263 research outputs found

    Development of workflow task analysis during cerebral diagnostic angiographies: Time-based comparison of junior and senior tasks

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    International audienceOBJECTIVE: Assessing neuroradiologists' skills in the operating room (OR) is difficult and often subjective. This study used a workflow time-based task analysis approach while performing cerebral angiography. METHODS: Eight angiographies performed by a senior neuroradiologist and eight performed by a junior neuroradiologist were compared. Dedicated software with specific terminology was used to record the tasks. Procedures were subdivided into phases, each comprising multiple tasks. Each task was defined as a triplet, associating an action, an instrument and an anatomical structure. The duration of each task was the metric. Total duration of the procedure, task duration and the number of times a task was repeated were identified. The focus was on tasks using fluoroscopy and for moving the X-ray table/tube. RESULTS: The total duration of tasks to complete the entire procedure was longer for the junior operators than for the seniors (P=0.012). The mean duration per task during the navigation phase was 86s for the juniors and 43s for the seniors (P=0.002). The total and mean durations of tasks involving the use of fluoroscopy were also longer for the juniors (P=0.002 and P=0.033, respectively). For tasks involving the table/tube, the total and mean durations were again longer for the juniors (P=0.019 and P=0.082, respectively). CONCLUSION: This approach allows reliable skill assessment in the radiology OR and comparison of junior and senior competencies during cerebral diagnostic angiography. This new tool can improve the quality and safety of procedures, and facilitate the learning process for neuroradiologists

    Anatomie du tractus cortico-spinal en tractographie : évaluation d'une méthode déterministe

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    Introduction : Si la substance grise a Ă©tĂ© largement Ă©tudiĂ©e en IRM fonctionnelle (IRMf), l'Ă©tude in vivo des tractus de substance blanche est plus rĂ©cente. L'IRM en tenseur de diffusion permet dĂ©sormais d'Ă©tudier son anatomie grĂące Ă  la tractographie. Notre objectif Ă©tait l'Ă©tude du tractus cortico-spinal (TCS) en tenseur de diffusion et en tractographie chez des sujets sains. MatĂ©riel et mĂ©thodes : La population concernait 15 volontaires sains droitiers. Une IRM 3T anatomique T1 a permis la dĂ©termination des rĂ©gions d'intĂ©rĂȘts (ROI) au niveau du mĂ©sencĂ©phale. L'IRMf a Ă©tĂ© analysĂ©e par le logiciel SPM5 afin d'obtenir une carte d'activation reprĂ©sentant l'activation motrice de la main au niveau du cortex moteur. L'IRM de diffusion a servi Ă  reconstruire un tenseur (matrice 3x3) en chaque voxel de l'image. AprĂšs recalage des 3 sĂ©quences, nous avons effectuĂ© une tractographie du TCS par une mĂ©thode dĂ©terministe utilisant l'algorithme (Mori et al). Les tractographies ont Ă©tĂ© rĂ©alisĂ©es entre les deux ROI de chaque cĂŽtĂ©. RĂ©sultat : Cette mĂ©thode donne une reprĂ©sentation anatomique du TSC mĂ©connaissent la partie ventro-latĂ©rale de la ROI fonctionnelle. Cette partie correspond aux croisements de fibres des autres faisceaux de fibres blanches traversant la rĂ©gion. Conclusion : La limite principale du tenseur se situe au niveau des croisements des fibres, car il ne reprĂ©sente correctement qu'une seule direction de diffusion. Cela ne permet pas actuellement de retrouver l'anatomie des faisceaux de fibres telle que nous la connaissons pas les dissections. Les mĂ©thodes dĂ©terministes mono-directionnelles ne sont pas suffisantes notamment dans le contexte de la chirurgie guidĂ©e par l'image. Elles doivent ĂȘtre enrichies de mĂ©thodes multidirectionnelles en utilisant des algorithmes plus complexes

    HIV-1-infected patients from the French National Observatory experiencing virological failure while receiving enfuvirtide

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    Objectives We studied gp41 mutations associated with failing enfuvirtide salvage therapy. Methods This multicentre study involved patients with HIV-1 plasma viral load (pVL) > 5000 copies/mL after at least 3 months of uninterrupted enfuvirtide therapy and with plasma samples available at inclusion (T0), at initial enfuvirtide failure (T1) and at last follow-up visit during continued failing enfuvirtide therapy (T2). The HR-1 and HR-2 domains of the gp41 gene were sequenced at T0, T1 and T2. Results Ninety-nine patients were enrolled. At baseline, the median pVL and CD4 cell count were 5.1 log copies/mL and 72 cells/mm3, respectively. Based on the ANRS Resistance Group algorithm, the proportion of patients harbouring viruses with enfuvirtide resistance mutations increased significantly between T0 and T1. In the HR-1 domain, the V38A/M, Q40H, N42T, N43D and L45M mutations wereselected (P < 0.02). In the HR-2 domain, no mutations were significantly selected during the follow-up. None of the mutations was associated with a CD4 cell count increment. Conclusions Mutations selected during failing enfuvirtide salvage therapy are mainly located in the HR-1 domain of the gp41 gene, between codons 38 and 45. No mutations were associated with an increase in the CD4 cell coun

    Non-random, individual-specific methylation profiles are present at the sixth CTCF binding site in the human H19/IGF2 imprinting control region

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    Expression of imprinted genes is classically associated with differential methylation of specific CpG-rich DNA regions (DMRs). The H19/IGF2 locus is considered a paradigm for epigenetic regulation. In mice, as in humans, the essential H19 DMR—target of the CTCF insulator—is located between the two genes. Here, we performed a pyrosequencing-based quantitative analysis of its CpG methylation in normal human tissues. The quantitative analysis of the methylation level in the H19 DMR revealed three unexpected discrete, individual-specific methylation states. This epigenetic polymorphism was confined to the sixth CTCF binding site while a unique median-methylated profile was found at the third CTCF binding site as well as in the H19 promoter. Monoallelic expression of H19 and IGF2 was maintained independently of the methylation status at the sixth CTCF binding site and the IGF2 DMR2 displayed a median-methylated profile in all individuals and tissues analyzed. Interestingly, the methylation profile was genetically transmitted. Transgenerational inheritance of the H19 methylation profile was compatible with a simple model involving one gene with three alleles. The existence of three individual-specific epigenotypes in the H19 DMR in a non-pathological situation means it is important to reconsider the diagnostic value and functional importance of the sixth CTCF binding site

    Innovation et développement dans les systÚmes agricoles et alimentaires

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    L’innovation est souvent prĂ©sentĂ©e comme l’un des principaux leviers pour promouvoir un dĂ©veloppement plus durable et plus inclusif. Dans les domaines de l’agriculture et de l’alimentation, l’innovation est marquĂ©e par des spĂ©cificitĂ©s liĂ©es Ă  sa relation Ă  la nature, mais aussi Ă  la grande diversitĂ© d’acteurs concernĂ©s, depuis les agriculteurs jusqu’aux consommateurs, en passant par les services de recherche et de dĂ©veloppement. L’innovation Ă©merge des interactions entre ces acteurs, qui mobilisent des ressources et produisent des connaissances dans des dispositifs collaboratifs, afin de gĂ©nĂ©rer des changements. Elle recouvre des domaines aussi variĂ©s que les pratiques de production, l’organisation des marchĂ©s, ou les pratiques alimentaires. L’innovation est reliĂ©e aux grands enjeux de dĂ©veloppement : innovation agro-Ă©cologique, innovation sociale, innovation territoriale, etc. Cet ouvrage porte un regard sur l’innovation dans les systĂšmes agricoles et alimentaires. Il met un accent particulier sur l’accompagnement de l’innovation, en interrogeant les mĂ©thodes et les organisations, et sur l’évaluation de l’innovation au regard de diffĂ©rents critĂšres. Il s’appuie sur des rĂ©flexions portĂ©es par diffĂ©rentes disciplines scientifiques, sur des travaux de terrain conduits tant en France que dans de nombreux pays du Sud, et enfin sur les expĂ©riences acquises en accompagnant des acteurs qui innovent. Il combine des synthĂšses sur l’innovation et des Ă©tudes de cas emblĂ©matiques pour illustrer les propos. L’ouvrage est destinĂ© aux enseignants, professionnels, Ă©tudiants et chercheurs

    45 e CongrÚs de la Société française de neuroradiologie

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    International audienc

    Advanced techniques using contrast media in neuroimaging.

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    International audienceThis article presents an overview of advanced magnetic resonance (MR) imaging techniques using contrast media in neuroimaging, focusing on T2*-weighted dynamic susceptibility contrast MR imaging and T1-weighted dynamic contrast-enhanced MR imaging. Image acquisition and data processing methods and their clinical application in brain tumors, stroke, dementia, and multiple sclerosis are discussed
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