a coherent overview of the nuanced interplay between social relationships and neural processes, offering valuable insights for future investigations in this field.
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Affiliation(s)
- Chao Ma
- School of Psychology, Northeast Normal University, Changchun 130024, China;
- Jilin Provincial Key Laboratory of Cognitive Neuroscience and Brain Development, Changchun 130024, China
| | - Yi Liu
- School of Psychology, Northeast Normal University, Changchun 130024, China;
- Jilin Provincial Key Laboratory of Cognitive Neuroscience and Brain Development, Changchun 130024, China
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Tong G, Ananth R, Vaughan JT, Geethanath S. Expanding access to magnetic resonance education through open-source web tutorials. NMR IN BIOMEDICINE 2024; 37:e5109. [PMID: 38440915 DOI: 10.1002/nbm.5109] [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: 07/13/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 03/06/2024]
Abstract
This study presents a tool that introduces the fundamental concepts of magnetic resonance (MR) by integrating related science, technology, engineering, arts, and mathematical (STEAM) topics in the form of games to improve the access to MR education.
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Affiliation(s)
- Gehua Tong
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, New York, USA
- Columbia MR Research Center, Columbia University in the City of New York, New York, New York, USA
| | - Rishi Ananth
- North Creek High School, North Creek, Washington, USA
| | - John Thomas Vaughan
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, New York, USA
- Columbia MR Research Center, Columbia University in the City of New York, New York, New York, USA
| | - Sairam Geethanath
- Columbia MR Research Center, Columbia University in the City of New York, New York, New York, USA
- Accessible MR Laboratory, Johns Hopkins University, Baltimore, Maryland, USA
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12
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Duncan NW, Rae CL. Geographical and economic influences on neuroimaging modality choice. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231496. [PMID: 38699551 PMCID: PMC11061638 DOI: 10.1098/rsos.231496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/01/2024] [Accepted: 02/23/2024] [Indexed: 05/05/2024]
Abstract
The current neuroimaging literature is unrepresentative of the world's population due to bias towards particular types of people living in a subset of geographical locations. This is true of both the people running the research and those participating in it. These biases mean we may be missing insights into how the brain works. As neuroimaging research expands out to more of the world, the reality of global economic disparities becomes salient. With economic conditions having an effect on many background conditions for research, we can ask whether they also influence the neuroimaging research being done. To investigate this, the number of neuroimaging publications originating from a country was used as a proxy for the type of research being done there in terms of imaging modalities employed. This was then related to local economic conditions, as represented by national gross domestic product and research and development spending. National financial metrics were positively associated with neuroimaging output. The imaging modalities used were also found to be associated with local economic conditions, with magnetic resonance imaging (MRI) research positively and electroencephalography (EEG) negatively associated with national research spending. These results suggest that economic conditions may be relevant when planning how neuroimaging research can be expanded globally.
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Affiliation(s)
- Niall W. Duncan
- Graduate Institute of Mind, Brain and Consciousness, Taipei Medical University, Taipei, Taiwan
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13
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Vike NL, Bari S, Kim BW, Katsaggelos AK, Blood AJ, Breiter HC. Characterizing major depressive disorder and substance use disorder using heatmaps and variable interactions: The utility of operant behavior and brain structure relationships. PLoS One 2024; 19:e0299528. [PMID: 38466739 PMCID: PMC10927130 DOI: 10.1371/journal.pone.0299528] [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: 02/02/2023] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Rates of depression and addiction have risen drastically over the past decade, but the lack of integrative techniques remains a barrier to accurate diagnoses of these mental illnesses. Changes in reward/aversion behavior and corresponding brain structures have been identified in those with major depressive disorder (MDD) and cocaine-dependence polysubstance abuse disorder (CD). Assessment of statistical interactions between computational behavior and brain structure may quantitatively segregate MDD and CD. METHODS Here, 111 participants [40 controls (CTRL), 25 MDD, 46 CD] underwent structural brain MRI and completed an operant keypress task to produce computational judgment metrics. Three analyses were performed: (1) linear regression to evaluate groupwise (CTRL v. MDD v. CD) differences in structure-behavior associations, (2) qualitative and quantitative heatmap assessment of structure-behavior association patterns, and (3) the k-nearest neighbor machine learning approach using brain structure and keypress variable inputs to discriminate groups. RESULTS This study yielded three primary findings. First, CTRL, MDD, and CD participants had distinct structure-behavior linear relationships, with only 7.8% of associations overlapping between any two groups. Second, the three groups had statistically distinct slopes and qualitatively distinct association patterns. Third, a machine learning approach could discriminate between CTRL and CD, but not MDD participants. CONCLUSIONS These findings demonstrate that variable interactions between computational behavior and brain structure, and the patterns of these interactions, segregate MDD and CD. This work raises the hypothesis that analysis of interactions between operant tasks and structural neuroimaging might aide in the objective classification of MDD, CD and other mental health conditions.
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Affiliation(s)
- Nicole L. Vike
- Department of Computer Science, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Sumra Bari
- Department of Computer Science, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Byoung Woo Kim
- Department of Computer Science, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Aggelos K. Katsaggelos
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois, United States of America
- Department of Computer Science, Northwestern University, Evanston, Illinois, United States of America
- Department of Radiology, Northwestern University, Chicago, Illinois, United States of America
| | - Anne J. Blood
- Department of Psychiatry, Mood and Motor Control Laboratory (MAML), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Psychiatry, Laboratory of Neuroimaging and Genetics, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, United States of America
| | - Hans C. Breiter
- Department of Computer Science, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Psychiatry, Mood and Motor Control Laboratory (MAML), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Psychiatry, Laboratory of Neuroimaging and Genetics, Massachusetts General Hospital and Harvard School of Medicine, Boston, Massachusetts, United States of America
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, United States of America
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14
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Selvaganesan K, Ha Y, Sun H, Zhang Z, Sun C, Samardzija A, Galiana G, Constable RT. Encoding scheme design for gradient-free, nonlinear projection imaging using Bloch-Siegert RF spatial encoding in a low-field, open MRI system. Sci Rep 2024; 14:3307. [PMID: 38332252 PMCID: PMC10853509 DOI: 10.1038/s41598-024-53703-y] [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: 07/10/2023] [Accepted: 02/03/2024] [Indexed: 02/10/2024] Open
Abstract
Eliminating conventional pulsed B0-gradient coils for magnetic resonance imaging (MRI) can significantly reduce the cost of and increase access to these devices. Phase shifts induced by the Bloch-Siegert shift effect have been proposed as a means for gradient-free, RF spatial encoding for low-field MR imaging. However, nonlinear phasor patterns like those generated from loop coils have not been systematically studied in the context of 2D spatial encoding. This work presents an optimization algorithm to select an efficient encoding trajectory among the nonlinear patterns achievable with a given hardware setup. Performance of encoding trajectories or projections was evaluated through simulated and experimental image reconstructions. Results show that the encodings schemes designed by this algorithm provide more efficient spatial encoding than comparison encoding sets, and the method produces images with the predicted spatial resolution and minimal artifacts. Overall, the work demonstrates the feasibility of performing 2D gradient-free, low-field imaging using the Bloch-Siegert shift which is an important step towards creating low-cost, point-of-care MR systems.
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Affiliation(s)
| | - Yonghyun Ha
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Heng Sun
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Zhehong Zhang
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Chenhao Sun
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Anja Samardzija
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Gigi Galiana
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - R Todd Constable
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
- Yale University School of Medicine, Magnetic Resonance Research Center, 300 Cedar Street, New Haven, CT, 06520, USA.
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15
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Lucas A, Campbell Arnold T, Okar SV, Vadali C, Kawatra KD, Ren Z, Cao Q, Shinohara RT, Schindler MK, Davis KA, Litt B, Reich DS, Stein JM. Multi-contrast high-field quality image synthesis for portable low-field MRI using generative adversarial networks and paired data. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.28.23300409. [PMID: 38234785 PMCID: PMC10793526 DOI: 10.1101/2023.12.28.23300409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Introduction Portable low-field strength (64mT) MRI scanners promise to increase access to neuroimaging for clinical and research purposes, however these devices produce lower quality images compared to high-field scanners. In this study, we developed and evaluated a deep learning architecture to generate high-field quality brain images from low-field inputs using a paired dataset of multiple sclerosis (MS) patients scanned at 64mT and 3T. Methods A total of 49 MS patients were scanned on portable 64mT and standard 3T scanners at Penn (n=25) or the National Institutes of Health (NIH, n=24) with T1-weighted, T2-weighted and FLAIR acquisitions. Using this paired data, we developed a generative adversarial network (GAN) architecture for low- to high-field image translation (LowGAN). We then evaluated synthesized images with respect to image quality, brain morphometry, and white matter lesions. Results Synthetic high-field images demonstrated visually superior quality compared to low-field inputs and significantly higher normalized cross-correlation (NCC) to actual high-field images for T1 (p=0.001) and FLAIR (p<0.001) contrasts. LowGAN generally outperformed the current state-of-the-art for low-field volumetrics. For example, thalamic, lateral ventricle, and total cortical volumes in LowGAN outputs did not differ significantly from 3T measurements. Synthetic outputs preserved MS lesions and captured a known inverse relationship between total lesion volume and thalamic volume. Conclusions LowGAN generates synthetic high-field images with comparable visual and quantitative quality to actual high-field scans. Enhancing portable MRI image quality could add value and boost clinician confidence, enabling wider adoption of this technology.
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Affiliation(s)
- Alfredo Lucas
- Perelman School of Medicine, University of Pennsylvania
- Center for Neuroengineering and Therapeutics, Departments of Bioengineering and Neurology, University of Pennsylvania
| | - T Campbell Arnold
- Center for Neuroengineering and Therapeutics, Departments of Bioengineering and Neurology, University of Pennsylvania
| | - Serhat V Okar
- National Institute of Neurological Disorders and Stroke, National Institutes of Health
| | - Chetan Vadali
- Center for Neuroengineering and Therapeutics, Departments of Bioengineering and Neurology, University of Pennsylvania
- Department of Radiology, University of Pennsylvania
| | - Karan D Kawatra
- National Institute of Neurological Disorders and Stroke, National Institutes of Health
| | - Zheng Ren
- Penn Statistics in Imaging and Visualization Center, Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania
| | - Quy Cao
- Penn Statistics in Imaging and Visualization Center, Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania
| | - Russell T Shinohara
- Penn Statistics in Imaging and Visualization Center, Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania
- Center for Biomedical Image Computing and Analytics (CBICA), University of Pennsylvania
| | - Matthew K Schindler
- Perelman School of Medicine, University of Pennsylvania
- Department of Neurology, University of Pennsylvania
| | - Kathryn A Davis
- Perelman School of Medicine, University of Pennsylvania
- Center for Neuroengineering and Therapeutics, Departments of Bioengineering and Neurology, University of Pennsylvania
- Department of Neurology, University of Pennsylvania
| | - Brian Litt
- Perelman School of Medicine, University of Pennsylvania
- Center for Neuroengineering and Therapeutics, Departments of Bioengineering and Neurology, University of Pennsylvania
- Department of Neurology, University of Pennsylvania
| | - Daniel S Reich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health
| | - Joel M Stein
- Perelman School of Medicine, University of Pennsylvania
- Center for Neuroengineering and Therapeutics, Departments of Bioengineering and Neurology, University of Pennsylvania
- Department of Radiology, University of Pennsylvania
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16
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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.
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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
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17
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Aggarwal K, Manso Jimeno M, Ravi KS, Gonzalez G, Geethanath S. Developing and deploying deep learning models in brain magnetic resonance imaging: A review. NMR IN BIOMEDICINE 2023; 36:e5014. [PMID: 37539775 DOI: 10.1002/nbm.5014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 08/05/2023]
Abstract
Magnetic resonance imaging (MRI) of the brain has benefited from deep learning (DL) to alleviate the burden on radiologists and MR technologists, and improve throughput. The easy accessibility of DL tools has resulted in a rapid increase of DL models and subsequent peer-reviewed publications. However, the rate of deployment in clinical settings is low. Therefore, this review attempts to bring together the ideas from data collection to deployment in the clinic, building on the guidelines and principles that accreditation agencies have espoused. We introduce the need for and the role of DL to deliver accessible MRI. This is followed by a brief review of DL examples in the context of neuropathologies. Based on these studies and others, we collate the prerequisites to develop and deploy DL models for brain MRI. We then delve into the guiding principles to develop good machine learning practices in the context of neuroimaging, with a focus on explainability. A checklist based on the United States Food and Drug Administration's good machine learning practices is provided as a summary of these guidelines. Finally, we review the current challenges and future opportunities in DL for brain MRI.
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Affiliation(s)
- Kunal Aggarwal
- Accessible MR Laboratory, Biomedical Engineering and Imaging Institute, Department of Diagnostic, Molecular and Interventional Radiology, Mount Sinai Hospital, New York, USA
- Department of Electrical and Computer Engineering, Technical University Munich, Munich, Germany
| | - 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
| | - Keerthi Sravan Ravi
- 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
| | - Gilberto Gonzalez
- Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Sairam Geethanath
- Accessible MR Laboratory, Biomedical Engineering and Imaging Institute, Department of Diagnostic, Molecular and Interventional Radiology, Mount Sinai Hospital, New York, USA
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18
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Torres E, Wang P, Kantesaria S, Jenkins P, DelaBarre L, Cosmo Pizetta D, Froelich T, Steyn L, Tannús A, Papas KK, Sakellariou D, Garwood M. Development of a compact NMR system to measure pO 2 in a tissue-engineered graft. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 357:107578. [PMID: 37952431 PMCID: PMC10787953 DOI: 10.1016/j.jmr.2023.107578] [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: 08/05/2023] [Revised: 10/19/2023] [Accepted: 10/25/2023] [Indexed: 11/14/2023]
Abstract
Cellular macroencapsulation devices, known as tissue engineered grafts (TEGs), enable the transplantation of allogeneic cells without the need for life-long systemic immunosuppression. Islet containing TEGs offer promise as a potential functional cure for type 1 diabetes. Previous research has indicated sustained functionality of implanted islets at high density in a TEG requires external supplementary oxygen delivery and an effective tool to monitor TEG oxygen levels. A proven oxygen-measurement approach employs a 19F oxygen probe molecule (a perfluorocarbon) implanted alongside therapeutic cells to enable oxygen- and temperature- dependent NMR relaxometry. Although the approach has proved effective, the clinical translation of 19F oxygen relaxometry for TEG monitoring will be limited by the current inaccessibility and high cost of MRI. Here, we report the development of an affordable, compact, and tabletop 19F NMR relaxometry system for monitoring TEG oxygenation. The system uses a 0.5 T Halbach magnet with a bore diameter (19 cm) capable of accommodating the human arm, a potential site of future TEG implantation. 19F NMR relaxometry was performed while controlling the temperature and oxygenation levels of a TEG using a custom-built perfusion setup. Despite the magnet's nonuniform field, a pulse sequence of broadband adiabatic full-passage pulses enabled accurate 19F longitudinal relaxation rate (R1) measurements in times as short as ∼2 min (R1 vs oxygen partial pressure and temperature (R2 > 0.98)). The estimated sensitivity of R1 to oxygen changes at 0.5 T was 1.62-fold larger than the sensitivity previously reported for 16.4 T. We conclude that TEG oxygenation monitoring with a compact, tabletop 19F NMR relaxometry system appears feasible.
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Affiliation(s)
- Efraín Torres
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Paul Wang
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Saurin Kantesaria
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Parker Jenkins
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
| | - Lance DelaBarre
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA.
| | - Daniel Cosmo Pizetta
- Centro de Imagens e Espectroscopia por Ressonância Magnética - CIERMag - São Carlos Physics Institute, University of São Paulo - IFSC-USP, São Carlos, Brazil.
| | - Taylor Froelich
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA.
| | - Leah Steyn
- Department of Surgery, The University of Arizona, Tucson, AZ, USA.
| | - Alberto Tannús
- Centro de Imagens e Espectroscopia por Ressonância Magnética - CIERMag - São Carlos Physics Institute, University of São Paulo - IFSC-USP, São Carlos, Brazil.
| | | | | | - Michael Garwood
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA.
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Shing H, Caine A, Cherubini GB, Sparks T, Housley D. Accuracy of low-field magnetic resonance imaging for differentiating intervertebral disc extrusions and protrusions at the lumbosacral disc space in dogs. Front Vet Sci 2023; 10:1279378. [PMID: 38026646 PMCID: PMC10657993 DOI: 10.3389/fvets.2023.1279378] [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: 08/17/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction/Purpose MRI features differentiating extrusion from protrusion in thoracolumbar discs have been published, however little specifically evaluates the lumbosacral disc. The high prevalence of degenerative changes in apparently normal animals complicates assessment of this region and features relevant elsewhere in the spine may not apply. The aims of this study were to determine the accuracy of MRI in differentiating IVDE and IVDP at the lumbosacral disc space in dogs and determine which MRI characteristics discriminate between IVDE and IVDP. Method MRI examinations from dogs with surgically confirmed IVDE or IVDP at the lumbosacral disc space were collected retrospectively (2011-2019). Two radiologists independently recorded a diagnosis of IVDE or IVDP, gave a confidence rating, and evaluated specific MRI features. Univariable statistical analysis was performed to identify which MRI characteristics might help distinguish IVDE from IVDP. Results 117 dogs with lumbosacral IVDE (n = 16) or IVDP (n = 101) were included. Features associated with IVDE were in concordance with previous studies and included interruption of the dorsal annulus, suspected epidural hemorrhage, dispersed (rather than confined) intervertebral disc herniation on T2W sagittal images, lateralized intervertebral disc herniation and displacement of the cauda equina. Overall diagnostic accuracy was 68.8% and interobserver agreement was fair (κ = 0.37), which is lower than has been reported in thoracolumbar disc herniation, but accuracy increased to 85.3% with substantially improved agreement (κ = 0.87) in "confident" diagnoses. Discussion/Conclusion MRI characteristics used in differentiating thoracolumbar IVDE and IVDP can be extrapolated to the lumbosacral intervertebral disc space, but diagnostic accuracy in low-field MRI is lower than previously reported in herniations involving the thoracolumbar spine.
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Affiliation(s)
- Hannah Shing
- Dick White Referrals, Part of Linnaeus Veterinary Limited, Cambridgeshire, United Kingdom
| | - Abby Caine
- Dick White Referrals, Part of Linnaeus Veterinary Limited, Cambridgeshire, United Kingdom
| | | | - Tim Sparks
- Waltham Petcare Science Institute, Leicestershire, United Kingdom
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20
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Breit HC, Vosshenrich J, Hofmann V, Rusche T, Kovacs BK, Bach M, Manneck S, Harder D. Image Quality of Lumbar Spine Imaging at 0.55T Low-Field MRI is Comparable to Conventional 1.5T MRI - Initial Observations in Healthy Volunteers. Acad Radiol 2023; 30:2440-2446. [PMID: 36841743 DOI: 10.1016/j.acra.2023.01.037] [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: 10/13/2022] [Revised: 01/29/2023] [Accepted: 01/29/2023] [Indexed: 02/27/2023]
Abstract
RATIONALE AND OBJECTIVES To assess the potential of 0.55T low-field MRI system in lumbar spine imaging with and without the use of additional advanced postprocessing techniques. MATERIALS AND METHODS The lumbar spine of 14 volunteers (32.9 ± 3.6 years) was imaged both at 0.55T and 1.5T using sequences from clinical routine. On the 0.55T scanner system, additional sequences with simultaneous multi-slice acquisition and artificial intelligence-based postprocessing techniques were acquired. Image quality of all 28 examinations was assessed by three musculoskeletal radiologists with respect to signal/contrast, resolution, and assessability of the spinal canal and neuroforamina using a 5-point Likert scale (1 = non-diagnostic to 5 = perfect quality). Interrater agreement was evaluated with the Intraclass Correlation Coefficient and the Mann-Whitney U test (significance level: p < 0.05). RESULTS Image quality at 0.55T was rated lower on the 5-point Likert scale compared to 1.5T regarding signal/contrast (mean: 4.16 ± 0.29 vs. 4.54 ± 0.29; p < 0.001), resolution (4.07 ± 0.31 vs. 4.49 ± 0.30; p < 0.001), assessability of the spinal canal (4.28 ± 0.13 vs. 4.73 ± 0.26; p < 0.001) and the neuroforamina (4.14 ± 0.28 vs. 4.70 ± 0.27; p < 0.001). Image quality for the AI-processed sagittal T1 TSE and T2 TSE at 0.55T was also rated slightly lower, but still good to perfect with a concomitant reduction in measurement time. Interrater agreement was good to excellent (range: 0.60-0.91). CONCLUSION While lumbar spine image quality at 0.55T is perceived inferior to imaging at 1.5T by musculoskeletal radiologists, good overall examination quality was observed with high interrater agreement. Advanced postprocessing techniques may accelerate intrinsically longer acquisition times at 0.55T.
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Affiliation(s)
- Hanns-Christian Breit
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
| | - Jan Vosshenrich
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland.
| | - Verena Hofmann
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
| | - Thilo Rusche
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
| | - Balázs K Kovacs
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
| | - Michael Bach
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
| | - Sebastian Manneck
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland; Department of Radiology, Gesundheitszentrum Fricktal AG, Rheinfelden, Switzerland
| | - Dorothee Harder
- Department of Radiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
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Bloom PA, Pagliaccio D, Zhang J, Bauer CCC, Kyler M, Greene KD, Treves I, Morfini F, Durham K, Cherner R, Bajwa Z, Wool E, Olafsson V, Lee RF, Bidmead F, Cardona J, Kirshenbaum JS, Ghosh S, Hinds O, Wighton P, Galfalvy H, Simpson HB, Whitfield-Gabrieli S, Auerbach RP. Mindfulness-based real-time fMRI neurofeedback: a randomized controlled trial to optimize dosing for depressed adolescents. BMC Psychiatry 2023; 23:757. [PMID: 37848857 PMCID: PMC10580563 DOI: 10.1186/s12888-023-05223-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 09/26/2023] [Indexed: 10/19/2023] Open
Abstract
BACKGROUND Adolescence is characterized by a heightened vulnerability for Major Depressive Disorder (MDD) onset, and currently, treatments are only effective for roughly half of adolescents with MDD. Accordingly, novel interventions are urgently needed. This study aims to establish mindfulness-based real-time fMRI neurofeedback (mbNF) as a non-invasive approach to downregulate the default mode network (DMN) in order to decrease ruminatory processes and depressive symptoms. METHODS Adolescents (N = 90) with a current diagnosis of MDD ages 13-18-years-old will be randomized in a parallel group, two-arm, superiority trial to receive either 15 or 30 min of mbNF with a 1:1 allocation ratio. Real-time neurofeedback based on activation of the frontoparietal network (FPN) relative to the DMN will be displayed to participants via the movement of a ball on a computer screen while participants practice mindfulness in the scanner. We hypothesize that within-DMN (medial prefrontal cortex [mPFC] with posterior cingulate cortex [PCC]) functional connectivity will be reduced following mbNF (Aim 1: Target Engagement). Additionally, we hypothesize that participants in the 30-min mbNF condition will show greater reductions in within-DMN functional connectivity (Aim 2: Dosing Impact on Target Engagement). Aim 1 will analyze data from all participants as a single-group, and Aim 2 will leverage the randomized assignment to analyze data as a parallel-group trial. Secondary analyses will probe changes in depressive symptoms and rumination. DISCUSSION Results of this study will determine whether mbNF reduces functional connectivity within the DMN among adolescents with MDD, and critically, will identify the optimal dosing with respect to DMN modulation as well as reduction in depressive symptoms and rumination. TRIAL REGISTRATION This study has been registered with clinicaltrials.gov, most recently updated on July 6, 2023 (trial identifier: NCT05617495).
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Affiliation(s)
- Paul A Bloom
- Department of Psychiatry, Columbia University, New York, NY, USA.
| | - David Pagliaccio
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Jiahe Zhang
- Department of Psychology, Northeastern University, Boston, MA, USA
| | - Clemens C C Bauer
- Department of Psychology, Northeastern University, Boston, MA, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mia Kyler
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Keara D Greene
- Department of Psychology, Northeastern University, Boston, MA, USA
| | - Isaac Treves
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Katherine Durham
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Rachel Cherner
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Zia Bajwa
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Emma Wool
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Valur Olafsson
- Northeastern University Biomedical Imaging Center, Boston, MA, USA
| | - Ray F Lee
- Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, NY, USA
| | - Fred Bidmead
- Northeastern University Biomedical Imaging Center, Boston, MA, USA
| | - Jonathan Cardona
- Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, NY, USA
| | | | | | | | - Paul Wighton
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Hanga Galfalvy
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - H Blair Simpson
- Department of Psychiatry, Columbia University, New York, NY, USA
| | - Susan Whitfield-Gabrieli
- Department of Psychology, Northeastern University, Boston, MA, USA
- Northeastern University Biomedical Imaging Center, Boston, MA, USA
| | - Randy P Auerbach
- Department of Psychiatry, Columbia University, New York, NY, USA
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22
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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.
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Affiliation(s)
| | | | | | - Vahid Yaghmai
- Department of Radiological Sciences, School of Medicine, University of California, Irvine, Irvine, CA, United States
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23
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Lee YJ, Lee SH, Ahn SM, Hong S, Oh JS, Lee CK, Yoo B, Kim YG. When MRI would be useful in patients without evidence of sacroiliitis on radiographs? Rheumatol Int 2023:10.1007/s00296-023-05468-2. [PMID: 37733041 DOI: 10.1007/s00296-023-05468-2] [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: 07/05/2023] [Accepted: 09/10/2023] [Indexed: 09/22/2023]
Abstract
We aimed to identify when magnetic resonance imaging (MRI) would be useful to diagnose patients with suspected axial spondyloarthropathy (AxSpA) without evidence of sacroiliitis on radiographs. We retrospectively reviewed electronic medical records of patients who underwent pelvis MRI after radiographs at the rheumatology clinic in a single tertiary center in Korea. Patients underwent imaging from January 2020 to July 2022. We collected data including complete blood count, erythrocyte sedimentation rate, C-reactive protein (CRP), human leukocyte antigen (HLA)-B27, history of acute anterior uveitis (AAU), peripheral arthritis, dactylitis, inflammatory bowel disease (IBD), enthesopathy, and psoriasis. A total of 105 patients who showed no evidence of sacroiliitis on radiographs were included. The median age of patients was 41.0 years, and 44.8% were male. Of them, 34 showed sacroiliitis on MRI (group 1), and 71 showed no evidence of sacroiliitis even on MRI (group 2). Known AxSpA-related clinical features including AAU, peripheral arthritis, dactylitis, IBD, enthesopathy, and psoriasis were not different between the two groups. HLA-B27 positivity (79.4% vs. 40.0%, p < 0.001), median white blood cell count (7700 vs. 6300, p = 0.007), mean platelet count (307.7 ± 69.7 vs. 265.3 ± 68.9 × 103/µL, p = 0.005), and median CRP level (0.38 vs. 0.10, p = 0.001) showed significant differences between the two groups. In a multivariate analysis, HLA-B27 positivity and platelet count were significantly associated with sacroiliitis on MRI. In our cohort, sacroiliitis was observed on MRI in one-third of patients without radiographic evidence. MRI could be recommended to evaluate sacroiliitis in patients with positive HLA-B27 and a high platelet count.
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Affiliation(s)
- Yeo-Jin Lee
- Department of Rheumatology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Republic of Korea
| | - Sang Hoon Lee
- Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Soo-Min Ahn
- Department of Rheumatology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Republic of Korea
| | - Seokchan Hong
- Department of Rheumatology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Republic of Korea
| | - Ji-Seon Oh
- Department of Information Medicine, Big Data Research Center, Asan Medical Center, Seoul, Republic of Korea
| | - Chang-Keun Lee
- Department of Rheumatology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Republic of Korea
| | - Bin Yoo
- Department of Rheumatology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Republic of Korea
| | - Yong-Gil Kim
- Department of Rheumatology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Seoul, 05505, Republic of Korea.
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24
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Liang Y, Zhang M, Zhang Y, Zhang M. Ultrasound Sonosensitizers for Tumor Sonodynamic Therapy and Imaging: A New Direction with Clinical Translation. Molecules 2023; 28:6484. [PMID: 37764260 PMCID: PMC10537038 DOI: 10.3390/molecules28186484] [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: 07/24/2023] [Revised: 08/25/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
With the rapid development of sonodynamic therapy (SDT), sonosensitizers have evolved from traditional treatments to comprehensive diagnostics and therapies. Sonosensitizers play a crucial role in the integration of ultrasound imaging (USI), X-ray computed tomography (CT), and magnetic resonance imaging (MRI) diagnostics while also playing a therapeutic role. This review was based on recent articles on multifunctional sonosensitizers that were used in SDT for the treatment of cancer and have the potential for clinical USI, CT, and MRI applications. Next, some of the shortcomings of the clinical examination and the results of sonosensitizers in animal imaging were described. Finally, this paper attempted to inform the future development of sonosensitizers in the field of integrative diagnostics and therapeutics and to point out current problems and prospects for their application.
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Affiliation(s)
- Yunlong Liang
- Second Clinical Medical College, Shaanxi University of Chinese Medicine, Xianyang 712046, China;
| | - Mingzhen Zhang
- School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China;
| | - Yujie Zhang
- School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China;
| | - Mingxin Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Xi’an Medical University, Xi’an 710077, China
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25
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Geethanath S, Nunes RG, Nielsen JF. Editorial: Autonomous magnetic resonance imaging. FRONTIERS IN NEUROIMAGING 2023; 2:1277580. [PMID: 37711975 PMCID: PMC10497867 DOI: 10.3389/fnimg.2023.1277580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023]
Affiliation(s)
- Sairam Geethanath
- Accessible Magnetic Resonance Imaging Laboratory, Icahn School of Medicine at Mt. Sinai, New York, NY, United States
| | - Rita G. Nunes
- Department of Bioengineering, Institute for Systems and Robotics–Lisboa, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Jon-Fredrik Nielsen
- Department of Radiology, University of Michigan, Ann Arbor, MI, United States
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26
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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.
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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
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27
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Sanpitak P, Bhusal B, Vu J, Golestanirad L. Low-field MRI's Spark on Implant Safety: A Closer Look at Radiofrequency Heating. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38083021 PMCID: PMC10842192 DOI: 10.1109/embc40787.2023.10340861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Advances in low-field magnetic resonance imaging (MRI) are making imaging more accessible without significant losses in image quality. In addition to being more cost-effective and easier to place without as much needed infrastructure, it has been publicized that the lower field strengths make MRI safer for patients with implants. To test this claim, we conducted a total of 368 simulations with wires of various lengths and geometries in a gel phantom during radiofrequency (RF) exposure at 23 MHz and 63.6 MHz (corresponding to MRI at 0.55 T and 1.5 T). Our results showed that heating in the gel around wire tips could be higher in certain cases at 0.55 T. To examine the impact on real patients, we simulated two models of patients with deep brain stimulation (DBS) implants of different lengths. These simulations provide quantitative evidence that low-field MRI is not always safer, and this paper serves to illustrate some of the basic principles involved in RF heating of elongated implants in MRI environments.Clinical Relevance- This paper illustrates the physical concepts of resonance and inductive coupling in RF heating during MRI scanning with implants through systematic simulations and discusses the impact of these principles in practice.
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28
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Hermens DF. How could brain fingerprinting lead to the early detection of mental illness in adolescents and what are the next steps? Expert Rev Neurother 2023; 23:567-570. [PMID: 37323019 DOI: 10.1080/14737175.2023.2226870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 06/14/2023] [Indexed: 06/17/2023]
Affiliation(s)
- Daniel F Hermens
- Thompson Institute, University of the Sunshine Coast, Birtinya, Queensland, Australia
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29
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Obungoloch J, Muhumuza I, Teeuwisse W, Harper J, Etoku I, Asiimwe R, Tusiime P, Gombya G, Mugume C, Namutebi MH, Nassejje MA, Nayebare M, Kavuma JM, Bukyana B, Natukunda F, Ninsiima P, Muwanguzi A, Omadi P, van Gijzen M, Schiff SJ, Webb A, O’Reilly T. On-site construction of a point-of-care low-field MRI system in Africa. NMR IN BIOMEDICINE 2023; 36:e4917. [PMID: 36914258 PMCID: PMC10330026 DOI: 10.1002/nbm.4917] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/14/2023] [Accepted: 03/05/2023] [Indexed: 06/15/2023]
Abstract
PURPOSE To describe the construction and testing of a portable point-of-care low-field MRI system on site in Africa. METHODS All of the components to assemble a 50 mT Halbach magnet-based system, together with the necessary tools, were air-freighted from the Netherlands to Uganda. The construction steps included individual magnet sorting, filling of each ring of the magnet assembly, fine-tuning the inter-ring separations of the 23-ring magnet assembly, gradient coil construction, integration of gradient coils and magnet assembly, construction of the portable aluminum trolley and finally testing of the entire system with an open source MR spectrometer. RESULTS With four instructors and six untrained personnel, the complete project from delivery to first image took approximately 11 days. CONCLUSIONS An important step in translating scientific developments in the western world from high-income industrialized countries to low- and middle-income countries (LMICs) is to produce technology that can be assembled and ultimately constructed locally. Local assembly and construction are associated with skill development, low costs and jobs. Point-of-care systems have a large potential to increase the accessibility and sustainability of MRI in LMICs, and this work demonstrates that technology and knowledge transfer can be performed relatively seamlessly.
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Affiliation(s)
- Johnes Obungoloch
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Ivan Muhumuza
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Wouter Teeuwisse
- Department of Radiology, Leiden University Medical Center, The Netherlands
| | | | - Ivan Etoku
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Robert Asiimwe
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Patricia Tusiime
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - George Gombya
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Chris Mugume
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Mary Hellen Namutebi
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Mary Anthony Nassejje
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Maureen Nayebare
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Joseph Mark Kavuma
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Benedicto Bukyana
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Faith Natukunda
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | - Patience Ninsiima
- Department of Biomedical Engineering, Mberara University of Science and Technology, Uganda
| | | | | | - Martin van Gijzen
- Delft Institute of Applied Mathematics, Technical University of Delft, The Netherlands
| | | | - Andrew Webb
- Department of Radiology, Leiden University Medical Center, The Netherlands
| | - Tom O’Reilly
- Department of Radiology, Leiden University Medical Center, The Netherlands
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30
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Froelich T, DelaBarre L, Wang P, Radder J, Torres E, Garwood M. Fast spin-echo approach for accelerated B 1 gradient-based MRI. Magn Reson Med 2023; 89:2204-2216. [PMID: 36669882 PMCID: PMC10050123 DOI: 10.1002/mrm.29592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/06/2022] [Accepted: 01/05/2023] [Indexed: 01/22/2023]
Abstract
PURPOSE To expand on the previously developedB 1 + $$ {\mathrm{B}}_1^{+} $$ -encoding technique, frequency-modulated Rabi-encoded echoes (FREE), to perform accelerated image acquisition by collecting multiple lines of k-space in an echo train. METHODS FREE uses adiabatic full-passage pulses and a spatially varying RF field to encode unique spatial information without the use of traditional B0 gradients. The original implementation relied on acquiring single lines of k-space, leading to long acquisitions. In this work, an acceleration scheme is presented in which multiple echoes are acquired in a single shot, analogous to conventional fast spin-echo sequences. Theoretical analysis and computer simulations investigated the feasibility of this approach and presented a framework to analyze important imaging parameters of FREE-based sequences. Experimentally, the multi-echo approach was compared with conventional phase-encoded images of the human visual cortex using a simple surface transceiver coil. Finally, different contrasts demonstrated the clinical versatility of the new accelerated sequence. RESULTS Images were acquired with an acceleration factor of 3.9, compared with the previous implementation of FREE, without exceeding specific absorption rate limits. Different contrasts can easily be acquired without major modifications, including inversion recovery-type images. CONCLUSION FREE initially illustrated the feasibility of performing slice-selective 2D imaging of the human brain without the need for a B0 gradient along the y-direction. The multi-echo version maintains the advantages thatB 1 + $$ {\mathrm{B}}_1^{+} $$ encoding provides but represents an important step toward improving the clinical feasibility of such sequences. Additional acceleration and more advanced reconstruction techniques could further improve the clinical viability of FREE-based techniques.
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Affiliation(s)
- Taylor Froelich
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Lance DelaBarre
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Paul Wang
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jerahmie Radder
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Efraín Torres
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Michael Garwood
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA
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31
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O'Reilly T, Börnert P, Liu H, Webb A, Koolstra K. 3D magnetic resonance fingerprinting on a low-field 50 mT point-of-care system prototype: evaluation of muscle and lipid relaxation time mapping and comparison with standard techniques. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01092-0. [PMID: 37202655 PMCID: PMC10386962 DOI: 10.1007/s10334-023-01092-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/11/2023] [Accepted: 04/17/2023] [Indexed: 05/20/2023]
Abstract
OBJECTIVE To implement magnetic resonance fingerprinting (MRF) on a permanent magnet 50 mT low-field system deployable as a future point-of-care (POC) unit and explore the quality of the parameter maps. MATERIALS AND METHODS 3D MRF was implemented on a custom-built Halbach array using a slab-selective spoiled steady-state free precession sequence with 3D Cartesian readout. Undersampled scans were acquired with different MRF flip angle patterns and reconstructed using matrix completion and matched to the simulated dictionary, taking excitation profile and coil ringing into account. MRF relaxation times were compared to that of inversion recovery (IR) and multi-echo spin echo (MESE) experiments in phantom and in vivo. Furthermore, B0 inhomogeneities were encoded in the MRF sequence using an alternating TE pattern, and the estimated map was used to correct for image distortions in the MRF images using a model-based reconstruction. RESULTS Phantom relaxation times measured with an optimized MRF sequence for low field were in better agreement with reference techniques than for a standard MRF sequence. In vivo muscle relaxation times measured with MRF were longer than those obtained with an IR sequence (T1: 182 ± 21.5 vs 168 ± 9.89 ms) and with an MESE sequence (T2: 69.8 ± 19.7 vs 46.1 ± 9.65 ms). In vivo lipid MRF relaxation times were also longer compared with IR (T1: 165 ± 15.1 ms vs 127 ± 8.28 ms) and with MESE (T2: 160 ± 15.0 ms vs 124 ± 4.27 ms). Integrated ΔB0 estimation and correction resulted in parameter maps with reduced distortions. DISCUSSION It is possible to measure volumetric relaxation times with MRF at 2.5 × 2.5 × 3.0 mm3 resolution in a 13 min scan time on a 50 mT permanent magnet system. The measured MRF relaxation times are longer compared to those measured with reference techniques, especially for T2. This discrepancy can potentially be addressed by hardware, reconstruction and sequence design, but long-term reproducibility needs to be further improved.
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Affiliation(s)
- Thomas O'Reilly
- Radiology, C.J. Gorter Center for MRI, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Peter Börnert
- Radiology, C.J. Gorter Center for MRI, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
- Philips Research, Röntgenstraβe 24-26, 22335, Hamburg, Germany
| | - Hongyan Liu
- Computational Imaging Group for MR Diagnostics & Therapy, Center for Imaging Sciences, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Andrew Webb
- Radiology, C.J. Gorter Center for MRI, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Kirsten Koolstra
- Radiology, Division of Image Processing, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
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Lyu M, Mei L, Huang S, Liu S, Li Y, Yang K, Liu Y, Dong Y, Dong L, Wu EX. M4Raw: A multi-contrast, multi-repetition, multi-channel MRI k-space dataset for low-field MRI research. Sci Data 2023; 10:264. [PMID: 37164976 PMCID: PMC10172399 DOI: 10.1038/s41597-023-02181-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/25/2023] [Indexed: 05/12/2023] Open
Abstract
Recently, low-field magnetic resonance imaging (MRI) has gained renewed interest to promote MRI accessibility and affordability worldwide. The presented M4Raw dataset aims to facilitate methodology development and reproducible research in this field. The dataset comprises multi-channel brain k-space data collected from 183 healthy volunteers using a 0.3 Tesla whole-body MRI system, and includes T1-weighted, T2-weighted, and fluid attenuated inversion recovery (FLAIR) images with in-plane resolution of ~1.2 mm and through-plane resolution of 5 mm. Importantly, each contrast contains multiple repetitions, which can be used individually or to form multi-repetition averaged images. After excluding motion-corrupted data, the partitioned training and validation subsets contain 1024 and 240 volumes, respectively. To demonstrate the potential utility of this dataset, we trained deep learning models for image denoising and parallel imaging tasks and compared their performance with traditional reconstruction methods. This M4Raw dataset will be valuable for the development of advanced data-driven methods specifically for low-field MRI. It can also serve as a benchmark dataset for general MRI reconstruction algorithms.
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Affiliation(s)
- Mengye Lyu
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China.
| | - Lifeng Mei
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
| | - Shoujin Huang
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
| | - Sixing Liu
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
| | - Yi Li
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
| | - Kexin Yang
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
| | - Yilong Liu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration (Ministry of Education), Jinan University, Guangzhou, China
| | - Yu Dong
- Department of Neurosurgery, Shenzhen Samii Medical Center, Shenzhen, China
| | - Linzheng Dong
- Department of Neurosurgery, Shenzhen Samii Medical Center, Shenzhen, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
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Haskell MW, Nielsen JF, Noll DC. Off-resonance artifact correction for MRI: A review. NMR IN BIOMEDICINE 2023; 36:e4867. [PMID: 36326709 PMCID: PMC10284460 DOI: 10.1002/nbm.4867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 09/25/2022] [Accepted: 11/01/2022] [Indexed: 06/06/2023]
Abstract
In magnetic resonance imaging (MRI), inhomogeneity in the main magnetic field used for imaging, referred to as off-resonance, can lead to image artifacts ranging from mild to severe depending on the application. Off-resonance artifacts, such as signal loss, geometric distortions, and blurring, can compromise the clinical and scientific utility of MR images. In this review, we describe sources of off-resonance in MRI, how off-resonance affects images, and strategies to prevent and correct for off-resonance. Given recent advances and the great potential of low-field and/or portable MRI, we also highlight the advantages and challenges of imaging at low field with respect to off-resonance.
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Affiliation(s)
- Melissa W Haskell
- Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, USA
- Hyperfine Research, Guilford, Connecticut, USA
| | | | - Douglas C Noll
- Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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Wei S, Wei Z, Wang Z, Wang H, He Q, He H, Li L, Yang W. Optimization design of a permanent magnet used for a low field (0.2 T) movable MRI system. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01090-2. [PMID: 37081246 DOI: 10.1007/s10334-023-01090-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 04/06/2023] [Accepted: 04/11/2023] [Indexed: 04/22/2023]
Abstract
OBJECTIVE To design a lightweight permanent magnet for a lowfield movable head imaging MRI system. MATERIALS AND METHODS To reduce the weight of the magnet, the pole pieces, anti-eddy current plates, and shimming rings were removed, and the distance between the two vertical yokes was shortened as much as possible. To compensate for the magnetic field deformation caused by the shortened distance between two vertical iron yokes, two side magnetic poles were added to the vertical yokes. The magnetic field distributions in magnetic poles, the iron yoke, and the spherical imaging region were simulated. Phantom and in vivo head imaging were conducted with a lowfield movable MRI prototype scanner equipped with the proposed permanent magnet. RESULTS A permanent magnet with a center field of 0.19815 T, a homogeneity of 46 ppm over the 20 cm spherical imaging region, and a weight of 654 kg have been achieved. Acceptable images of a phantom and a human brain have been acquired with the prototype MRI scanner. DISCUSSION The proposed permanent magnet design significantly reduces the magnet's weight compared with the conventional magnet structure and shows promise in promoting the development of lowfield compact MRI systems.
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Affiliation(s)
- Shufeng Wei
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China
| | - Zhao Wei
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China
| | - Zheng Wang
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China
| | - Huixian Wang
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China
| | - Qingyuan He
- Peking University Third Hospital, Beijing, 100191, China
| | - Hongyan He
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Li
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenhui Yang
- Department of Electromagnetic Detection and Imaging Research, Institute of Electrical Engineering, Chinese Academy of Sciences, Zhongguancun Beiertiao NO.6, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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35
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Ravi KS, Nandakumar G, Thomas N, Lim M, Qian E, Jimeno MM, Poojar P, Jin Z, Quarterman P, Srinivasan G, Fung M, Vaughan JT, Geethanath S. Accelerated MRI using intelligent protocolling and subject-specific denoising applied to Alzheimer's disease imaging. FRONTIERS IN NEUROIMAGING 2023; 2:1072759. [PMID: 37554641 PMCID: PMC10406274 DOI: 10.3389/fnimg.2023.1072759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 03/15/2023] [Indexed: 08/10/2023]
Abstract
Magnetic Resonance Imaging (MR Imaging) is routinely employed in diagnosing Alzheimer's Disease (AD), which accounts for up to 60-80% of dementia cases. However, it is time-consuming, and protocol optimization to accelerate MR Imaging requires local expertise since each pulse sequence involves multiple configurable parameters that need optimization for contrast, acquisition time, and signal-to-noise ratio (SNR). The lack of this expertise contributes to the highly inefficient utilization of MRI services diminishing their clinical value. In this work, we extend our previous effort and demonstrate accelerated MRI via intelligent protocolling of the modified brain screen protocol, referred to as the Gold Standard (GS) protocol. We leverage deep learning-based contrast-specific image-denoising to improve the image quality of data acquired using the accelerated protocol. Since the SNR of MR acquisitions depends on the volume of the object being imaged, we demonstrate subject-specific (SS) image-denoising. The accelerated protocol resulted in a 1.94 × gain in imaging throughput. This translated to a 72.51% increase in MR Value-defined in this work as the ratio of the sum of median object-masked local SNR values across all contrasts to the protocol's acquisition duration. We also computed PSNR, local SNR, MS-SSIM, and variance of the Laplacian values for image quality evaluation on 25 retrospective datasets. The minimum/maximum PSNR gains (measured in dB) were 1.18/11.68 and 1.04/13.15, from the baseline and SS image-denoising models, respectively. MS-SSIM gains were: 0.003/0.065 and 0.01/0.066; variance of the Laplacian (lower is better): 0.104/-0.135 and 0.13/-0.143. The GS protocol constitutes 44.44% of the comprehensive AD imaging protocol defined by the European Prevention of Alzheimer's Disease project. Therefore, we also demonstrate the potential for AD-imaging via automated volumetry of relevant brain anatomies. We performed statistical analysis on these volumetric measurements of the hippocampus and amygdala from the GS and accelerated protocols, and found that 27 locations were in excellent agreement. In conclusion, accelerated brain imaging with the potential for AD imaging was demonstrated, and image quality was recovered post-acquisition using DL-based image denoising models.
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Affiliation(s)
- Keerthi Sravan Ravi
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, NY, United States
- Columbia University Magnetic Resonance Research Center, Columbia University in the City of New York, New York, NY, United States
| | | | | | | | - Enlin Qian
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, NY, United States
- Columbia University Magnetic Resonance Research Center, Columbia University in the City of New York, New York, NY, United States
| | - Marina Manso Jimeno
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, NY, United States
- Columbia University Magnetic Resonance Research Center, Columbia University in the City of New York, New York, NY, United States
| | - Pavan Poojar
- Department of Diagnostic, Molecular and Interventional Radiology, Accessible MRI Laboratory, Biomedical Engineering and Imaging Institute, Icahn School of Medicine at Mt. Sinai, New York, NY, United States
| | - Zhezhen Jin
- Mailman School of Public Health, Columbia University in the City of New York, New York, NY, United States
| | | | | | - Maggie Fung
- MR Clinical Solutions, GE Healthcare, New York, NY, United States
| | - John Thomas Vaughan
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, NY, United States
- Columbia University Magnetic Resonance Research Center, Columbia University in the City of New York, New York, NY, United States
| | - Sairam Geethanath
- Columbia University Magnetic Resonance Research Center, Columbia University in the City of New York, New York, NY, United States
- Department of Diagnostic, Molecular and Interventional Radiology, Accessible MRI Laboratory, Biomedical Engineering and Imaging Institute, Icahn School of Medicine at Mt. Sinai, New York, NY, United States
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36
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Hilabi BS, Alghamdi SA, Almanaa M. Impact of Magnetic Resonance Imaging on Healthcare in Low- and Middle-Income Countries. Cureus 2023; 15:e37698. [PMID: 37081900 PMCID: PMC10112545 DOI: 10.7759/cureus.37698] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2023] [Indexed: 04/22/2023] Open
Abstract
Magnetic resonance imaging (MRI) played a significant role in the digital health platforms that influenced and supported modern medicine. However, there is a shortage of MRI in low- and middle-income countries (LMICs). The International Society of Radiology offers a detailed plan for LMICs to advance imaging quality in the global health agenda. The overarching objective of this scoping review was to determine the impact of MRI in healthcare in LMICs. This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify available evidence. We systematically searched four academic databases for peer-reviewed literature published between 2018 and 2021, namely, Medline, PubMed, Web of Science, and Scopus, as well as Google Scholar as a source for gray literature. The search identified 54 articles. We identified a range of reasons for introducing MRI in LMICs. Nonetheless, some challenges to accepting MRI as a method of healthcare have been reported, including technological, regulatory, and economical challenges. To implement the proposed plan, the involvement of professional and international organizations is considered crucial. The establishment of an International Commission on Medical Imaging under the umbrella of international organizations is suggested and collaboration with other diagnostic disciplines is encouraged to raise awareness of the importance of upscale diagnostics at large and to foster its integration into the care pathway globally.
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37
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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.
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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
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38
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Murthy S, Fritz J. Metal Artifact Reduction MRI in the Diagnosis of Periprosthetic Hip Joint Infection. Radiology 2023; 306:e220134. [PMID: 36318029 DOI: 10.1148/radiol.220134] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
A 54-year-old woman presented with progressive right hip pain after hip arthroplasty 9 years earlier. The emerging role of metal artifact reduction MRI in the noninvasive diagnosis of infectious synovitis as the surrogate marker for periprosthetic hip joint infection and differentiation from other synovitis types is discussed.
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Affiliation(s)
- Sindhoora Murthy
- From the Department of Radiology, New York University Grossman School of Medicine, 660 1st Ave, 3rd Floor, Room 313, New York, NY 10016
| | - Jan Fritz
- From the Department of Radiology, New York University Grossman School of Medicine, 660 1st Ave, 3rd Floor, Room 313, New York, NY 10016
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Anazodo UC, Ng JJ, Ehiogu B, Obungoloch J, Fatade A, Mutsaerts HJMM, Secca MF, Diop M, Opadele A, Alexander DC, Dada MO, Ogbole G, Nunes R, Figueiredo P, Figini M, Aribisala B, Awojoyogbe BO, Aduluwa H, Sprenger C, Wagner R, Olakunle A, Romeo D, Sun Y, Fezeu F, Orunmuyi AT, Geethanath S, Gulani V, Nganga EC, Adeleke S, Ntobeuko N, Minja FJ, Webb AG, Asllani I, Dako F. A framework for advancing sustainable magnetic resonance imaging access in Africa. NMR IN BIOMEDICINE 2023; 36:e4846. [PMID: 36259628 DOI: 10.1002/nbm.4846] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Magnetic resonance imaging (MRI) technology has profoundly transformed current healthcare systems globally, owing to advances in hardware and software research innovations. Despite these advances, MRI remains largely inaccessible to clinicians, patients, and researchers in low-resource areas, such as Africa. The rapidly growing burden of noncommunicable diseases in Africa underscores the importance of improving access to MRI equipment as well as training and research opportunities on the continent. The Consortium for Advancement of MRI Education and Research in Africa (CAMERA) is a network of African biomedical imaging experts and global partners, implementing novel strategies to advance MRI access and research in Africa. Upon its inception in 2019, CAMERA sets out to identify challenges to MRI usage and provide a framework for addressing MRI needs in the region. To this end, CAMERA conducted a needs assessment survey (NAS) and a series of symposia at international MRI society meetings over a 2-year period. The 68-question NAS was distributed to MRI users in Africa and was completed by 157 clinicians and scientists from across Sub-Saharan Africa (SSA). On average, the number of MRI scanners per million people remained at less than one, of which 39% were obsolete low-field systems but still in use to meet daily clinical needs. The feasibility of coupling stable energy supplies from various sources has contributed to the growing number of higher-field (1.5 T) MRI scanners in the region. However, these systems are underutilized, with only 8% of facilities reporting clinical scans of 15 or more patients per day, per scanner. The most frequently reported MRI scans were neurological and musculoskeletal. The CAMERA NAS combined with the World Health Organization and International Atomic Energy Agency data provides the most up-to-date data on MRI density in Africa and offers a unique insight into Africa's MRI needs. Reported gaps in training, maintenance, and research capacity indicate ongoing challenges in providing sustainable high-value MRI access in SSA. Findings from the NAS and focused discussions at international MRI society meetings provided the basis for the framework presented here for advancing MRI capacity in SSA. While these findings pertain to SSA, the framework provides a model for advancing imaging needs in other low-resource settings.
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Affiliation(s)
- Udunna C Anazodo
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Jinggang J Ng
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Boaz Ehiogu
- Lawson Health Research Institute, London, Ontario, Canada
| | | | | | - Henk J M M Mutsaerts
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Brain Imaging, Amsterdam, The Netherlands
| | | | - Mamadou Diop
- Lawson Health Research Institute, London, Ontario, Canada
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Abayomi Opadele
- Molecular and Cellular Dynamics Research, Graduate School of Biomedical Science and Engineering, Hokkaido University, Hokkaido, Japan
| | | | - Michael O Dada
- Department of Physics, Federal University of Technology, Minna, Niger State, Nigeria
| | - Godwin Ogbole
- Department of Radiology, University College Hospital Ibadan, Ibadan, Nigeria
| | - Rita Nunes
- Department of Bioengineering, Instituto Superior, Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Patricia Figueiredo
- Department of Bioengineering, Instituto Superior, Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Matteo Figini
- Department of Computer Science, University College London, London, UK
| | | | - Bamidele O Awojoyogbe
- Department of Physics, Federal University of Technology, Minna, Niger State, Nigeria
| | | | - Christian Sprenger
- Department of Anesthesiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rachel Wagner
- Mbarara University of Science and Technology, Mbarara, Uganda
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | | | - Dominic Romeo
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yusha Sun
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Francis Fezeu
- Neurosurgery & Neurology, BRAIN Global, Salisbury, Maryland, USA
| | - Akintunde T Orunmuyi
- Department of Nuclear Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Sairam Geethanath
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, USA
| | - Vikas Gulani
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Sola Adeleke
- Department of Oncology, Guy's & St Thomas' Hospital, London, UK
| | - Ntusi Ntobeuko
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Frank J Minja
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA
| | - Andrew G Webb
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Iris Asllani
- Department of Neuroscience, University of Sussex, Brighton, UK
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, New York, USA
| | - Farouk Dako
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- RAD-AID International, Chevy Chase, Maryland, USA
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40
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Sien ME, Robinson AL, Hu HH, Nitkin CR, Hall AS, Files MG, Artz NS, Pitts JT, Chan SS. Feasibility of and experience using a portable MRI scanner in the neonatal intensive care unit. Arch Dis Child Fetal Neonatal Ed 2023; 108:45-50. [PMID: 35788031 PMCID: PMC9763199 DOI: 10.1136/archdischild-2022-324200] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/02/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE A portable, low-field MRI system is now Food and Drug Administration cleared and has been shown to be safe and useful in adult intensive care unit settings. No neonatal studies have been performed. The objective is to assess our preliminary experience and assess feasibility of using the portable MRI system at the bedside in a neonatal intensive care unit (NICU) at a quaternary children's hospital. STUDY DESIGN This was a single-site prospective cohort study in neonates ≥2 kg conducted between October and December 2020. All parents provided informed consent. Neonates underwent portable MRI examination in the NICU with support equipment powered on and attached to the neonate during the examination. A paediatric radiologist interpreted each portable MRI examination. The study outcome variable was percentage of portable MRI examinations completed without artefacts that would hinder diagnosis. Findings were compared between portable MRI examinations and standard of care examinations. RESULTS Eighteen portable, low-field MRI examinations were performed on 14 neonates with an average age of 29.7 days (range 1-122 days). 94% (17 of 18) of portable MRI examinations were acquired without significant artefact. Significant intracranial pathology was visible on portable MRI, but subtle abnormalities were missed. The examination reads were concordant in 59% (10 of 17) of cases and significant pathology was missed in 12% (2 of 17) of cases. CONCLUSION This single-centre series demonstrated portable MRI examinations can be performed safely with standard patient support equipment present in the NICU. These findings demonstrate that portable MRI could be used in the future to guide care in the NICU setting. TRIAL REGISTRATION NUMBER NCT04629469.
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Affiliation(s)
- Maura E Sien
- Department of Radiology, Children's Mercy, Kansas City, Missouri, USA
| | - Amie L Robinson
- Department of Radiology, Children's Mercy, Kansas City, Missouri, USA
| | | | - Chris R Nitkin
- Department of Pediatrics, Children's Mercy, Kansas City, Missouri, USA,Department of Pediatrics, University of Missouri Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Ara S Hall
- Department of Pediatrics, Children's Mercy, Kansas City, Missouri, USA,Department of Pediatrics, University of Missouri Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Marcie G Files
- Department of Pediatrics, Children's Mercy, Kansas City, Missouri, USA,Department of Pediatrics, University of Missouri Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Nathan S Artz
- Department of Radiology, Children's Mercy, Kansas City, Missouri, USA,Department of Radiology, University of Missouri at Kansas City School of Medicine, Kansas City, Missouri, USA
| | | | - Sherwin S Chan
- Department of Radiology, Children's Mercy, Kansas City, Missouri, USA .,Department of Radiology, University of Missouri at Kansas City School of Medicine, Kansas City, Missouri, USA
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41
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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: 50] [Impact Index Per Article: 50.0] [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.
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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
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42
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Al-Haj Husain A, Schönegg D, Valdec S, Stadlinger B, Piccirelli M, Winklhofer S. Appearance of nasopalatine duct cysts on dental magnetic resonance imaging using a mandibular coil: Two case reports with a literature review. Imaging Sci Dent 2023. [DOI: 10.5624/isd.20220215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Affiliation(s)
- Adib Al-Haj Husain
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Daphne Schönegg
- Department of Cranio-Maxillo-Facial and Oral Surgery, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Silvio Valdec
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Bernd Stadlinger
- Clinic of Cranio-Maxillofacial and Oral Surgery, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Sebastian Winklhofer
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
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Okubo Y, Yamamoto Y, Terao H, Suzuki T, Koizumi M, Yoshioka E, Washimi K, Sato S, Yokose T, Kishida T, Miyagi Y. Significance of non-standardized magnetic resonance imaging abnormalities and subsequent targeted prostate cancer biopsy for pathologists: A retrospective observational study. Pathol Res Pract 2022; 240:154188. [DOI: 10.1016/j.prp.2022.154188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 10/21/2022] [Accepted: 10/22/2022] [Indexed: 11/05/2022]
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Zhang W, Lv Z, Zhang Y, Gopinath SCB, Yuan Y, Huang D, Miao L. Targeted Diagnosis, Therapeutic Monitoring, and Assessment of Atherosclerosis Based on Mesoporous Silica Nanoparticles Coated with cRGD-Platelets. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:6006601. [PMID: 36211824 PMCID: PMC9537012 DOI: 10.1155/2022/6006601] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/20/2022] [Indexed: 12/07/2022]
Abstract
Objective The off-target effects and severe side effects of PPARα and LXRα agonists greatly limit their application in atherosclerosis (AS). Therefore, this study intended to use mesoporous silica nanoparticles as carriers to generate MnO nanoparticles in situ with T1WI-MRI in mesoporous pores and simultaneously load PPARα and LXRα agonists. Afterward, cRGD-chelated platelet membranes can be used for coating to construct a new nanotheranostic agent. Methods cRGD-platelet@MnO/MSN@PPARα/LXRα nanoparticles were synthesized by a chemical method. Dynamic light scattering (DLS) was utilized to detect the size distribution and polydispersity index (PDI) of the nanoparticles. The safety of the nanoparticles was detected by CCK8 in vitro and HE staining and kidney function in vivo. Cell apoptosis was detected by flow cytometry detection and TUNEL staining. Oxidative stress responses (ROS, SOD, MDA, and NOX levels) were tested via a DCFH-DA assay and commercial kits. Immunofluorescence and phagocytosis experiments were used to detect the targeting of nanoparticles. Magnetic resonance imaging (MRI) was used to detect the imaging performance of cRGD-platelet@MnO/MSN@PPARα/LXRα nanoparticles. Using western blotting, the expression changes in LXRα and ABCA1 were identified. Results cRGD-platelet@MnO/MSN@PPARα/LXRα nanoparticles were successfully established, with a particle size of approximately 150 nm and PDI less than 0.3, and showed high safety both in vitro and in vivo. cRGD-platelet@MnO/MSN@PPARα/LXRα nanoparticles showed good targeting properties and better MRI imaging performance in AS. cRGD-platelet@MnO/MSN@PPARα/LXRα nanoparticles showed better antioxidative capacities, MRI imaging performance, and diagnostic and therapeutic effects on AS by regulating the expression of LXRα and ABCA1. Conclusion In the present study, cRGD-platelet@MnO/MSN@PPARα/LXRα nanoparticles with high safety and the capacity to target vulnerable plaques of AS were successfully established. They showed better performance on MRI images and treatment effects on AS by promoting cholesterol efflux through the regulation of ABCA1. These findings might address the problems of off-target effects and side effects of nanoparticle-mediated drug delivery, which will enhance the efficiency of AS treatment and provide new ideas for the clinical treatment of AS.
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Affiliation(s)
- Wei Zhang
- Department of Radiology, Liuzhou People's Hospital Affiliated to Guangxi Medical University, Liuzhou, Guangxi 545006, China
| | - Zheng Lv
- Department of Radiology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, China
| | - Yupeng Zhang
- Department of Radiology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, China
| | - Subash C. B. Gopinath
- Faculty of Chemical Engineering & Technology, Micro System Technology, Centre of Excellence (CoE), and Institute of Nano Electronic Engineering, Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia
| | - Yi Yuan
- Institute of Life Sciences, Jiangsu University, Zhengjiang, Jiangsu 212013, China
| | - Deyou Huang
- Department of Radiology, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi 533000, China
| | - Liu Miao
- Department of Cardiology, Liuzhou People's Hospital Affiliated to Guangxi Medical University, Liuzhou, Guangxi 545006, China
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Younis MH, Tang Z, Cai W. Multimodality imaging of nanoparticle-based vaccines: Shedding light on immunology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2022; 14:e1807. [PMID: 35501142 PMCID: PMC9481661 DOI: 10.1002/wnan.1807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
In recent years, there have been significant innovations in the development of nanoparticle-based vaccines and vaccine delivery systems. For the purposes of both design and evaluation, these nanovaccines are imaged using the wealth of understanding established around medical imaging of nanomaterials. An important insight to the advancement of the field of nanovaccines can be given by an analysis of the design rationale of an imaging platform, as well as the significance of the information provided by imaging. Nanovaccine imaging strategies can be categorized by the imaging modality leveraged, but it is also worth understanding the superiority or convenience of a given modality over others in a given context of a particular nanovaccine. The most important imaging modalities in this endeavor are optical imaging including near-infrared fluorescence imaging (NIRF), emission tomography methods such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) with or without computed tomography (CT) or magnetic resonance (MR), the emerging magnetic particle imaging (MPI), and finally, multimodal applications of imaging which include molecular imaging with magnetic resonance imaging (MRI) and photoacoustic (PA) imaging. One finds that each of these modalities has strengths and weaknesses, but optical and PET imaging tend, in this context, to be currently the most accessible, convenient, and informative modalities. Nevertheless, an important principle is that there is not a one-size-fits-all solution, and that the specific nanovaccine in question must be compatible with a particular imaging modality. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.
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Affiliation(s)
- Muhsin H. Younis
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Zhongmin Tang
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Weibo Cai
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
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Arnold TC, Tu D, Okar SV, Nair G, By S, Kawatra KD, Robert-Fitzgerald TE, Desiderio LM, Schindler MK, Shinohara RT, Reich DS, Stein JM. Sensitivity of portable low-field magnetic resonance imaging for multiple sclerosis lesions. Neuroimage Clin 2022; 35:103101. [PMID: 35792417 PMCID: PMC9421456 DOI: 10.1016/j.nicl.2022.103101] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/25/2022]
Abstract
Paired, same-day, 3T and 64mT MRI studies were analyzed in 33 MS patients. 64mT MRI showed 94% sensitivity for detecting any lesions in 3T confirmed cases. The diameter of the smallest detected lesion was larger at 64mT compared to 3T. Total lesion volume estimates were strongly correlated between 3T and 64mT scans. Portable low-field MRI detects white matter lesions, but smaller lesions may be missed.
Magnetic resonance imaging (MRI) is a fundamental tool in the diagnosis and management of neurological diseases such as multiple sclerosis (MS). New portable, low-field strength, MRI scanners could potentially lower financial and technical barriers to neuroimaging and reach underserved or disabled populations, but the sensitivity of these devices for MS lesions is unknown. We sought to determine if white matter lesions can be detected on a portable 64mT scanner, compare automated lesion segmentations and total lesion volume between paired 3T and 64mT scans, identify features that contribute to lesion detection accuracy, and explore super-resolution imaging at low-field. In this prospective, cross-sectional study, same-day brain MRI (FLAIR, T1w, and T2w) scans were collected from 36 adults (32 women; mean age, 50 ± 14 years) with known or suspected MS using Siemens 3T (FLAIR: 1 mm isotropic, T1w: 1 mm isotropic, and T2w: 0.34–0.5 × 0.34–0.5 × 3–5 mm) and Hyperfine 64mT (FLAIR: 1.6 × 1.6 × 5 mm, T1w: 1.5 × 1.5 × 5 mm, and T2w: 1.5 × 1.5 × 5 mm) scanners at two centers. Images were reviewed by neuroradiologists. MS lesions were measured manually and segmented using an automated algorithm. Statistical analyses assessed accuracy and variability of segmentations across scanners and systematic scanner biases in automated volumetric measurements. Lesions were identified on 64mT scans in 94% (31/33) of patients with confirmed MS. The average smallest lesions manually detected were 5.7 ± 1.3 mm in maximum diameter at 64mT vs 2.1 ± 0.6 mm at 3T, approaching the spatial resolution of the respective scanner sequences (3T: 1 mm, 64mT: 5 mm slice thickness). Automated lesion volume estimates were highly correlated between 3T and 64mT scans (r = 0.89, p < 0.001). Bland-Altman analysis identified bias in 64mT segmentations (mean = 1.6 ml, standard error = 5.2 ml, limits of agreement = –19.0–15.9 ml), which over-estimated low lesion volume and under-estimated high volume (r = 0.74, p < 0.001). Visual inspection revealed over-segmentation was driven venous hyperintensities on 64mT T2-FLAIR. Lesion size drove segmentation accuracy, with 93% of lesions > 1.0 ml and all lesions > 1.5 ml being detected. Using multi-acquisition volume averaging, we were able to generate 1.6 mm isotropic images on the 64mT device. Overall, our results demonstrate that in established MS, a portable 64mT MRI scanner can identify white matter lesions, and that automated estimates of total lesion volume correlate with measurements from 3T scans.
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Affiliation(s)
- T Campbell Arnold
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Danni Tu
- Penn Statistics in Imaging and Visualization Center and Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Serhat V Okar
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Govind Nair
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | | | - Karan D Kawatra
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Timothy E Robert-Fitzgerald
- Penn Statistics in Imaging and Visualization Center and Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lisa M Desiderio
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew K Schindler
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Russell T Shinohara
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Statistics in Imaging and Visualization Center and Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daniel S Reich
- National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD 20892, USA.
| | - Joel M Stein
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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An Update on the Measurement of Motor Cerebellar Dysfunction in Multiple Sclerosis. THE CEREBELLUM 2022:10.1007/s12311-022-01435-y. [PMID: 35761144 PMCID: PMC9244122 DOI: 10.1007/s12311-022-01435-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 06/15/2022] [Indexed: 12/03/2022]
Abstract
Multiple sclerosis (MS) is a progressive disease that often affects the cerebellum. It is characterised by demyelination, inflammation, and neurodegeneration within the central nervous system. Damage to the cerebellum in MS is associated with increased disability and decreased quality of life. Symptoms include gait and balance problems, motor speech disorder, upper limb dysfunction, and oculomotor difficulties. Monitoring symptoms is crucial for effective management of MS. A combination of clinical, neuroimaging, and task-based measures is generally used to diagnose and monitor MS. This paper reviews the present and new tools used by clinicians and researchers to assess cerebellar impairment in people with MS (pwMS). It also describes recent advances in digital and home-based monitoring for people with MS.
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Ozoner B, Gungor A, Ture H, Ture U. Surgical Treatment of Trochlear Nerve Schwannomas: Case Series and Systematic Review. World Neurosurg 2022; 162:e288-e300. [PMID: 35276398 DOI: 10.1016/j.wneu.2022.03.006] [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: 12/14/2021] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE Cranial nerve schwannomas almost always arise from sensory or mixed nerves. Motor cranial nerves, such as the trochlear nerve, are rarely associated with schwannomas. No consensus has yet been made for surgical intervention because of the low number of reported cases of trochlear nerve schwannomas. This study comprises a systematic review of the literature and our experience for surgically treated trochlear nerve schwannomas. METHODS Three databases (Web of Science, PubMed, and Cochrane Library) were searched without date restrictions. Studies were included if they were published in the English literature and presented patients of any age who underwent surgical treatment for trochlear schwannoma. Data extracted from the included studies were combined with our experience. RESULTS Forty-one studies, presenting 43 patients, met the inclusion criteria. The total number of patients was 45 after our experience was added. The most common symptoms were diplopia (62.2%), headache (46.7%), and motor weakness (37.8%). Mean age during the diagnosis was 45.1 years. Although the subtemporal transtentorial approach (n = 14) is the most preferred method, its application has decreased in recent years. In the last decade, the lateral suboccipital approach (n = 11) has gained popularity. Residual postoperative trochlear nerve deficit was detected in 81% of patients. The probability of neurologic deficit was not statistically associated with tumor volume (P = 0.914), location (P = 0.669), or resection rate (P = 0.554). CONCLUSIONS Although trochlear schwannomas are rare and their treatment involves challenges, total resection with the proper approach provides the most desirable results.
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Affiliation(s)
- Baris Ozoner
- Department of Neurosurgery, Kartal Dr. Lutfi Kirdar Research and Education Hospital, Istanbul, Turkey; Department of Neurosurgery, Yeditepe University School of Medicine, Istanbul, Turkey
| | - Abuzer Gungor
- Department of Neurosurgery, Yeditepe University School of Medicine, Istanbul, Turkey; Department of Neurosurgery, Bakirkoy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul, Turkey
| | - Hatice Ture
- Department of Anesthesiology, Yeditepe University School of Medicine, Istanbul, Turkey
| | - Ugur Ture
- Department of Neurosurgery, Yeditepe University School of Medicine, Istanbul, Turkey.
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Su J, Pellicer-Guridi R, Edwards T, Fuentes M, Rosen MS, Vegh V, Reutens D. A CNN Based Software Gradiometer for Electromagnetic Background Noise Reduction in Low Field MRI Applications. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:1007-1016. [PMID: 35089856 DOI: 10.1109/tmi.2022.3147450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The shielding of electromagnetic noise is critical in obtaining magnetic resonance imaging measurements in the ultra-low magnetic field regime where the intrinsic signal-to-noise ratio is very small. The traditional approach of using an enclosure for electromagnetic shielding is expensive and hinders system portability. We describe here the use of a CNN-based software gradiometer to suppress the effect of electromagnetic ambient background noise sources that inductively couple into the signal detection coils. The system involves three ambient noise monitoring coils placed at a distance from the magnetic resonance signal detector. The three coils were used to synthesize the ambient noise captured by the signal detector; a convolutional neural network approach was used. Mathematical foundations are provided to justify the noise suppression framework. The results show that as much as 20-fold noise suppression can be achieved using an optimized convolutional neural network and simultaneous ambient noise measurements. The proposed approach has the potential to replace the requirement for magnetically shielded enclosures and make ultra-low field magnetic resonance imaging truly portable.
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50
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Vosshenrich J, Breit HC, Bach M, Merkle EM. [Economic aspects of low-field magnetic resonance imaging : Acquisition, installation, and maintenance costs of 0.55 T systems]. Radiologe 2022; 62:400-404. [PMID: 35348808 PMCID: PMC9061693 DOI: 10.1007/s00117-022-00986-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND Low-field magnetic resonance imaging (MRI) scanners offer an opportunity for cost reduction in the healthcare system. This is due to lower manufacturing costs and reduced construction requirements for installation and operation. OBJECTIVES To discuss potential cost reductions in acquisition, installation, and maintenance by using new low-field MRI systems. METHODS We provide an overview of key cost drivers and an evaluation of the potential savings of a recent generation 0.55T low-field MRI compared to conventional 1.5T and 3T MRI systems in routine clinical practice. RESULTS In terms of purchase price, the savings potential of a 0.55T MRI compared to a 1.5T MRI system is about 40-50%. The 25% lower weight of the system reduces the transportation costs incurred, and the smaller size of the unit allows for installation by a remotely controlled mobile robotic system without opening the exterior façade, if the operating site is at ground level. Together with the lack of need to install a quench pipe, this reduces the total cost of installation by up to 70%. The maintenance cost of a 0.55T MRI is approximately 45% less than that of a 1.5T unit with a comparable service contract. Further cost reductions result from the smaller room size and potentially lower energy consumption for examinations and cooling. CONCLUSION The use of lower field strength MRI systems offers enormous economic and environmental potential for both hospitals and practice operators, as well as for the healthcare system as a whole.
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Affiliation(s)
- Jan Vosshenrich
- Klinik für Radiologie und Nuklearmedizin, Universitätsspital Basel, Petersgraben 4, 4031, Basel, Schweiz
| | - Hanns-Christian Breit
- Klinik für Radiologie und Nuklearmedizin, Universitätsspital Basel, Petersgraben 4, 4031, Basel, Schweiz.
| | - Michael Bach
- Klinik für Radiologie und Nuklearmedizin, Universitätsspital Basel, Petersgraben 4, 4031, Basel, Schweiz
| | - Elmar M Merkle
- Klinik für Radiologie und Nuklearmedizin, Universitätsspital Basel, Petersgraben 4, 4031, Basel, Schweiz
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