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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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Wang W, Sánchez-Heredia JD, Olin RB, Hansen ESS, Laustsen C, Zhurbenko V, Ardenkjaer-Larsen JH. A cryogenic 14-channel 13 C receiver array for 3T human head imaging. Magn Reson Med 2023; 89:1265-1277. [PMID: 36321576 PMCID: PMC10092528 DOI: 10.1002/mrm.29508] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/09/2022] [Accepted: 10/11/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE This article presents a novel 14-channel receive-only array for 13 C human head imaging at 3 T that explores the SNR gain by operating at cryogenic temperature cooled by liquid nitrogen. METHODS Cryostats are developed to evaluate single-coil bench SNR performance and cool the 14-channel array with liquid nitrogen while having enough thermal insulation between the coils and the sample. The temperature distribution for the coil array is measured. Circuits are adapted to the -189°C environment and implemented in the 14-channel array. 13 C images are acquired with the array at cryogenic and room temperature in a 3T scanner. RESULTS Compared with room temperature, the array at cryogenic temperature provides 27%-168% SNR improvement over all voxels and 47% SNR improvement near the image center. The measurements show a decrease of the element noise correlation at cryogenic temperature. CONCLUSION It is demonstrated that higher SNR can be achieved by cryogenically cooling the 14-channel array. A cryogenic array suitable for clinical imaging can be further developed on the array proposed. The cryogenic coil array is most likely suited for scenarios in which high SNR deep in a head and decent SNR on the periphery are required.
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Affiliation(s)
- Wenjun Wang
- National Space Institute, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Rie Beck Olin
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Christoffer Laustsen
- MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Vitaliy Zhurbenko
- National Space Institute, Technical University of Denmark, Kongens Lyngby, Denmark
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Song M, Chen JH, Chen J, Lin IT. Comparisons between the 35 mm quadrature surface resonator at 300 K and the 40 mm high-temperature superconducting surface resonator at 77 K in a 3T MRI imager. PLoS One 2015; 10:e0118892. [PMID: 25812124 PMCID: PMC4374922 DOI: 10.1371/journal.pone.0118892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 01/22/2015] [Indexed: 11/29/2022] Open
Abstract
This study attempts to compare the signal-to-noise ratio (SNR) of the 40 mm High-Temperature Superconducting (HTS) surface resonator at 77 K and the 35 mm commercial quadrature (QD) surface resonator at 300 K in a 3 Tesla (T) MRI imager. To aquire images for the comparison, we implemented a phantom experiment using the 40 mm diameter Bi2Sr2Ca2Cu3Ox (Bi-2223) HTS surface resonator, the 35 mm commercial QD surface resonator and the 40 mm professionally-made copper surface resonator. The HTS surface resonator at 77 K provided a 1.43-fold SNR gain over the QD surface resonator at 300 K and provided a 3.84-fold SNR gain over the professionally-made copper surface resonator at 300 K on phantom images. The results agree with the predictions, and the difference between the predicted SNR gains and measured SNR gains is 1%. Although the geometry of the HTS surface resonator is different from the QD surface resonator, its SNR is still higher. The results demonstrate that a higher image quality can be obtained with the HTS surface resonator at 77 K. With the HTS surface resonator, the SNR can be improved, suggesting that the HTS surface resonator is a potentially helpful diagnostic tool for MRI imaging in various applications.
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Affiliation(s)
- Manli Song
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen Fujian, China
- Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen Fujian, China
| | - Jyh-Horng Chen
- Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Ji Chen
- Department of Physiology and Neurobiology, Medical College of Xiamen University, Xiamen Fujian, China
| | - In-Tsang Lin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen Fujian, China
- Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen Fujian, China
- * E-mail:
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Elabyad IA, Kalayciyan R, Shanbhag NC, Schad LR. First In Vivo Potassium-39 $(^{\bf 39}$K) MRI at 9.4 T Using Conventional Copper Radio Frequency Surface Coil Cooled to 77 K. IEEE Trans Biomed Eng 2014; 61:334-45. [DOI: 10.1109/tbme.2013.2294277] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Liang D, Tat Hui H, Soon Yeo T. Improved Signal-to-Noise Ratio Performance in Magnetic Resonance Imaging by Using a Multilayered Surface Coil Array—A Simulation Study. IEEE J Biomed Health Inform 2013; 17:756-62. [DOI: 10.1109/jbhi.2013.2253113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Dandan Liang, Hon Tat Hui, Tat Soon Yeo, Bing Keong Li. Stacked phased array coils for increasing the signal-to-noise ratio in magnetic resonance imaging. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2013; 7:24-30. [PMID: 23853276 DOI: 10.1109/tbcas.2012.2194144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A new concept of using a stacked phased coil array to increase the signal-to-circuit noise ratio (SCNR) in magnetic resonance imaging (MRI) is introduced. Unlike conventional phased coil arrays, the proposed stacked phased coil array is constructed by stacking the coil elements closely together in the vertical direction. Through a proper combination of the coil terminal voltages, the SCNR is shown to increase with the square root of the number of coil elements. A prototype two-element array is constructed and an experimental method is designed to determine the combiner coefficients in a simulated MRI electromagnetic field environment. The experimental results show that the mutual coupling effect among the array coils can be totally removed and the combiner output voltage increases with the number of coil elements. This demonstrates the feasibility of the proposed method.
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Liang D, Hui HT, Yeo TS. Increasing the signal-to-noise ratio by using vertically stacked phased array coils for low-field magnetic resonance imaging. IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE : A PUBLICATION OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY 2012; 16:1150-1156. [PMID: 22575694 DOI: 10.1109/titb.2012.2197633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A new method is introduced to increase the signal-to-noise ratio (SNR) in low-field magnetic resonance imaging (MRI) systems by using a vertically stacked phased coil array. It is shown theoretically that the SNR is increased with the square root of the number of coils in the array if the array signals are properly combined to remove the mutual coupling effect. Based on this, a number of vertically stacked phased coil arrays have been designed and characterized by a numerical simulation method. The performance of these arrays confirms the significant increase of SNR by increasing the number of coils in the arrays. This provides a simple and efficient method to improve the SNR for low-field MRI systems.
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Lin IT, Yang HC, Chen JH. Whole body screening using high-temperature superconducting MR volume resonators: mice studies. PLoS One 2012; 7:e33207. [PMID: 22493666 PMCID: PMC3320880 DOI: 10.1371/journal.pone.0033207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 02/12/2012] [Indexed: 11/18/2022] Open
Abstract
High temperature superconducting (HTS) surface resonators have been used as a low loss RF receiver resonator for improving magnetic resonance imaging image quality. However, the application of HTS surface resonators is significantly limited by their filling factor. To maximize the filling factor, it is desirable to have the RF resonator wrapped around the sample so that more nuclear magnetic dipoles can contribute to the signal. In this study, a whole new Bi(2)Sr(2)Ca(2)Cu(2)O(3) (Bi-2223) superconducting saddle resonator (width of 5 cm and length of 8 cm) was designed for the magnetic resonance image of a mouse's whole body in Bruker 3 T MRI system. The experiment was conducted with a professionally-made copper saddle resonator and a Bi-2223 saddle resonator to show the difference. Signal-to-noise ratio (SNR) with the HTS saddle resonator at 77 K was 2.1 and 2 folds higher than that of the copper saddle resonator at 300 K for a phantom and an in-vivo mice whole body imaging. Testing results were in accordance with predicted ones, and the difference between the predicted SNR gains and measured SNR gains were 2.4%∼2.7%. In summary, with this HTS saddle system, a mouse's whole body can be imaged in one scan and could reach a high SNR due to a 2 folds SNR gain over the professionally-made prototype of copper saddle resonator at 300 K. The use of HTS saddle resonator not only improves SNR but also enables a mouse's whole body screen in one scan.
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Affiliation(s)
- In-Tsang Lin
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
- Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
| | - Hong-Chang Yang
- Department of Physics, National Taiwan University, Taipei, Taiwan
- * E-mail: (H-CY); (J-HC)
| | - Jyh-Horng Chen
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
- Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- * E-mail: (H-CY); (J-HC)
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Baltes C, Radzwill N, Bosshard S, Marek D, Rudin M. Micro MRI of the mouse brain using a novel 400 MHz cryogenic quadrature RF probe. NMR IN BIOMEDICINE 2009; 22:834-42. [PMID: 19536757 DOI: 10.1002/nbm.1396] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The increasing number of mouse models of human disease used in biomedical research applications has led to an enhanced interest in non-invasive imaging of mice, e.g. using MRI for phenotyping. However, MRI of small rodents puts high demands on the sensitivity of data acquisition. This requirement can be addressed by using cryogenic radio-frequency (RF) detection devices. The aim of this work was to investigate the in vivo performance of a 400 MHz cryogenic transmit/receive RF probe (CryoProbe) designed for MRI of the mouse brain. To characterize this novel probe, MR data sets were acquired with both the CryoProbe and a matched conventional receive-only surface coil operating at room temperature (RT) using conventional acquisition protocols (gradient and spin echo) with identical parameter settings. Quantitative comparisons in phantom and in vivo experiments revealed gains in the signal-to-noise ratio (SNR) of 2.4 and 2.5, respectively. The increased sensitivity of the CryoProbe was invested to enhance the image quality of high resolution structural images acquired in scan times compatible with routine operation (< 45 min). In high resolution (30 x 30 x 300 microm(3)) structural images of the mouse cerebellum, anatomical details such as Purkinje cell and molecular layers could be identified. Similarly, isotropic (60 x 60 x 60 microm(3)) imaging of mouse cortical and subcortical areas revealed anatomical structures smaller than 100 microm. Finally, 3D MR angiography (52 x 80 x 80 microm(3)) of the brain vasculature enabled the detailed reconstruction of intracranial vessels (anterior and middle cerebral artery). In conclusion, this low temperature detection device represents an attractive option to increase the performance of small animal MR systems operating at 9.4 Tesla.
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Affiliation(s)
- Christof Baltes
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
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Ratering D, Baltes C, Nordmeyer-Massner J, Marek D, Rudin M. Performance of a 200-MHz cryogenic RF probe designed for MRI and MRS of the murine brain. Magn Reson Med 2008; 59:1440-7. [DOI: 10.1002/mrm.21629] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2005; 18:205-12. [PMID: 15920785 DOI: 10.1002/nbm.964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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