6 research outputs found

    ECCENTRIC: a fast and unrestrained approach for high-resolution in vivo metabolic imaging at ultra-high field MR

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    A novel method for fast and high-resolution metabolic imaging, called ECcentric Circle ENcoding TRajectorIes for Compressed sensing (ECCENTRIC), has been developed and implemented on 7 Tesla human MRI. ECCENTRIC is a non-Cartesian spatial-spectral encoding method optimized for random undersampling of magnetic resonance spectroscopic imaging (MRSI) at ultra-high field. The approach provides flexible and random (k,t) sampling without temporal interleaving to improve spatial response function and spectral quality. ECCENTRIC needs low gradient amplitudes and slew-rates that reduces electrical, mechanical and thermal stress of the scanner hardware, and is robust to timing imperfection and eddy-current delays. Combined with a model-based low-rank reconstruction, this approach enables simultaneous imaging of up to 14 metabolites over the whole-brain at 2-3mm isotropic resolution in 4-10 minutes with high signal-to-noise ratio. In 20 healthy volunteers and 20 glioma patients ECCENTRIC demonstrated unprecedented mapping of fine structural details of metabolism in healthy brains and an extended metabolic fingerprinting of glioma tumors.Comment: 20 pages, 7 figures,2 tables, 10 pages supplementary materia

    Music impacts brain cortical microstructural maturation in very preterm infants: A longitudinal diffusion MR imaging study

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    Preterm birth disrupts important neurodevelopmental processes occurring from mid-fetal to term-age. Musicotherapy, by enriching infants’ sensory input, might enhance brain maturation during this critical period of activity-dependent plasticity. To study the impact of music on preterm infants’ brain structural changes, we recruited 54 very preterm infants randomized to receive or not a daily music intervention, that have undergone a longitudinal multi-shell diffusion MRI acquisition, before the intervention (at 33 weeks’ gestational age) and after it (at term-equivalent-age). Using whole-brain fixel-based (FBA) and NODDI analysis (n = 40), we showed a longitudinal increase of fiber cross-section (FC) and fiber density (FD) in all major cerebral white matter fibers. Regarding cortical grey matter, FD decreased while FC and orientation dispersion index (ODI) increased, reflecting intracortical multidirectional complexification and intracortical myelination. The music intervention resulted in a significantly higher longitudinal increase of FC and ODI in cortical paralimbic regions, namely the insulo-orbito-temporopolar complex, precuneus/posterior cingulate gyrus, as well as the auditory association cortex. Our results support a longitudinal early brain macro and microstructural maturation of white and cortical grey matter in preterm infants. The music intervention led to an increased intracortical complexity in regions important for socio-emotional development, known to be impaired in preterm infants

    In vivo magnetic resonance P-31-Spectral Analysis With Neural Networks: 31P-SPAWNN

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    Purpose: We have introduced an artificial intelligence framework, 31P-SPAWNN, in order to fully analyze phosphorus-31 (P-31) magnetic resonance spectra. The flexibility and speed of the technique rival traditional least-square fitting methods, with the performance of the two approaches, are compared in this work.Theory and Methods: Convolutional neural network architectures have been proposed for the analysis and quantification of P-31-spectroscopy. The generation of training and test data using a fully parameterized model is presented herein. In vivo unlocalized free induction decay and three-dimensional P-31-magnetic resonance spectroscopy imaging data were acquired from healthy volunteers before being quantified using either 31P-SPAWNN or traditional least-square fitting techniques.Results: The presented experiment has demonstrated both the reliability and accuracy of 31P-SPAWNN for estimating metabolite concentrations and spectral parameters. Simulated test data showed improved quantification using 31P-SPAWNN compared with LCModel. In vivo data analysis revealed higher accuracy at low signal-to-noise ratio using 31P-SPAWNN, yet with equivalent precision. Processing time using 31P-SPAWNN can be further shortened up to two orders of magnitude.Conclusion: The accuracy, reliability, and computational speed of the method open new perspectives for integrating these applications in a clinical setting

    Method for the production of crystalline forms and crystalline forms of optical enantiomers of modafinil

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    The invention relates to a process for the preparation of crystalline forms of the optical enantiomers of modafinil, comprising stages comprising: i) dissolving one of the optical enantiomers of modafinil in a solvent other than ethanol, ii) crystallising the modafinil enantiomer, iii) recovering the crystalline form of the modafinil enantiomer so obtained. The invention also relates to a process for the preparation of the optical enantiomers of modafinil

    A potential role for chlamydial infection in rheumatoid arthritis development

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    Objectives: To assess the relationship between self-reported and serologic evidence of prior chlamydial infection, rheumatoid arthritis (RA)-related autoantibodies and risk of RA-development. Methods: This is a nested study within a prospective Swiss-based cohort including all first-degree relatives of RA patients (RA-FDR) who answered a question on past chlamydial infections. Primary outcome was systemic autoimmunity associated with RA (RA-autoimmunity) defined as positivity for anti-citrullinated peptide antibodies (ACPA) and/or rheumatoid factor (RF). Secondary outcomes were high levels of RA-autoimmunity, RA-associated symptoms and RA-autoimmunity, and subsequent seropositive RA diagnosis. We conducted a nested case-control analysis by measuring the serological status against Chlamydia trachomatis' major outer membrane protein. We replicated our analysis in an independent United States-based RA-FDR cohort. Results: Among 1231 RA-FDRs, 168 (13.6%) developed RA-autoimmunity. Prevalence of self-reported chlamydial infection was significantly higher in individuals with RA-autoimmunity compared with controls (17.9% vs 9.8%, OR = 2.00, 95%CI: 1.27-3.09, p &lt; 0.01). This association remained significant after adjustments (OR = 1.91, 95%CI: 1.20-2.95). Stronger effect sizes were observed in later stages of RA development. There was a similar trend between a positive C. trachomatis serology and high levels of RA-autoimmunity (OR = 3.05, 95% CI: 1.10-8.46, p= 0.032). In the replication cohort, there were significant associations between chlamydial infection and RF positivity and incident RA, but not anti-CCP positivity. Conclusions: Self-reported chlamydial infections are associated with elevated RA-autoimmunity in at risk individuals. The differing association of chlamydial infections and ACPA/RF between cohorts will need to be explored in future studies but is consistent with a role of mucosal origin of RA-related autoimmunity.</p

    Ovarian and peritoneal psammocarcinoma: Results of a multicenter study on 25 patients

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    International audiencePurpose: Psammocarcinoma (PK) is a rare disease of unknown origin. We aimed to report the characteristics, management and survival of patients operated on for PK within the French Network for Rare Peritoneal Malignancies (RENAPE) expert centers.Patients and methods: All consecutive cases of PK operated within all 26 RENAPE centers between 1997 and 2018 were retrospectively analyzed.Results: Twenty-five patients were identified. The median age was 53 years [range 17–78]. None of the patients had extra peritoneal metastases at diagnosis. A median of 6 cycles of carboplatin-based systemic chemotherapy was delivered in 52% preoperatively (n = 13) and 56% postoperatively (n = 14); associated with placlitaxel for 12 patients. All patients were operated on. The median PCI was 23 [0–33]. Eighty-four percent had a complete cytoreductive surgery through digestive (n = 7), spleen (n = 3), pancreas (n = 1) resections and/or multiple peritonectomies (n = 11). Five patients (20%) had intraperitoneal chemotherapy. Morbidity (Dindo-Clavien ≥3) was 12%. No postoperative death occurred. After a median follow-up of 42 months (range [2–194]), the median overall (OS) and progression-free (DFS) survival times were respectively 128 months and 31 months. Eighteen patients recurred (72%), mainly in the peritoneum (n = 16). Four of them (22%) were reoperated. The 5 and 10-year DFS rates were both 20.3%. The 5 and 10-year OS rates were 62% and 51.7%, respectively. A complete cytoreductive surgery was associated with a better OS and DFS in a univariate analysis.Conclusion: Complete cytoreductive surgery is the cornerstone of the PK's management as a primary treatment. Recurrence remains common and new adjuvant strategies seem needed
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