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Rallapalli H, McCall EC, Koretsky AP. Genetic control of MRI contrast using the manganese transporter Zip14. Magn Reson Med 2024; 92:820-835. [PMID: 38573932 PMCID: PMC11142883 DOI: 10.1002/mrm.29993] [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: 09/22/2023] [Revised: 11/15/2023] [Accepted: 12/12/2023] [Indexed: 04/06/2024]
Abstract
PURPOSE Gene-expression reporter systems, such as green fluorescent protein, have been instrumental to understanding biological processes in living organisms at organ system, tissue, cell, and molecular scales. More than 30 years of work on developing MRI-visible gene-expression reporter systems has resulted in a variety of clever application-specific methods. However, these techniques have not yet been widely adopted, so a general-purpose expression reporter is still required. Here, we demonstrate that the manganese ion transporter Zip14 is an in vivo MRI-visible, flexible, and robust gene-expression reporter to meet this need. METHODS Plasmid constructs consisting of a cell type-specific promoter, gene coding for human Zip14, and a histology-visible tag were packaged into adeno-associated viruses. These viruses were intracranially injected into the mouse brain. Serial in vivo MRI was performed using a vendor-supplied 3D-MPRAGE sequence. No additional contrast agents were administered. Animals were sacrificed after the last imaging timepoint for immunohistological validation. RESULTS Neuron-specific overexpression of Zip14 produced substantial and long-lasting changes in MRI contrast. Using appropriate viruses enabled both anterograde and retrograde neural tracing. Expression of Zip14 in astrocytes also enabled MRI of glia populations in the living mammalian brain. CONCLUSIONS The flexibility of this system as an MRI-visible gene-expression reporter will enable many applications of serial, high-resolution imaging of gene expression for basic science and therapy development.
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Affiliation(s)
- Harikrishna Rallapalli
- Section on Plasticity and Imaging of the Nervous System, NINDS/NIH, Bethesda, Maryland, USA
| | - Eleanor C McCall
- Section on Plasticity and Imaging of the Nervous System, NINDS/NIH, Bethesda, Maryland, USA
| | - Alan P Koretsky
- Section on Plasticity and Imaging of the Nervous System, NINDS/NIH, Bethesda, Maryland, USA
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2
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Lewis D, Li KL, Waqar M, Coope DJ, Pathmanaban ON, King AT, Djoukhadar I, Zhao S, Cootes TF, Jackson A, Zhu X. Low-dose GBCA administration for brain tumour dynamic contrast enhanced MRI: a feasibility study. Sci Rep 2024; 14:4905. [PMID: 38418818 PMCID: PMC10902320 DOI: 10.1038/s41598-024-53871-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
A key limitation of current dynamic contrast enhanced (DCE) MRI techniques is the requirement for full-dose gadolinium-based contrast agent (GBCA) administration. The purpose of this feasibility study was to develop and assess a new low GBCA dose protocol for deriving high-spatial resolution kinetic parameters from brain DCE-MRI. Nineteen patients with intracranial skull base tumours were prospectively imaged at 1.5 T using a single-injection, fixed-volume low GBCA dose, dual temporal resolution interleaved DCE-MRI acquisition. The accuracy of kinetic parameters (ve, Ktrans, vp) derived using this new low GBCA dose technique was evaluated through both Monte-Carlo simulations (mean percent deviation, PD, of measured from true values) and an in vivo study incorporating comparison with a conventional full-dose GBCA protocol and correlation with histopathological data. The mean PD of data from the interleaved high-temporal-high-spatial resolution approach outperformed use of high-spatial, low temporal resolution datasets alone (p < 0.0001, t-test). Kinetic parameters derived using the low-dose interleaved protocol correlated significantly with parameters derived from a full-dose acquisition (p < 0.001) and demonstrated a significant association with tissue markers of microvessel density (p < 0.05). Our results suggest accurate high-spatial resolution kinetic parameter mapping is feasible with significantly reduced GBCA dose.
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Affiliation(s)
- Daniel Lewis
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
- Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, UK.
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Stott Lane, Salford, Greater Manchester, M6 8HD, UK.
| | - Ka-Loh Li
- Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, UK
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Mueez Waqar
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
- Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - David J Coope
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
- Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, UK
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Omar N Pathmanaban
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
- Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, UK
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Andrew T King
- Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
- Geoffrey Jefferson Brain Research Centre, University of Manchester, Manchester, UK
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Ibrahim Djoukhadar
- Department of Neuroradiology, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Sha Zhao
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Timothy F Cootes
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Alan Jackson
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Xiaoping Zhu
- Division of Informatics, Imaging and Data Sciences, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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3
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Singh T, Joshi S, Kershaw LE, Dweck MR, Semple SI, Newby DE. Manganese-Enhanced Magnetic Resonance Imaging of the Heart. J Magn Reson Imaging 2023; 57:1011-1028. [PMID: 36314991 PMCID: PMC10947173 DOI: 10.1002/jmri.28499] [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: 05/02/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 02/23/2023] Open
Abstract
Manganese-based contrast media were the first in vivo paramagnetic agents to be used in magnetic resonance imaging (MRI). The uniqueness of manganese lies in its biological function as a calcium channel analog, thus behaving as an intracellular contrast agent. Manganese ions are taken up by voltage-gated calcium channels in viable tissues, such as the liver, pancreas, kidneys, and heart, in response to active calcium-dependent cellular processes. Manganese-enhanced magnetic resonance imaging (MEMRI) has therefore been used as a surrogate marker for cellular calcium handling and interest in its potential clinical applications has recently re-emerged, especially in relation to assessing cellular viability and myocardial function. Calcium homeostasis is central to myocardial contraction and dysfunction of myocardial calcium handling is present in various cardiac pathologies. Recent studies have demonstrated that MEMRI can detect the presence of abnormal myocardial calcium handling in patients with myocardial infarction, providing clear demarcation between the infarcted and viable myocardium. Furthermore, it can provide more subtle assessments of abnormal myocardial calcium handling in patients with cardiomyopathies and being excluded from areas of nonviable cardiomyocytes and severe fibrosis. As such, MEMRI offers exciting potential to improve cardiac diagnoses and provide a noninvasive measure of myocardial function and contractility. This could be an invaluable tool for the assessment of both ischemic and nonischemic cardiomyopathies as well as providing a measure of functional myocardial recovery, an accurate prediction of disease progression and a method of monitoring treatment response. EVIDENCE LEVEL: 5: TECHNICAL EFFICACY: STAGE 5.
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Affiliation(s)
- Trisha Singh
- BHF/University Centre for Cardiovascular ScienceUniversity of EdinburghUK
- Edinburgh Heart CentreRoyal Infirmary of EdinburghUK
- Edinburgh ImagingUniversity of EdinburghUK
| | - Shruti Joshi
- BHF/University Centre for Cardiovascular ScienceUniversity of EdinburghUK
- Edinburgh Heart CentreRoyal Infirmary of EdinburghUK
- Edinburgh ImagingUniversity of EdinburghUK
| | - Lucy E Kershaw
- BHF/University Centre for Cardiovascular ScienceUniversity of EdinburghUK
- Edinburgh ImagingUniversity of EdinburghUK
| | - Marc R Dweck
- BHF/University Centre for Cardiovascular ScienceUniversity of EdinburghUK
- Edinburgh Heart CentreRoyal Infirmary of EdinburghUK
- Edinburgh ImagingUniversity of EdinburghUK
| | - Scott I Semple
- BHF/University Centre for Cardiovascular ScienceUniversity of EdinburghUK
- Edinburgh ImagingUniversity of EdinburghUK
| | - David E Newby
- BHF/University Centre for Cardiovascular ScienceUniversity of EdinburghUK
- Edinburgh Heart CentreRoyal Infirmary of EdinburghUK
- Edinburgh ImagingUniversity of EdinburghUK
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4
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Zhuang D, Zhang H, Hu G, Guo B. Recent development of contrast agents for magnetic resonance and multimodal imaging of glioblastoma. J Nanobiotechnology 2022; 20:284. [PMID: 35710493 PMCID: PMC9204881 DOI: 10.1186/s12951-022-01479-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 05/29/2022] [Indexed: 11/28/2022] Open
Abstract
Glioblastoma (GBM) as the most common primary malignant brain tumor exhibits a high incidence and degree of malignancy as well as poor prognosis. Due to the existence of formidable blood–brain barrier (BBB) and the aggressive growth and infiltrating nature of GBM, timely diagnosis and treatment of GBM is still very challenging. Among different imaging modalities, magnetic resonance imaging (MRI) with merits including high soft tissue resolution, non-invasiveness and non-limited penetration depth has become the preferred tool for GBM diagnosis. Furthermore, multimodal imaging with combination of MRI and other imaging modalities would not only synergistically integrate the pros, but also overcome the certain limitation in each imaging modality, offering more accurate morphological and pathophysiological information of brain tumors. Since contrast agents contribute to amplify imaging signal output for unambiguous pin-pointing of tumors, tremendous efforts have been devoted to advances of contrast agents for MRI and multimodal imaging. Herein, we put special focus on summary of the most recent advances of not only MRI contrast agents including iron oxide-, manganese (Mn)-, gadolinium (Gd)-, 19F- and copper (Cu)-incorporated nanoplatforms for GBM imaging, but also dual-modal or triple-modal nanoprobes. Furthermore, potential obstacles and perspectives for future research and clinical translation of these contrast agents are discussed. We hope this review provides insights for scientists and students with interest in this area.
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Affiliation(s)
- Danping Zhuang
- The Second Clinical Medical College, Jinan University, Shenzhen, Guangdong, 518020, China
| | - Huifen Zhang
- Department of Radiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, Guangdong, China
| | - Genwen Hu
- Department of Radiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, Guangdong, China.
| | - Bing Guo
- School of Science and Shenzhen Key Laboratory of Flexible Printed Electronics Technology, Harbin Institute of Technology, Shenzhen, 518055, China.
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5
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Uselman TW, Medina CS, Gray HB, Jacobs RE, Bearer EL. Longitudinal manganese-enhanced magnetic resonance imaging of neural projections and activity. NMR IN BIOMEDICINE 2022; 35:e4675. [PMID: 35253280 PMCID: PMC11064873 DOI: 10.1002/nbm.4675] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/19/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) holds exceptional promise for preclinical studies of brain-wide physiology in awake-behaving animals. The objectives of this review are to update the current information regarding MEMRI and to inform new investigators as to its potential. Mn(II) is a powerful contrast agent for two main reasons: (1) high signal intensity at low doses; and (2) biological interactions, such as projection tracing and neural activity mapping via entry into electrically active neurons in the living brain. High-spin Mn(II) reduces the relaxation time of water protons: at Mn(II) concentrations typically encountered in MEMRI, robust hyperintensity is obtained without adverse effects. By selectively entering neurons through voltage-gated calcium channels, Mn(II) highlights active neurons. Safe doses may be repeated over weeks to allow for longitudinal imaging of brain-wide dynamics in the same individual across time. When delivered by stereotactic intracerebral injection, Mn(II) enters active neurons at the injection site and then travels inside axons for long distances, tracing neuronal projection anatomy. Rates of axonal transport within the brain were measured for the first time in "time-lapse" MEMRI. When delivered systemically, Mn(II) enters active neurons throughout the brain via voltage-sensitive calcium channels and clears slowly. Thus behavior can be monitored during Mn(II) uptake and hyperintense signals due to Mn(II) uptake captured retrospectively, allowing pairing of behavior with neural activity maps for the first time. Here we review critical information gained from MEMRI projection mapping about human neuropsychological disorders. We then discuss results from neural activity mapping from systemic Mn(II) imaged longitudinally that have illuminated development of the tonotopic map in the inferior colliculus as well as brain-wide responses to acute threat and how it evolves over time. MEMRI posed specific challenges for image data analysis that have recently been transcended. We predict a bright future for longitudinal MEMRI in pursuit of solutions to the brain-behavior mystery.
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Affiliation(s)
- Taylor W. Uselman
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | | | - Harry B. Gray
- Beckman Institute, California Institute of Technology, Pasadena, California, USA
| | - Russell E. Jacobs
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Elaine L. Bearer
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
- Beckman Institute, California Institute of Technology, Pasadena, California, USA
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6
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Komatsu C, van der Merwe Y, He L, Kasi A, Sims JR, Miller MR, Rosner IA, Khatter NJ, Su AJA, Schuman JS, Washington KM, Chan KC. In vivo MRI evaluation of anterograde manganese transport along the visual pathway following whole eye transplantation. J Neurosci Methods 2022; 372:109534. [PMID: 35202613 PMCID: PMC8940646 DOI: 10.1016/j.jneumeth.2022.109534] [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: 11/04/2021] [Revised: 02/12/2022] [Accepted: 02/18/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND Since adult mammalian retinal ganglion cells cannot regenerate after injury, we have recently established a whole-eye transplantation (WET) rat model that provides an intact optical system to investigate potential surgical restoration of irreversible vision loss. However, it remains to be elucidated whether physiological axoplasmic transport exists in the transplanted visual pathway. New Method: We developed an in vivo imaging model system to assess WET integration using manganese-enhanced magnetic resonance imaging (MEMRI) in rats. Since Mn2+ is a calcium analogue and an active T1-positive contrast agent, the levels of anterograde manganese transport can be evaluated in the visual pathways upon intravitreal Mn2+ administration into both native and transplanted eyes. RESULTS No significant intraocular pressure difference was found between native and transplanted eyes, whereas comparable manganese enhancement was observed between native and transplanted intraorbital optic nerves, suggesting the presence of anterograde manganese transport after WET. No enhancement was detected across the coaptation site in the higher visual areas of the recipient brain. Comparison with Existing Methods: Existing imaging methods to assess WET focus on either the eye or local optic nerve segments without direct visualization and longitudinal quantification of physiological transport along the transplanted visual pathway, hence the development of in vivo MEMRI. CONCLUSION Our established imaging platform indicated that essential physiological transport exists in the transplanted optic nerve after WET. As neuroregenerative approaches are being developed to connect the transplanted eye to the recipient's brain, in vivo MEMRI is well-suited to guide strategies for successful WET integration for vision restoration. Keywords (Max 6): Anterograde transport, magnetic resonance imaging, manganese, neuroregeneration, optic nerve, whole-eye transplantation.
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Affiliation(s)
- Chiaki Komatsu
- Department of Plastic and Reconstructive Surgery, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Yolandi van der Merwe
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Lin He
- Department of Plastic and Reconstructive Surgery, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Department of Plastic, Aesthetic & Maxillofacial Surgery, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Anisha Kasi
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States
| | - Jeffrey R Sims
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States
| | - Maxine R Miller
- Department of Plastic and Reconstructive Surgery, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Ian A Rosner
- Department of Plastic and Reconstructive Surgery, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Neil J Khatter
- Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Colorado, Denver, CO, United States; William Beaumont School of Medicine, Oakland University, Rochester, MI, United States
| | - An-Jey A Su
- Department of Plastic and Reconstructive Surgery, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Colorado, Denver, CO, United States
| | - Joel S Schuman
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States; Neuroscience Institute, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States; Center for Neural Science, College of Arts and Science, New York University, New York, NY, United States; Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY, United States
| | - Kia M Washington
- Department of Plastic and Reconstructive Surgery, Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Colorado, Denver, CO, United States; Veterans Administration Pittsburgh Healthcare System, Pittsburgh, PA, United States
| | - Kevin C Chan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States; Neuroscience Institute, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States; Center for Neural Science, College of Arts and Science, New York University, New York, NY, United States; Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY, United States; Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, United States.
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7
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Ammari S, Bône A, Balleyguier C, Moulton E, Chouzenoux É, Volk A, Menu Y, Bidault F, Nicolas F, Robert P, Rohé MM, Lassau N. Can Deep Learning Replace Gadolinium in Neuro-Oncology?: A Reader Study. Invest Radiol 2022; 57:99-107. [PMID: 34324463 DOI: 10.1097/rli.0000000000000811] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
MATERIALS AND METHODS This monocentric retrospective study leveraged 200 multiparametric brain MRIs acquired between November 2019 and February 2020 at Gustave Roussy Cancer Campus (Villejuif, France). A total of 145 patients were included: 107 formed the training sample (55 ± 14 years, 58 women) and 38 the separate test sample (62 ± 12 years, 22 women). Patients had glioma, brain metastases, meningioma, or no enhancing lesion. T1, T2-FLAIR, diffusion-weighted imaging, low-dose, and standard-dose postcontrast T1 sequences were acquired. A deep network was trained to process the precontrast and low-dose sequences to predict "virtual" surrogate images for contrast-enhanced T1. Once trained, the deep learning method was evaluated on the test sample. The discrepancies between the predicted virtual images and the standard-dose MRIs were qualitatively and quantitatively evaluated using both automated voxel-wise metrics and a reader study, where 2 radiologists graded image qualities and marked all visible enhancing lesions. RESULTS The automated analysis of the test brain MRIs computed a structural similarity index of 87.1% ± 4.8% between the predicted virtual sequences and the reference contrast-enhanced T1 MRIs, a peak signal-to-noise ratio of 31.6 ± 2.0 dB, and an area under the curve of 96.4% ± 3.1%. At Youden's operating point, the voxel-wise sensitivity (SE) and specificity were 96.4% and 94.8%, respectively. The reader study found that virtual images were preferred to standard-dose MRI in terms of image quality (P = 0.008). A total of 91 reference lesions were identified in the 38 test T1 sequences enhanced with full dose of contrast agent. On average across readers, the brain lesion SE of the virtual images was 83% for lesions larger than 10 mm (n = 42), and the associated false detection rate was 0.08 lesion/patient. The corresponding positive predictive value of detected lesions was 92%, and the F1 score was 88%. Lesion detection performance, however, dropped when smaller lesions were included: average SE was 67% for lesions larger than 5 mm (n = 74), and 56% with all lesions included regardless of their size. The false detection rate remained below 0.50 lesion/patient in all cases, and the positive predictive value remained above 73%. The composite F1 score was 63% at worst. CONCLUSIONS The proposed deep learning method for virtual contrast-enhanced T1 brain MRI prediction showed very high quantitative performance when evaluated with standard voxel-wise metrics. The reader study demonstrated that, for lesions larger than 10 mm, good detection performance could be maintained despite a 4-fold division in contrast agent usage, unveiling a promising avenue for reducing the gadolinium exposure of returning patients. Small lesions proved, however, difficult to handle for the deep network, showing that full-dose injections remain essential for accurate first-line diagnosis in neuro-oncology.
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Affiliation(s)
| | | | | | | | - Émilie Chouzenoux
- Center for Visual Computing, CentraleSupélec, Inria, Université Paris-Saclay, Gif-sur-Yvette, France
| | | | - Yves Menu
- From the Imaging Department, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif
| | - François Bidault
- From the Imaging Department, Gustave Roussy Cancer Campus, Université Paris-Saclay, Villejuif
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8
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Gómez-Arnaiz S, Tate RJ, Grant MH. Cobalt Neurotoxicity: Transcriptional Effect of Elevated Cobalt Blood Levels in the Rodent Brain. TOXICS 2022; 10:toxics10020059. [PMID: 35202246 PMCID: PMC8878729 DOI: 10.3390/toxics10020059] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/11/2022]
Abstract
Metal-on-metal (MoM) hip implants made of cobalt chromium (CoCr) alloy have shown early failure compared with other bearing materials. A consequence of the abnormal wear produced by these prostheses is elevated levels of cobalt in the blood of patients, which can lead to systemic conditions involving cardiac and neurological symptoms. In order to better understand the implications for patients with these implants, we carried out metal content and RNA-Seq analysis of excised tissue from rats treated intraperitonially for 28 days with low concentrations of cobalt. Cobalt blood levels in dosed rats were found to be similar to those seen in some patients with MoM implants (range: 4–38 μg/L Co in blood). Significant accumulation of cobalt was measured in a range of tissues including kidney, liver, and heart, but also in brain tissue. RNA-Seq analysis of neural tissue revealed that exposure to cobalt induces a transcriptional response in the prefrontal cortex (pref. cortex), cerebellum, and hippocampus. Many of the most up- and downregulated genes appear to correspond to choroid plexus transcripts. These results indicate that the choroid plexus could be the brain tissue most affected by cobalt. More specifically, the differentially expressed genes show a disruption of steroidogenesis and lipid metabolism. Several other transcripts also demonstrate that cobalt induces an immune response. In summary, cobalt exposure induces alterations in the brain transcriptome, more specifically, the choroid plexus, which is in direct contact with neurotoxicants at the blood–cerebrospinal fluid barrier.
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Affiliation(s)
- Sara Gómez-Arnaiz
- Wolfson Centre, Biomedical Engineering Department, University of Strathclyde, Glasgow G4 0NW, UK;
| | - Rothwelle J. Tate
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK;
| | - Mary Helen Grant
- Wolfson Centre, Biomedical Engineering Department, University of Strathclyde, Glasgow G4 0NW, UK;
- Correspondence:
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9
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Kalkowski L, Golubczyk D, Kwiatkowska J, Holak P, Milewska K, Janowski M, Oliveira JM, Walczak P, Malysz-Cymborska I. Two in One: Use of Divalent Manganese Ions as Both Cross-Linking and MRI Contrast Agent for Intrathecal Injection of Hydrogel-Embedded Stem Cells. Pharmaceutics 2021; 13:pharmaceutics13071076. [PMID: 34371767 PMCID: PMC8309201 DOI: 10.3390/pharmaceutics13071076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 12/04/2022] Open
Abstract
Cell therapy is a promising tool for treating central nervous system (CNS) disorders; though, the translational efforts are plagued by ineffective delivery methods. Due to the large contact surface with CNS and relatively easy access, the intrathecal route of administration is attractive in extensive or global diseases such as stroke or amyotrophic lateral sclerosis (ALS). However, the precision and efficacy of this approach are still a challenge. Hydrogels were introduced to minimize cell sedimentation and improve cell viability. At the same time, contrast agents were integrated to allow image-guided injection. Here, we report using manganese ions (Mn2+) as a dual agent for cross-linking alginate-based hydrogels and magnetic resonance imaging (MRI). We performed in vitro studies to test the Mn2+ alginate hydrogel formulations for biocompatibility, injectability, MRI signal retention time, and effect on cell viability. The selected formulation was injected intrathecally into pigs under MRI control. The biocompatibility test showed a lack of immune response, and cells suspended in the hydrogel showed greater viability than monolayer culture. Moreover, Mn2+-labeled hydrogel produced a strong T1 MRI signal, which enabled MRI-guided procedure. We confirmed the utility of Mn2+ alginate hydrogel as a carrier for cells in large animals and a contrast agent at the same time.
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Affiliation(s)
- Lukasz Kalkowski
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Dominika Golubczyk
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Joanna Kwiatkowska
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Piotr Holak
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, 10-719 Olsztyn, Poland;
| | - Kamila Milewska
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Miroslaw Janowski
- Center for Advanced Imaging Research, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (M.J.); (P.W.)
| | - Joaquim Miguel Oliveira
- a3B’s Research Group, I3Bs—Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal;
- ICVS/3B’s—PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Piotr Walczak
- Center for Advanced Imaging Research, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (M.J.); (P.W.)
| | - Izabela Malysz-Cymborska
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
- Correspondence: ; Tel.: +48-605118887
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Tamis A, Drapaca CS. Modeling NO Biotransport in Brain Using a Space-Fractional Reaction-Diffusion Equation. Front Physiol 2021; 12:644149. [PMID: 34248655 PMCID: PMC8267530 DOI: 10.3389/fphys.2021.644149] [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: 12/20/2020] [Accepted: 05/24/2021] [Indexed: 11/18/2022] Open
Abstract
Nitric oxide (NO) is a small gaseous molecule that is involved in some critical biochemical processes in the body such as the regulation of cerebral blood flow and pressure. Infection and inflammatory processes such as those caused by COVID-19 produce a disequilibrium in the NO bioavailability and/or a delay in the interactions of NO with other molecules contributing to the onset and evolution of cardiocerebrovascular diseases. A link between the SARS-CoV-2 virus and NO is introduced. Recent experimental observations of intracellular transport of metabolites in the brain and the NO trapping inside endothelial microparticles (EMPs) suggest the possibility of anomalous diffusion of NO, which may be enhanced by disease processes. A novel space-fractional reaction-diffusion equation to model NO biotransport in the brain is further proposed. The model incorporates the production of NO by synthesis in neurons and by mechanotransduction in the endothelial cells, and the loss of NO due to its reaction with superoxide and interaction with hemoglobin. The anomalous diffusion is modeled using a generalized Fick’s law that involves spatial fractional order derivatives. The predictive ability of the proposed model is investigated through numerical simulations. The implications of the methodology for COVID-19 outlined in the section “Discussion” are purely exploratory.
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Affiliation(s)
- Andrew Tamis
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA, United States
| | - Corina S Drapaca
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA, United States
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11
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In vivo multi-parametric manganese-enhanced MRI for detecting amyloid plaques in rodent models of Alzheimer's disease. Sci Rep 2021; 11:12419. [PMID: 34127752 PMCID: PMC8203664 DOI: 10.1038/s41598-021-91899-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/28/2021] [Indexed: 12/14/2022] Open
Abstract
Amyloid plaques are a hallmark of Alzheimer's disease (AD) that develop in its earliest stages. Thus, non-invasive detection of these plaques would be invaluable for diagnosis and the development and monitoring of treatments, but this remains a challenge due to their small size. Here, we investigated the utility of manganese-enhanced MRI (MEMRI) for visualizing plaques in transgenic rodent models of AD across two species: 5xFAD mice and TgF344-AD rats. Animals were given subcutaneous injections of MnCl2 and imaged in vivo using a 9.4 T Bruker scanner. MnCl2 improved signal-to-noise ratio but was not necessary to detect plaques in high-resolution images. Plaques were visible in all transgenic animals and no wild-types, and quantitative susceptibility mapping showed that they were more paramagnetic than the surrounding tissue. This, combined with beta-amyloid and iron staining, indicate that plaque MR visibility in both animal models was driven by plaque size and iron load. Longitudinal relaxation rate mapping revealed increased manganese uptake in brain regions of high plaque burden in transgenic animals compared to their wild-type littermates. This was limited to the rhinencephalon in the TgF344-AD rats, while it was most significantly increased in the cortex of the 5xFAD mice. Alizarin Red staining suggests that manganese bound to plaques in 5xFAD mice but not in TgF344-AD rats. Multi-parametric MEMRI is a simple, viable method for detecting amyloid plaques in rodent models of AD. Manganese-induced signal enhancement can enable higher-resolution imaging, which is key to visualizing these small amyloid deposits. We also present the first in vivo evidence of manganese as a potential targeted contrast agent for imaging plaques in the 5xFAD model of AD.
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12
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Verheggen ICM, Freeze WM, de Jong JJA, Jansen JFA, Postma AA, van Boxtel MPJ, Verhey FRJ, Backes WH. Application of contrast-enhanced magnetic resonance imaging in the assessment of blood-cerebrospinal fluid barrier integrity. Neurosci Biobehav Rev 2021; 127:171-183. [PMID: 33930471 DOI: 10.1016/j.neubiorev.2021.04.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/15/2021] [Accepted: 04/22/2021] [Indexed: 10/21/2022]
Abstract
VERHEGGEN, I.C.M., W. Freeze, J. de Jong, J. Jansen, A. Postma, M. van Boxtel, F. Verhey and W. Backes. The application of contrast-enhanced MRI in the assessment of blood-cerebrospinal fluid barrier integrity. Choroid plexus epithelial cells form a barrier that enables active, bidirectional exchange between the blood plasma and cerebrospinal fluid (CSF), known as the blood-CSF barrier (BCSFB). Through its involvement in CSF composition, the BCSFB maintains homeostasis in the central nervous system. While the relation between blood-brain barrier disruption, aging and neurodegeneration is extensively studied using contrast-enhanced MRI, applying this technique to investigate BCSFB disruption in age-related neurodegeneration has received little attention. This review provides an overview of the current status of contrast-enhanced MRI to assess BCSFB permeability. Post-contrast ventricular gadolinium enhancement has been used to indicate BCSFB permeability. Moreover, new techniques highly sensitive to low gadolinium concentrations in the CSF, for instance heavily T2-weighted imaging with cerebrospinal fluid suppression, seem promising. Also, attempts are made at using other contrast agents, such as manganese ions or very small superparamagnetic iron oxide particles, that seem to be cleared from the brain at the choroid plexus. Advancing and applying new developments such as these could progress the assessment of BCSFB integrity.
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Affiliation(s)
- Inge C M Verheggen
- Alzheimer Center Limburg, Department of Psychiatry and Neuropsychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands.
| | - Whitney M Freeze
- Alzheimer Center Limburg, Department of Psychiatry and Neuropsychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Radiology, Leiden University Medical Center, Leiden, P.O. Box 9600, 2300 RC Leiden, the Netherlands
| | - Joost J A de Jong
- School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands
| | - Jacobus F A Jansen
- School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands
| | - Alida A Postma
- School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands
| | - Martin P J van Boxtel
- Alzheimer Center Limburg, Department of Psychiatry and Neuropsychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands
| | - Frans R J Verhey
- Alzheimer Center Limburg, Department of Psychiatry and Neuropsychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands
| | - Walter H Backes
- School for Mental Health and Neuroscience (MHeNs), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands; School for Cardiovascular Diseases (CARIM), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands
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13
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Ahmad F, Treanor L, McGrath TA, Walker D, McInnes MD, Schieda N. Safety of Off‐Label Use of Ferumoxtyol as a Contrast Agent for
MRI
: A Systematic Review and Meta‐Analysis of Adverse Events. J Magn Reson Imaging 2020; 53:840-858. [DOI: 10.1002/jmri.27405] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/04/2020] [Accepted: 10/06/2020] [Indexed: 12/13/2022] Open
Affiliation(s)
- Faraz Ahmad
- Faculty of Medicine University of Ottawa Ottawa Ontario Canada
| | - Lee Treanor
- Faculty of Medicine University of Ottawa Ottawa Ontario Canada
| | | | - Daniel Walker
- Department of Radiology University of Ottawa Ottawa Ontario Canada
| | - Matthew D.F. McInnes
- University of Ottawa Department of Radiology and Epidemiology Ottawa Ontario Canada
- Clinical Epidemiology Program Ottawa Hospital Research Institute Ottawa Ontario Canada
| | - Nicola Schieda
- University of Ottawa Department of Radiology and Epidemiology Ottawa Ontario Canada
- Clinical Epidemiology Program Ottawa Hospital Research Institute Ottawa Ontario Canada
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14
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MnDPDP: Contrast Agent for Imaging and Protection of Viable Tissue. CONTRAST MEDIA & MOLECULAR IMAGING 2020; 2020:3262835. [PMID: 32994754 PMCID: PMC7501573 DOI: 10.1155/2020/3262835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/12/2020] [Indexed: 01/22/2023]
Abstract
The semistable chelate manganese (Mn) dipyridoxyl diphosphate (MnDPDP, mangafodipir), previously used as an intravenous (i.v.) contrast agent (Teslascan™, GE Healthcare) for Mn-ion-enhanced MRI (MEMRI), should be reappraised for clinical use but now as a diagnostic drug with cytoprotective properties. Approved for imaging of the liver and pancreas, MnDPDP enhances contrast also in other targets such as the heart, kidney, glandular tissue, and potentially retina and brain. Transmetallation releases paramagnetic Mn2+ for cellular uptake in competition with calcium (Ca2+), and intracellular (IC) macromolecular Mn2+ adducts lower myocardial T1 to midway between native values and values obtained with gadolinium (Gd3+). What is essential is that T1 mapping and, to a lesser degree, T1 weighted imaging enable quantification of viability at a cellular or even molecular level. IC Mn2+ retention for hours provides delayed imaging as another advantage. Examples in humans include quantitative imaging of cardiomyocyte remodeling and of Ca2+ channel activity, capabilities beyond the scope of Gd3+ based or native MRI. In addition, MnDPDP and the metabolite Mn dipyridoxyl diethyl-diamine (MnPLED) act as catalytic antioxidants enabling prevention and treatment of oxidative stress caused by tissue injury and inflammation. Tested applications in humans include protection of normal cells during chemotherapy of cancer and, potentially, of ischemic tissues during reperfusion. Theragnostic use combining therapy with delayed imaging remains to be explored. This review updates MnDPDP and its clinical potential with emphasis on the working mode of an exquisite chelate in the diagnosis of heart disease and in the treatment of oxidative stress.
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Suto DJ, Nair G, Sudarshana DM, Steele SU, Dwyer J, Beck ES, Ohayon J, McFarland H, Koretsky AP, Cortese ICM, Reich DS. Manganese-Enhanced MRI in Patients with Multiple Sclerosis. AJNR Am J Neuroradiol 2020; 41:1569-1576. [PMID: 32763897 DOI: 10.3174/ajnr.a6665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/31/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND PURPOSE Cellular uptake of the manganese ion, when administered as a contrast agent for MR imaging, can noninvasively highlight cellular activity and disease processes in both animals and humans. The purpose of this study was to explore the enhancement profile of manganese in patients with multiple sclerosis. MATERIALS AND METHODS Mangafodipir is a manganese chelate that was clinically approved for MR imaging of liver lesions. We present a case series of 6 adults with multiple sclerosis who were scanned at baseline with gadolinium, then injected with mangafodipir, and followed at variable time points thereafter. RESULTS Fourteen new lesions formed during or shortly before the study, of which 10 demonstrated manganese enhancement of varying intensity, timing, and spatial pattern. One gadolinium-enhancing extra-axial mass, presumably a meningioma, also demonstrated enhancement with manganese. Most interesting, manganese enhancement was detected in lesions that formed in the days after mangafodipir injection, and this enhancement persisted for several weeks, consistent with contrast coming from intracellular uptake of manganese. Some lesions demonstrated a diffuse pattern of manganese enhancement in an area larger than that of both gadolinium enhancement and T2-FLAIR signal abnormality. CONCLUSIONS This work demonstrates the first use of a manganese-based contrast agent to enhance MS lesions on MR imaging. Multiple sclerosis lesions were enhanced with a temporal and spatial profile distinct from that of gadolinium. Further experiments are necessary to uncover the mechanism of manganese contrast enhancement as well as cell-specific uptake.
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Affiliation(s)
- D J Suto
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - G Nair
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - D M Sudarshana
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - S U Steele
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - J Dwyer
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - E S Beck
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - J Ohayon
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - H McFarland
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - A P Koretsky
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - I C M Cortese
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - D S Reich
- From the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.
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Abstract
Patients with diabetes continue to suffer from impaired visual performance before the appearance of overt damage to the retinal microvasculature and later sight-threatening complications. This diabetic retinopathy (DR) has long been thought to start with endothelial cell oxidative stress. Yet newer data surprisingly finds that the avascular outer retina is the primary site of oxidative stress before microvascular histopathology in experimental DR. Importantly, correcting this early oxidative stress is sufficient to restore vision and mitigate the histopathology in diabetic models. However, translating these promising results into the clinic has been stymied by an absence of methods that can measure and optimize anti-oxidant treatment efficacy in vivo. Here, we review imaging approaches that address this problem. In particular, diabetes-induced oxidative stress impairs dark-light regulation of subretinal space hydration, which regulates the distribution of interphotoreceptor binding protein (IRBP). IRBP is a vision-critical, anti-oxidant, lipid transporter, and pro-survival factor. We show how optical coherence tomography can measure subretinal space oxidative stress thus setting the stage for personalizing anti-oxidant treatment and prevention of impactful declines and loss of vision in patients with diabetes.
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17
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Yang J, Li Q. Manganese-Enhanced Magnetic Resonance Imaging: Application in Central Nervous System Diseases. Front Neurol 2020; 11:143. [PMID: 32161572 PMCID: PMC7052353 DOI: 10.3389/fneur.2020.00143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/07/2020] [Indexed: 12/12/2022] Open
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) relies on the strong paramagnetism of Mn2+. Mn2+ is a calcium ion analog and can enter excitable cells through voltage-gated calcium channels. Mn2+ can be transported along the axons of neurons via microtubule-based fast axonal transport. Based on these properties, MEMRI is used to describe neuroanatomical structures, monitor neural activity, and evaluate axonal transport rates. The application of MEMRI in preclinical animal models of central nervous system (CNS) diseases can provide more information for the study of disease mechanisms. In this article, we provide a brief review of MEMRI use in CNS diseases ranging from neurodegenerative diseases to brain injury and spinal cord injury.
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Affiliation(s)
- Jun Yang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital & Cancer Center, Kunming, China
| | - Qinqing Li
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital & Cancer Center, Kunming, China
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18
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Blomlie V, Sivanandan R, Jynge P. Manganese Uptake and Accumulation in the Human Brain. AJNR Am J Neuroradiol 2020; 41:E3. [PMID: 31896571 DOI: 10.3174/ajnr.a6347] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- V Blomlie
- Department of Radiology Innlandet Trust Hospital, Gjøvik Hospital Gjøvik, Norway
| | - R Sivanandan
- Department of Radiology Innlandet Trust Hospital, Gjøvik Hospital Gjøvik, Norway
| | - P Jynge
- Department of Radiology Innlandet Trust Hospital, Gjøvik Hospital Gjøvik, Norway
- Norwegian University of Science and Technology Trondheim, Norway University of Linkøping Linkøping, Sweden
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