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Martínez-Tazo P, Santos A, Selim MK, Espinós-Soler E, De Santis S. Sex matters: The MouseX DW-ALLEN Atlas for mice diffusion-weighted MR imaging. Neuroimage 2024; 292:120573. [PMID: 38521211 DOI: 10.1016/j.neuroimage.2024.120573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/25/2024] Open
Abstract
Overcoming sex bias in preclinical research requires not only including animals of both sexes in the experiments, but also developing proper tools to handle such data. Recent work revealed sensitivity of diffusion-weighted MRI to glia morphological changes in response to inflammatory stimuli, opening up exciting possibilities to characterize inflammation in a variety of preclinical models of pathologies, the great majority of them available in mice. However, there are limited resources dedicated to mouse imaging, like those required for the data processing and analysis. To fill this gap, we build a mouse MRI template of both structural and diffusion contrasts, with anatomical annotation according to the Allen Mouse Brain Atlas, the most detailed public resource for mouse brain investigation. To achieve a standardized resource, we use a large cohort of animals in vivo, and include animals of both sexes. To prove the utility of this resource to integrate imaging and molecular data, we demonstrate significant association between the mean diffusivity from MRI and gene expression-based glia density. To demonstrate the need of equitable sex representation, we compared across sexes the warp fields needed to match a male-based template, and our template built with both sexes. Then, we use both templates for analysing mice imaging data obtained in animals of different ages, demonstrating that using a male-based template creates spurious significant sex effects, not present otherwise. All in all, our MouseX DW-ALLEN Atlas will be a widely useful resource getting us one step closer to equitable healthcare.
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Affiliation(s)
| | - Alexandra Santos
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
| | - Mohamed Kotb Selim
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
| | - Elena Espinós-Soler
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain
| | - Silvia De Santis
- Instituto de Neurociencias de Alicante, CSIC-UMH, San Juan de Alicante, Spain.
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Selim MK, Harel M, De Santis S, Perini I, Sommer WH, Heilig M, Zangen A, Canals S. Repetitive deep TMS in alcohol dependent patients halts progression of white matter changes in early abstinence. Psychiatry Clin Neurosci 2024; 78:176-185. [PMID: 38085120 DOI: 10.1111/pcn.13624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 10/04/2023] [Accepted: 11/15/2023] [Indexed: 03/13/2024]
Abstract
AIM Alcohol use disorder (AUD) is the most prevalent form of addiction, with a great burden on society and limited treatment options. A recent clinical trial reported significant clinical benefits of deep transcranial magnetic stimulations (Deep TMS) targeting midline frontocortical areas. However, the underlying biological substrate remained elusive. Here, we report the effect of Deep TMS on the microstructure of white matter. METHODS A total of 37 (14 females) AUD treatment-seeking patients were randomized to sham or active Deep TMS. Twenty (six females) age-matched healthy controls were included. White matter integrity was evaluated by fractional anisotropy (FA). Secondary measures included brain functional connectivity and self-reports of craving and drinking units in the 3 months of follow-up period. RESULTS White matter integrity was compromised in patients with AUD relative to healthy controls, as reflected by the widespread reduction in FA. This alteration progressed during early abstinence (3 weeks) in the absence of Deep TMS. However, stimulation of midline frontocortical areas arrested the progression of FA changes in association with decreased craving and relapse scores. Reconstruction of axonal tracts from white-matter regions showing preserved FA values identified cortical regions in the posterior cingulate and dorsomedial prefrontal cortices where functional connectivity was persistently modulated. These effects were absent in the sham-stimulated group. CONCLUSIONS By integrating brain structure and function to characterize the alcohol-dependent brain, this study provides mechanistic insights into the TMS effect, pointing to myelin plasticity as a possible mediator.
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Affiliation(s)
- Mohamed Kotb Selim
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Miguel Hernández (UMH), Sant Joan d'Alacant, Spain
| | - Maayan Harel
- Department of Life Sciences, Ben-Gurion University, Beer Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University, Beer Sheva, Israel
| | - Silvia De Santis
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Miguel Hernández (UMH), Sant Joan d'Alacant, Spain
| | - Irene Perini
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University Hospital, Linköping, Sweden
| | - Wolfgang H Sommer
- Department of Addiction Medicine, Department of Clinical Psychology, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Markus Heilig
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University Hospital, Linköping, Sweden
| | - Abraham Zangen
- Department of Life Sciences, Ben-Gurion University, Beer Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University, Beer Sheva, Israel
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Miguel Hernández (UMH), Sant Joan d'Alacant, Spain
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Cerdán Cerdá A, Toschi N, Treaba CA, Barletta V, Herranz E, Mehndiratta A, Gomez-Sanchez JA, Mainero C, De Santis S. A translational MRI approach to validate acute axonal damage detection as an early event in multiple sclerosis. eLife 2024; 13:e79169. [PMID: 38192199 PMCID: PMC10776086 DOI: 10.7554/elife.79169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 12/05/2023] [Indexed: 01/10/2024] Open
Abstract
Axonal degeneration is a central pathological feature of multiple sclerosis and is closely associated with irreversible clinical disability. Current noninvasive methods to detect axonal damage in vivo are limited in their specificity and clinical applicability, and by the lack of proper validation. We aimed to validate an MRI framework based on multicompartment modeling of the diffusion signal (AxCaliber) in rats in the presence of axonal pathology, achieved through injection of a neurotoxin damaging the neuronal terminal of axons. We then applied the same MRI protocol to map axonal integrity in the brain of multiple sclerosis relapsing-remitting patients and age-matched healthy controls. AxCaliber is sensitive to acute axonal damage in rats, as demonstrated by a significant increase in the mean axonal caliber along the targeted tract, which correlated with neurofilament staining. Electron microscopy confirmed that increased mean axonal diameter is associated with acute axonal pathology. In humans with multiple sclerosis, we uncovered a diffuse increase in mean axonal caliber in most areas of the normal-appearing white matter, preferentially affecting patients with short disease duration. Our results demonstrate that MRI-based axonal diameter mapping is a sensitive and specific imaging biomarker that links noninvasive imaging contrasts with the underlying biological substrate, uncovering generalized axonal damage in multiple sclerosis as an early event.
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Affiliation(s)
| | - Nicola Toschi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
- Department of Biomedicine and Prevention, University of Rome Tor VergataRomeItaly
| | - Constantina A Treaba
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
| | - Valeria Barletta
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
| | - Elena Herranz
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
| | - Ambica Mehndiratta
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
| | - Jose A Gomez-Sanchez
- Instituto de Neurociencias de Alicante, CSIC-UMHSan Juan de AlicanteSpain
- Instituto de Investigación Sanitaria y Biomédica de Alicante (ISABIAL)AlicanteSpain
- Millennium Nucleus for the Study of Pain (MiNuSPain)SantiagoChile
| | - Caterina Mainero
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical SchoolBostonUnited States
| | - Silvia De Santis
- Instituto de Neurociencias de Alicante, CSIC-UMHSan Juan de AlicanteSpain
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Pérez-Cervera L, De Santis S, Marcos E, Ghorbanzad-Ghaziany Z, Trouvé-Carpena A, Selim MK, Pérez-Ramírez Ú, Pfarr S, Bach P, Halli P, Kiefer F, Moratal D, Kirsch P, Sommer WH, Canals S. Alcohol-induced damage to the fimbria/fornix reduces hippocampal-prefrontal cortex connection during early abstinence. Acta Neuropathol Commun 2023; 11:101. [PMID: 37344865 PMCID: PMC10286362 DOI: 10.1186/s40478-023-01597-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/30/2023] [Indexed: 06/23/2023] Open
Abstract
INTRODUCTION Alcohol dependence is characterized by a gradual reduction in cognitive control and inflexibility to contingency changes. The neuroadaptations underlying this aberrant behavior are poorly understood. Using an animal model of alcohol use disorders (AUD) and complementing diffusion-weighted (dw)-MRI with quantitative immunohistochemistry and electrophysiological recordings, we provide causal evidence that chronic intermittent alcohol exposure affects the microstructural integrity of the fimbria/fornix, decreasing myelin basic protein content, and reducing the effective communication from the hippocampus (HC) to the prefrontal cortex (PFC). Using a simple quantitative neural network model, we show how disturbed HC-PFC communication may impede the extinction of maladaptive memories, decreasing flexibility. Finally, combining dw-MRI and psychometric data in AUD patients, we discovered an association between the magnitude of microstructural alteration in the fimbria/fornix and the reduction in cognitive flexibility. Overall, these findings highlight the vulnerability of the fimbria/fornix microstructure in AUD and its potential contribution to alcohol pathophysiology. Fimbria vulnerability to alcohol underlies hippocampal-prefrontal cortex dysfunction and correlates with cognitive impairment.
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Affiliation(s)
- Laura Pérez-Cervera
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain
| | - Silvia De Santis
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain
| | - Encarni Marcos
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain
| | - Zahra Ghorbanzad-Ghaziany
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain
- Radiation Science and Biomedical Imaging, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - Alejandro Trouvé-Carpena
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain
| | - Mohamed Kotb Selim
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain
| | - Úrsula Pérez-Ramírez
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Simone Pfarr
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Patrick Bach
- Department of Addiction Medicine, Department of Clinical Psychology, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Patrick Halli
- Department of Psychology, University of Heidelberg, Heidelberg, Germany
| | - Falk Kiefer
- Department of Addiction Medicine, Department of Clinical Psychology, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - David Moratal
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Peter Kirsch
- Department of Psychology, University of Heidelberg, Heidelberg, Germany
| | - Wolfgang H Sommer
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical faculty Mannheim, University of Heidelberg, Mannheim, Germany.
- Department of Addiction Medicine, Department of Clinical Psychology, Medical Faculty Mannheim, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany.
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d'Alacant, Alicante, Spain.
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Garcia-Hernandez R, Cerdán Cerdá A, Trouve Carpena A, Drakesmith M, Koller K, Jones DK, Canals S, De Santis S. Mapping microglia and astrocyte activation in vivo using diffusion MRI. Sci Adv 2022; 8:eabq2923. [PMID: 35622913 PMCID: PMC9140964 DOI: 10.1126/sciadv.abq2923] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/13/2022] [Indexed: 05/04/2023]
Abstract
While glia are increasingly implicated in the pathophysiology of psychiatric and neurodegenerative disorders, available methods for imaging these cells in vivo involve either invasive procedures or positron emission tomography radiotracers, which afford low resolution and specificity. Here, we present a noninvasive diffusion-weighted magnetic resonance imaging (MRI) method to image changes in glia morphology. Using rat models of neuroinflammation, degeneration, and demyelination, we demonstrate that diffusion-weighted MRI carries a fingerprint of microglia and astrocyte activation and that specific signatures from each population can be quantified noninvasively. The method is sensitive to changes in glia morphology and proliferation, providing a quantitative account of neuroinflammation, regardless of the existence of a concomitant neuronal loss or demyelinating injury. We prove the translational value of the approach showing significant associations between MRI and histological microglia markers in humans. This framework holds the potential to transform basic and clinical research by clarifying the role of inflammation in health and disease.
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Affiliation(s)
| | | | | | - Mark Drakesmith
- CUBRIC, School of Psychology, Cardiff University, Cardiff, UK
| | - Kristin Koller
- CUBRIC, School of Psychology, Cardiff University, Cardiff, UK
| | - Derek K. Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff, UK
| | - Santiago Canals
- Instituto de Neurociencias, CSIC/UMH, San Juan de Alicante, Alicante, Spain
| | - Silvia De Santis
- Instituto de Neurociencias, CSIC/UMH, San Juan de Alicante, Alicante, Spain
- CUBRIC, School of Psychology, Cardiff University, Cardiff, UK
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Eed A, Cerdán Cerdá A, Lerma J, De Santis S. Diffusion-weighted MRI in neurodegenerative and psychiatric animal models: Experimental strategies and main outcomes. J Neurosci Methods 2020; 343:108814. [PMID: 32569785 DOI: 10.1016/j.jneumeth.2020.108814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/31/2022]
Abstract
Preclinical MRI approaches constitute a key tool to study a wide variety of neurological and psychiatric illnesses, allowing a more direct investigation of the disorder substrate and, at the same time, the possibility of back-translating such findings to human subjects. However, the lack of consensus on the optimal experimental scheme used to acquire the data has led to relatively high heterogeneity in the choice of protocols, which can potentially impact the comparison between results obtained by different groups, even using the same animal model. This is especially true for diffusion-weighted MRI data, where certain experimental choices can impact not only on the accuracy and precision of the extracted biomarkers, but also on their biological meaning. With this in mind, we extensively examined preclinical imaging studies that used diffusion-weighted MRI to investigate neurodegenerative, neurodevelopmental and psychiatric disorders in rodent models. In this review, we discuss the main findings for each preclinical model, with a special focus on the analysis and comparison of the different acquisition strategies used across studies and their impact on the heterogeneity of the findings.
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Affiliation(s)
- Amr Eed
- Instituto de Neurociencias, CSIC, UMH, San Juan de Alicante, Alicante, Spain
| | | | - Juan Lerma
- Instituto de Neurociencias, CSIC, UMH, San Juan de Alicante, Alicante, Spain
| | - Silvia De Santis
- Instituto de Neurociencias, CSIC, UMH, San Juan de Alicante, Alicante, Spain; CUBRIC, School of Psychology, Cardiff University, Cardiff, UK.
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De Santis S, Cosa-Linan A, Garcia-Hernandez R, Dmytrenko L, Vargova L, Vorisek I, Stopponi S, Bach P, Kirsch P, Kiefer F, Ciccocioppo R, Sykova E, Moratal D, Sommer WH, Canals S. Chronic alcohol consumption alters extracellular space geometry and transmitter diffusion in the brain. Sci Adv 2020; 6:eaba0154. [PMID: 32637601 PMCID: PMC7314532 DOI: 10.1126/sciadv.aba0154] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 05/14/2020] [Indexed: 05/08/2023]
Abstract
Already moderate alcohol consumption has detrimental long-term effects on brain function. However, how alcohol produces its potent addictive effects despite being a weak reinforcer is a poorly understood conundrum that likely hampers the development of successful interventions to limit heavy drinking. In this translational study, we demonstrate widespread increased mean diffusivity in the brain gray matter of chronically drinking humans and rats. These alterations appear soon after drinking initiation in rats, persist into early abstinence in both species, and are associated with a robust decrease in extracellular space tortuosity explained by a microglial reaction. Mathematical modeling of the diffusivity changes unveils an increased spatial reach of extrasynaptically released transmitters like dopamine that may contribute to alcohol's progressively enhanced addictive potency.
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Affiliation(s)
- Silvia De Santis
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d’Alacant, Spain
| | - Alejandro Cosa-Linan
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d’Alacant, Spain
- Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
| | - Raquel Garcia-Hernandez
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d’Alacant, Spain
| | - Lesia Dmytrenko
- Institute of Experimental Medicine AS CR, 142 20 Prague 4, Czech Republic
| | - Lydia Vargova
- Institute of Experimental Medicine AS CR, 142 20 Prague 4, Czech Republic
- Charles University, 2nd Faculty of Medicine, 150 06 Prague 5, Czech Republic
| | - Ivan Vorisek
- Charles University, 2nd Faculty of Medicine, 150 06 Prague 5, Czech Republic
| | | | - Patrick Bach
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
| | - Peter Kirsch
- Department of Clinical Psychology, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
| | - Falk Kiefer
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
| | | | - Eva Sykova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - David Moratal
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Wolfgang H. Sommer
- Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d’Alacant, Spain
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8
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Gonzalez-Escamilla G, Ciolac D, De Santis S, Radetz A, Fleischer V, Droby A, Roebroeck A, Meuth SG, Muthuraman M, Groppa S. Gray matter network reorganization in multiple sclerosis from 7-Tesla and 3-Tesla MRI data. Ann Clin Transl Neurol 2020; 7:543-553. [PMID: 32255566 PMCID: PMC7187719 DOI: 10.1002/acn3.51029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/13/2020] [Accepted: 03/13/2020] [Indexed: 12/21/2022] Open
Abstract
Objective The objective of this study was to determine the ability of 7T‐MRI for characterizing brain tissue integrity in early relapsing‐remitting MS patients compared to conventional 3T‐MRI and to investigate whether 7T‐MRI improves the performance for detecting cortical gray matter neurodegeneration and its associated network reorganization dynamics. Methods Seven early relapsing‐remitting MS patients and seven healthy individuals received MRI at 7T and 3T, whereas 30 and 40 healthy controls underwent separate 3T‐ and 7T‐MRI sessions, respectively. Surface‐based cortical thickness (CT) and gray‐to‐white contrast (GWc) measures were used to model morphometric networks, analyzed with graph theory by means of modularity, clustering coefficient, path length, and small‐worldness. Results 7T‐MRI had lower CT and higher GWc compared to 3T‐MRI in MS. CT and GWc measures robustly differentiated MS from controls at 3T‐MRI. 7T‐ and 3T‐MRI showed high regional correspondence for CT (r = 0.72, P = 2e‐78) and GWc (r = 0.83, P = 5.5e‐121) in MS patients. MS CT and GWc morphometric networks at 7T‐MRI showed higher modularity, clustering coefficient, and small‐worldness than 3T, also compared to controls. Interpretation 7T‐MRI allows to more precisely quantify morphometric alterations across the cortical mantle and captures more sensitively MS‐related network reorganization. Our findings open new avenues to design more accurate studies quantifying brain tissue loss and test treatment effects on tissue repair.
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Affiliation(s)
- Gabriel Gonzalez-Escamilla
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dumitru Ciolac
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Angela Radetz
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Vinzenz Fleischer
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Amgad Droby
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Alard Roebroeck
- Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Sven G Meuth
- Department of Neurology with Institute of Translational Neurology, University of Münster, Münster, Germany
| | - Muthuraman Muthuraman
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sergiu Groppa
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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De Santis S, Herranz E, Treaba CA, Barletta V, Mehndiratta A, Mainero C, Toschi N. Whole brain in vivo axonal diameter mapping in multiple sclerosis. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2019:204-207. [PMID: 31945878 DOI: 10.1109/embc.2019.8856433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Traditional techniques based on diffusion MR imaging suffer from extremely low specificity in separating disease-related alterations in white matter microstructure, which can involve multiple phenomena including axonal loss, demyelination and changes in axonal size. Multi-shell diffusion MRI is able to greatly increase specificity by concomitantly exploring multiple diffusion timescales. If multi-shell acquisition is combined with an exploration of different diffusion times, diffusion data allows the estimation of sophisticated compartmental models, which provide greatly enhanced specificity to the presence of different tissue sub-compartments, as well as estimates of intra-voxel axonal diameter distributions. In this paper, we apply a multiple-b-value, high angular resolution multi-shell diffusion MRI protocol with varying diffusion times to a cohort of multiple sclerosis (MS) patients and compare them to a population of healthy controls. By fitting the AxCaliber model, we are able to extract indices for axonal diameter across the whole brain. We show that MS is associated with widespread increases of axonal diameter and that our axonal diameter estimation provides the highest discrimination power for local alterations in normal-appearing white matter in MS compared to controls. AxCaliber has the potential to disentangle microstructural alterations in MS and holds great promises to become a sensitive and specific non-invasive biomarker of irreversible disease progression.
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Toschi N, Gisbert RA, Passamonti L, Canals S, De Santis S. Multishell diffusion imaging reveals sex-specific trajectories of early white matter degeneration in normal aging. Neurobiol Aging 2019; 86:191-200. [PMID: 31902522 DOI: 10.1016/j.neurobiolaging.2019.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 10/08/2019] [Accepted: 11/21/2019] [Indexed: 02/08/2023]
Abstract
During aging, human white matter (WM) is subject to dynamic structural changes which have a deep impact on healthy and pathological evolution of the brain through the lifespan; characterizing this pattern is of key importance for understanding brain development, maturation, and aging as well as for studying its pathological alterations. Diffusion magnetic resonance imaging (MRI) can provide a quantitative assessment of the white-matter microstructural organization that characterizes these trajectories. Here, we use both conventional and advanced diffusion MRI in a cohort of 91 individuals (age range: 13-62 years) to study region- and sex-specific features of WM microstructural integrity in healthy aging. We focus on the age at which microstructural imaging parameters invert their development trend as the time point which marks the onset of microstructural decline in WM. Importantly, our results indicate that age-related brain changes begin earlier in males than females and affect more frontal regions-in accordance with evolutionary theories and numerous evidences across non-MRI domains. Advanced diffusion MRI reveals age-related WM modification patterns which cannot be detected using conventional diffusion tensor imaging.
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Affiliation(s)
- Nicola Toschi
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | | | - Luca Passamonti
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Istituto di Bioimmagini e Fisiologia Molecolare (IBFM), Consiglio Nazionale delle Ricerche (CNR), Segrate, Milano, Italia
| | - Santiago Canals
- Instituto de Neurociencias de Alicante (CSIC-UMH), San Juan de Alicante, Spain
| | - Silvia De Santis
- Instituto de Neurociencias de Alicante (CSIC-UMH), San Juan de Alicante, Spain; Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University, Cardiff, UK.
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Abstract
While alcohol's detrimental effects on the brain are widely acknowledged, diagnostic markers for detection and monitoring alcohol-induced brain damage are lacking. A recent study showed that diffusion tensor imaging can be used to monitor this damage and characterized the progression of the observed changes into early abstinence. Here, we discuss the main findings of that study and highlight current technical limitations which, once addressed, can pave the way to the development of new powerful diagnostic markers for alcohol-induced brain damage.
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Affiliation(s)
- Silvia De Santis
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d’Alacant 03550, Spain
| | | | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Sant Joan d’Alacant 03550, Spain
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De Santis S, Bach P, Pérez-Cervera L, Cosa-Linan A, Weil G, Vollstädt-Klein S, Hermann D, Kiefer F, Kirsch P, Ciccocioppo R, Sommer WH, Canals S. Microstructural White Matter Alterations in Men With Alcohol Use Disorder and Rats With Excessive Alcohol Consumption During Early Abstinence. JAMA Psychiatry 2019; 76:749-758. [PMID: 30942831 PMCID: PMC6583663 DOI: 10.1001/jamapsychiatry.2019.0318] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
IMPORTANCE Although the detrimental effects of alcohol on the brain are widely acknowledged, observed structural changes are highly heterogeneous, and diagnostic markers for characterizing alcohol-induced brain damage, especially in early abstinence, are lacking. This heterogeneity, likely contributed to by comorbidity factors in patients with alcohol use disorder (AUD), challenges a direct link of brain alterations to the pathophysiology of alcohol misuse. Translational studies in animal models may help bridge this causal gap. OBJECTIVE To compare microstructural properties extracted using advanced diffusion tensor imaging (DTI) in the brains of patients with AUD and a well-controlled rat model of excessive alcohol consumption and monitor the progression of these properties during early abstinence. DESIGN, SETTING, AND PARTICIPANTS This prospective observational study included 2 cohorts of hospitalized patients with AUD (n = 91) and Marchigian Sardinian alcohol-preferring (msP) rats (n = 27). In humans cross-sectional comparison were performed with control participants (healthy men [n = 36]) and longitudinal comparisons between different points after alcohol withdrawal. In rats, longitudinal comparisons were performed in alcohol-exposed (n = 27) and alcohol-naive msP rats (n = 9). Human data were collected from March 7, 2013, to August 3, 2016, and analyzed from June 14, 2017, to May 31, 2018; rat data were collected from January 15, 2017, to May 12, 2017, and analyzed from October 11, 2017, to May 28, 2018. MAIN OUTCOMES AND MEASURES Fractional anisotropy and other DTI measures of white matter properties after long-term alcohol exposure and during early abstinence in both species and clinical and demographic variables and time of abstinence after discharge from hospital in patients. RESULTS The analysis included 91 men with AUD (mean [SD] age, 46.1 [9.6] years) and 27 male rats in the AUD groups and 36 male controls (mean [SD] age, 41.7 [9.3] years) and 9 male control rats. Comparable DTI alterations were found between alcohol and control groups in both species, with a preferential involvement of the corpus callosum (fractional anisotropy Cohen d = -0.84 [P < .01] corrected in humans and Cohen d = -1.17 [P < .001] corrected in rats) and the fornix/fimbria (fractional anisotropy Cohen d = -0.92 [P < .001] corrected in humans and d = -1.24 [P < .001] corrected in rats). Changes in DTI were associated with preadmission consumption patterns in patients and progress in humans and rats during 6 weeks of abstinence. Mathematical modeling shows this process to be compatible with a sustained demyelination and/or a glial reaction. CONCLUSIONS AND RELEVANCE Using a translational DTI approach, comparable white matter alterations were found in patients with AUD and rats with long-term alcohol consumption. In humans and rats, a progression of DTI alterations into early abstinence (2-6 weeks) suggests an underlying process that evolves soon after cessation of alcohol use.
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Affiliation(s)
- Silvia De Santis
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas–Universidad Miguel Hernández de Elche, Sant Joan d’Alacant, Alicante, Spain
| | - Patrick Bach
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Laura Pérez-Cervera
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas–Universidad Miguel Hernández de Elche, Sant Joan d’Alacant, Alicante, Spain
| | - Alejandro Cosa-Linan
- Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Georg Weil
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Sabine Vollstädt-Klein
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Derik Hermann
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Falk Kiefer
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Peter Kirsch
- Department of Clinical Psychology, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | | | - Wolfgang H. Sommer
- Department of Addiction Medicine, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany,Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany
| | - Santiago Canals
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas–Universidad Miguel Hernández de Elche, Sant Joan d’Alacant, Alicante, Spain
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13
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Affiliation(s)
- Silvia De Santis
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, 03550 San Juan de Alicante, Spain
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, 03550 San Juan de Alicante, Spain.
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De Santis S, Granberg T, Ouellette R, Treaba CA, Herranz E, Fan Q, Mainero C, Toschi N. Evidence of early microstructural white matter abnormalities in multiple sclerosis from multi-shell diffusion MRI. Neuroimage Clin 2019; 22:101699. [PMID: 30739842 PMCID: PMC6370560 DOI: 10.1016/j.nicl.2019.101699] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/07/2018] [Accepted: 01/28/2019] [Indexed: 12/29/2022]
Abstract
Irreversible white matter (WM) damage, including severe demyelination and axonal loss, is a main determinant of long-term disability in multiple sclerosis (MS). Non-invasive detection of changes in microstructural WM integrity in the disease is challenging since commonly used imaging metrics lack the necessary sensitivity, especially in the early phase of the disease. This study aims at assessing microstructural WM abnormalities in early-stage MS by using ultra-high gradient strength multi-shell diffusion MRI and the restricted signal fraction (FR) from the Composite Hindered and Restricted Model of Diffusion (CHARMED), a metric sensitive to the volume fraction of axons. In 22 early MS subjects (disease duration ≤5 years) and 15 age-matched healthy controls, restricted fraction estimates were obtained through the CHARMED model along with conventional Diffusion Tensor Imaging (DTI) metrics. All imaging parameters were compared cross-sectionally between the MS subjects and controls both in WM lesions and normal-appearing white matter (NAWM). We found a significant reduction in FR focally in WM lesions and widespread in the NAWM in MS patients relative to controls (corrected p < .05). Signal fraction changes in NAWM were not driven by perilesional tissue, nor were they influenced by proximity to the ventricles, challenging the hypothesis of an outside-in pathological process driven by CSF-mediated immune cytotoxic factors. No significant differences were found in conventional DTI parameters. In a cross-validated classification task, FR showed the largest effect size and outperformed all other diffusion imaging metrics in discerning lesions from contralateral NAWM. Taken together, our data provide evidence for the presence of widespread microstructural changes in the NAWM in early MS stages that are, at least in part, unrelated to focal demyelinating lesions. Interestingly, these pathological changes were not yet detectable by conventional diffusion imaging at this early disease stage, highlighting the sensitivity and value of multi-shell diffusion imaging for better characterizing axonal microstructure in MS.
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Affiliation(s)
- Silvia De Santis
- Instituto de Neurociencias de Alicante (CSIC-UMH), San Juan de Alicante, Spain; Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University, Cardiff, UK
| | - Tobias Granberg
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Radiology, Karolinska University Hospital, Stockholm, Sweden; Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Russell Ouellette
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Constantina A Treaba
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Elena Herranz
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Qiuyun Fan
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Caterina Mainero
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Nicola Toschi
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA.; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
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Toschi N, De Santis S, Granberg T, Ouellette R, Treaba CA, Herranz E, Mainero C. Evidence for Progressive Microstructural Damage in Early Multiple Sclerosis by Multi-Shell Diffusion Magnetic Resonance Imaging. Neuroscience 2019; 403:27-34. [PMID: 30708049 DOI: 10.1016/j.neuroscience.2019.01.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 01/12/2019] [Accepted: 01/14/2019] [Indexed: 12/21/2022]
Abstract
In multiple sclerosis (MS), it would be of clinical value to be able to track the progression of axonal pathology, especially before the manifestation of clinical disability. However, non-invasive evaluation of short-term longitudinal progression of white matter integrity is challenging. This study aims at assessing longitudinal changes in the restricted (i.e. intracellular) diffusion signal fraction (FR) in early-stage MS by using ultra-high gradient strength multi-shell diffusion magnetic resonance imaging. In 11 early MS subjects (disease duration ≤5 years), FR was obtained at two timepoints (one year apart) through the Composite Hindered and Restricted Model of Diffusion, along with conventional Diffusion Tensor Imaging metrics. At follow-up, no statistically significant change was detected in clinical variables, while all imaging metrics showed statistically significant longitudinal changes (p < 0.01, corrected for multiple comparisons) in widespread regions in normal-appearing white matter (NAWM). The most extensive longitudinal changes were observed in FR, including areas known to include a large fraction of crossing fibers. Furthermore, FR was also the only metric showing significant longitudinal changes in lesions that were present at both time points (p = 0.007), with no significant differences found for conventional diffusion metrics. Finally, FR was the only diffusion metric (as compared to Diffusion Tensor Imaging) that revealed pre-lesional changes already present at baseline. Taken together, our data provide evidence for progressive microstructural damage in the NAWM of early MS cases detectable already at 1-year follow-up. Our study highlights the value of multi-shell diffusion imaging for sensitive tracking of disease evolution in MS before any clinical changes are observed. This article is part of a Special Issue entitled: SI: MRI and Neuroinflammation.
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Affiliation(s)
- Nicola Toschi
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
| | - Silvia De Santis
- Instituto de Neurociencias de Alicante (CSIC-UMH), San Juan de Alicante, Spain; Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University, Cardiff, UK
| | - Tobias Granberg
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Russell Ouellette
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Constantina A Treaba
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Elena Herranz
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
| | - Caterina Mainero
- Athinoula A. Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, USA
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De Santis S, Granberg T, Ouellette R, Treaba CA, Herranz E, Mainero C, Toschi N. Early axonal damage in normal appearing white matter in multiple sclerosis: Novel insights from multi-shell diffusion MRI. Annu Int Conf IEEE Eng Med Biol Soc 2018; 2017:3024-3027. [PMID: 29060535 DOI: 10.1109/embc.2017.8037494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Conventional diffusion-weighted MR imaging techniques provide limited specificity in disentangling disease-related microstructural alterations involving changes in both axonal density and myelination. By simultaneously probing multiple diffusion regimens, multi-shell diffusion MRI is capable of increasing specificity to different tissue sub-compartments and hence separate different contributions to changes in diffusion-weighted signal attenuation. Advanced multi-shell diffusion models impose significant requirements on the amount of diffusion weighting (i.e. gradient coil performance) and angular resolution (i.e. in-scanner subject time), which commonly limits their applicability in a clinical setting. In this paper, we apply a high-b-value, high angular resolution multi-shell diffusion MRI protocol to a population of early multiple sclerosis (MS) patients and healthy controls. Through the Composite Hindered and Restricted Model of Diffusion (CHARMED) model, we extract indices for axonal density as well as parameters sensitive to myelin. We demonstrate increased sensitivity to microstructural changes in normal appearing white matter and in lesions in MS as compared to traditional models like DTI. These changes appear to be predominantly in axonal density, pointing towards the existence of axonal damage mechanisms in early MS.
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De Santis S, Assaf Y, Jeurissen B, Jones DK, Roebroeck A. T1 relaxometry of crossing fibres in the human brain. Neuroimage 2016; 141:133-142. [PMID: 27444568 PMCID: PMC5035137 DOI: 10.1016/j.neuroimage.2016.07.037] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 07/13/2016] [Accepted: 07/15/2016] [Indexed: 12/13/2022] Open
Abstract
A comprehensive tract-based characterisation of white matter should include the ability to quantify myelin and axonal attributes irrespective of the complexity of fibre organisation within the voxel. Recently, a new experimental framework that combines inversion recovery and diffusion MRI, called inversion recovery diffusion tensor imaging (IR-DTI), was introduced and applied in an animal study. IR-DTI provides the ability to assign to each unique fibre population within a voxel a specific value of the longitudinal relaxation time, T1, which is a proxy for myelin content. Here, we apply the IR-DTI approach to the human brain in vivo on 7 healthy subjects for the first time. We demonstrate that the approach is able to measure differential tract properties in crossing fibre areas, reflecting the different myelination of tracts. We also show that tract-specific T1 has less inter-subject variability compared to conventional T1 in areas of crossing fibres, suggesting increased specificity to distinct fibre populations. Finally we show in simulations that changes in myelination selectively affecting one fibre bundle in crossing fibre areas can potentially be detected earlier using IR-DTI. We apply the inversion recovery DTI approach to the human brain in vivo for the first time. We demonstrate that IR-DTI can measure tract-specific T1 in crossing fibres. IR-DTI T1 has less inter-subject variability compared to conventional T1 in crossing fibres. Changes in myelination affecting one fibre in crossing fibres can be detected earlier using IR-DTI.
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Affiliation(s)
- Silvia De Santis
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF24 4HQ,UK; Maastricht University, Maastricht, The Netherlands.
| | - Yaniv Assaf
- Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ben Jeurissen
- iMinds-Vision Lab, Dept. of Physics, University of Antwerp, Antwerp, Belgium
| | - Derek K Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF24 4HQ,UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT,UK
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De Santis S, Jones DK, Roebroeck A. Including diffusion time dependence in the extra-axonal space improves in vivo estimates of axonal diameter and density in human white matter. Neuroimage 2016; 130:91-103. [PMID: 26826514 PMCID: PMC4819719 DOI: 10.1016/j.neuroimage.2016.01.047] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 01/14/2016] [Accepted: 01/20/2016] [Indexed: 12/01/2022] Open
Abstract
Axonal density and diameter are two fundamental properties of brain white matter. Recently, advanced diffusion MRI techniques have made these two parameters accessible in vivo. However, the techniques available to estimate such parameters are still under development. For example, current methods to map axonal diameters capture relative trends over different structures, but consistently over-estimate absolute diameters. Axonal density estimates are more accessible experimentally, but different modeling approaches exist and the impact of the experimental parameters has not been thoroughly quantified, potentially leading to incompatibility of results obtained in different studies using different techniques. Here, we characterise the impact of diffusion time on axonal density and diameter estimates using Monte Carlo simulations and STEAM diffusion MRI at 7 T on 9 healthy volunteers. We show that axonal density and diameter estimates strongly depend on diffusion time, with diameters almost invariably overestimated and density both over and underestimated for some commonly used models. Crucially, we also demonstrate that these biases are reduced when the model accounts for diffusion time dependency in the extra-axonal space. For axonal density estimates, both upward and downward bias in different situations are removed by modeling extra-axonal time-dependence, showing increased accuracy in these estimates. For axonal diameter estimates, we report increased accuracy in ground truth simulations and axonal diameter estimates decreased away from high values given by earlier models and towards known values in the human corpus callosum when modeling extra-axonal time-dependence. Axonal diameter feasibility under both advanced and clinical settings is discussed in the light of the proposed advances.
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Affiliation(s)
- Silvia De Santis
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Derek K Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
| | - Alard Roebroeck
- Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands
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Goveas J, O'Dwyer L, Mascalchi M, Cosottini M, Diciotti S, De Santis S, Passamonti L, Tessa C, Toschi N, Giannelli M. Diffusion-MRI in neurodegenerative disorders. Magn Reson Imaging 2015; 33:853-76. [PMID: 25917917 DOI: 10.1016/j.mri.2015.04.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 04/18/2015] [Accepted: 04/19/2015] [Indexed: 12/11/2022]
Abstract
The ability to image the whole brain through ever more subtle and specific methods/contrasts has come to play a key role in understanding the basis of brain abnormalities in several diseases. In magnetic resonance imaging (MRI), "diffusion" (i.e. the random, thermally-induced displacements of water molecules over time) represents an extraordinarily sensitive contrast mechanism, and the exquisite structural detail it affords has proven useful in a vast number of clinical as well as research applications. Since diffusion-MRI is a truly quantitative imaging technique, the indices it provides can serve as potential imaging biomarkers which could allow early detection of pathological alterations as well as tracking and possibly predicting subtle changes in follow-up examinations and clinical trials. Accordingly, diffusion-MRI has proven useful in obtaining information to better understand the microstructural changes and neurophysiological mechanisms underlying various neurodegenerative disorders. In this review article, we summarize and explore the main applications, findings, perspectives as well as challenges and future research of diffusion-MRI in various neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease and degenerative ataxias.
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Affiliation(s)
- Joseph Goveas
- Department of Psychiatry and Behavioral Medicine, and Institute for Health and Society, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Laurence O'Dwyer
- Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe University, Frankfurt, Germany
| | - Mario Mascalchi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy; Quantitative and Functional Neuroradiology Research Program at Meyer Children and Careggi Hospitals of Florence, Florence, Italy
| | - Mirco Cosottini
- Department of Translational Research and New Surgical and Medical Technologies, University of Pisa, Pisa, Italy; Unit of Neuroradiology, Pisa University Hospital "Azienda Ospedaliero-Universitaria Pisana", Pisa, Italy
| | - Stefano Diciotti
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy
| | - Silvia De Santis
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
| | - Luca Passamonti
- Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy; Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Carlo Tessa
- Division of Radiology, "Versilia" Hospital, AUSL 12 Viareggio, Lido di Camaiore, Italy
| | - Nicola Toschi
- Department of Biomedicine and Prevention, Medical Physics Section, University of Rome "Tor Vergata", Rome, Italy; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Marco Giannelli
- Unit of Medical Physics, Pisa University Hospital "Azienda Ospedaliero-Universitaria Pisana", Pisa, Italy.
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De Santis S, Barazany D, Jones DK, Assaf Y. Resolving relaxometry and diffusion properties within the same voxel in the presence of crossing fibres by combining inversion recovery and diffusion-weighted acquisitions. Magn Reson Med 2015; 75:372-80. [PMID: 25735538 PMCID: PMC4737246 DOI: 10.1002/mrm.25644] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/18/2014] [Accepted: 12/10/2014] [Indexed: 12/13/2022]
Abstract
Purpose A comprehensive image‐based characterization of white matter should include the ability to quantify myelin and axonal attributes irrespective of the complexity of fibre organization within the voxel. While progress has been made with diffusion MRI‐based approaches to measure axonal morphology, to date available myelin metrics simply assign a single scalar value to the voxel, reflecting some form of average of its constituent fibres. Here, a new experimental framework that combines diffusion MRI and relaxometry is introduced. It provides, for the first time, the ability to assign to each unique fibre system within a voxel, a unique value of the longitudinal relaxation time, T1, which is largely influenced by the myelin content. Methods We demonstrate the method through simulations, in a crossing fibres phantom, in fixed brains and in vivo. Results The method is capable of recovering unique values of T1 for each fibre population. Conclusion The ability to extract fibre‐specific relaxometry properties will provide enhanced specificity and, therefore, sensitivity to differences in white matter architecture, which will be invaluable in many neuroimaging studies. Further the enhanced specificity should ultimately lead to earlier diagnosis and access to treatment in a range of white matter diseases where axons are affected. Magn Reson Med 75:372–380, 2016. © 2015 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.
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Affiliation(s)
- Silvia De Santis
- CUBRIC, School of Psychology, Cardiff University, Cardiff, CF10 3AT, UK.,Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Daniel Barazany
- CUBRIC, School of Psychology, Cardiff University, Cardiff, CF10 3AT, UK.,Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Derek K Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff, CF10 3AT, UK.,Neuroscience & Mental Health Research Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Yaniv Assaf
- Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
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De Santis S, Drakesmith M, Bells S, Assaf Y, Jones DK. Why diffusion tensor MRI does well only some of the time: variance and covariance of white matter tissue microstructure attributes in the living human brain. Neuroimage 2013; 89:35-44. [PMID: 24342225 PMCID: PMC3988851 DOI: 10.1016/j.neuroimage.2013.12.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 12/01/2013] [Accepted: 12/03/2013] [Indexed: 01/07/2023] Open
Abstract
Fundamental to increasing our understanding of the role of white matter microstructure in normal/abnormal function in the living human is the development of MR-based metrics that provide increased specificity to distinct attributes of the white matter (e.g., local fibre architecture, axon morphology, and myelin content). In recent years, different approaches have been developed to enhance this specificity, and the Tractometry framework was introduced to combine the resulting multi-parametric data for a comprehensive assessment of white matter properties. The present work exploits that framework to characterise the statistical properties, specifically the variance and covariance, of these advanced microstructural indices across the major white matter pathways, with the aim of giving clear indications on the preferred metric(s) given the specific research question. A cohort of healthy subjects was scanned with a protocol that combined multi-component relaxometry with conventional and advanced diffusion MRI acquisitions to build the first comprehensive MRI atlas of white matter microstructure. The mean and standard deviation of the different metrics were analysed in order to understand how they vary across different brain regions/individuals and the correlation between them. Characterising the fibre architectural complexity (in terms of number of fibre populations in a voxel) provides clear insights into correlation/lack of correlation between the different metrics and explains why DT-MRI is a good model for white matter only some of the time. The study also identifies the metrics that account for the largest inter-subject variability and reports the minimal sample size required to detect differences in means, showing that, on the other hand, conventional DT-MRI indices might still be the safest choice in many contexts. We report an atlas of key white matter pathways in standard space. CHARMED provide more specific measures of axonal properties than DT-MRI metrics. Crossing fibres explain the correlation between myelin and diffusion indices. DT-MRI metrics need the smallest sample size to detect differences between groups.
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Affiliation(s)
- Silvia De Santis
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK.
| | - Mark Drakesmith
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
| | - Sonya Bells
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
| | - Yaniv Assaf
- Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 Israel
| | - Derek K Jones
- CUBRIC, School of Psychology, Cardiff University, Cardiff CF10 3AT, UK; Neuroscience & Mental Health Research Institute, Cardiff University, CF10 3AT, UK
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Palombo M, Gabrielli A, De Santis S, Capuani S. The γ parameter of the stretched-exponential model is influenced by internal gradients: validation in phantoms. J Magn Reson 2012; 216:28-36. [PMID: 22277782 DOI: 10.1016/j.jmr.2011.12.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 05/15/2023]
Abstract
In this paper, we investigate the image contrast that characterizes anomalous and non-gaussian diffusion images obtained using the stretched exponential model. This model is based on the introduction of the γ stretched parameter, which quantifies deviation from the mono-exponential decay of diffusion signal as a function of the b-value. To date, the biophysical substrate underpinning the contrast observed in γ maps, in other words, the biophysical interpretation of the γ parameter (or the fractional order derivative in space, β parameter) is still not fully understood, although it has already been applied to investigate both animal models and human brain. Due to the ability of γ maps to reflect additional microstructural information which cannot be obtained using diffusion procedures based on gaussian diffusion, some authors propose this parameter as a measure of diffusion heterogeneity or water compartmentalization in biological tissues. Based on our recent work we suggest here that the coupling between internal and diffusion gradients provide pseudo-superdiffusion effects which are quantified by the stretching exponential parameter γ. This means that the image contrast of Mγ maps reflects local magnetic susceptibility differences (Δχ(m)), thus highlighting better than T(2)(∗) contrast the interface between compartments characterized by Δχ(m). Thanks to this characteristic, Mγ imaging may represent an interesting tool to develop contrast-enhanced MRI for molecular imaging. The spectroscopic and imaging experiments (performed in controlled micro-beads dispersion) that are reported here, strongly suggest internal gradients, and as a consequence Δχ(m), to be an important factor in fully understanding the source of contrast in anomalous diffusion methods that are based on a stretched exponential model analysis of diffusion data obtained at varying gradient strengths g.
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Affiliation(s)
- Marco Palombo
- Physics Department, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, Italy
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De Santis S, Assaf Y, Jones DK. Using the biophysical CHARMED model to elucidate the underpinnings of contrast in diffusional kurtosis analysis of diffusion-weighted MRI. Magn Reson Mater Phy 2011; 25:267-76. [DOI: 10.1007/s10334-011-0292-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 10/14/2011] [Accepted: 10/19/2011] [Indexed: 10/15/2022]
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De Santis S, Gabrielli A, Palombo M, Maraviglia B, Capuani S. Non-Gaussian diffusion imaging: a brief practical review. Magn Reson Imaging 2011; 29:1410-6. [PMID: 21601404 DOI: 10.1016/j.mri.2011.04.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Revised: 02/15/2011] [Accepted: 04/03/2011] [Indexed: 11/30/2022]
Abstract
The departure from purely mono-exponential decay of the signal, as observed from brain tissue following a diffusion-sensitized sequence, has prompted the search for alternative models to characterize these unconventional water diffusion dynamics. Several approaches have been proposed in the last few years. While multi-exponential models have been applied to characterize brain tissue, several unresolved controversies about the interpretations of the results have motivated the search for alternative models that do not rely on the Gaussian diffusion hypothesis. In this brief review, diffusional kurtosis imaging (DKI) and anomalous diffusion imaging (ADI) techniques are addressed and compared with diffusion tensor imaging. Theoretical and experimental issues are briefly described to allow readers to understand similarities, differences and limitations of these two non-Gaussian models. However, since the ultimate goal is to improve specificity, sensitivity and spatial localization of diffusion MRI for the detection of brain diseases, special attention will be paid on the clinical feasibility of the proposed techniques as well as on the context of brain pathology investigations.
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Affiliation(s)
- Silvia De Santis
- Physics Department, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy.
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Breccia M, Carmosino I, Diverio D, De Santis S, De Propris MS, Romano A, Petti MC, Mandelli F, Lo-Coco F. Early detection of meningeal localization in acute promyelocytic leukaemia patients with high presenting leucocyte count. Br J Haematol 2003; 120:266-70. [PMID: 12542484 DOI: 10.1046/j.1365-2141.2003.04056.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Extramedullary relapse occurs infrequently in acute promyelocytic leukaemia (APL) but has been increasingly reported after the advent of all-trans retinoic acid (ATRA) treatment, probably as a consequence of improved patient survival. We describe our single centre experience of six APL patients who had disease localization in the central nervous system (CNS). In three patients, clinical symptoms (headache and/or nausea) that presented during follow-up led to the performance of a lumbar puncture and detection of overt CNS infiltration. Two of these patients had simultaneous haematological relapse and one was in molecular remission when CNS leukaemia was documented. One patient with no local symptoms showed CNS infiltration at the time of molecular relapse. Following the introduction of routine lumbar puncture, carried out after front-line induction in all newly diagnosed patients with white blood cell count (WBC) greater than 10 x 109/l, two additional patients in molecular remission with no local symptoms were found to have initial APL localization in the CNS. Presenting features included in 6/6 patients an elevated WBC count (> 10 x 109/l) and a predominance of the PML/RAR bcr3 type (5/6 patients) and of microgranular morphology (5/6 patients). Our findings highlight the importance of carrying out lumbar puncture in APL patients presenting with high-risk features.
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Affiliation(s)
- Massimo Breccia
- Department of Cellular Biotechnologies and Haematology, University La Sapienza of Rome, Italy
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Abstract
Genetic markers associated with hematologic malignancies such as acute promyelocytic leukemia (APL) can be detected with high sensitivity and specificity using the reverse-transcription polymerase chain reaction (RT-PCR). This procedure can be applied to monitor minimal residual disease. In patients with APL, RT-PCR is now being used to detect molecular relapse, and a strong association has been found between outcome and the treatment of molecular as opposed to hematologic relapse. In APL, results from PCR assays are also being used to guide therapy. Prognostic groups can be defined using molecular and clinical characteristics of the disease as well as patient characteristics. In the future, PCR monitoring strategies may be adapted to the risk of relapse of individual patients. Patients at high risk of relapse may be monitored much more rigorously than patients at low risk of relapse. Although RT-PCR is in routine use as a clinical tool, the lack of standardization of techniques in different laboratories has resulted in some difficulties in interpretation of results. There is a real need for an international consensus on standardization of PCR techniques.
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Affiliation(s)
- Francesco Lo Coco
- Department of Cellular Biotechnologies and Hematology, Università La Sapienza, Rome, Italy
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