Search

Your search keyword '"Jean-Philippe Ranjeva"' showing total 235 results
Start Over Author "Jean-Philippe Ranjeva"
235 results on '"Jean-Philippe Ranjeva"'

1. Inhomogeneous Magnetization Transfer (ihMT) imaging in the acute cuprizone mouse model of demyelination/remyelination

Author

Andreea Hertanu, Lucas Soustelle, Julie Buron, Julie Le Priellec, Myriam Cayre, Arnaud Le Troter, Valentin H. Prevost, Jean-Philippe Ranjeva, Gopal Varma, David C. Alsop, Pascale Durbec, Olivier M. Girard, and Guillaume Duhamel

Subjects
Myelin MR imaging, ihmt T1D-filters, Demyelination, Remyelination, cuprizone mouse model, histology, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

ABSTRACT: Background: To investigate the association of ihMT (inhom signals with the demyelination and remyelination phases of the acute cuprizone mouse model in comparison with histology, and to assess the extent of tissue damage and repair from MRI data. Methods: Acute demyelination by feeding 0.2% cuprizone for five weeks, followed by a four-week remyelination period was applied on genetically modified plp-GFP mice. Animals were scanned at different time points of the demyelination and remyelination phases of the cuprizone model using a multimodal MRI protocol, including ihMT T1D-filters, MPF (Macromolecular Proton Fraction) and R1 (longitudinal relaxation rate). For histology, plp-GFP (proteolipid protein – Green Fluorescent Protein) microscopy and LFB (Luxol Fast Blue) staining were employed as references for the myelin content. Comparison of MRI with histology was performed in the medial corpus callosum (mCC) and cerebral cortex (CTX) at two brain levels whereas ROI-wise and voxel-based analyses of the MRI metrics allowed investigating in vivo the spatial extent of myelin alterations. Results: IhMT high-pass T1D-filters, targeted toward long T1D components, showed significant temporal variations in the mCC consistent with the effects induced by the cuprizone toxin. In addition, the corresponding signals correlated strongly and significantly with the myelin content assessed by GFP fluorescence and LFB staining over the demyelination and the remyelination phases. The signal of the band-pass T1D-filter, which isolates short T1D components, showed changes over time that were poorly correlated with histology, hence suggesting a sensitivity to pathological processes possibly not related to myelin. Although MPF was also highly correlated to histology, ihMT high-pass T1D-filters showed better capability to characterize the spatial-temporal patterns during the demyelination and remyelination phases of the acute cuprizone model (e.g., rostro-caudal gradient of demyelination in the mCC previously described in the literature). Conclusions: IhMT sequences selective for long T1D components are specific and sensitive in vivo markers of demyelination and remyelination and have successfully captured the spatially heterogeneous pattern of the demyelination and remyelination mechanisms in the cuprizone model. Interestingly, differences in signal variations between the ihMT high-pass and band-pass T1D-filter, suggest a sensitivity of the ihMT sequences targeted to short T1Ds to alterations other than those of myelin. Future studies will need to further address these differences by examining more closely the origin of the short T1D components and the variation of each T1D component in pathology.

Published
2023
Full Text
View/download PDF

2. Comparison of single-voxel 1H-cardiovascular magnetic resonance spectroscopy techniques for in vivo measurement of myocardial creatine and triglycerides at 3T

Author

Joevin Sourdon, Tangi Roussel, Claire Costes, Patrick Viout, Maxime Guye, Jean-Philippe Ranjeva, Monique Bernard, Frank Kober, and Stanislas Rapacchi

Subjects
Cardiac metabolism, CMR spectroscopy, Proton magnetic resonance spectroscopy, 3 T, SLASER, Creatine, Diseases of the circulatory (Cardiovascular) system, RC666-701
Abstract

Abstract Background Single-voxel proton cardiovascular magnetic resonance spectroscopy (1H-CMRS) benefits from 3 T to detect metabolic abnormalities with the quantification of intramyocardial fatty acids (FA) and creatine (Cr). Conventional point resolved spectroscopy (PRESS) sequence remains the preferred choice for CMRS, despite its chemical shift displacement error (CSDE) at high field (≥ 3 T). Alternative candidate sequences are the semi-adiabatic Localization by Adiabatic SElective Refocusing (sLASER) recommended for brain and musculoskeletal applications and the localized stimulated echo acquisition mode (STEAM). In this study, we aim to compare these three single-voxel 1H-CMRS techniques: PRESS, sLASER and STEAM for reproducible quantification of myocardial FA and Cr at 3 T. Sequences are compared both using breath-hold (BH) and free-breathing (FB) acquisitions. Methods CMRS accuracy and theoretical CSDE were verified on a purposely-designed fat–water phantom. FA and Cr CMRS data quality and reliability were evaluated in the interventricular septum of 10 healthy subjects, comparing repeated BH and free-breathing with retrospective gating. Results Measured FA/W ratio deviated from expected phantom ratio due to CSDE with all sequences. sLASER supplied the lowest bias (10%, vs -28% and 27% for PRESS and STEAM). In vivo, PRESS provided the highest signal-to-noise ratio (SNR) in FB scans (27.5 for Cr and 103.2 for FA). Nevertheless, a linear regression analysis between the two BH showed a better correlation between myocardial Cr content measured with sLASER compared to PRESS (r = 0.46; p = 0.03 vs. r = 0.35; p = 0.07) and similar slopes of regression lines for FA measurements (r = 0.94; p

Published
2021
Full Text
View/download PDF

3. Spinal cord and brain tissue impairments as long-term effects of rugby practice? An exploratory study based on T1 and ihMTsat measures

Author

Arash Forodighasemabadi, Guillaume Baucher, Lucas Soustelle, Thomas Troalen, Olivier M. Girard, Maxime Guye, Jean-Baptiste Grisoli, Jean-Philippe Ranjeva, Guillaume Duhamel, and Virginie Callot

Subjects
Rugby, Brain, Cervical spinal cord, T1 MP2RAGE, Inhomogeneous magnetization transfer, Neurodegeneration, Computer applications to medicine. Medical informatics, R858-859.7, Neurology. Diseases of the nervous system, RC346-429
Abstract

Rugby players are subject to multiple impacts to their head and neck that could have adverse neurological effects and put them at increased risk of neurodegeneration.Previous studies demonstrated altered default mode network and diffusion metrics on brain, as well as more foraminal stenosis, disc protrusion and neck pain among players of contact sports as compared to healthy controls. However, the long-term effects of practice and repetitive impacts on brain and cervical spinal cord (cSC) of the rugby players have never been systematically investigated.In this study, 15 retired professional and amateur rugby players (R) and 15 age-matched healthy controls (HC) (all males; mean age R: 46.8 ± 7.6; and HC: 48.6 ± 9.5) were recruited both to investigate cord impairments and further characterize brain structure damage. Medical questionnaires including modified Japanese Orthopedic Association scale (mJOA) and Neck Disability Index (NDI) were filled by all participants. A 3 T multi-parametric MR protocol including conventional qualitative techniques such as T1-, T2-, and T2*-weighted sequences, as well as state-of-the art quantitative techniques including MP2RAGE T1 mapping and 3D ihMTRAGE, was used on both brain and cSC. Normalized brain WM and GM volumes, spine Overall Stenosis Score, cord cross-sectional area and regional T1 and ihMT metrics were derived from these acquisitions.Rugby players showed significantly higher NDI scores, as well as a faster decline of normalized brain GM volume with age as compared to HC. Moreover, higher T1 values on cSC suggestive of structural degeneration, together with higher T1 and lower ihMTsat on brain WM suggestive of demyelination, were observed in retired rugby players as compared to age-matched controls, which may suggest cumulative effects of long-term impacts on the tissues. Metrics also suggest early aging and different aging processes on brain tissue in the players.These preliminary observations provide new insights in the domain, which should now be further investigated on larger cohorts and multicentric longitudinal studies, and further correlated to the likelihood of neurodegenerative diseases and risk factors.

Published
2022
Full Text
View/download PDF

4. The Role of the Human Hypothalamus in Food Intake Networks: An MRI Perspective

Author

Coleen Roger, Adèle Lasbleiz, Maxime Guye, Anne Dutour, Bénédicte Gaborit, and Jean-Philippe Ranjeva

Subjects
MRI, networks, anorexia, obesity, resting state, diffusion, Nutrition. Foods and food supply, TX341-641
Abstract

Hypothalamus (HT), this small structure often perceived through the prism of neuroimaging as morphologically and functionally homogeneous, plays a key role in the primitive act of feeding. The current paper aims at reviewing the contribution of magnetic resonance imaging (MRI) in the study of the role of the HT in food intake regulation. It focuses on the different MRI techniques that have been used to describe structurally and functionally the Human HT. The latest advances in HT parcellation as well as perspectives in this field are presented. The value of MRI in the study of eating disorders such as anorexia nervosa (AN) and obesity are also highlighted.

Published
2022
Full Text
View/download PDF

5. Increased Sodium Concentration in Substantia Nigra in Early Parkinson's Disease: A Preliminary Study With Ultra-High Field (7T) MRI

Author

Stephan Grimaldi, Mohamed Mounir El Mendili, Wafaa Zaaraoui, Jean-Philippe Ranjeva, Jean-Philippe Azulay, Alexandre Eusebio, and Maxime Guye

Subjects
Parkinson's disease, neurodegeneration, sodium, biomarker, ultra high field magnetic resonance imaging, Neurology. Diseases of the nervous system, RC346-429
Abstract

Pathophysiology of idiopathic Parkinson's disease (iPD) is complex and still misunderstood. At a time when treatments with disease-modifying potential are being developed, identification of early markers of neurodegeneration is essential. Intracerebral sodium accumulation could be one of them. Indeed, it may be in relation to the mitochondrial dysfunction that early exists in iPD. For the first time, we used brain sodium (23Na) MRI to explore sodium concentration changes that have already been reported to be related to neurodegeneration in other diseases. We prospectively included 10 iPD patients (mean age 52.2 ± 5.9 years-old) with motor symptoms that started

Published
2021
Full Text
View/download PDF

6. High levels of serum soluble TWEAK are associated with neuroinflammation during multiple sclerosis

Author

Adil Maarouf, Delphine Stephan, Marie-Pierre Ranjeva, Jean-Philippe Ranjeva, Jean Pelletier, Bertrand Audoin, Michel Khrestchatisky, and Sophie Desplat-Jégo

Subjects
TWEAK, Multiple sclerosis, Neuroinflammation, Biomarker, Cytokine, Medicine
Abstract

Abstract Background Inflammation and demyelination are the main processes in multiple sclerosis. Nevertheless, to date, blood biomarkers of inflammation are lacking. TWEAK, a transmembrane protein that belongs to the TNF ligand family, has been previously identified as a potential candidate. Methods Twenty-eight patients (9 males, 19 females) were prospectively included after a first clinical episode suggestive of multiple sclerosis and clinically followed during 3 years. Fifty-seven healthy controls were also included. TWEAK serum levels and MRI exams including magnetization transfer imaging were performed at baseline, 6- and 12-month follow-up. Results TWEAK serum levels were significantly increased in the patient group (mean baseline = 1086 ± 493 pg/mL, mean M6 = 624 ± 302 pg/mL and mean M12 = 578 ± 245 pg/mL) compared to healthy controls (mean = 467 ± 177 pg/mL; respectively p

Published
2019
Full Text
View/download PDF

7. Modular slowing of resting-state dynamic functional connectivity as a marker of cognitive dysfunction induced by sleep deprivation

Author

Diego Lombardo, Catherine Cassé-Perrot, Jean-Philippe Ranjeva, Arnaud Le Troter, Maxime Guye, Jonathan Wirsich, Pierre Payoux, David Bartrés-Faz, Régis Bordet, Jill C. Richardson, Olivier Felician, Viktor Jirsa, Olivier Blin, Mira Didic, and Demian Battaglia

Subjects
Dynamic functional connectivity, Resting-state, fMRI, Sleep deprivation, Cognitive decline, Cognitive challenge model, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Dynamic Functional Connectivity (dFC) in the resting state (rs) is considered as a correlate of cognitive processing. Describing dFC as a flow across morphing connectivity configurations, our notion of dFC speed quantifies the rate at which FC networks evolve in time. Here we probe the hypothesis that variations of rs dFC speed and cognitive performance are selectively interrelated within specific functional subnetworks.In particular, we focus on Sleep Deprivation (SD) as a reversible model of cognitive dysfunction. We found that whole-brain level (global) dFC speed significantly slows down after 24h of SD. However, the reduction in global dFC speed does not correlate with variations of cognitive performance in individual tasks, which are subtle and highly heterogeneous. On the contrary, we found strong correlations between performance variations in individual tasks –including Rapid Visual Processing (RVP, assessing sustained visual attention)– and dFC speed quantified at the level of functional sub-networks of interest. Providing a compromise between classic static FC (no time) and global dFC (no space), modular dFC speed analyses allow quantifying a different speed of dFC reconfiguration independently for sub-networks overseeing different tasks. Importantly, we found that RVP performance robustly correlates with the modular dFC speed of a characteristic frontoparietal module.

Published
2020
Full Text
View/download PDF

8. Amygdalar nuclei and hippocampal subfields on MRI: Test-retest reliability of automated volumetry across different MRI sites and vendors

Author

Giulia Quattrini, Michela Pievani, Jorge Jovicich, Marco Aiello, Núria Bargalló, Frederik Barkhof, David Bartres-Faz, Alberto Beltramello, Francesca B. Pizzini, Olivier Blin, Regis Bordet, Massimo Caulo, Manos Constantinides, Mira Didic, Antonios Drevelegas, Antonio Ferretti, Ute Fiedler, Piero Floridi, Hélène Gros-Dagnac, Tilman Hensch, Karl-Titus Hoffmann, Joost P. Kuijer, Renaud Lopes, Camillo Marra, Bernhard W. Müller, Flavio Nobili, Lucilla Parnetti, Pierre Payoux, Agnese Picco, Jean-Philippe Ranjeva, Luca Roccatagliata, Paolo M. Rossini, Marco Salvatore, Peter Schonknecht, Björn H. Schott, Julien Sein, Andrea Soricelli, Roberto Tarducci, Magda Tsolaki, Pieter J. Visser, Jens Wiltfang, Jill C. Richardson, Giovanni B. Frisoni, and Moira Marizzoni

Subjects
Amygdalar nuclei, Hippocampal subfields, Multicenter MRI study, FreeSurfer, Reliability analysis, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Background: The amygdala and the hippocampus are two limbic structures that play a critical role in cognition and behavior, however their manual segmentation and that of their smaller nuclei/subfields in multicenter datasets is time consuming and difficult due to the low contrast of standard MRI. Here, we assessed the reliability of the automated segmentation of amygdalar nuclei and hippocampal subfields across sites and vendors using FreeSurfer in two independent cohorts of older and younger healthy adults. Methods: Sixty-five healthy older (cohort 1) and 68 younger subjects (cohort 2), from the PharmaCog and CoRR consortia, underwent repeated 3D-T1 MRI (interval 1–90 days). Segmentation was performed using FreeSurfer v6.0. Reliability was assessed using volume reproducibility error (ε) and spatial overlapping coefficient (DICE) between test and retest session. Results: Significant MRI site and vendor effects (p ​0.43, p ​ ​0.80). Conclusion: Our results support the use of volumetric measures of larger amygdalar nuclei and hippocampal subfields in multisite MRI studies. These measures could be useful for disease tracking and assessment of efficacy in drug trials.

Published
2020
Full Text
View/download PDF

9. Aerobic Exercise Induces Functional and Structural Reorganization of CNS Networks in Multiple Sclerosis: A Randomized Controlled Trial

Author

Jan-Patrick Stellmann, Adil Maarouf, Karl-Heinz Schulz, Lisa Baquet, Jana Pöttgen, Stefan Patra, Iris-Katharina Penner, Susanne Gellißen, Gesche Ketels, Pierre Besson, Jean-Philippe Ranjeva, Maxime Guye, Guido Nolte, Andreas K. Engel, Bertrand Audoin, Christoph Heesen, and Stefan M. Gold

Subjects
CNS networks, neuroplasticity, exercise, multiple sclerosis, randomized controlled trial, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Objectives: Evidence from animal studies suggests that aerobic exercise may promote neuroplasticity and could, therefore, provide therapeutic benefits for neurological diseases such as multiple sclerosis (MS). However, the effects of exercise in human CNS disorders on the topology of brain networks, which might serve as an outcome at the interface between biology and clinical performance, remain poorly understood.Methods: We investigated functional and structural networks in patients with relapsing-remitting MS in a clinical trial of standardized aerobic exercise. Fifty-seven patients were randomly assigned to moderate-intensity exercise for 3 months or a non-exercise control group. We reconstructed functional networks based on resting-state functional magnetic resonance imaging (MRI) and used probabilistic tractography on diffusion-weighted imaging data for structural networks.Results: At baseline, compared to 30 healthy controls, patients exhibited decreased structural connectivity that was most pronounced in hub regions of the brain. Vice versa, functional connectivity was increased in hubs. After 3 months, we observed hub independent increased functional connectivity in the exercise group while the control group presented a loss of functional hub connectivity. On a structural level, the control group remained unchanged, while the exercise group had also increased connectivity. Increased clustering of hubs indicates a better structural integration and internal connectivity at the top of the network hierarchy.Conclusion: Increased functional connectivity of hubs contrasts a loss of structural connectivity in relapsing-remitting MS. Under an exercise condition, a further hub independent increase of functional connectivity seems to translate in higher structural connectivity of the whole brain.

Published
2020
Full Text
View/download PDF

10. Brain sodium MRI in human epilepsy: Disturbances of ionic homeostasis reflect the organization of pathological regions

Author

Ben Ridley, Angela Marchi, Jonathan Wirsich, Elisabeth Soulier, Sylviane Confort-Gouny, Lothar Schad, Fabrice Bartolomei, Jean-Philippe Ranjeva, Maxime Guye, and Wafaa Zaaraoui

Subjects
Sodium MRI, Epilepsy, Intracranial EEG, Cortical localisation, Epilepsy surgery, Ionic imaging, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

In light of technical advancements supporting exploration of MR signals other than 1H, sodium (23Na) has received attention as a marker of ionic homeostasis and cell viability. Here, we evaluate for the first time the possibility that 23Na-MRI is sensitive to pathological processes occurring in human epilepsy. A normative sample of 27 controls was used to normalize regions of interest (ROIs) from 1424 unique brain locales on quantitative 23Na-MRI and high-resolution 1H-MPRAGE images. ROIs were based on intracerebral electrodes in ten patients undergoing epileptic network mapping. The stereo-EEG gold standard was used to define regions as belonging to primarily epileptogenic, secondarily irritative and to non-involved regions. Estimates of total sodium concentration (TSC) on 23Na-MRI and cerebrospinal fluid (CSF) on 1H imaging were extracted for each patient ROI, and normalized against the same region in controls. ROIs with disproportionate CSF contributions (ZCSF≥1.96) were excluded. TSC levels were found to be elevated in patients relative to controls except in one patient, who suffered non-convulsive seizures during the scan, in whom we found reduced TSC levels. In the remaining patients, an ANOVA (F1100= 12.37, p

Published
2017
Full Text
View/download PDF

11. Specific brain activation patterns associated with two neuromuscular electrical stimulation protocols

Author

Jennifer Wegrzyk, Jean-Philippe Ranjeva, Alexandre Fouré, Anne Kavounoudias, Christophe Vilmen, Jean-Pierre Mattei, Maxime Guye, Nicola A. Maffiuletti, Nicolas Place, David Bendahan, and Julien Gondin

Subjects
Medicine, Science
Abstract

Abstract The influence of neuromuscular electrical stimulation (NMES) parameters on brain activation has been scarcely investigated. We aimed at comparing two frequently used NMES protocols - designed to vary in the extent of sensory input. Whole-brain functional magnetic resonance imaging was performed in sixteen healthy subjects during wide-pulse high-frequency (WPHF, 100 Hz–1 ms) and conventional (CONV, 25 Hz–0.05 ms) NMES applied over the triceps surae. Each protocol included 20 isometric contractions performed at 10% of maximal force. Voluntary plantar flexions (VOL) were performed as control trial. Mean force was not different among the three protocols, however, total current charge was higher for WPHF than for CONV. All protocols elicited significant activations of the sensorimotor network, cerebellum and thalamus. WPHF resulted in lower deactivation in the secondary somatosensory cortex and precuneus. Bilateral thalami and caudate nuclei were hyperactivated for CONV. The modulation of the NMES parameters resulted in differently activated/deactivated regions related to total current charge of the stimulation but not to mean force. By targeting different cerebral brain regions, the two NMES protocols might allow for individually-designed rehabilitation training in patients who can no longer execute voluntary movements.

Published
2017
Full Text
View/download PDF

12. Structural Connectivity Alterations in Amyotrophic Lateral Sclerosis: A Graph Theory Based Imaging Study

Author

Etienne Fortanier, Aude-Marie Grapperon, Arnaud Le Troter, Annie Verschueren, Ben Ridley, Maxime Guye, Shahram Attarian, Jean-Philippe Ranjeva, and Wafaa Zaaraoui

Subjects
ALS, MRI, connectivity, DTI, hub, graph theory, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

BackgroundAmyotrophic lateral sclerosis (ALS) is a relentlessly progressive neurodegenerative disorder. Diffusion magnetic resonance imagining (MRI) studies have consistently showed widespread alterations in both motor and non-motor brain regions. However, connectomics and graph theory based approaches have shown inconsistent results. Hub-centered lesion patterns and their impact on local and large-scale brain networks remain to be established. The objective of this work is to characterize topological properties of structural brain connectivity in ALS using an array of local, global and hub-based network metrics.Materials and MethodsMagnetic resonance imagining data were acquired from 25 patients with ALS and 26 age-matched healthy controls. Structural network graphs were constructed from diffusion tensor MRI. Network-based statistics (NBS) and graph theory metrics were used to compare structural networks without a priori regions of interest.ResultsPatients with ALS exhibited global network alterations with decreased global efficiency (Eglob) (p = 0.03) and a trend of reduced whole brain mean degree (p = 0.05) compared to controls. Six nodes showed significantly decreased mean degree in ALS: left postcentral gyrus, left interparietal and transverse parietal sulcus, left calcarine sulcus, left occipital temporal medial and lingual sulcus, right precentral gyrus and right frontal inferior sulcus (p < 0.01). Hub distribution was comparable between the two groups. There was no selective hub vulnerability or topological reorganization centered on these regions as the hub disruption index (κ) was not significant for the relevant metrics (degree, local efficiency and betweenness centrality). Using NBS, we identified an impaired motor subnetwork of 11 nodes and 10 edges centered on the precentral and the paracentral nodes (p < 0.01). Significant clinical correlations were identified between degree in the frontal area and the disease progression rate of ALS patients (p < 0.01).ConclusionOur study provides evidence that alterations of structural connectivity in ALS are primarily driven by node degree and white matter tract degeneration within an extended network around the precentral and the paracentral areas without hub-centered reorganization.

Published
2019
Full Text
View/download PDF

13. Whole-brain analytic measures of network communication reveal increased structure-function correlation in right temporal lobe epilepsy

Author

Jonathan Wirsich, Alistair Perry, Ben Ridley, Timothée Proix, Mathieu Golos, Christian Bénar, Jean-Philippe Ranjeva, Fabrice Bartolomei, Michael Breakspear, Viktor Jirsa, and Maxime Guye

Subjects
Structural connectivity, Functional connectivity, Temporal lobe epilepsy, Network communication, Rich club, Network based statistics, Computer applications to medicine. Medical informatics, R858-859.7, Neurology. Diseases of the nervous system, RC346-429
Abstract

The in vivo structure-function relationship is key to understanding brain network reorganization due to pathologies. This relationship is likely to be particularly complex in brain network diseases such as temporal lobe epilepsy, in which disturbed large-scale systems are involved in both transient electrical events and long-lasting functional and structural impairments. Herein, we estimated this relationship by analyzing the correlation between structural connectivity and functional connectivity in terms of analytical network communication parameters. As such, we targeted the gradual topological structure-function reorganization caused by the pathology not only at the whole brain scale but also both in core and peripheral regions of the brain. We acquired diffusion (dMRI) and resting-state fMRI (rsfMRI) data in seven right-lateralized TLE (rTLE) patients and fourteen healthy controls and analyzed the structure-function relationship by using analytical network communication metrics derived from the structural connectome. In rTLE patients, we found a widespread hypercorrelated functional network. Network communication analysis revealed greater unspecific branching of the shortest path (search information) in the structural connectome and a higher global correlation between the structural and functional connectivity for the patient group. We also found evidence for a preserved structural rich-club in the patient group. In sum, global augmentation of structure-function correlation might be linked to a smaller functional repertoire in rTLE patients, while sparing the central core of the brain which may represent a pathway that facilitates the spread of seizures.

Published
2016
Full Text
View/download PDF

14. Predictive value of imaging markers at multiple sclerosis disease onset based on gadolinium- and USPIO-enhanced MRI and machine learning.

Author

Alessandro Crimi, Olivier Commowick, Adil Maarouf, Jean-Christophe Ferré, Elise Bannier, Ayman Tourbah, Isabelle Berry, Jean-Philippe Ranjeva, Gilles Edan, and Christian Barillot

Subjects
Medicine, Science
Abstract

ObjectivesA novel characterization of Clinically Isolated Syndrome (CIS) patients according to lesion patterns is proposed. More specifically, patients are classified according to the nature of inflammatory lesions patterns. It is expected that this characterization can infer new prospective figures from the earliest imaging signs of Multiple Sclerosis (MS), since it can provide a classification of different types of lesions across patients.MethodsThe method is based on a two-tiered classification. Initially, the spatio-temporal lesion patterns are classified. The discovered lesion patterns are then used to characterize groups of patients. The patient groups are validated using statistical measures and by correlations at 24-month follow-up with hypointense lesion loads.ResultsThe methodology identified 3 statistically significantly different clusters of lesion patterns showing p-values smaller than 0.01. Moreover, these patterns defined at baseline correlated with chronic hypointense lesion volumes by follow-up with an R(2) score of 0.90.ConclusionsThe proposed methodology is capable of identifying three major different lesion patterns that are heterogeneously present in patients, allowing a patient classification using only two MRI scans. This finding may lead to more accurate prognosis and thus to more suitable treatments at early stage of MS.

Published
2014
Full Text
View/download PDF

15. Prevalence of grey matter pathology in early multiple sclerosis assessed by magnetization transfer ratio imaging.

Author

Lydie Crespy, Wafaa Zaaraoui, Mathias Lemaire, Audrey Rico, Anthony Faivre, Françoise Reuter, Irina Malikova, Sylviane Confort-Gouny, Patrick J Cozzone, Jean Pelletier, Jean-Philippe Ranjeva, and Bertrand Audoin

Subjects
Medicine, Science
Abstract

The aim of the study was to assess the prevalence, the distribution and the impact on disability of grey matter (GM) pathology in early multiple sclerosis. Eighty-eight patients with a clinically isolated syndrome with a high risk developing multiple sclerosis were included in the study. Forty-four healthy controls constituted the normative population. An optimized statistical mapping analysis was performed to compare each subject's GM Magnetization Transfer Ratio (MTR) imaging maps with those of the whole group of controls. The statistical threshold of significant GM MTR decrease was determined as the maximum p value (p

Published
2011
Full Text
View/download PDF

16. Interictal functional connectivity of human epileptic networks assessed by intracerebral EEG and BOLD signal fluctuations.

Author

Gaelle Bettus, Jean-Philippe Ranjeva, Fabrice Wendling, Christian G Bénar, Sylviane Confort-Gouny, Jean Régis, Patrick Chauvel, Patrick J Cozzone, Louis Lemieux, Fabrice Bartolomei, and Maxime Guye

Subjects
Medicine, Science
Abstract

In this study, we aimed to demonstrate whether spontaneous fluctuations in the blood oxygen level dependent (BOLD) signal derived from resting state functional magnetic resonance imaging (fMRI) reflect spontaneous neuronal activity in pathological brain regions as well as in regions spared by epileptiform discharges. This is a crucial issue as coherent fluctuations of fMRI signals between remote brain areas are now widely used to define functional connectivity in physiology and in pathophysiology. We quantified functional connectivity using non-linear measures of cross-correlation between signals obtained from intracerebral EEG (iEEG) and resting-state functional MRI (fMRI) in 5 patients suffering from intractable temporal lobe epilepsy (TLE). Functional connectivity was quantified with both modalities in areas exhibiting different electrophysiological states (epileptic and non affected regions) during the interictal period. Functional connectivity as measured from the iEEG signal was higher in regions affected by electrical epileptiform abnormalities relative to non-affected areas, whereas an opposite pattern was found for functional connectivity measured from the BOLD signal. Significant negative correlations were found between the functional connectivities of iEEG and BOLD signal when considering all pairs of signals (theta, alpha, beta and broadband) and when considering pairs of signals in regions spared by epileptiform discharges (in broadband signal). This suggests differential effects of epileptic phenomena on electrophysiological and hemodynamic signals and/or an alteration of the neurovascular coupling secondary to pathological plasticity in TLE even in regions spared by epileptiform discharges. In addition, indices of directionality calculated from both modalities were consistent showing that the epileptogenic regions exert a significant influence onto the non epileptic areas during the interictal period. This study shows that functional connectivity measured by iEEG and BOLD signals give complementary but sometimes inconsistent information in TLE.

Published
2011
Full Text
View/download PDF

17. Inflammatory multiple-sclerosis plaques generate characteristic metabolic profiles in cerebrospinal fluid.

Author

Norbert W Lutz, Angèle Viola, Irina Malikova, Sylviane Confort-Gouny, Bertrand Audoin, Jean-Philippe Ranjeva, Jean Pelletier, and Patrick J Cozzone

Subjects
Medicine, Science
Abstract

BackgroundMultiple sclerosis (MS), an inflammatory disease of the central nervous system, manifests itself in numerous forms and stages. A number of brain metabolic alterations have been reported for MS patients vs. control subjects. However, metabolite profiles of cerebrospinal fluid (CSF) are not consistent among the published MS studies, most probably due to variations in the patient cohorts studied. We undertook the first investigation of highly homogeneous MS patient cohorts to determine characteristic effects of inflammatory MS plaques on the CSF metabolome, including only patients with clinically isolated syndrome (CIS) with or without inflammatory brain plaques, and controls.Methodology/principal findingsCSF obtained by lumbar puncture was analyzed by proton magnetic resonance spectroscopy. 27 metabolites were quantified. Differences between groups of control subjects (n = 10), CIS patients with (n = 21) and without (n = 12) inflammatory plaques were evaluated by univariate statistics and principal component analysis (PCA). Seven metabolites showed statistically significant inter-group differences (pConclusions/significanceCSF metabolic profiles suggest a close link between MS plaque activity in CIS patients on the one hand and organic-acid metabolism on the other. Our detection of increased BHIB levels points to a hitherto unsuspected role for this compound in MS with active plaques, and serves as a basis for further investigation. The metabolic effects described in our study are crucial elements in the explanation of biochemical mechanisms involved in specific MS manifestations.

Published
2007
Full Text
View/download PDF

18. Quantitative magnetization transfer MRI unbiased by on‐resonance saturation and dipolar order contributions

Author

Lucas Soustelle, Thomas Troalen, Andreea Hertanu, Jean‐Philippe Ranjeva, Maxime Guye, Gopal Varma, David C. Alsop, Guillaume Duhamel, Olivier M. Girard, Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Siemens Healthcare [France], Siemens AG [Munich], Division of MR Research, Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA, ANR-22-CE17-0060,NormaBRAIN,IRM quantitative et base normative pour la caractérisation des altérations tissulaires cérébrales à haut et ultra-haut champ magnétique(2022), ANR-22-CE18-0041,ULTIMO,Imagerie quantitative des membranes lipidiques par ihMT: un nouveau marqueur IRM de la myéline(2022), ANR-17-CE18-0030,verISMO,IRM du transfert d'aimantation inhomogène : vers un nouveau biomarqueur in vivo spécifique et sensible de la myéline(2017), and ANR-11-INBS-0006,FLI,France Life Imaging(2011)

Subjects
neuroimaging, T1 relaxometry, quantitative magnetization transfer, Radiology, Nuclear Medicine and imaging, [SDV.IB]Life Sciences [q-bio]/Bioengineering, dipolar order, inhomogeneous magnetization transfer
Abstract

International audience; To demonstrate the bias in quantitative MT (qMT) measures introduced by the presence of dipolar order and on-resonance saturation (ONRS) effects using magnetization transfer (MT) spoiled gradient-recalled (SPGR) acquisitions, and propose changes to the acquisition and analysis strategies to remove these biases. Methods: The proposed framework consists of SPGR sequences prepared with simultaneous dual-offset frequency-saturation pulses to cancel out dipolar order and associated relaxation (T 1D) effects in Z-spectrum acquisitions, and a matched quantitative MT (qMT) mathematical model that includes ONRS effects of readout pulses. Variable flip angle and MT data were fitted jointly to simultaneously estimate qMT parameters (macromolecular proton fraction [MPF], T 2,f , T 2,b , R, and free pool T 1). This framework is compared with standard qMT and investigated in terms of reproducibility, and then further developed to follow a joint single-point qMT methodology for combined estimation of MPF and T 1. Results: Bland-Altman analyses demonstrated a systematic underestimation of MPF (−2.5% and −1.3%, on average, in white and gray matter, respectively) and overestimation of T 1 (47.1 ms and 38.6 ms, on average, in white and gray matter, respectively) if both ONRS and dipolar order effects are ignored. Reproducibility of the proposed framework is excellent (ΔMPF = −0.03% and ΔT 1 = −19.0 ms). The single-point methodology yielded consistent MPF and T 1 values with respective maximum relative average bias of −0.15% and −3.5 ms found in white matter. Conclusion: The influence of acquisition strategy and matched mathematical model with regard to ONRS and dipolar order effects in qMT-SPGR frameworks has been investigated. The proposed framework holds promise for improved accuracy with reproducibility.

Published
2023
Full Text
View/download PDF

19. Brain sodium MRI-derived priors support the estimation of epileptogenic zones using personalized model-based methods in Epilepsy

Author

Mikhael Azilinon, Huifang E. Wang, Julia Makhalova, Wafaa Zaaraoui, Jean-Philippe Ranjeva, Fabrice Bartolomei, Maxime Guye, and Viktor Jirsa

Abstract

Epilepsy patients with drug-resistant epilepsy are eligible for surgery aiming to remove the regions involved in the production of seizure activities (the so-called epileptogenic zone network (EZN). Thus the accurate estimation of the EZN is crucial. A data-driven, personalized virtual brain models derived from patient-specific anatomical and functional data are used in Virtual Epileptic Patient (VEP) to estimate the EZN via optimization methods from Bayesian inference. The Bayesian inference approach used in previous VEP integrates priors, based on the features of stereotactic-electroencephalography (SEEG) seizures’ recordings. Here, we propose new priors, based on quantitative23Na-MRI. The23Na-MRI data were acquired at 7T and provided several features characterizing the sodium signal decay. The hypothesis is that the sodium features are biomarkers of neuronal excitability related to the EZN and will add additional information to VEP estimation. In this paper, we first proposed the mapping from23Na-MRI features to predict the EZN via a machine learning approach. Then, exploiting these predictions as priors in the VEP pipeline, we demonstrated that23Na-MRI prior based VEP estimation of the EZN improved the results in terms of balanced accuracy and as good as SEEG priors in terms of the weighted harmonic mean of the precision and recall.AUTHOR SUMMARYFor the first time quantitative23Na-MRI were used as prior information to improve estimation of EZN using the model-based method of VEP pipeline. The priors were based on logistic regression predictions of the EZN, using23Na-MRI features as predictors. The23Na-MRI priors inferred EZNs significantly closer to the clinical hypotheses - in terms of balanced accuracy - than the previously used priors or the no-prior condition.

Published
2022
Full Text
View/download PDF

20. Inhomogeneous Magnetization Transfer (ihMT) imaging in the acute cuprizone mouse model of demyelination/remyelination

Author

Andreea Hertanu, Lucas Soustelle, Julie Buron, Julie Le Priellec, Myriam Cayre, Arnaud Le Troter, Valentin H. Prevost, Jean-Philippe Ranjeva, Gopal Varma, David C. Alsop, Pascale Durbec, Olivier M. Girard, Guillaume Duhamel, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie du Développement de Marseille (IBDM), Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS), Beth Israel Deaconess Medical Center [Boston] (BIDMC), and Harvard Medical School [Boston] (HMS)

Subjects
Neurology, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Cognitive Neuroscience
Abstract

To investigate the association of ihMT (inhom signals with the demyelination and remyelination phases of the acute cuprizone mouse model in comparison with histology, and to assess the extent of tissue damage and repair from MRI data.Acute demyelination by feeding 0.2% cuprizone for five weeks, followed by a four-week remyelination period was applied on genetically modified plp-GFP mice. Animals were scanned at different time points of the demyelination and remyelination phases of the cuprizone model using a multimodal MRI protocol, including ihMT TIhMT high-pass TIhMT sequences selective for long T

Published
2022
Full Text
View/download PDF

21. Multi-scale structural alterations of the thalamus and basal ganglia in focal epilepsy as demonstrated by 7T MRI

Author

Roy AM Haast, Benoit Testud, Julia Makhalova, Hugo Dary, Alexandre Cabane, Arnaud Le Troter, Jean-Philippe Ranjeva, Fabrice Bartolomei, and Maxime Guye

Abstract

Focal epilepsy is characterized by repeated spontaneous seizures that originate from cortical epileptogenic zone networks (EZN). More recently, analysis of intracerebral recordings showed that subcortical structures, and in particular the thalamus, play an important role in facilitating and/or propagating epileptic activity. This supports previously reported structural alterations of these structures. Nonetheless, between-patient differences in EZN (e.g., temporal vs. non-temporal lobe epilepsy) as well as other clinical features (e.g., number of epileptogenic regions) might impact the magnitude as well as spatial distribution of subcortical structural changes. Here we used 7 Tesla MRI T1data to provide a comprehensive description of subcortical morphological (volume, tissue deformation, and shape) and longitudinal relaxation (T1) changes in focal epilepsy patients to evaluate the impact of the EZN and patient-specific clinical features. Our results showed widespread morphometric and T1changes. Focusing on the thalamus, atrophy varied across nuclei but appeared most prominent for the TLE group and the ipsilateral side, while shortening of T1was observed for the lateral thalamus, in particular. Multivariate analyses across thalamic nuclei and basal ganglia showed that volume acted as the dominant discriminator between patients and controls, while (posterolateral) thalamic T1measures looked promising to further differentiate patients based on EZN. In particular, the observed differences in T1changes between thalamic nuclei indicated differential involvement of thalamic nuclei based on EZN. Finally, the number of epileptogenic regions was found to best explain the observed variability between patients. To conclude, this work revealed multi-scale subcortical alterations in focal epilepsy as well as their dependence on several clinical characteristics. Our results provide a basis for further, in-depth investigations using (quantitative) MRI and SEEG data and warrant further personalization of intervention strategies, such as deep brain stimulation, for treating focal epilepsy patients.

Published
2022
Full Text
View/download PDF

22. Altered correlation of concurrently recorded EEG-fMRI connectomes in temporal lobe epilepsy

Author

Jonathan Wirsich, Giannina Rita Iannotti, Ben Ridley, Elhum A Shamshiri, Laurent Sheybani, Frédéric Grouiller, Fabrice Bartolomei, Margitta Seeck, François Lazeyras, Jean-Philippe Ranjeva, Maxime Guye, and Serge Vulliemoz

Abstract

Whole brain, large-scale functional connectivity networks or connectomes have been characterized on different temporal and spatial scales in humans using EEG and fMRI. Whole brain epileptic networks have been investigated with both EEG and fMRI, but due to the different acquisition approaches it is unclear to what extent those results can be related. In consequence clinical research in epilepsy would profit from a unified multimodal functional connectome description as a linking framework to better map underlying brain function and pathological functional networks. In this study we aim to characterize the spatial correlation between EEG and fMRI connectivity in temporal lobe epilepsy.From two independent centers, we acquired resting-state concurrent EEG-fMRI from a total of 35 healthy controls and 34 TLE patients (18 right TLE and 16 left TLE). Data was projected into the Desikan brain atlas (mean BOLD activity for fMRI and source reconstruction for EEG). Whole brain functional connectivity from fMRI (Pearson correlation) and EEG (corrected imaginary part of the coherency) were correlated for all subjects.In healthy controls, average EEG and fMRI whole-brain connectivity was moderately correlated (r∼0.3). For both imaging centers, correlation between EEG and fMRI whole brain connectivity was increased in rTLE when compared to controls for lower frequency bands (EEG-delta, theta and alpha). Conversely correlation between EEG and fMRI connectivity of lTLE patients was decreased in respect to healthy subjects (EEG-beta vs. fMRI connectivity only). While the alteration of the EEG-fMRI correlation in rTLE patients could not be related to a local effect, in lTLE patients it was locally linked to the Default Mode Network.We demonstrated, using two independent datasets, that EEG and fMRI connectivity is correlated for both healthy subjects and patients. The increased correlation of EEG and fMRI connectivity in rTLE patients vs. controls and decreased correlation in lTLE patients vs. controls suggests a differential organization of mono-lateral focal epilepsy of the same type, which needs to be considered when comparing fMRI to EEG connectivity. It also demonstrates that each modality provides distinct information, highlighting the benefit of multimodal assessment in epilepsy. The observed property of distinct topological patterns depending on the lateralization of the epilepsy could be taken into account when clinically defining the epileptic focus of patients.

Published
2022
Full Text
View/download PDF

23. Combining Sodium MRI, Proton MR Spectroscopic Imaging and Intracerebral EEG in Epilepsy

Author

Mikhael Azilinon, Julia Scholly, Wafaa Zaaraoui, Samuel Medina Villalon, Patrick Viout, Tangi Roussel, Mohamed Mounir El Mendili, Ben Ridley, Jean-Philippe Ranjeva, Fabrice Bartolomei, Viktor Jirsa, Maxime Guye, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service d'Epileptologie et de Rythmologie Cérébrale [Hôpital de la Timone, AP-HM], Aix Marseille Université (AMU)- Hôpital de la Timone [CHU - APHM] (TIMONE), IRCCS Istituto delle Scienze Neurologiche di Bologna [Bologna, Italy], Ospedale Bellaria [Bologna, Italy], ANR-17-EURE-0029,nEURo*AMU,Marseille NeuroSchool, une formation d'excellence(2017), ANR-17-RHUS-0004,EPINOV,Improving EPilepsy surgery management and progNOsis using Virtual brain technology(2017), European Project: 785907,H2020,HBP SGA2(2018), European Project: 945539,H2020,H2020-SGA-FETFLAG-HBP-2019,HBP SGA3(2020), RANJEVA, Jean-Philippe, Marseille NeuroSchool, une formation d'excellence - - nEURo*AMU2017 - ANR-17-EURE-0029 - EURE - VALID, Improving EPilepsy surgery management and progNOsis using Virtual brain technology - - EPINOV2017 - ANR-17-RHUS-0004 - RHUS - VALID, Human Brain Project Specific Grant Agreement 2 - HBP SGA2 - - H20202018-04-01 - 2020-03-31 - 785907 - VALID, Human Brain Project Specific Grant Agreement 3 - HBP SGA3 - - H20202020-01-01 - 2023-09-30 - 945539 - VALID, Centre d'Exploration Métabolique par Résonance Magnétique [Marseille] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE), and APHM, Timone hospital, Epileptology department, Marseille, France

Subjects
HC, echoplanar spectroscopic imaging, GeneRalized Autocalibrating Partial Parallel Acquisition, N-acetyl aspartate, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, fraction of sodium signal with short T 2 * decays, dysembryoplastic neuroepithelial tumor, achieved significance level, Na+/K+ pump, voltage-gated sodium channel, choline compounds, extracellular volume, repetition time, sodium, CRLB, FOV, total sodium concentration, Radiological and Ultrasound Technology, magnetization prepared 2 rapid acquisition gradient echo, pH, EAAT, propagation zone, Metabolite Imaging and Data Analyses System, sodium hydrogen antiporter, stereotactic EEG, MP2RAGE, DNET, Neurology, sodium longT 2 * relaxation time, GRAPPA, EPSI, fluorodeoxyglucose PET, Anatomy, MNI, ultrashort echo time, focal cortical dysplasia, field of view, MIDAS, sodium short T 2 * relaxation time, magnetization prepared rapid acquisition gradient echo, inversion time, sodium potassium pump, echo time, total creatine, FDR, Cramer-Rao lower bound, anterior commissure-posterior commissure, Radiology, Nuclear Medicine and imaging, sodium potassium chloride cotransporter, potential of hydrogen, apparent concentrations of sodium with long T2* decays, healthy control, noninvolved zone, apparent concentrations of sodium with short apparent T2* decay, Montreal Neurological Institute, bicarbonate sodium cotransporter, Epileptogenicity Index, sodium calcium exchanger, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, MPRAGE, hydrogen, Neurology (clinical), false discovery rate, region of interest, glutamate transporter, epileptogenic zone
Abstract

Whole brain ionic and metabolic imaging has potential as a powerful tool for the characterization of brain diseases. In this study we combined sodium MRI (23Na MRI) and 1H-MR Spectroscopic Imaging (1H-MRSI) and compared ionic/metabolic changes probed by this multimodal approach to intracerebral stereotactic-EEG (SEEG) recordings.We applied a multi-echo density adapted 3D projection reconstruction pulse sequence at 7T (23Na MRI) and a 3D echo planar spectroscopic imaging sequence at 3T (1H-MRSI) in 19 patients suffering from drug-resistant focal epilepsy who underwent presurgical SEEG. We investigated 23Na MRI parameters including total sodium concentration (TSC) and the sodium signal fraction associated of with the short component of T2* decay (f), alongside the level of metabolites N-acetyl aspartate (NAA), choline compounds (Cho) and total creatine (tCr). All measures were extracted from spherical regions of interest (ROIs) centered between two adjacent SEEG electrode contacts and z-scored against the same ROI in controls.Group comparison showed a significant increase in f only in the epileptogenic zone (EZ) compared to controls and compared to patients propagation zone (PZ) and non-involved zone (NIZ). TSC was significantly increased in all patients’ regions compared to controls. Conversely, NAA levels were significantly lower in patients compared to controls, and lower in the EZ compared to PZ and NIZ. Multiple regression analyzing the relationship between sodium and metabolites levels revealed significant relations in PZ and in NIZ but not in EZ.Our results are in agreement with the energetic failure hypothesis in epileptic regions associated with widespread tissue reorganization.

Published
2022
Full Text
View/download PDF

24. Grey-matter sodium concentration as an individual marker of multiple sclerosis severity

Author

Adil Maarouf, Bertrand Audoin, Soraya Gherib, Mohamed Mounir El Mendili, Patrick Viout, Fanelly Pariollaud, Clémence Boutière, Audrey Rico, Maxime Guye, Jean-Philippe Ranjeva, Wafaa Zaaraoui, Jean Pelletier, Pôle de Neurosciences Cliniques, Service de Neurologie, APHM, Hôpital de la Timone, Aix-Marseille University, Marseille, France, Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre de résonance magnétique biologique et médicale (CRMBM), and Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Sodium, sodium MRI, Brain, Multiple Sclerosis, Chronic Progressive, multiple sclerosis, Magnetic Resonance Imaging, Multiple Sclerosis, Relapsing-Remitting, Neurology, disability, Humans, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Neurology (clinical), Gray Matter, benign, neuronal degeneration, Biomarkers
Abstract

Objective: Quantification of brain injury in patients with variable disability despite similar disease duration may be relevant to identify the mechanisms underlying disability in multiple sclerosis (MS). We aimed to compare grey-matter sodium abnormalities (GMSAs), a parameter reflecting neuronal and astrocyte dysfunction, in MS patients with benign multiple sclerosis (BMS) and non-benign multiple sclerosis (NBMS). Methods: We identified never-treated BMS patients in our local MS database of 1352 patients. A group with NBMS was identified with same disease duration. All participants underwent 23Na magnetic resonance imaging (MRI). The existence of GMSA was detected by statistical analysis. Results: In total, 102 individuals were included (21 BMS, 25 NBMS and 56 controls). GMSA was detected in 10 BMS and 19 NBMS (11/16 relapsing-remitting multiple sclerosis (RRMS) and 8/9 secondary progressive multiple sclerosis (SPMS) patients) ( p = 0.05). On logistic regression including the presence or absence of GMSA, thalamic volume, cortical grey-matter volume and T2-weighted lesion load, thalamic volume was independently associated with BMS status (odds ratio (OR) = 0.64 for each unit). Nonetheless, the absence of GMSA was independently associated when excluding patients with significant cognitive alteration ( n = 7) from the BMS group (OR = 4.6). Conclusion: Detection of GMSA in individuals and thalamic volume are promising to differentiate BMS from NBMS as compared with cortical or whole grey-matter atrophy and T2-weighted lesions.

Published
2022
Full Text
View/download PDF

25. T1-Based Synthetic Magnetic Resonance Contrasts Improve Multiple Sclerosis and Focal Epilepsy Imaging at 7 T

Author

Jean-Philippe Ranjeva, Thomas Troalen, Tobias Kober, Axel Bartoli, Aurélien Massire, Virginie Callot, Charlotte Seiler, Gilles Brun, Olivier M. Girard, Pierre Lehmann, Maxime Guye, Fabrice Bartolomei, Jean Pelletier, Bertrand Audoin, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille Université (AMU), and Assistance Publique - Hôpitaux de Marseille (APHM)

Subjects
medicine.medical_specialty, Magnetic Resonance Spectroscopy, genetic structures, Lesion Identification, Wilcoxon signed-rank test, Image quality, [SDV]Life Sciences [q-bio], 7 t, ultra-high field mri, multiple sclerosis, 030218 nuclear medicine & medical imaging, Lesion, [SPI]Engineering Sciences [physics], 03 medical and health sciences, Epilepsy, 0302 clinical medicine, medicine, Humans, neuroradiology, Radiology, Nuclear Medicine and imaging, ComputingMilieux_MISCELLANEOUS, Retrospective Studies, medicine.diagnostic_test, synthetic mri, business.industry, Multiple sclerosis, Brain, Magnetic resonance imaging, General Medicine, medicine.disease, Magnetic Resonance Imaging, 3. Good health, Multiple comparisons problem, epilepsy, Epilepsies, Partial, Radiology, medicine.symptom, business, mp2rage, 030217 neurology & neurosurgery
Abstract

Objectives, Ultra-high field magnetic resonance imaging (MRI) (>= 7 T) is a unique opportunity to improve the clinical diagnosis of brain pathologies, such as multiple sclerosis or focal epilepsy. However, several shortcomings of 7 T MRI, such as radiofrequency field inhomogeneities, could degrade image quality and hinder radiological interpretation. To address these challenges, an original synthetic MRI method based on T-1 mapping achieved with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) sequence was developed. The radiological quality of on-demand T-1-based contrasts generated by this technique was evaluated in multiple sclerosis and focal epilepsy imaging at 7 T. Materials and Methods, This retrospective study was carried out from October 2017 to September 2019 and included 21 patients with different phenotypes of multiple sclerosis and 35 patients with focal epilepsy who underwent MRI brain examinations using a whole-body investigative 7 T magnetic resonance system. The quality of 2 proposed synthetic contrast images were assessed and compared with conventional images acquired at 7 T using the MP2RAGE sequence by 4 radiologists, evaluating 3 qualitative criteria: signal homogeneity, contrast intensity, and lesion visualization. Statistical analyses were performed on reported quality scores using Wilcoxon rank tests and further multiple comparisons tests. Intraobserver and interobserver reliabilities were calculated as well. Results, Radiological quality scores were reported higher for synthetic images when compared with original images, regardless of contrast, pathologies, or raters considered, with significant differences found for all 3 criteria (P < 0.0001, Wilcoxon rank test). None of the 4 radiologists ever rated a synthetic image "markedly worse" than an original image. Synthetic images were rated slightly less satisfying for only 3 epileptic patients, without precluding lesion identification. Conclusion, T-1-based synthetic MRI with the MP2RAGE sequence provided on-demand contrasts and high-quality images to the radiologist, facilitating lesion visualization in multiple sclerosis and focal epilepsy, while reducing the magnetic resonance examination total duration by removing an additional sequence.

Published
2020
Full Text
View/download PDF

26. An Alzheimer Disease Challenge Model: 24-Hour Sleep Deprivation in Healthy Volunteers, Impact on Working Memory, and Reversal Effect of Pharmacological Intervention

Author

Jean-Philippe Ranjeva, Romain Truillet, Christine Audebert, Joëlle Micallef, Alexandra Auffret, Jill C. Richardson, Marie-Noëlle Lefebvre, Céline Vervueren, Dominique Deplanque, Laura Lanteaume, David Bartrés-Faz, Anna Chan Kwong, Arnaud Beck, Catherine Cassé-Perrot, Pierre Payoux, Amélie Ponchel, Franck Rouby, Elisabeth Jouve, Marie-Claude Costes-Salon, Olivier Blin, Claudio Babilon, and Régis Bordet

Subjects
Adult, Male, Modafinil, Models, Psychological, Neuropsychological Tests, Placebo, law.invention, 03 medical and health sciences, 0302 clinical medicine, Double-Blind Method, Randomized controlled trial, Alzheimer Disease, Memantine, law, Reaction Time, medicine, Humans, Cognitive Dysfunction, Donepezil, Pharmacology (medical), Nootropic Agents, Cross-Over Studies, business.industry, medicine.disease, Crossover study, Healthy Volunteers, 030227 psychiatry, 3. Good health, Psychiatry and Mental health, Sleep deprivation, Memory, Short-Term, Anesthesia, Sleep Deprivation, medicine.symptom, Alzheimer's disease, business, 030217 neurology & neurosurgery, medicine.drug
Abstract

Purpose/background Alzheimer disease (AD) is a public health issue because of the low number of symptomatic drugs and the difficulty to diagnose it at the prodromal stage. The need to develop new treatments and to validate sensitive tests for early diagnosis could be met by developing a challenge model reproducing cognitive impairments of AD. Therefore, we implemented a 24-hour sleep deprivation (SD) design on healthy volunteers in a randomized, double-blind, placebo-controlled, crossover study on 36 healthy volunteers. Methods/procedure To validate the SD model, cognitive tests were chosen to assess a transient worsening of cognitive functions after SD and a restoration under modafinil as positive control (one dose of 200 mg). Then, the same evaluations were replicated after 15 days of donepezil (5 mg/d) or memantine (10 mg/d). The working memory (WM) function was assessed by the N-back task and the rapid visual processing (RVP) task. Findings/results The accuracy of the N-back task and the reaction time of the RVP revealed the alteration of the WM with SD and its restoration with modafinil (changes in score after SD compared with baseline before SD), respectively, in the placebo group and in the modafinil group (-0.2% and +1.0% of satisfactory answers, P = 0.022; +21.3 and +1.9 milliseconds of reaction time, P = 0.025). Alzheimer disease drugs also tended to reverse this deterioration: the accuracy of the N-back task was more stable through SD (compared with -3.0% in the placebo group, respectively, in the memantine group and in the donepezil group: -1.4% and -1.6%, P = 0.027 and P = 0.092) and RVP reaction time was less impacted (compared with +41.3 milliseconds in the placebo group, respectively, in the memantine group and in the donepezil group: +16.1 and +29.3 milliseconds, P = 0.034 and P = 0.459). Implications/conclusions Our SD challenge model actually led to a worsening of WM that was moderated by both modafinil and AD drugs. To use this approach, the cognitive battery, the vulnerability of the subjects to SD, and the expected drug effect should be carefully considered.

Published
2020
Full Text
View/download PDF

27. Respiratory-triggered quantitative MR spectroscopy of the human cervical spinal cord at 7 T

Author

Tangi Roussel, Yann Le Fur, Maxime Guye, Patrick Viout, Jean‐Philippe Ranjeva, Virginie Callot, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), International Laboratory on Spine Imaging and Biomechanics (iLab-Spine), ANR-11-INBS-0006,FLI,France Life Imaging(2011), and ANR-11-EQPX-0001,7T AMI,Projet d'Aix-Marseille Université pour l'IRM 7T chez l'homme(2011)

Subjects
Magnetic Resonance Spectroscopy, Spinal Cord, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Cervical Cord, Humans, Reproducibility of Results, Radiology, Nuclear Medicine and imaging, ComputingMilieux_MISCELLANEOUS, Algorithms
Abstract

International audience; PurposeUltra-high fieldH MR spectroscopy (MRS) is of great interest to help characterizing human spinal cord pathologies. However, very few studies have been reported so far in this small size structure at these fields due to challenging experimental difficulties caused by static and radiofrequency field heterogeneities, as well as physiological motion. In this work, in line with the recent developments proposed to strengthen spinal cord MRS feasibility at 7 T, a respiratory-triggered acquisition approach was optimized to compensate for dynamic Bfield heterogeneities and to provide robust cervical spinal cord MRS data.MethodsA semi-LASER sequence was purposely used, and a dedicated raw data processing algorithm was developed to enhance MR spectral quality by discarding corrupted scans. To legitimate the choices done during the optimization stage, additional tests were carried out to determine the impact of breathing, voluntary motion, body mass index, and fitting algorithm. An in-house quantification tool was concomitantly designed for accurate estimation of the metabolite concentration ratios for choline, N-acetyl-aspartate (NAA), myo-inositol and glutathione. The method was tested on a cohort of 14 healthy volunteers.ResultsAverage water linewidth and NAA signal-to-noise ratio reached 0.04 ppm and 11.01, respectively. The group-average metabolic ratios were in good agreement with previous studies and showed intersession reproducibility variations below 30%.ConclusionThe developed approach allows a rise of the acquired MRS signal quality and of the quantification robustness as compared to previous studies hence offering strengthened possibilities to probe the metabolism of degenerative and traumatic spinal cord pathologies.

Published
2022
Full Text
View/download PDF

28. Automatic segmentation of deep grey nuclei using a high‐resolution 7T magnetic resonance imaging atlas—Quantification of T1 values in healthy volunteers

Author

Gilles Brun, Benoit Testud, Olivier M. Girard, Pierre Lehmann, Ludovic de Rochefort, Pierre Besson, Aurélien Massire, Ben Ridley, Nadine Girard, Maxime Guye, Jean‐Philippe Ranjeva, Arnaud Le Troter, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), and Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Brain Mapping, T1 relaxometry, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, General Neuroscience, Ultra-high field, Template, 7Tesla, Brain, Magnetic Resonance Imaging, Healthy Volunteers, 030218 nuclear medicine & medical imaging, MP2RAGE, Shape-Based Averaging, 03 medical and health sciences, 0302 clinical medicine, Deep Grey Nuclei, Thalamic Nuclei, Image Processing, Computer-Assisted, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Humans, 030217 neurology & neurosurgery, Consensus-Atlas
Abstract

International audience; We present a new consensus atlas of deep grey nuclei obtained by shape-based averaging of manual segmentation of two experienced neuroradiologists and optimized from 7T MP2RAGE images acquired at (0.6mm) 3 in 60 healthy subjects. A group-wise normalization method was used to build a high-contrast and high-resolution T1-weighted brain template (0.5mm) 3 using data from 30 out of the 60 controls. Delineation of 24 deep grey nuclei per hemisphere, including the claustrum and twelve thalamic nuclei, was then performed by two expert neuroradiologists and reviewed by a third neuroradiologist according to tissue contrast and external references based on the Morel atlas. Corresponding deep grey matter structures were also extracted from the Morel and CIT168 atlases. The data-derived, Morel and CIT168 atlases were all applied at the individual level using non-linear registration to fit the subject reference and to extract absolute mean quantitative T1 values derived from the 3D-MP2RAGE volumes, after correction for residual B1 + biases. Three metrics (The Dice and the volumetric similarity coefficients, and a novel Hausdorff distance) were used to estimate the inter-rater agreement of manual MRI segmentation and inter-atlas variability, and these metrics were measured to quantify biases due to image registration and their impact on the measurements of the quantitative T1 values was highlighted. This represents a fully-automated segmentation process permitting the extraction of unbiased normative T1 values in a population of young healthy controls as a reference for characterizing subtle structural alterations of deep grey nuclei relevant to a range of neurological diseases.

Published
2022
Full Text
View/download PDF

29. Comparison of single-voxel 1H-cardiovascular magnetic resonance spectroscopy techniques for in vivo measurement of myocardial creatine and triglycerides at 3T

Author

Frank Kober, Jean-Philippe Ranjeva, Claire Costes, Stanislas Rapacchi, Tangi Roussel, Patrick Viout, Monique Bernard, Maxime Guye, Joevin Sourdon, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), ANR-11-IDEX-0001,Amidex,INITIATIVE D'EXCELLENCE AIX MARSEILLE UNIVERSITE(2011), ANR-11-INBS-0006,FLI,France Life Imaging(2011), and AP-HM, Pôle d'imagerie médicale, Hôpital de la Timone, CEMEREM, Marseille, France

Subjects
medicine.medical_specialty, Magnetic Resonance Spectroscopy, Single voxel, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, SLASER, 030204 cardiovascular system & hematology, Creatine, Imaging phantom, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Nuclear magnetic resonance, Predictive Value of Tests, In vivo, Linear regression, medicine, Diseases of the circulatory (Cardiovascular) system, Humans, Radiology, Nuclear Medicine and imaging, 3 T, Interventricular septum, Triglycerides, Retrospective Studies, Angiology, Proton magnetic resonance spectroscopy, Radiological and Ultrasound Technology, business.industry, Research, CMR spectroscopy, Reproducibility of Results, Nuclear magnetic resonance spectroscopy, Lipids, medicine.anatomical_structure, chemistry, RC666-701, Protons, Cardiology and Cardiovascular Medicine, business, Cardiac metabolism
Abstract

Background Single-voxel proton cardiovascular magnetic resonance spectroscopy (1H-CMRS) benefits from 3 T to detect metabolic abnormalities with the quantification of intramyocardial fatty acids (FA) and creatine (Cr). Conventional point resolved spectroscopy (PRESS) sequence remains the preferred choice for CMRS, despite its chemical shift displacement error (CSDE) at high field (≥ 3 T). Alternative candidate sequences are the semi-adiabatic Localization by Adiabatic SElective Refocusing (sLASER) recommended for brain and musculoskeletal applications and the localized stimulated echo acquisition mode (STEAM). In this study, we aim to compare these three single-voxel 1H-CMRS techniques: PRESS, sLASER and STEAM for reproducible quantification of myocardial FA and Cr at 3 T. Sequences are compared both using breath-hold (BH) and free-breathing (FB) acquisitions. Methods CMRS accuracy and theoretical CSDE were verified on a purposely-designed fat–water phantom. FA and Cr CMRS data quality and reliability were evaluated in the interventricular septum of 10 healthy subjects, comparing repeated BH and free-breathing with retrospective gating. Results Measured FA/W ratio deviated from expected phantom ratio due to CSDE with all sequences. sLASER supplied the lowest bias (10%, vs -28% and 27% for PRESS and STEAM). In vivo, PRESS provided the highest signal-to-noise ratio (SNR) in FB scans (27.5 for Cr and 103.2 for FA). Nevertheless, a linear regression analysis between the two BH showed a better correlation between myocardial Cr content measured with sLASER compared to PRESS (r = 0.46; p = 0.03 vs. r = 0.35; p = 0.07) and similar slopes of regression lines for FA measurements (r = 0.94; p Conclusion When quantifying myocardial lipids and creatine with CMR proton spectroscopy at 3 T, PRESS provided higher SNR, while sLASER was more reproducible both with single BH and FB scans.

Published
2021
Full Text
View/download PDF

31. A Motion Correction Strategy for Multi-Contrast based 3D parametric imaging: Application to Inhomogeneous Magnetization Transfer (ihMT)

Author

Jean-Philippe Ranjeva, Maxime Guye, Lucas Soustelle, Olivier M. Girard, Gopal Varma, Guillaume Duhamel, Jean Pelletier, Arnaud Le Troter, David C. Alsop, Andreea Hertanu, Julien Lamy, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Harvard Medical School [Boston] (HMS), ANR-17-CE18-0030,verISMO,IRM du transfert d'aimantation inhomogène : vers un nouveau biomarqueur in vivo spécifique et sensible de la myéline(2017), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Duhamel, Guillaume, IRM du transfert d'aimantation inhomogène : vers un nouveau biomarqueur in vivo spécifique et sensible de la myéline - - verISMO2017 - ANR-17-CE18-0030 - AAPG2017 - VALID, and Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM)

Subjects
Computer science, business.industry, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Image registration, Function (mathematics), Motion correction, 030218 nuclear medicine & medical imaging, Image (mathematics), 03 medical and health sciences, 0302 clinical medicine, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, Multi contrast, Parametric imaging, Computer vision, Magnetization transfer, Artificial intelligence, business, 030217 neurology & neurosurgery
Abstract

PurposeTo propose an efficient retrospective image-based method for motion correction of multi-contrast acquisitions with a low number of available images (MC-MoCo) and evaluate its use in 3D inhomogeneous Magnetization Transfer (ihMT) experiments in the human brain.MethodsA framework for motion correction, including image pre-processing enhancement and rigid registration to an iteratively improved target image, was developed. The proposed method was compared to Motion Correction with FMRIB’s Linear Image Registration Tool (MCFLIRT) function in FSL over 13 subjects. Native (pre-correction) and residual (post-correction) motions were evaluated by means of markers positioned at well-defined anatomical regions over each image.ResultsBoth motion correction strategies significantly reduced inter-image misalignment, and the MC-MoCo method yielded significantly better results than MCFLIRT.ConclusionMC-MoCo is a high-performance method for motion correction of multi-contrast volumes as in 3D ihMT imaging.

Published
2021

32. A strategy to reduce the sensitivity of inhomogeneous Magnetization Transfer (ihMT) imaging to radiofrequency transmit field variations at 3 T

Author

Maxime Guye, Thomas Troalen, Gopal Varma, Jean-Philippe Ranjeva, Andreea Hertanu, David C. Alsop, Guillaume Duhamel, Lucas Soustelle, Olivier M. Girard, Samira Mchinda, Centre de résonance magnétique biologique et médicale (CRMBM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Marseille] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE), Siemens Healthcare [France], Siemens AG [Munich], Beth Israel Deaconess Medical Center [Boston] (BIDMC), Harvard Medical School [Boston] (HMS), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), and ANR-17-CE18-0030,verISMO,IRM du transfert d'aimantation inhomogène : vers un nouveau biomarqueur in vivo spécifique et sensible de la myéline(2017)

Subjects
Reproducibility, Materials science, Radio Waves, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Brain, Reproducibility of Results, Magnetic Resonance Imaging, White Matter, Healthy Volunteers, 030218 nuclear medicine & medical imaging, Computational physics, Power (physics), Root mean square, 03 medical and health sciences, 0302 clinical medicine, Humans, Radiology, Nuclear Medicine and imaging, Radio frequency, Magnetization transfer, Sensitivity (control systems), Saturation (chemistry), 030217 neurology & neurosurgery, Energy (signal processing)
Abstract

International audience; PurposeTo minimize the sensitivity of inhomogeneous magnetization transfer gradient-echo (ihMT-GRE) imaging to radiofrequency (RF) transmit field (urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0003) inhomogeneities at 3 T.MethodsThe ihMT-GRE sequence was optimized by varying the concentration of the RF saturation energy over time, obtained by increasing the saturation pulse power while extending the sequence repetition time (TR). Different protocols were tested using numerical simulations and human in vivo experiments in the brain white matter (WM) of healthy subjects at 3 T. The sensitivity of the ihMT ratio (ihMTR) to urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0004 variations was investigated by comparing measurements obtained at nominal transmitter adjustments and following a 20% global urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0005 drop. The resulting relative variations (δihMTR) were evaluated voxelwise as a function of the local urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0006 distribution. The reproducibility of the protocol providing minimal urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0007 bias was assessed in a test-retest experiment.ResultsIn line with simulations, ihMT-GRE experiments conducted at high concentration of the RF energy over time demonstrated strong reduction of the urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0008 inhomogeneity effects in the human WM. Under the optimal conditions of 350-ms TR and 3-µT root mean square (RMS) saturation power, 73% of all WM voxels presented δihMTR below 10%. Reproducibility analysis yielded a close-to-zero systematic bias (ΔihMTR = −0.081%) and a high correlation (ρ² = 0.977) between test and retest experiments.ConclusionConcentrating RF saturation energy in ihMT-GRE sequences mitigates the sensitivity of the ihMTR to urn:x-wiley:07403194:media:mrm29055:mrm29055-math-0009 variations and allows for clinical-ready ihMT imaging at 3 T. This feature is of particular interest for high and ultra-high field applications.

Published
2021
Full Text
View/download PDF

34. Quantitative Brain Sodium MRI Depicts Corticospinal Impairment in Amyotrophic Lateral Sclerosis

Author

Lothar R. Schad, Shahram Attarian, Wafaa Zaaraoui, Aude-Marie Grapperon, Maxime Guye, Jean-Philippe Ranjeva, Ben Ridley, Sylviane Confort-Gouny, Etienne Fortanier, Annie Verschueren, Adil Maarouf, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS), Centre de référence des maladies rares neuromusculaires, Assistance Publique - Hôpitaux de Marseille (APHM)-CHU Marseille, AP-HM, Pôle d'imagerie médicale, Hôpital de la Timone, CEMEREM, Marseille, France, University of Heidelberg, Medical Faculty, Centre de référence des maladies neuromusculaires et de la SLA, Hôpital de la Timone [CHU - APHM] (TIMONE), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), and Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Adult, Male, medicine.medical_specialty, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, medicine.medical_treatment, Sodium, Pyramidal Tracts, chemistry.chemical_element, Corpus callosum, computer.software_genre, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Atrophy, Voxel, Internal medicine, medicine, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, Amyotrophic lateral sclerosis, Prospective cohort study, ComputingMilieux_MISCELLANEOUS, Aged, business.industry, Amyotrophic Lateral Sclerosis, Brain, Middle Aged, medicine.disease, Magnetic Resonance Imaging, Transcranial magnetic stimulation, chemistry, Evaluation Studies as Topic, 030220 oncology & carcinogenesis, Sodium MRI, Cardiology, Female, Sodium Isotopes, business, computer
Abstract

Background Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that mainly affects the upper and lower motor neurons. Recent sodium (23Na) MRI studies have shown that abnormal sodium concentration is related to neuronal suffering in neurodegenerative conditions. Purpose To use 23Na MRI to investigate abnormal sodium concentrations and map their distribution in the brains of study participants with ALS as compared with healthy control subjects. Materials and Methods Twenty-seven participants with ALS (mean age, 54 years ± 10 [standard deviation], eight women) and 30 healthy control subjects (mean age, 50 years ± 10; 16 women) were prospectively recruited between September 2015 and October 2017 and were examined by using conventional proton MRI and sodium MRI at 3 T. Voxel-based statistical mapping was used to compare quantitative whole-brain total sodium concentration (TSC) maps in participants with ALS with those in control subjects and to localize regions of abnormal elevated TSC. Potential overlap of abnormal elevated TSC with regions of atrophy as detected with 1H MRI also was investigated. Results Voxel-based statistical mapping analyses revealed higher sodium concentration in motor regions (bilateral precentral gyri, corticospinal tracts, and the corpus callosum) of participants with ALS (two-sample t test, P < .005; age and sex as covariates). In these regions, mean TSC was higher in participants with ALS (mean, 45.6 mmol/L wet tissue ± 3.2) than in control subjects (mean, 41.8 mmol/L wet tissue ± 2.7; P < .001; Cohen d = 1.28). Brain regions showing higher TSC represented a volume of 15.4 cm3 that did not overlap with gray matter atrophy occupying a volume of 16.9 cm3. Elevated TSC correlated moderately with corticospinal conduction failure assessed with transcranial magnetic stimulation in the right upper limb (Spearman ρ = -0.57; 95% confidence interval: -0.78, -0.16; P = .005; n = 23). Conclusion Quantitative 23Na MRI is sensitive to alterations of brain sodium homeostasis within disease-relevant regions in patients with amyotrophic lateral sclerosis (ALS). This supports further investigation of abnormal sodium concentration as a potential marker of neurodegenerative processes in patients with ALS that could be used as a secondary endpoint in clinical trials. © RSNA, 2019 Online supplemental material is available for this article.

Published
2019
Full Text
View/download PDF

35. Epileptogenic networks in drug-resistant epilepsy with amygdala enlargement: Assessment with stereo-EEG and 7 T MRI

Author

Maxime Guye, Jean-Philippe Ranjeva, Samuel Medina Villalon, Julia Makhalova, Sandrine Aubert-Conil, Agnès Trébuchon, Romain Carron, Christian Bénar, Bernard Giusiano, Aileen McGonigal, Fabrice Bartolomei, Arnaud Le Troter, Centre de résonance magnétique biologique et médicale (CRMBM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Service de neurophysiologie clinique [Hôpital de la Timone - APHM], Hôpital de la Timone [CHU - APHM] (TIMONE), AP-HM, Pôle d'imagerie médicale, Hôpital de la Timone, CEMEREM, Marseille, France, Institut de Neurosciences des Systèmes (INS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Adult, Male, Drug Resistant Epilepsy, Adolescent, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Amygdala, Epileptogenesis, 03 medical and health sciences, Epilepsy, Young Adult, 0302 clinical medicine, Stereo eeg, Physiology (medical), Medicine, Humans, Child, ComputingMilieux_MISCELLANEOUS, Depression (differential diagnoses), 030304 developmental biology, 0303 health sciences, Brain Mapping, business.industry, Electroencephalography, medicine.disease, Magnetic Resonance Imaging, Sensory Systems, medicine.anatomical_structure, nervous system, Neurology, Child, Preschool, Etiology, Anxiety, Female, Neurology (clinical), Epilepsies, Partial, medicine.symptom, Nerve Net, business, Neuroscience, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, psychological phenomena and processes, 030217 neurology & neurosurgery
Abstract

Objective Amygdala enlargement is increasingly described in association with temporal lobe epilepsies. Its significance, however, remains uncertain both in terms of etiology and its link with psychiatric disorders and of its involvement in the epileptogenic zone. We assessed the epileptogenic networks underlying drug-resistant epilepsy with amygdala enlargement and investigated correlations between clinical features, epileptogenicity and morphovolumetric amygdala characteristics. Methods We identified 12 consecutive patients suffering from drug-resistant epilepsy with visually suspected amygdala enlargement and available stereoelectroencephalographic recording. The epileptogenic zone was defined using the Connectivity Epileptogenicity Index. Morphovolumetric measurements were performed using automatic segmentation and co-registration on the 7TAMIbrain Amygdala atlas. Results The epileptogenic zone involved the enlarged amygdala in all but three cases and corresponded to distributed, temporal-insular, temporal-insular-prefrontal or prefrontal-temporal networks in ten cases, while only two were temporo-mesial networks. Morphovolumetrically, amygdala enlargement was bilateral in 75% of patients. Most patients presented psychiatric comorbidities (anxiety, depression, posttraumatic stress disorder). The level of depression defined by screening questionnaire was positively correlated with the extent of amygdala enlargement. Conclusions Drug-resistant epilepsy with amygdala enlargement is heterogeneous; most cases implied “temporal plus” networks. Significance The enlarged amygdala could reflect an interaction of stress-mediated limbic network alterations and mechanisms of epileptogenesis.

Published
2021
Full Text
View/download PDF

36. Aquaporin 4 distribution in the brain and its relevance for the radiological appearance of neuromyelitis optica spectrum disease

Author

Roxana Ameli, Charles R.G. Guttmann, Juan Carlos Prieto, Fabien Rollot, Miklos Palotai, Sandra Vukusic, Romain Marignier, François Cotton, René Anxionnat, Jean-Paul Armspach, Bertrand Audoin, Christian Barillot, Isabelle Berry, Fabrice Bonneville, Claire Boutet, Giovanni Castelnovo, Frédéric Cervenanski, Mikael Cohen, Olivier Commowick, Jerome De Seze, Vincent Dousset, Francoise Durand-Dubief, Gilles Edan, Jean-Christophe Ferre, Damien Galanaud, Tristan Glattard, Sylvie Grand, Justine Guillaumont, Rémy Guillevin, Salem Hannoun, Fabrice Heitz, Alexandre Krainik, Stéphane Kremer, Pierre Labauge, Nicolas Menjot De Champfleur, Jean-Philippe Ranjeva, Jean-Amédée Roch, Dominique Sappey-Marinier, Julien Savatovsky, Bruno Stankoff, Ayman Tourbah, Thomas Tourdias, Bruno Brochet, Michel Clanet, Nathalie Dufay, David Laplaud, Marie-Claire Maze, Thibault Moreau, Cédric Trolliet, Bernard Frangoulis, Javier Olaiz, Jean Pelletier, Bertrand Bourre, David Brassat, Philippe Cabre, Jean-Philippe Camdessanche, William Camu, Olivier Casez, Pierre Clavelou, Nicolas Collongues, Alain Creange, Gilles Defer, Marc Debouverie, Olivier Gout, Christine Lebrun-Frenay, Catherine Lubetzki, Caroline Papeix, Patrick Vermersch, Hélène Zephir, Service de Radiologie [Hôpital Femme Mère Enfant - HCL], Hôpital Femme Mère Enfant [CHU - HCL] (HFME), Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Department of Radiology [Boston], Brigham and Women's Hospital [Boston], Observatoire Français de la Sclérose En Plaques [Lyon] (OFSEP), Service de Neurologie [Lyon], CHU Lyon, Centre de recherche en neurosciences de Lyon - Lyon Neuroscience Research Center (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie Adaptative Diagnostique et Interventionnelle (IADI), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL), Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Neuroimagerie: méthodes et applications (Empenn), Institut National de la Santé et de la Recherche Médicale (INSERM)-Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-SIGNAUX ET IMAGES NUMÉRIQUES, ROBOTIQUE (IRISA-D5), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Service de Médecine Nucléaire - Pierre-Paul Riquet [CHU Toulouse], Pôle imagerie médicale [CHU Toulouse], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Pôle Neurosciences [CHU Toulouse], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Service de Radiologie [CHU Saint-Etienne], Centre Hospitalier Universitaire de Saint-Etienne [CHU Saint-Etienne] (CHU ST-E)-Université Jean Monnet - Saint-Étienne (UJM), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Service de Neurologie [CHU Nice], Hôpital Pasteur [Nice] (CHU)-Centre Hospitalier Universitaire de Nice (CHU Nice), CHU Strasbourg, Neurocentre Magendie : Physiopathologie de la Plasticité Neuronale (U1215 Inserm - UB), Université de Bordeaux (UB)-Institut François Magendie-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de neuroradiologie [Grenoble], CHU Grenoble, Centre hospitalier universitaire de Poitiers (CHU Poitiers), Département de neurologie [Montpellier], Université Montpellier 1 (UM1)-Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Hôpital Gui de Chauliac [CHU Montpellier], Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Université de Montpellier (UM), Institut d’Imagerie Fonctionnelle Humaine [CHU Montpellier] (I2FH), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Hôpital privé Jean Mermoz [Lyon], CHU Rothschild [AP-HP], CHU Tenon [AP-HP], Université de Reims Champagne-Ardenne (URCA), Service de neurologie [Bordeaux], CHU Bordeaux [Bordeaux]-Groupe hospitalier Pellegrin, Neurologie Vasculaire [Toulouse], Service de neurochirurgie [CHU Nantes], Centre hospitalier universitaire de Nantes (CHU Nantes)-Hôpital Guillaume-et-René-Laennec [Saint-Herblain], Service de Neurologie générale, vasculaire et dégénérative (CHU de Dijon), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Fondation Eugène Devic EDMUS, Hôpital Charles Nicolle [Rouen], CHU Rouen, Normandie Université (NU)-Normandie Université (NU), Hôpital Albert Clarac [CHU de la Martinique], CHU de la Martinique [Fort de France], Centre Hospitalier Universitaire de Saint-Etienne [CHU Saint-Etienne] (CHU ST-E), Institut de Biologie Computationnelle (IBC), Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Département de neurologie, Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble, Service de Neurologie [CHU Clermont-Ferrand], CHU Gabriel Montpied [Clermont-Ferrand], CHU Clermont-Ferrand-CHU Clermont-Ferrand-CHU Estaing [Clermont-Ferrand], CHU Clermont-Ferrand, Hôpital de Hautepierre [Strasbourg], Département de neurosciences (CHU Henri Mondor), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Henri Mondor, Service de Neurologie [CHU Caen], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-CHU Caen, Normandie Université (NU)-Tumorothèque de Caen Basse-Normandie (TCBN)-Tumorothèque de Caen Basse-Normandie (TCBN), Service de neurologie [CHRU Nancy], Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy), Département de neurologie [Lille], Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Empenn, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes 1 (UR1), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Service de Médecine Nucléaire [Toulouse], CHU Toulouse [Toulouse], Pôle neurosciences [Hôpital de Purpan - Toulouse], Service de radiologie [Saint-Etienne], CHU Saint-Etienne-Université Jean Monnet [Saint-Étienne] (UJM), Service de Neuroradiologie [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université Montpellier 1 (UM1)-Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Hôpital Gui de Chauliac [Montpellier]-Université de Montpellier (UM), Hôpital Rothschild [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse], Service de neurochirurgie [Nantes], Hôpital Nord (Saint Etienne), Service de Neurologie [CHU Pitié-Salpêtrière], IFR70-CHU Pitié-Salpêtrière [AP-HP], and Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)

Subjects
Male, Pathology, medicine.medical_specialty, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Myelitis, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, medicine, Humans, Radiology, Nuclear Medicine and imaging, Clinical significance, Retrospective Studies, Aquaporin 4, Neuromyelitis optica, Radiological and Ultrasound Technology, business.industry, Incidence (epidemiology), Neuromyelitis Optica, Brain, Human brain, Middle Aged, medicine.disease, Spinal cord, Magnetic Resonance Imaging, medicine.anatomical_structure, Cohort, Female, Neurology (clinical), business, 030217 neurology & neurosurgery
Abstract

International audience; Background and purposeTo determine the precise incidence of lesions at sites of high Aquaporin-4 expression (hAQP4) and their possible association with known neuromyelitis optica spectrum disease (NMOSD) lesions patterns.Materials and methodsA retrospective analysis of brain and, when available, spinal cord MRI scans of 54 NMOSD patients recruited among the French NMOSD cohort was performed. Brain lesions were annotated as MS-like, non-specific, or evocative of NMOSD. The topography of hAQP4 was reassessed by human brain atlas. The incidence of lesions in hAQP4 and their association with lesions evocative of NMOSD was estimated.ResultsAmong those included (41/54 female, mean age: 45 years) 47/54 (87%) presented brain lesions. Twenty-six/47 (55%) had lesions in hAQP4. Thirty-two/54 patients (60%) had lesions considered evocative of NMOSD. The majority of them also presented lesions in hAQP4 (65%, 21/32). Patients with lesions in hAQP4 and lesions evocative of NMOSD demonstrated more extensive myelitis compared to the other patients (7 [6–10] versus 4 [3–5] vertebral segments, P = 0.009).ConclusionThe coexistence of lesions evocative of NMOSD and in hAQP4 is associated with significantly more extensive myelitis, and might have pathophysiological and clinical significance.

Published
2021
Full Text
View/download PDF

37. Delayed access to conscious processing in multiple sclerosis: Reduced cortical activation and impaired structural connectivity

Author

Arzu C, Has Silemek, Jean-Philippe, Ranjeva, Bertrand, Audoin, Christoph, Heesen, Stefan M, Gold, Simone, Kühn, Martin, Weygandt, and Jan-Patrick, Stellmann

Subjects
Adult, Male, Multiple Sclerosis, Time Factors, genetic structures, Consciousness, (un)consciousness, anterior visual system, visual backward masking paradigm, Retina, Humans, Cognitive Dysfunction, structural connectivity, Research Articles, Cerebral Cortex, optical coherence tomography, Brain, Middle Aged, Magnetic Resonance Imaging, functional magnetic resonance imaging, Diffusion Tensor Imaging, Pattern Recognition, Visual, Evoked Potentials, Visual, Female, Nerve Net, Perceptual Masking, Research Article
Abstract

Although multiple sclerosis (MS) is frequently accompanied by visuo‐cognitive impairment, especially functional brain mechanisms underlying this impairment are still not well understood. Consequently, we used a functional MRI (fMRI) backward masking task to study visual information processing stratifying unconscious and conscious in MS. Specifically, 30 persons with MS (pwMS) and 34 healthy controls (HC) were shown target stimuli followed by a mask presented 8–150 ms later and had to compare the target to a reference stimulus. Retinal integrity (via optical coherence tomography), optic tract integrity (visual evoked potential; VEP) and whole brain structural connectivity (probabilistic tractography) were assessed as complementary structural brain integrity markers. On a psychophysical level, pwMS reached conscious access later than HC (50 vs. 16 ms, p, Although multiple sclerosis (MS) is frequently accompanied by visuo‐cognitive impairment, especially functional brain mechanisms underlying this impairment are still not well understood. Consequently, we used a functional MRI (fMRI) backward masking task to study visual information processing stratifying unconscious and conscious in MS. Our study revealed slowed conscious access to visual stimulus material in MS and a complex pattern of functional and structural alterations coupled to unconscious processing of/delayed conscious access to visual stimulus material in MS.

Published
2021

38. Contributions of PET and MRI imaging in the evaluation of CNS drugs in human neurodegenerative diseases

Author

Pierre Payoux, Jean-Philippe Ranjeva, Toulouse Neuro Imaging Center (ToNIC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Purpan [Toulouse], CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse], Centre de résonance magnétique biologique et médicale (CRMBM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Toulouse Mind & Brain Institut (TMBI), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), and Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
2019-20 coronavirus outbreak, Mri imaging, Coronavirus disease 2019 (COVID-19), [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Neuroimaging, Bioinformatics, 03 medical and health sciences, 0302 clinical medicine, Clinical trials, Medicine, Humans, Pharmacology (medical), ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, 0303 health sciences, business.industry, Neurodegenerative diseases, Magnetic Resonance Imaging, 3. Good health, Clinical trial, PET, Pharmaceutical Preparations, New disease, Positron-Emission Tomography, business, 030217 neurology & neurosurgery, MRI
Abstract

International audience; This manuscript reviews the contributions of the neuroimaging methods including PET, conventional and advanced MRI methods to monitor the effect of new disease modifying drugs in neurodegenerative diseases. It now seems obvious that in many pathologies these two techniques are more and more complementary.

Published
2021
Full Text
View/download PDF

39. 7T Epilepsy Task Force Consensus Recommendations on the Use of 7T MRI in Clinical Practice

Author

Jacobus F.A. Jansen, Thomas R. Henry, Pierre-Francois Van de Moortele, Boris C. Bernhardt, Natalie L. Voets, Jonathan R. Polimeni, Tim J. Veersema, Lucie Hertz-Pannier, Jullie W. Pan, Giske Opheim, Lars H. Pinborg, Neda Bernasconi, Michael T. Jurkiewicz, Jean-Philippe Ranjeva, Mirco Cosottini, Heath R. Pardoe, Srinivasan Mukundan, Karl Rössler, Irene Wang, Renzo Guerrini, Albert J. Colon, Karin Markenroth Bloch, Maria Vargas, Andrea Bernasconi, Isabella M. Björkman-Burtscher, Esther Steijvers, Sandhitsu R. Das, Serge Vulliemoz, Rong Xue, Alexandre Vignaud, Shuli Liang, Ruoyun Emily Ma, Siegfried Trattnig, Maxime Guye, Stephen E. Jones, Fabrice Bartolomei, Kathryn A. Davis, Steven M. Stufflebeam, Sara Inati, Joel M. Stein, Christopher Wiggins, Anja G. van der Kolk, Maria Strandberg, Ali R. Khan, Neurobiology Research Unit, Department of Neurology Rigshospitalet Copenhagen University Hospital, UCPH, Faculty of Health and Medical Sciences, UCPH, Utrecht Brain Center [UMC], University Medical Center [Utrecht], Department of Radiology University Medical Center Utrecht, Lund University [Lund], Department of Neurology Neurophysiology and Neurosurgery, ACE Kempenhaeghe/MUMC, Heeze/Maastricht, PENN Epilepsy Center, University of Pennsylvania, Department of Neurology University of Minnesota, Minneapolis, Department of Radiology and Nuclear Medicine Maastricht University Medical Center, School for Mental Health and Neuroscience [Maastricht] (MHeNs), Maastricht University [Maastricht], Imaging Institute [Cleveland], Cleveland Clinic, Department of Neurology and Radiology University of Pittsburg, Medizinische Universität Wien = Medical University of Vienna, Department of Radiology Hospital of the University of Pennsylvania, Philadelphia, Departments of Neurology and Clinical Sciences Lund University Hospital, Center for Magnetic Resonance Research [Minneapolis] (CMRR), University of Minnesota Medical School, University of Minnesota System-University of Minnesota System, Neuroradiology Division, Diagnostic Unit University Hospitals and Faculty of Medicine of Geneva, Epilepsy Center Cleveland Clinic, Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de neurophysiologie clinique [Hôpital de la Timone - APHM], Hôpital de la Timone [CHU - APHM] (TIMONE), McConnell Brain Imaging Centre (MNI), Montreal Neurological Institute and Hospital, McGill University = Université McGill [Montréal, Canada]-McGill University = Université McGill [Montréal, Canada], University of Gothenburg (GU), Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa - Università di Pisa, Department of Neurology University of Pennsylvania, Philadelphia, Building large instruments for neuroimaging: from population imaging to ultra-high magnetic fields (BAOBAB), Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), EEG Section, NINDS, NIH, Bethesda, Department of Medical Imaging Children's Hospital at London Health Sciences Centre, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Imaging Research Laboratories, Robarts Research Institute, London, Functional Neurosurgery Department Beijing Children's Hospital of Capital Medical University, Beijing, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Epilepsy Clinic, Department of Neurology, Rigshospitalet Copenhagen University Hospital, Harvard-MIT Division of Health Sciences and Technology [Cambridge], Massachusetts Institute of Technology (MIT), Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School [Boston] (HMS)-Massachusetts General Hospital [Boston], Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Scannexus Ultrahigh Field MRI Research Center, Maastricht, Department of Radiology and Nuclear Medicine Meander Medical Center, Amersfoort, Laboratoire d'Imagerie et de Spectroscopie (LRMN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Wellcome Trust Centre for Integrative Neuroimaging (WIN - FMRIB), University of Oxford, Université de Genève = University of Geneva (UNIGE), State Key Laboratory of Cognitive Neuroscience and Learning, International Data Group/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China, Università degli Studi di Firenze = University of Florence (UniFI), IMAGO 7 Foundation, Florence, UMC Utrecht Brain Center, Utrecht University, Lund University Bioimaging Center, Lund University, University of Pennsylvania [Philadelphia], School for Mental Health and Neuroscience, Maastricht University, Department of Neurosurgery Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy [Medical University of Vienna], High Field MR Center, Medical University of Vienna, Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Department of Radiology Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Unité Baobab (BAOBAB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Massachusetts General Hospital [Boston]-Harvard Medical School [Boston] (HMS), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), University of Oxford [Oxford], EEG and Epilepsy Unit Neurology, Department of Clinical Neurosciences, University Hospitals and Faculty of Medicine of Geneva, and Neuroscience Department Children's Hospital A. Meyer-University of Florence

Subjects
medicine.medical_specialty, Neurology, Consensus, Referral, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, IMAGES, MEDLINE, ddc:616.0757, PROSPECTIVE MOTION-CORRECTION, CLASSIFICATION, 3T, 03 medical and health sciences, Epilepsy, 0302 clinical medicine, Medicine, Humans, In patient, Medical physics, 030212 general & internal medicine, Views & Reviews, medicine.diagnostic_test, business.industry, Task force, Brain, Magnetic resonance imaging, medicine.disease, CEREBRAL CAVERNOUS MALFORMATIONS, Magnetic Resonance Imaging, 3. Good health, ddc:616.8, Clinical Practice, FMRI, Neurology (clinical), business, 030217 neurology & neurosurgery, SYSTEM
Abstract

International audience; Identifying a structural brain lesion on MRI has important implications in epilepsy and is the most important factor that correlates with seizure freedom after surgery in patients with drug-resistant focal onset epilepsy. However, at conventional magnetic field strengths (1.5 and 3T), only approximately 60%–85% of MRI examinations reveal such lesions. Over the last decade, studies have demonstrated the added value of 7T MRI in patients with and without known epileptogenic lesions from 1.5 and/or 3T. However, translation of 7T MRI to clinical practice is still challenging, particularly in centers new to 7T, and there is a need for practical recommendations on targeted use of 7T MRI in the clinical management of patients with epilepsy. The 7T Epilepsy Task Force—an international group representing 21 7T MRI centers with experience from scanning over 2,000 patients with epilepsy—would hereby like to share its experience with the neurology community regarding the appropriate clinical indications, patient selection and preparation, acquisition protocols and setup, technical challenges, and radiologic guidelines for 7T MRI in patients with epilepsy. This article mainly addresses structural imaging; in addition, it presents multiple nonstructural MRI techniques that benefit from 7T and hold promise as future directions in epilepsy. Answering to the increased availability of 7T MRI as an approved tool for diagnostic purposes, this article aims to provide guidance on clinical 7T MRI epilepsy management by giving recommendations on referral, suitable 7T MRI protocols, and image interpretation.

Published
2021
Full Text
View/download PDF

40. Additional file 1 of Comparison of single-voxel 1H-cardiovascular magnetic resonance spectroscopy techniques for in vivo measurement of myocardial creatine and triglycerides at 3T

Author

Sourdon, Joevin, Roussel, Tangi, Costes, Claire, Viout, Patrick, Guye, Maxime, Jean-Philippe Ranjeva, Bernard, Monique, Kober, Frank, and Rapacchi, Stanislas

Subjects
body regions, food and beverages, equipment and supplies, complex mixtures, humanities
Abstract

Additional file 1. Results obtained on creatine phantom with PRESS, sLASER and STEAMs.

Published
2021
Full Text
View/download PDF

41. Amygdalar nuclei and hippocampal subfields on MRI: Test‐retest reliability of automated segmentation in old and young healthy volunteers

Author

Agnese Picco, Núria Bargalló, Antonios Drevelegas, Mira Didic, Régis Bordet, Moira Marizzoni, Bernhard W. Müller, Piero Floridi, Björn H. Schott, Michela Pievani, Giovanni B. Frisoni, Jill C. Richardson, Alberto Beltramello, Tilman Hensch, Marco Salvatore, Flavio Nobili, Pierre Payoux, Roberto Tarducci, Jorge Jovicich, Magda Tsolaki, Karl-Titus Hoffmann, Jens Wiltfang, Camillo Marra, Renaud Lopes, Jean-Philippe Ranjeva, Pieter Jelle Visser, Giulia Quattrini, Lucilla Parnetti, Manos Constantinides, Frederik Barkhof, David Bartrés-Faz, Francesca B. Pizzini, Julien Sein, Antonio Ferretti, Olivier Blin, Ute Fiedler, Luca Roccatagliata, Massimo Caulo, Andrea Soricelli, Paolo Maria Rossini, Joost P.A. Kuijer, Helene Gros-Dagnac, Marco Aiello, and Peter Schönknecht

Subjects
medicine.medical_specialty, Epidemiology, business.industry, Health Policy, Automated segmentation, Hippocampal formation, Audiology, Test (assessment), Psychiatry and Mental health, Cellular and Molecular Neuroscience, Developmental Neuroscience, Neuroimaging, Healthy volunteers, Medicine, Neurology (clinical), Geriatrics and Gerontology, business, Brain aging, Reliability (statistics)
Published
2020
Full Text
View/download PDF

42. CSF cutoffs for MCI due to AD depend on APOEε4 carrier status

Author

Jean-Philippe Ranjeva, Frederik Barkhof, Jorge Jovicich, Régis Bordet, Jill C. Richardson, Elena Rolandi, Magda Tsolaki, Andrea Soricelli, Olivier Blin, Lucilla Parnetti, Marco Salvatore, Claudio Babiloni, Tilman Hensch, Jens Wiltfang, Camillo Marra, José Luis Molinuevo, Libera Cavaliere, Samantha Galluzzi, Moira Marizzoni, Diego Albani, Mira Didic, Clarissa Ferrari, Flavio Nobili, Federica Fusco, Paolo Maria Rossini, Giovanni B. Frisoni, Gianluigi Forloni, Federica Ribaldi, Pierre Payoux, Pieter Jelle Visser, Centro San Giovanni di Dio, Fatebenefratelli, Brescia (IRCCS), Università degli Studi di Brescia [Brescia], Department of Physiology and Pharmacology 'Vittorio Erspamer', Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Neuroscience Department, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milano, Department of Radiology and Nuclear Medicine [Amsterdam], VU University Medical Center [Amsterdam], Institutes of Neurology and Healthcare Engineering, UCL, London, Institut de Neurosciences des Systèmes (INS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Department of Psychiatry and Psychotherapy, University of Leipzig Medical Center, Leipzig, Center for Mind/Brain Sciences, University of Trento, Corso Bettini, 31, 38068, Rovereto, TN, Italy, Department of Gerontology, Neurosciences & Orthopedics, Catholic University, Rome, Alzheimer's Disease Unit and Other Cognitive Disorders Unit, Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Dipartimento di Neuroscienze, riabilitazione, oftalmologia, genetica e scienze materno-infantili [Genova] (DINOGMI), Universita degli studi di Genova, Section of Neurology, Centre for Memory Disturbances, University of Perugia, Toulouse Neuro Imaging Center (ToNIC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Purpan [Toulouse], CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse], Centre de résonance magnétique biologique et médicale (CRMBM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Area Neuroscience, IRCCS San Raffaele, Rome, IRCCS SDN Napoli, Department of Neurology (Aristotle University of Thessaloniki), Aristotle University of Thessaloniki, Alzheimer Center Amsterdam, LVR-Clinic for Psychiatry and Psychotherapy, Institutes and Clinics of the University Duisburg-Essen, GlaxoSmithKline [Stevenage, UK] (GSK), GlaxoSmithKline [Headquarters, London, UK] (GSK), Lille Neurosciences & Cognition - U 1172 (LilNCog (ex-JPARC)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Centre investigation clinique - Unité de pharmacologie clinique et d'évaluations thérapeutiques (CIC-UPCET), Assistance Publique - Hôpitaux de Marseille (APHM), Laboratory of Neuroimaging of aging, Memory clinic and LANVIE, Geneva University Hospital and Geneva University, Amsterdam Neuroscience - Neurodegeneration, Radiology and nuclear medicine, Università degli Studi di Brescia = University of Brescia (UniBs), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Leipzig University, Università degli Studi di Trento (UNITN), Università degli studi di Genova = University of Genoa (UniGe), Università degli Studi di Perugia = University of Perugia (UNIPG), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Toulouse Mind & Brain Institut (TMBI), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), and Lille Neurosciences & Cognition - U 1172 (LilNCog)

Subjects
Male, 0301 basic medicine, Oncology, Apolipoprotein E, Aging, Medizin, Cohort Studies, 0302 clinical medicine, Cerebrospinal fluid, Cutoff, ComputingMilieux_MISCELLANEOUS, Aged, 80 and over, biology, General Neuroscience, Alzheimer's disease, 3. Good health, Settore MED/26 - NEUROLOGIA, Biomarker (medicine), Female, Heterozygote, medicine.medical_specialty, CSF cutoff, Disease progression, Mild cognitive impairment, Tau protein, tau Proteins, 03 medical and health sciences, Apolipoproteins E, Neuroimaging, Alzheimer Disease, Internal medicine, mental disorders, medicine, Humans, Cognitive Dysfunction, Aged, Amyloid beta-Peptides, Receiver operating characteristic, business.industry, medicine.disease, Peptide Fragments, ddc:616.8, 030104 developmental biology, [SDV.MHEP.PSM]Life Sciences [q-bio]/Human health and pathology/Psychiatrics and mental health, biology.protein, Neurology (clinical), Geriatrics and Gerontology, business, Biomarkers, 030217 neurology & neurosurgery, Developmental Biology
Abstract

Amyloid and tau pathological accumulation should be considered for Alzheimer's disease (AD) definition and before subjects' enrollment in disease-modifying trials. Although age, APOEε4, and sex influence cerebrospinal fluid (CSF) biomarker levels, none of these variables are considered by current normality/abnormality cutoffs. Using baseline CSF data from 2 independent cohorts (PharmaCOG/European Alzheimer's Disease Neuroimaging Initiative and Alzheimer's Disease Neuroimaging Initiative), we investigated the effect of age, APOEε4 status, and sex on CSF Aβ42/P-tau distribution and cutoff extraction by applying mixture models with covariates. The Aβ42/P-tau distribution revealed the presence of 3 subgroups (AD-like, intermediate, control-like) and 2 cutoffs. The identification of the intermediate subgroup and of the higher cutoff was APOEε4 dependent in both cohorts. APOE-specific classification (higher cutoff for APOEε4+, lower cutoff for APOEε4-) showed higher diagnostic accuracy in identifying MCI due to AD compared to single Aβ42 and Aβ42/P-tau cutoffs. APOEε4 influences amyloid and tau CSF markers and AD progression in MCI patients supporting i) the use of APOE-specific cutoffs to identify MCI due to AD and ii) the utility of considering APOE genotype for early AD diagnosis.

Published
2020
Full Text
View/download PDF

43. High levels of serum soluble TWEAK are associated with neuroinflammation during multiple sclerosis

Author

Michel Khrestchatisky, Adil Maarouf, Sophie Desplat-Jégo, Jean Pelletier, Delphine Stephan, Bertrand Audoin, Marie-Pierre Ranjeva, Jean-Philippe Ranjeva, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL), Institut de neurophysiopathologie (INP), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), École pratique des hautes études (EPHE), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Adult, Male, 0301 basic medicine, medicine.medical_specialty, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, medicine.medical_treatment, lcsh:Medicine, Gadolinium, Inflammation, Nervous System, Gastroenterology, General Biochemistry, Genetics and Molecular Biology, Lesion, Multiple sclerosis, 03 medical and health sciences, 0302 clinical medicine, Neuroinflammation, Recurrence, Internal medicine, TWEAK, Humans, Medicine, Cytokine, business.industry, Research, lcsh:R, Cytokine TWEAK, General Medicine, Biomarker, medicine.disease, Magnetic Resonance Imaging, 030104 developmental biology, Solubility, Blood biomarkers, 030220 oncology & carcinogenesis, Biomarker (medicine), Female, Tumor necrosis factor alpha, medicine.symptom, business
Abstract

International audience; Background: Inflammation and demyelination are the main processes in multiple sclerosis. Nevertheless, to date, blood biomarkers of inflammation are lacking. TWEAK, a transmembrane protein that belongs to the TNF ligand family , has been previously identified as a potential candidate. Methods: Twenty-eight patients (9 males, 19 females) were prospectively included after a first clinical episode suggestive of multiple sclerosis and clinically followed during 3 years. Fifty-seven healthy controls were also included. TWEAK serum levels and MRI exams including magnetization transfer imaging were performed at baseline, 6-and 12-month follow-up. Results: TWEAK serum levels were significantly increased in the patient group (mean baseline = 1086 ± 493 pg/ mL, mean M6 = 624 ± 302 pg/mL and mean M12 = 578 ± 245 pg/mL) compared to healthy controls (mean = 467 ± 177 pg/mL; respectively p < 0.0001, 0.01 and 0.06). Serum levels of soluble TWEAK were significantly increased during relapses, compared to time periods without any relapse (respectively 935 ± 489 pg/mL and 611 ± 292 pg/mL, p = 0.0005). Moreover, patients presenting at least one gadolinium-enhanced CNS lesion at base-line (n = 7) displayed significantly increased serum TWEAK levels in comparison with patients without any gadolin-ium-enhanced lesion at baseline (n = 21) (respectively 1421 ± 657 pg/mL vs 975 ± 382 pg/mL; p = 0.02). Finally, no correlation was evidenced between TWEAK serum levels and the extent of brain tissue damage assessed by magneti-zation transfer ratio. Conclusions: The present study showed that TWEAK serum levels are increased in MS patients, in relation to the disease activity. This simple and reproducible serum test could be used as a marker of ongoing inflammation, contributing in the follow-up and the care of MS patients. Thus, TWEAK is a promising serum marker of the best window to perform brain MRI, optimizing the disease control in patients.

Published
2019
Full Text
View/download PDF

44. Feasibility of single-shot multi-level multi-angle diffusion tensor imaging of the human cervical spinal cord at 7T

Author

Aurélien Massire, Maxime Guye, Thorsten Feiweier, Virginie Callot, Manuel Taso, Henitsoa Rasoanandrianina, and Jean-Philippe Ranjeva

Subjects
Physics, business.industry, Single shot, Spinal cord, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Text mining, medicine.anatomical_structure, medicine, Radiology, Nuclear Medicine and imaging, business, 030217 neurology & neurosurgery, Diffusion MRI, Biomedical engineering
Published
2018
Full Text
View/download PDF

45. Whole brain inhomogeneous magnetization transfer (ihMT) imaging: Sensitivity enhancement within a steady‐state gradient echo sequence

Author

Arnaud Le Troter, Samira Mchinda, Jean Pelletier, David C. Alsop, Jean-Philippe Ranjeva, Gopal Varma, Olivier M. Girard, Stanislas Rapacchi, Maxime Guye, Guillaume Duhamel, Valentin H. Prevost, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Harvard Medical School [Boston] (HMS), Beth Israel Deaconess Medical Center [Boston] (BIDMC), Neurologie, maladies neuro-musculaires [Hôpital de la Timone - APHM], Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)- Hôpital de la Timone [CHU - APHM] (TIMONE), and ARSEP Foundation 2015- Grant sponsor: IRME 2016- ANR-11- IDEX-0001-02- Grant sponsor: France Life Imaging Network ANR-11-INBS-0006.

Subjects
Adult, Male, Offset (computer science), [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, magnetization transfer model, ihMT, dipolar order, 030218 nuclear medicine & medical imaging, Young Adult, 03 medical and health sciences, 0302 clinical medicine, Nuclear magnetic resonance, dual frequency RF saturation, Image Interpretation, Computer-Assisted, crmbm, medicine, Humans, Computer Simulation, Radiology, Nuclear Medicine and imaging, snc, Magnetization transfer, Saturation (magnetic), Reproducibility, Fourier Analysis, medicine.diagnostic_test, Chemistry, Isotropy, Brain, Magnetic resonance imaging, Magnetic Resonance Imaging, 3. Good health, Computational physics, myelin, Dipole, Inhomogeneous magnetization transfer, Female, [SDV.IB]Life Sciences [q-bio]/Bioengineering, Provotorov theory of radiofrequency saturation, 030217 neurology & neurosurgery, Gradient echo
Abstract

Purpose To implement, characterize, and optimize an interleaved inhomogeneous magnetization transfer (ihMT) gradient echo sequence allowing for whole-brain imaging within a clinically compatible scan time. Theory and Methods A general framework for ihMT modelling was developed based on the Provotorov theory of radiofrequency saturation, which accounts for the dipolar order underpinning the ihMT effect. Experimental studies and numerical simulations were performed to characterize and optimize the ihMT-gradient echo dependency with sequence timings, saturation power, and offset frequency. The protocol was optimized in terms of maximum signal intensity and the reproducibility assessed for a nominal resolution of 1.5 mm isotropic. All experiments were performed on healthy volunteers at 1.5T. Results An important mechanism driving signal optimization and leading to strong ihMT signal enhancement that relies on the dynamics of radiofrequency energy deposition has been identified. By taking advantage of the delay allowed for readout between ihMT pulse bursts, it was possible to boost the ihMT signal by almost 2-fold compared to previous implementation. Reproducibility of the optimal protocol was very good, with an intra-individual error

Published
2017
Full Text
View/download PDF

46. Multi-timescale hybrid components of the functional brain connectome: A bimodal EEG-fMRI decomposition

Author

Maxime Guye, Anne-Lise Giraud, Jean-Philippe Ranjeva, Enrico Amico, Sepideh Sadaghiani, Joaquín Goñi, and Jonathan Wirsich

Subjects
Computer science, Concurrent EEG-fMRI, Neurosciences. Biological psychiatry. Neuropsychiatry, Electroencephalography, EEG-fMRI, 03 medical and health sciences, Functional brain, 0302 clinical medicine, Artificial Intelligence, Component (UML), medicine, Brain connectivity, ICA, Research Articles, 030304 developmental biology, 0303 health sciences, Resting state fMRI, medicine.diagnostic_test, Applied Mathematics, General Neuroscience, Functional connectivity, Human Connectome, Independent component analysis, Computer Science Applications, ddc:616.8, Human connectome, Connectome, Functional magnetic resonance imaging, Neuroscience, 030217 neurology & neurosurgery, RC321-571
Abstract

Concurrent electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) bridge brain connectivity across timescales. During concurrent EEG-fMRI resting-state recordings, whole-brain functional connectivity (FC) strength is spatially correlated across modalities. However, cross-modal investigations have commonly remained correlational, and joint analysis of EEG-fMRI connectivity is largely unexplored. Here we investigated if there exist (spatially) independent FC networks linked between modalities. We applied the recently proposed hybrid connectivity independent component analysis (connICA) framework to two concurrent EEG-fMRI resting-state datasets (total 40 subjects). Two robust components were found across both datasets. The first component has a uniformly distributed EEG frequency fingerprint linked mainly to intrinsic connectivity networks (ICNs) in both modalities. Conversely, the second component is sensitive to different EEG frequencies and is primarily linked to intra-ICN connectivity in fMRI but to inter-ICN connectivity in EEG. The first hybrid component suggests that connectivity dynamics within well-known ICNs span timescales, from millisecond range in all canonical frequencies of FCEEG to second range of FCfMRI. Conversely, the second component additionally exposes linked but spatially divergent neuronal processing at the two timescales. This work reveals the existence of joint spatially independent components, suggesting that parts of resting-state connectivity are co-expressed in a linked manner across EEG and fMRI over individuals., Author Summary Functional connectivity is governed by a whole-brain organization measurable over multiple timescales by functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). The relationship across the whole-brain organization captured at the different timescales of EEG and fMRI is largely unknown. Using concurrent EEG-fMRI, we identified spatially independent components consisting of brain connectivity patterns that co-occur in EEG and fMRI over subjects. We observed a component with similar connectivity organization across EEG and fMRI as well as a component with divergent connectivity. The former component governed all EEG frequencies while the latter was modulated by frequency. These findings show that part of functional connectivity organizes in a common spatial layout over several timescales, while a spatially independent part is modulated by frequency-specific information.

Published
2019
Full Text
View/download PDF

47. Regional T 1 mapping of the whole cervical spinal cord using an optimized MP2RAGE sequence

Author

Jean-Philippe Ranjeva, Virginie Callot, Maxime Guye, Tobias Kober, Henitsoa Rasoanandrianina, Aurélien Massire, Manuel Taso, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Siemens AG Healthcare Sector, Erlangen, ANR-11-INBS-0006,FLI,France Life Imaging(2011), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), and Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Reproducibility, Relaxometry, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, relaxometry, spinal cord, gray matter, T1 mapping, Biology, Spinal cord, spinal cord template, MP2RAGE, 030218 nuclear medicine & medical imaging, White matter, 03 medical and health sciences, 0302 clinical medicine, medicine.anatomical_structure, medicine, Molecular Medicine, Radiology, Nuclear Medicine and imaging, white matter, 030217 neurology & neurosurgery, Spectroscopy, Biomedical engineering
Abstract

International audience; While T1 measurements present multiple challenges (robustness, acquisition time), the recently proposed MP2RAGE sequence (magnetization‐prepared two rapid acquisition gradient echoes) has opened new perspectives to characterize tissue microstructure changes occurring in a pathological or developmental context. Extensively used for brain studies, it was herein adapted to investigate the cervical spinal cord (SC) at 3 T.By integrating Bloch equations, the MP2RAGE sequence parameters were chosen to optimize SC gray matter/white matter (GM/WM) T1 contrast with sub‐millimetric resolution, a scan time less than 10 min and a reliable T1 determination with minimal B1+ variation effect, within a range of values compatible with different pathologies and surrounding structures. The residual B1+ effect on T1 values was corrected using a look‐up‐table approach and B1+ mapping. The accuracy of B1+‐corrected T1 measurements was assessed on a phantom with respect to conventional inversion recovery. In vivo MP2RAGE acquisitions were performed on five young (28.8 ± 4.3 years old) and five elderly (60.2 ± 2.9 years old) volunteers and analyzed using a template‐based approach.Phantom experiments led to high agreements between inversion‐recovery spin‐echo and MP2RAGE‐based T1 values (R2 = 0.997). In vivo T1 values for cervical WM, anterior GM (aGM), posterior sensory tracts (PSTs) and lateral motor tracts (LMTs) were 917 ± 29 s, 934 ± 33 ms, 920 ± 37 ms and 877 ± 35 ms, respectively, with all subjects and cervical levels considered. Significant differences were observed between aGM and LMTs, and between LMTs and PSTs, in agreement with the literature. Repeated T1 measurements demonstrated high reproducibility of the MP2RAGE in the SC (variation coefficient < 5% in all regions of interest). Finally, preliminary assessment of age‐related SC tissue microstructure variation additionally showed evidence of SC atrophy and slight trends of T1 decrease with age in all regions.Overall, this study shows that fast, robust and accurate sub‐millimetric resolution T1 mapping in the cervical SC using the MP2RAGE sequence is possible, paving the way for future multi‐centric and longitudinal clinical studies investigating the pathological cord.

Published
2019
Full Text
View/download PDF

48. Malformations of cortical development: The role of 7-Tesla magnetic resonance imaging in diagnosis

Author

Jean-Philippe Ranjeva, Fabrice Bartolomei, Maxime Guye, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM), Service de neurophysiologie clinique [Hôpital de la Timone - APHM], Hôpital de la Timone [CHU - APHM] (TIMONE), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), and CCSD, Accord Elsevier

Subjects
Computer science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, High resolution, White matter, 03 medical and health sciences, 0302 clinical medicine, Nuclear magnetic resonance, Image Processing, Computer-Assisted, medicine, Humans, 7 tesla mri, 030212 general & internal medicine, ComputingMilieux_MISCELLANEOUS, medicine.diagnostic_test, Functional Neuroimaging, Brain, Magnetic resonance imaging, Magnetic Resonance Imaging, Computational anatomy, 3. Good health, Malformations of Cortical Development, Clinical Practice, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, Rapid acquisition, medicine.anatomical_structure, Neurology, Neurology (clinical), Lower field, 030217 neurology & neurosurgery
Abstract

Comparison studies between 7T and 1.5 or 3T magnetic resonance imaging (MRI) have demonstrated the added value of ultra-high field (UHF) MRI to better identify, delineate and characterize malformations of cortical development (MCD), and to disambiguate doubtful findings observed at lower field strengths. High resolution structural sequences such as magnetization prepared two rapid acquisition gradient echoes (MP2RAGE), fluid and white matter suppression MP2RAGE (FLAWS), and susceptibility-weighted imaging (SWI) appear to be key to the improvement of MCD diagnosis in clinical practice. 7T MRI offers not only images of high resolution and contrast but also provides many quantitative approaches capable of acting as more efficient probes of microstructure and ameliorating the categorization of MCDs. Post-processing of multiparametric ultra-high resolution and quantitative data may also be used to improve automated detection of MCD via machine learning. Therefore, 7T MRI can be considered as a useful tool in the presurgical evaluation of drug-resistant partial epilepsies, particularly, but not exclusively, in cases of normal appearing conventional MRI. It also opens many perspectives in the fields of in vivo histology and computational anatomy.

Published
2019
Full Text
View/download PDF

49. Spinal cord involvement in multiple sclerosis and neuromyelitis optica spectrum disorders

Author

Eoin P. Flanagan, Benjamin Greenberg, Olga Ciccarelli, Olaf Stüve, Jean-Philippe Ranjeva, Maria Pia Sormani, Regina Schlaerger, Myla D. Goldman, Jeffrey A. Cohen, Emmanuelle Waubant, Franz Fazekas, Ellen M. Mowry, Daniel S. Reich, Frederik Barkhof, Hans Lassmann, Anthony Traboulsee, Sandra Vukusic, Mar Tintoré, Bernard M. J. Uitdehaag, Anke Henning, Daniel Pelletier, Alan J. Thompson, Junqian Xu, Jorge Correale, Burkhard Becher, Stephen Reingold, Nicola De Stefano, Bruce F. Bebo, Izlem Izbudak, Claudia Chien, Stephen C. Reingold, Steven Galetta, Claudia Gandini Wheeler-Kingshott, Sebastien Ourselin, Alex Rovira, Mark S. Freedman, Brenda Banwell, Aaron E. Miller, Xavier Montalban, Cornelia Laule, Claudia F. Lucchinetti, Giancarlo Comi, Peter A. Calabresi, Hans-Peter Hartung, Maria Trojano, Ludwig Kappos, Bernhard Hemmer, Bruce D. Trapp, Brian G. Weinshenker, Kazuo Fujihara, Tanuja Chitnis, Jérôme De Seze, Francois Bethoux, Per Soelberg Sørensen, Fred D. Lublin, Alexander U. Brandt, Carsten Lukas, Wallace J Brownlee, Maria Pia Amato, Jeremy Chatway, David Miller, Friedemann Paul, Maria A. Rocca, Ruth Ann Marrie, Michael J. Levy, University of Pennsylvania, VU University Medical Center [Amsterdam], University College of London [London] (UCL), Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Departamento de Neurologia, Instituto de Investigaciones Neurológicas 'Dr. Raul Carrea', Instituto de Investigaciones Neurológicas 'Dr. Raul Carrea', Service de Neurologie [Strasbourg], CHU Strasbourg-Hopital Civil, Dept. of Neurological and Behavioural Sciences, Siena, Department of Neurology [Austria], Medical University Graz, Ottawa Hospital Research Institute [Ottawa] (OHRI), Tohoku University Graduate School of Medicine, Munich Cluster of Systems Neurology (SyNery), Clinical Neuroimmunology, Department of Biomedicine, University of Basel, Basel, Matière et Systèmes Complexes (MSC), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), St. Josef Hospital, Ruhr-University Bochum, Vall Hebron Research Institute (VHIR), Translational imaging group [London] (TIG), Centre for Medical Image Computing (CMIC), University College of London [London] (UCL)-University College of London [London] (UCL)-Department of Medical Physics and Biomedical Engineering (UCL), Max Delbrueck Centre for Molecular Medicine, Departments of Neurology and Immunobiology [Yale], Yale School of Medicine [New Haven, Connecticut] (YSM), Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Centre National de la Recherche Scientifique (CNRS), National Institutes of Health [Bethesda] (NIH), Vall d'Hebron University Hospital [Barcelona], Dept. of Neurology, University Hospital Rigshospitalet, Centre d'Esclerosi Múltiple de Catalunya (CemCat), Division of Geriatric Medicine, University of British Columbia (UBC), Service de Neurologie [Lyon], CHU Lyon, Department of Neurology, University of California [San Francisco] (UC San Francisco), University of California (UC)-University of California (UC), NMR Research Unit [London], Institute of Neurology [London], University College of London [London] (UCL)-University College of London [London] (UCL), Icahn School of Medicine at Mount Sinai [New York] (MSSM), University of Pennsylvania [Philadelphia], Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Yale University School of Medicine, Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - AP-HM] (CEMEREM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)- Hôpital de la Timone [CHU - APHM] (TIMONE), University of California [San Francisco] (UCSF), and University of California-University of California

Subjects
0301 basic medicine, Pediatrics, medicine.medical_specialty, Multiple Sclerosis, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Spinal cord involvement, 03 medical and health sciences, Myelopathy, 0302 clinical medicine, medicine, Humans, Pathological, ComputingMilieux_MISCELLANEOUS, business.industry, Multiple sclerosis, Neuromyelitis Optica, Clinical course, medicine.disease, Spinal cord, 3. Good health, Clinical trial, 030104 developmental biology, medicine.anatomical_structure, Spinal Cord, Neuromyelitis Optica Spectrum Disorders, Neurology (clinical), business, 030217 neurology & neurosurgery
Abstract

Spinal cord involvement is an important cause of disability in patients with multiple sclerosis or neuromyelitis optica spectrum disorders (NMOSDs). Multiple sclerosis and NMOSDs can be distinguished from other disorders that cause myelopathy by results from laboratory and radiological investigations. However, limitations in the sensitivity and specificity of spinal cord imaging and poor correlation with disability megasures have impeded the understanding of the relationship between spinal cord involvement and clinical manifestations. Nevertheless, studies of the pathological features of multiple sclerosis and NMOSDs have shown that quantitatively different mechanisms lead to differences in clinical course and pattern of accrual of permanent disability in the two disorders. Better understanding of these mechanisms is necessary to develop more informative clinical measures, electrophysiological methods, fluid biomarkers, and imaging techniques to detect and monitor spinal cord involvement in the diagnosis and management of patients with multiple sclerosis or NMOSDs, and as outcome measures in clinical trials.

Published
2019
Full Text
View/download PDF

50. Connectivity strength, time lag structure and the epilepsy network in resting-state fMRI

Author

Ben Ridley, Francesca Pizzo, Jean Régis, Maxime Guye, Fabrice Bartolomei, Romain Carron, Jean-Philippe Ranjeva, S. Kathleen Bandt, Pierre Besson, Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Exploration Métabolique par Résonance Magnétique [Hôpital de la Timone - APHM] (CEMEREM), Hôpital de la Timone [CHU - APHM] (TIMONE)-Centre de résonance magnétique biologique et médicale (CRMBM), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-Centre National de la Recherche Scientifique (CNRS), Service de neurophysiologie clinique [Hôpital de la Timone - APHM], Hôpital de la Timone [CHU - APHM] (TIMONE), Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de neurochirurgie fonctionnelle et stéréotaxique [CHU La Timone] (Gamma Knife Unit), Université de la Méditerranée - Aix-Marseille 2- Hôpital de la Timone [CHU - APHM] (TIMONE), Assistance Publique - Hôpitaux de Marseille (APHM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), AP-HM, Pôle d'imagerie médicale, Hôpital de la Timone, CEMEREM, Marseille, France, Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), and Hôpital de la Timone [CHU - APHM] (TIMONE)-Université de la Méditerranée - Aix-Marseille 2

Subjects
Male, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Neuropsychological Tests, Functional Laterality, lcsh:RC346-429, Correlation, Functional connectivity, Epilepsy, Seizure onset, 0302 clinical medicine, Neural Pathways, ComputingMilieux_MISCELLANEOUS, Brain Mapping, 05 social sciences, Brain, Electroencephalography, Regular Article, Middle Aged, Epileptogenic zone, Magnetic Resonance Imaging, Resting state networks, Epilepsy network, Neurology, lcsh:R858-859.7, Female, Algorithms, Adult, Rest, Cognitive Neuroscience, Time lag, Biology, lcsh:Computer applications to medicine. Medical informatics, 050105 experimental psychology, Brain findings, Young Adult, 03 medical and health sciences, Seizures, medicine, Humans, 0501 psychology and cognitive sciences, Radiology, Nuclear Medicine and imaging, lcsh:Neurology. Diseases of the nervous system, Resting state fMRI, medicine.disease, Neurology (clinical), Nerve Net, Neuroscience, 030217 neurology & neurosurgery, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract

Highlights • Stereo-encephalography informed high-resolution functional connectome analysis on the nodal and whole brain levels identifies consistent patterns of altered correlation strength and altered time lag architecture in epilepsy patients compared to controls. • Specific patterns of altered connectivity include:.○broadly distributed increased strength of correlation between the seizure onset node and the remainder of the brain.○decreased time lag within the seizure onset node.○globally increased time lag throughout all regions of the brain not involved in seizure onset or propagation. • Comparing the topographic distribution of findings against a functional atlas, all resting state networks were involved to a variable degree. These local and whole brain findings presented here lead us to propose the network steal hypothesis as a possible mechanistic explanation for the non-seizure clinical manifestations of epilepsy., The relationship between the epilepsy network, intrinsic brain networks and hypersynchrony in epilepsy remains incompletely understood. To converge upon a synthesized understanding of these features, we studied two elements of functional connectivity in epilepsy: correlation and time lag structure using resting state fMRI data from both SEEG-defined epileptic brain regions and whole-brain fMRI analysis. Functional connectivity (FC) was analyzed in 15 patients with epilepsy and 36 controls. Correlation strength and time lag were selected to investigate the magnitude of and temporal interdependency across brain regions. Zone-based analysis was carried out investigating directed correlation strength and time lag between both SEEG-defined nodes of the epilepsy network and between the epileptogenic zone and all other brain regions. Findings were compared between patients and controls and against a functional atlas. FC analysis on the nodal and whole brain levels identifies consistent patterns of altered correlation strength and altered time lag architecture in epilepsy patients compared to controls. These patterns include 1) broadly distributed increased strength of correlation between the seizure onset node and the remainder of the brain, 2) decreased time lag within the seizure onset node, and 3) globally increased time lag throughout all regions of the brain not involved in seizure onset or propagation. Comparing the topographic distribution of findings against a functional atlas, all resting state networks were involved to a variable degree. These local and whole brain findings presented here lead us to propose the network steal hypothesis as a possible mechanistic explanation for the non-seizure clinical manifestations of epilepsy.

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results