From medical imaging to numerical simulations

International audienceIn the last 20 years there have been lots of progress in 3D medical imaging (such as Magnetic Resonance Imaging, MRI, and X-ray Computed Tomography, CT) and in particular in modalities to visualise vascular structures. The resulting images have been successfully used in various clinical applications, in particular for cerebrovascular pathologies (e.g., neurosurgery planning; stenoses, aneurysm or thrombosis quantification; arteriovenous malformation detection and follow-up, etc.). The complexity of the processing and analysis of these images (size, information vs noise, artifacts, etc) led to the development of imaging tools such as vessel filtering, segmentation and quantification. There is however, until now, no database of synthetic images and associated ground-truths (segmented data) available in cerebrovascular images contrary to morphological brain image analysis (e.g. brainweb).In the ANR Vivabrain project, we combine the skills of several communities: computer science, applied mathematics, biophysics, and medicine to remedy the aforementioned observation. In particular we focus on complex multi-disciplinary problems such as (i) the handling of inter-individual cerebrovascular variability, (ii) the generation of computational meshes, (iii) the simulation of blood flows in the complete cerebrovascular system 3D+time (3D+t) including calibration and validation and (iv) the accurate simulation of the physical processes involved in MRA acquisition sequences in order to finally obtain realistic virtual angiographic images

Une mine de plomb argentifère dans un environnement montagnard : la mine médiévale du Fournel à L'Argentière-la-Bessée (Hautes-Alpes)

National audienceLa mine d'argent du Fournel a été en activité entre le Xe et le XIVe siècle. Les textes conservés concernent la phase de maturité du XIIe siècle et la phase de ralentissement du milieu du XIIIe siècle. Plusieurs panneaux filoniens ont été exploités à partir d'affleurements, depuis des escarpements rocheux abrupts, jusqu'au fond d'une gorge. La grande dureté de la roche a obligé les mineurs à recourir à l'abattage par le feu. Le relief a grandement facilité la prospection des filons, le démarrage de chantiers à ciel ouvert et l'organisation des exploitations souterraines. Les chantiers s'étendent jusqu'à 150 m du jour et sont assistés par des niveaux de circulation par traînage, des conduits d'aérage perchés en hauteur et des galeries de drainage ouvertes à la base. Ces ouvrages d'assistance reflètent une organisation opportuniste de la mine, facilitée par la topographie et la géologie du gisement. L'analyse sédimentologique et anthracologique des remblais, associée à des expérimentations sérielles, permet de caractériser la chaîne opératoire technique de l'abattage par le feu et son impact sur les modalités de gestion de la forêt arborescente d'altitude, comprimée entre les activités agropastorales et minières

De l'usage minier du feu : sources et expérimentations

Éditeur scientifique : Aline DurandNational audienceL'abattage par le feu est auréolé de mystères en raison de son caractère séculaire et archaïque . Les découvertes récentes liées au développement des méthodes de l'archéologie minière lèvent le voile. Or, des questions restent toujours posées notamment concernant la technique et la pratique du travail par le feu sous terre, son évolution, et ses conséquences sur l'architecture des ouvrages, la morphologie et la composition des déblais, l'organisation du travail et la gestion de la forêt. Cet article qui n'a pas la prétention d'être exhaustif sur la diversité des sources et des outils utilisés pour nourrir cette problématique, a pour objectif de dégager les traits forts d'une approche pluridisciplinaire située au croisement des sciences humaines et de l'environnement, pour accéder à des notions de mode opératoire, de systèmes techniques et d'adaptation - réaction entre les mineurs et leur environnement

ANGIOTK : An Open Platform to reconstruct vessels from MRI images and simulate blood flows to ultimately provide Virtual Angiographies

National audienceFrom medical images to numerical simulations ANGIOTK The platform is still a prototype, but reached a level of maturity that requires very little human intervention. The overall objective is to make available, to the medical community, tools for computer aided modeling for conducting experiments in silico, otherwise difficult or impossible to carry on patients. A specific aim is to create an ecosystem around the platform composed of academic, research centers and enterprises and to provide services such as training, specific developments, consulting or deployment. The platform is operated by Cemosis and Kitware. An Open Platform to reconstruct vessels from MRI images and simulate blood flows to ultimately provide Virtual Angiographie

Hyperbilirubinemia and Neurodevelopmental Outcome of Very Low Birthweight Infants: Results from the LIFT Cohort

Bilirubin-related neurotoxicity is an important clinical issue in very low birthweight (VLBW) infants, and the existing literature is inconsistent.To analyze the relationship between maximal serum unconjugated bilirubin levels (SBL) and neurodevelopmental outcome at 2-year corrected age in VLBW infants.Phototherapy was initiated in all infants born before 33 weeks of gestation, according to Maisels' recommendations. Neurodevelopmental assessment at 2-year corrected age was performed in all infants that survived. SBLs collected during the first week of life were used to define three tertiles of max-SBL. The first tertile corresponded to infants with the lowest max-SBL. percentile curves of SBLs in infants with an optimal outcome). When Maisels' recommendations were applied, max SBLs were higher in 8% of infants weighing 1001–1500 g and in 15% of infants weighing less than 1001 g. Our data seems to validate Maisels' recommendations in the overall population of infants born before 33 weeks of gestation, but not in infants weighing less than 1001 g

Une mine de plomb argentifère dans un environnement montagnard

La mine d’argent du Fournel a été en activité entre le xe et le xive siècle. Les textes conservés concernent la phase de maturité du xiie siècle et la phase de ralentissement du milieu du xiiie siècle. Plusieurs panneaux filoniens ont été exploités à partir d’affleurements, depuis des escarpements rocheux abrupts, jusqu’au fond d’une gorge. La grande dureté de la roche a obligé les mineurs à recourir à l’abattage par le feu. Le relief a grandement facilité la prospection des filons, le démarrage de chantiers à ciel ouvert et l’organisation des exploitations souterraines. Les chantiers s’étendent jusqu’à 150 m du jour et sont assistés par des niveaux de circulation par traînage, des conduits d’aérage perchés en hauteur et des galeries de drainage ouvertes à la base. Ces ouvrages d’assistance reflètent une organisation opportuniste de la mine, facilitée par la topographie et la géologie du gisement. L’analyse sédimentologique et anthracologique des remblais, associée à des expérimentations sérielles, permet de caractériser la chaîne opératoire technique de l’abattage par le feu et son impact sur les modalités de gestion de la forêt arborescente d’altitude, comprimée entre les activités agropastorales et minières.The Fournel silver mine was in operation between the tenth and fourteenth century. The extant texts concern the twelfth century mature phase and the mid-thirteenth century slowdown. Several vein panels were exploited from outcroppings, in steep rocky cliffs, to the bottom of a gorge. Because of the extreme hardness of the rock, the miners used firesetting. The topography of the site greatly facilitated vein exploration, initiating opencast sites and mine organisation. The stopes stretch up to 150 m from daylight, and were assisted by access levels by sledge, high perched ventilation ducts and drainage adits open to base level. These works reflect an opportunist support organisation in the mine, facilitated by relief and deposit geology. Sedimentological analysis of backfill and the use of anthracology associated with serial experiments, enable characterisation of the operative chain techniques of firesetting and its impact on high altitude forest management up to tree level, between the higher pastures and the mines

The apparent breastfeeding paradox in very preterm infants: relationship between breast feeding, early weight gain and neurodevelopment based on results from two cohorts, EPIPAGE and LIFT

Context: Supplementation of breast milk is difficult once infants suckle the breast and is often discontinued at end of hospitalisation and after discharge. Thus, breastfed preterm infants are exposed to an increased risk of nutritional deficit with a possible consequence on neurodevelopmental outcome. Objective: To assess the relationship between breast feeding at time of discharge, weight gain during hospitalisation and neurodevelopmental outcome. Design: Observational cohort study. Setting: Two large, independent population-based cohorts of very preterm infants: the Loire Infant Follow-up Team (LIFT) and the EPIPAGE cohorts. Patients: 2925 very preterm infants alive at discharge. Main outcome measure: Suboptimal neurodevelopmental outcome, defined as a score in the lower tercile, using Age and Stages Questionnaire at 2 years in LIFT and Kaufman Assessment Battery for Children Test at 5 years in EPIPAGE. Two propensity scores for breast feeding at discharge, one for each cohort, were used to reduce bias. Results: Breast feeding at time of discharge concerned only 278/1733 (16%) infants in LIFT and 409/2163 (19%) infants in EPIPAGE cohort. Breast feeding is significantly associated with an increased risk of losing one weight Z-score during hospitalisation (LIFT: n=1463, adjusted odd ratio (aOR)=2.51 (95% CI 1.87 to 3.36); EPIPAGE: n=1417, aOR=1.55 (95% CI 1.14 to 2.12)) and with a decreased risk for a suboptimal neurodevelopmental assessment (LIFT: n=1463, aOR=0.63 (95% CI 0.45 to 0.87); EPIPAGE: n=1441, aOR=0.65 (95% CI 0.47 to 0.89) and an increased chance of having a head circumference Z-score higher than 0.5 at 2 years in LIFT cohort (n=1276, aOR=1.43 (95% CI 1.02 to 2.02)) and at 5 years in EPIPAGE cohort (n=1412, aOR=1.47 (95% CI 1.10 to 1.95)). Conclusions: The observed better neurodevelopment in spite of suboptimal initial weight gain could be termed the 'apparent breastfeeding paradox' in very preterm infants. Regardless of the mechanisms involved, the current data provide encouragement for the use of breast feeding in preterm infants

Special Care and School Difficulties in 8-Year-Old Very Preterm Children: The Epipage Cohort Study

OBJECTIVES: To investigate school difficulties, special care and behavioral problems in 8 year-old very preterm (VPT) children. PATIENT AND METHODS: Longitudinal population-based cohort in nine regions of France of VPT children and a reference group born at 39-40 weeks of gestation (WG). The main outcome measures were information about school, special care and behavioral problems using Strengths and Difficulties Questionnaire from a questionnaire to parents. RESULTS: Among the 1439 VPT children, 5% (75/1439) were in a specialised school or class, 18% (259/1439) had repeated a grade in a mainstream class and 77% (1105/1439) were in the appropriate grade-level in mainstream class; these figures were 1% (3/327) , 5% (16/327) and 94% (308/327) , respectively, for the reference group. Also, 15% (221/1435) of VPT children in a mainstream class received support at school versus 5% (16/326) of reference group. More VPT children between the ages of five and eight years received special care (55% (794/1436)) than children born at term (38% (124/325)); more VPT children (21% (292/1387)) had behavioral difficulties than the reference group (11% (35/319)). School difficulties, support at school, special care and behavioral difficulties in VPT children without neuromotor or sensory deficits varied with gestational age, socioeconomic status, and cognitive score at the age of five. CONCLUSIONS: Most 8-year-old VPT children are in mainstream schools. However, they have a high risk of difficulty in school, with more than half requiring additional support at school and/or special care. Referral to special services has increased between the ages of 5 and 8 years, but remained insufficient for those with borderline cognitive scores