Multimodal medical case retrieval using the Dezert-Smarandache theory.

International audienceMost medical images are now digitized and stored with semantic information, leading to medical case databases. They may be used for aid to diagnosis, by retrieving similar cases to those in examination. But the information are often incomplete, uncertain and sometimes conflicting, so difficult to use. In this paper, we present a Case Based Reasoning (CBR) system for medical case retrieval, derived from the Dezert-Smarandache theory, which is well suited to handle those problems. We introduce a case retrieval specific frame of discernment theta, which associates each element of theta with a case in the database; we take advantage of the flexibility offered by the DSmT's hybrid models to finely model the database. The system is designed so that heterogeneous sources of information can be integrated in the system: in particular images, indexed by their digital content, and symbolic information. The method is evaluated on two classified databases: one for diabetic retinopathy follow-up (DRD) and one for screening mammography (DDSM). On these databases, results are promising: the retrieval precision at five reaches 81.8% on DRD and 84.8% on DDSM

Content based Medical Image Retrieval: use of Generalized Gaussian Density to model BEMD's IMF.

In this paper, we address the problem of medical ddiagnosis aid through content based image retrieval methods. We propose to characterize images without extracting local features, by using global information extracted from the image Bidimensional Empirical Mode Decomposition (BEMD). This method decompose image into a set of functions named Intrinsic Mode Functions (IMF) and a residu. The generalized Gaussian density function (GGD) is used to represent the coefficients derived from each IMF, and the Kullback–Leibler Distance (KLD) compute the similarity between GGDs. Retrieval efficiency is given for different databases including a diabetic retinopathy, and a face database. Results are promising: the retrieval efficiency is higher than 85% for some cases

Reconstruction du contour du globe oculaire sur des images échographiques.

Cet article présente une méthode de reconstruction du contour du globe oculaire dans les images échographiques. Après une présentation du système d'acquisition utilisé pour obtenir des images de qualité, la démarche suivie est présentée. Elle consiste, après passage en coordonnées polaires, à extraire des points de contours par fusion de l'image gradient et de l'image région. Dans une deuxième phase, un contour fermé est reconstruit par ajustement d'une courbe B-spline régularisée pondérée sur les points précédents. Les résultats sont affinés par itérative successives après élimination des points aberrants situés à l'extérieur d'un ruban centré sur la courbe spline. Les résultats présentés, obtenus après quelques itérations, montrent l'intérêt de la méthode

Supervised stereo visual acuity tests implemented on 3D TV monitors

International audienceIn this paper we discuss under which conditions standard stereo visual acuity tests can be implemented on 3D TV monitors. In particular, we emphasize the role of environmental lighting conditions, on the measurement of the stereo visual acuity, when using conventional 3D tests, such as Wirt stereotests. We investigate the impact of parameters such as luminance, backlight and contrast when these tests are implemented on 3D TV monitors. We demonstrate that some deviations are observed when modifying the room luminance and the type of displays used (e.g. plasma (PDP) or liquid crystal (LCD) displays). Our measurements carried out on an human sample are supervised by pupil size measurements, using an eyes-tracker, enabling a better interpretation of the results. Finally, we discuss the benefit of using 3D tools to implement stereo visual acuity measurements

Multimedia data mining for automatic diabetic retinopathy screening

International audience— This paper presents TeleOphta, an automatic sys-tem for screening diabetic retinopathy in teleophthalmology networks. Its goal is to reduce the burden on ophthalmologists by automatically detecting non referable examination records, i.e. examination records presenting no image quality problems and no pathological signs related to diabetic retinopathy or any other retinal pathology. TeleOphta is an attempt to put into practice years of algorithmic developments from our groups. It combines image quality metrics, specific lesion detectors and a generic pathological pattern miner to process the visual content of eye fundus photographs. This visual information is further combined with contextual data in order to compute an abnormality risk for each examination record. The TeleOphta system was trained and tested on a large dataset of 25,702 examination records from the OPHDIAT screening network in Paris. It was able to automatically detect 68% of the non referable examination records while achieving the same sensitivity as a second ophthalmologist. This suggests that it could safely reduce the burden on ophthalmologists by 56%

Segmentation, Classification, and Quality Assessment of UW-OCTA Images for the Diagnosis of Diabetic Retinopathy

Diabetic Retinopathy (DR) is a severe complication of diabetes that can cause blindness. Although effective treatments exist (notably laser) to slow the progression of the disease and prevent blindness, the best treatment remains prevention through regular check-ups (at least once a year) with an ophthalmologist. Optical Coherence Tomography Angiography (OCTA) allows for the visualization of the retinal vascularization, and the choroid at the microvascular level in great detail. This allows doctors to diagnose DR with more precision. In recent years, algorithms for DR diagnosis have emerged along with the development of deep learning and the improvement of computer hardware. However, these usually focus on retina photography. There are no current methods that can automatically analyze DR using Ultra-Wide OCTA (UW-OCTA). The Diabetic Retinopathy Analysis Challenge 2022 (DRAC22) provides a standardized UW-OCTA dataset to train and test the effectiveness of various algorithms on three tasks: lesions segmentation, quality assessment, and DR grading. In this paper, we will present our solutions for the three tasks of the DRAC22 challenge. The obtained results are promising and have allowed us to position ourselves in the TOP 5 of the segmentation task, the TOP 4 of the quality assessment task, and the TOP 3 of the DR grading task. The code is available at \url{https://github.com/Mostafa-EHD/Diabetic_Retinopathy_OCTA}

Exudate detection in color retinal images for mass screening of diabetic retinopathy

International audienceThe automatic detection of exudates in colour eye fundus images is an important task in applications such as diabetic retinopathy screening. The presented work has been undertaken in the framework of the TeleOphta project, whose main objective is to auto-matically detect normal exams in a tele-ophthalmology network, thus reducing the burden on the readers. A new clinical database, e-ophtha EX, containing precisely manually contoured exudates, is introduced. As opposed to previously available databases, e-ophtha EX is very heterogeneous. It contains images gathered within the OPHDIAT telemedicine network for diabetic retinopathy screening. Image definition, quality, as well as patients condition or the retinograph used for the acquisition, for example, are subject to important changes between different examinations. The proposed exudate detection method has been designed for this complex situation. We propose new preprocessing methods, which perform not only normalization and denoising tasks, but also de-tect reflections and artifacts in the image. A new candidates segmentation method, based on mathematical morphology, is proposed. These candidates are characterized using classical features, but also novel contextual features. Finally, a random forest algorithm is used to detect the exudates among the candidates. The method has been validated on the e-ophtha EX database, obtaining an AUC of 0.95. It has been also validated on other databases, obtaining an AUC between 0.93 and 0.95, outperforming state-of-the-art methods

Reconstruction en trois dimensions du segment antérieur par échographie haute fréquence (Application au dimensionnement des implants phaques)

La chirurgie réfractive par implantation phaque nécessite, pour un dimensionnement sur mesure de l'implant, de connaître avec précision la morphologie du segment antérieur. L'échographie haute fréquence tridimensionnelle répond à ces critères d'exigences. Après avoir exposé la technique retenue pour l'élaboration de la reconstruction tridimensionnelle, et démontré sa précision et sa reproductibilité, l'auteur étudie les caractéristiques morphologiques 3D du segment antérieur d'une population témoin de 45 yeux. Toutes les mesures sont comparées à l'OCT et au Pentacam. L'algorithme développé pour le choix de l'implant est testé sur cette population témoin. Dans une deuxième partie, l'auteur a évalué en pré et post opératoire l'échographie 3D dans une population de 14 patients. La première partie démontre que le segment antérieur n'est pas rond mais proche d'une ellipse. Les mesures 3D ne sont pas corrélées aux autres imageurs. Les implants sélectionnés sont proches de ceux sélectionnés par le fabriquant. La deuxième partie retrouve cette constatation pour le choix des implants. Pour certains patients, la différence est significative et pourrait expliquer certaines erreurs de dimensionnement. En conclusion, ce nouvel outil d'exploration du segment antérieur est prometteur. Nous avons prouvé sa précision. L'intégration de l'anatomie tridimensionnelle du segment antérieur semble apporter un gain significatif dans le dimensionnement des implants phaques.BREST-BU Médecine-Odontologie (290192102) / SudocSudocFranceF

: Encountering a situated practice of technology: a look at technology universities in France

International audienceThis contribution aims to reflect the lineaments of technological education through research that is currently being carried out in some higher education institutions, the questions raised by this research, its impasses and its paths. In short, what does the notion of technology encompass today, beyond discourses, as it is declined, as it is exercised in places where it is intended to be embodied? But before that, technology had to win another battle, that of discipline after a long process of legitimization in the second half of the twentieth century. History shows that beyond epistemological postures, debates on higher technical education and attempts to develop a reflection on technology, an institutionalization movement has shaped the term in the research and higher education landscape since the 1960s.Cette contribution aspire à rendre compte des linéaments d’un enseignement technologique par la recherche qui se déploie aujourd’hui dans certains lieux d’enseignement supérieur, des questionnements que suscite cette recherche, de ses impasses comme de ses cheminements. En somme, que recouvre la notion de technologie aujourd’hui, au-delà des discours, telle qu’elle est déclinée, telle qu’elle s’exerce dans des lieux où elle a vocation à être incarnée ? Mais auparavant, il a fallu que la technologie gagne une autre bataille, celle de la disciplinarisation au terme d’un long processus légitimatoire au cours la seconde moitié du XXe siècle. L’histoire montre qu’au-delà des postures épistémologiques, des débats sur l’enseignement supérieur technique et des tentatives de développer une réflexion sur la technologie, un mouvement d’institutionnalisation campe le vocable dans le paysage de la recherche et l’enseignement supérieur à partir des années 1960