Validation of a novel microradiography device for characterization of bone mineralization

International audienceIn order to simplify bone mineralization measurements, a system using radiographic films has been updated with a digital detector. The objective of this paper was to validate this new device. Technologies and physical phenomena involved in both systems (radiographic films and digital detector) are different. The methodology used to compare the two systems was based on image quality and assessed on two main parameters: contrast to noise ratio and spatial resolution. Results showed that the contrast to noise ratio was similar between the two systems, provided that acquisition parameters were optimized. With regard to spatial resolution, a magnification factor of at least 4 or more was required to achieve the same resolution as films. A final validation was also shown on a real image of a bone sample. The results showed that both systems have similar image quality performances, and the system using digital detector has several advantages (easier to use than films, no consumables and faster acquisition time)

Visualization of Vascular Perfusion of Human Pancreatic Cancer Tissue in the CAM Model and Its Impact on Future Personalized Drug Testing

Although significant improvements have been made in the treatment of pancreatic cancer, its prognosis remains poor with an overall 5-year survival rate of less than 10%. New experimental approaches are necessary to develop novel therapeutics. In this study, the investigation of pancreatic cancer tissue growth in the chorioallantoic membrane (CAM) model and the subsequent use of indocyanine green (ICG) injections for the verification of intratumoral perfusion was conducted. ICG was injected into the CAM vasculature to visualize the perfusion of the tumor tissue. The presence of metastasis was investigated through PCR for the human-specific ALU element in the liver of the chicken embryo. Additionally, the usage of cryopreserved pancreatic tumors was established. Intratumoral perfusion of tumor tissue on the CAM was observed in recently obtained and cryopreserved tumors. ALU-PCR detected metastasis in the chick embryos’ livers. After cryopreservation, the tissue was still vital, and the xenografts generated from these tumors resembled the histological features of the primary tumor. This methodology represents the proof of principle for intravenous drug testing of pancreatic cancer in the CAM model. The cryopreserved tumors can be used for testing novel therapeutics and can be integrated into the molecular tumor board, facilitating personalized tumor treatment

New methods of waste sorting by X-ray

Les travaux proposés portent sur la caractérisation par rayons X des matériaux, en vue du tri de certains d'entre eux dans un flux de déchets. L'objectif final du tri est la valorisation de certains matériaux par le biais des circuits de recyclage. Deux méthodes d'analyse utilisant les rayons X sont décrites : la méthode par transmission bi-énergie et la fluorescence X. Ces deux méthodes sont abordées sous un angle théorique et expérimental. Le mémoire se compose de trois parties. La première partie présente le contexte général de l'étude, les différents scénarios de tri envisagés, les différentes méthodes existantes ainsi que les machines de tri industrielles déjà commercialisées. La seconde partie est consacrée à l'analyse par transmission X bi-énergie. Dans cette partie nous présentons tout d'abord le principe de la décomposition d'un matériau dans une base de deux autres matériaux. Ensuite nous utilisons un code de simulation analytique développé au laboratoire afin d'une part d'optimiser la géométrie du détecteur mais également de prévoir les performances de cette méthode en fonction des scénarios et des matériaux recherchés. Nous avons introduit un critère permettant de quantifier la performance d'un scénario donné. Cette méthode a permis de montrer que plusieurs scénarios de tri et en particulier celui du tri des retardateurs de flamme dans un flux de plastiques sont envisageables par cette méthode. Un prototype de machine industrielle a été construit par la société Bertin Technologies et installé dans les locaux de la société Pellenc ST pour réaliser des tests en conditions réelles de tri. Les résultats de simulation ont été comparés aux essais en conditions réelles. Cette partie se conclue avec une introduction aux méthodes multi-énergie. La troisième et dernière partie s'intéresse à la fluorescence X. L'objectif est de mettre au point une méthode permettant d'identifier la nature du matériau en tenant compte des contraintes industrielles (temps d'acquisition faible), c'est-à-dire lorsque le niveau de signal contenu dans le spectre de fluorescence est faible et bruité. Un banc expérimental a été mis au point au laboratoire et a permis de définir la limite de détection qui dépend du matériau analysé et du temps d'acquisition pour réaliser la mesure. Le second point développé dans cette partie est la mise au point d'une technique de simulation de fluorescence combinant le calcul analytique et le calcul par méthode Monte Carlo. L'avantage de cette technique est d'avoir une méthode de simulation plus rapide par rapport à un calcul qui serait réalisé entièrement par Monte Carlo. En conclusion, nous discutons de la complémentarité des informations issues de ces différentes techniques ainsi que leurs avantages et inconvénients.The proposed work focuses on the characterization of materials by X-ray to sort some of them in a waste stream. The main aim is the valorization of certain of these materials through recycling loops. Two methods of analysis using X-rays are described : dual energy X-ray transmission and X-ray fluorescence. These two methods are discussed from a theoretical and experimental point of view. The memory consists of four parts. The first part presents the general context of the study, the different sorting scenarios considered, the existing methods and industrial sorting systems already in application. The second part is devoted to analysis by dual energy X-ray transmission. In this section we first present the principle of decomposition of a material in a basis of two other materials. Then we use the VXI simulation tool to optimize the geometry of the detector and to predict the performances of the method according to the scenarios and refined materials. This method showed that several sorting scenarios and particularly sorting of flame retardants in plastic flow are possible by this method. An industrial prototype was built by Bertin Technologies and installed in the premises of Pellenc ST to realize sorting tests under actual conditions. Then the results of simulation have been compared to these tests. This section concludes with an introduction of multi-energy methods. The third part deals with X-ray fluorescence. The aim is to develop a method to identify the nature of the material even if the signal contained in its fluorescence spectrum is low and noisy. A experimental bench was developed in the laboratory to define the limit of detection wich depends on the material analyzed and the acquisition time of the measurement. The second point developed in this part is the development of a simulation technique that combines fluorescence analytical calculation and Monte Carlo calculation. The advantage of this technique is to have a faster simulation method compared to a calculation that would be fully realized by Monte Carlo. In conclusion, we discuss the complementarity of information extracted from these different techniques and their respective advantages and drawbacks

Dual Energy Radioscopy Applied to Waste Sorting

International audienceDual energy X-ray transmission technique is used since many years in the medical field for bone /soft tissues separation, as well as in luggage inspection for light/heavy materials distinction. Its application to waste sorting first implies a feasibility study for performance assessment of different sorting scenarios. We have used the “Virtual X-ray Imaging” simulation software developed at INSA-Lyon (LVA laboratory) in order to optimize the dual line detector geometry (sandwich or parallel), but also to assess performances of the method

Validation of a novel microradiography device for characterization of bone ineralization

International audienceIn order to simplify bone mineralization measurements, a system using radiographic films has been updated with a 13 digital detector. The objective of this paper was to validate this new device. Technologies and physical phenomena involved 14 in both systems (radiographic films and digital detector) are different. The methodology used to compare the two systems was 15 based on image quality and assessed on two main parameters: contrast to noise ratio and spatial resolution. Results showed 16 that the contrast to noise ratio was similar between the two systems, provided that acquisition parameters were optimized. With 17 regard to spatial resolution, a magnification factor of at least 4 or more was required to achieve the same resolution as films. 18 A final validation was also shown on a real image of a bone sample. The results showed that both systems have similar image 19 quality performances, and the system using digital detector has several advantages (easier to use than films, no consumables 20 and faster acquisition time)