Search results for " imaging"
showing 10 items of 6262 documents
K-nearest neighbor driving active contours to delineate biological tumor volumes
2019
Abstract An algorithm for tumor delineation in positron emission tomography (PET) is presented. Segmentation is achieved by a local active contour algorithm, integrated and optimized with the k-nearest neighbor (KNN) classification method, which takes advantage of the stratified k-fold cross-validation strategy. The proposed approach is evaluated considering the delineation of cancers located in different body districts (i.e. brain, head and neck, and lung), and considering different PET radioactive tracers. Data are pre-processed in order to be expressed in terms of standardized uptake value, the most widely used PET quantification index. The algorithm uses an initial, operator selected re…
Food tray sealing fault detection using hyperspectral imaging and PCANet
2020
Abstract Food trays are very common in shops and supermarkets. Fresh food packaged in trays must be correctly sealed to protect the internal atmosphere and avoid contamination or deterioration. Due to the speed of production, it is not possible to have human quality inspection. Thus, automatic fault detection is a must to reach high production volume. This work describes a deep neural network based on Principal Component Analysis Network (PCANet) for food tray sealing fault detection. The input data come from hyperspectral cameras, showing more characteristics than regular industrial cameras or the human eye as they capture the spectral properties for each pixel. The proposed classification…
Abnormal Textures Identification Based on Digital Hilbert Optics Methods: Fundamental Transforms and Models
2017
The article presents the abnormal textures identification technology based on structural and statistical models of amplitude-phase images (APIm) – multidimensional data arrays (semantic models) and statistical correlation analysis methods using the generalized discrete Hilbert transforms (DHT) – 2D Hilbert (Foucault) isotropic (HTI), anisotropic (HTA) and total transforms – AP-analysis (APA) to calculate the APIm. The identified fragments of textures are obtained as examples of experimental observation of real mammograms contains areas of pathological tissues. The DHT based information technology as conceptual chart description is discussed and illustrated with DHO domain images. As additio…
Ecografía intestinal y abdomen agudo: más allá de la apendicitis aguda
2021
Resumen El abdomen agudo es un motivo de consulta habitual en los servicios de urgencias. Sus causas son multiples, y entre ellas se encuentran diversas enfermedades del tracto gastrointestinal. Si bien la tomografia computarizada es la tecnica mas aceptada, con frecuencia se lleva a cabo una ecografia abdominal inicialmente, mediante la cual es posible establecer la sospecha de patologia intestinal. Este articulo describe las caracteristicas ecograficas de diversos trastornos intestinales que cursan con abdomen agudo, como la diverticulitis aguda, la obstruccion intestinal, la perforacion gastrointestinal, la isquemia intestinal, la necrosis aguda de la grasa intraabdominal y una miscelane…
Paraganglioma carotídeo maligno. A propósito de un caso
2019
Resumen Los tumores del cuerpo carotideo son neoplasias poco frecuentes, de lento crecimiento, muy destructivos y vascularizados, que tienen un origen neuroectodermico. Los tumores malignos representan el 5-13% de los casos y presentan un comportamiento agresivo local con infiltracion de los ganglios linfaticos adyacentes o metastasis a distancia. Presentamos el caso de un varon de 60 anos al que en el estudio por dolor y parestesias en miembro superior se le realiza una resonancia magnetica donde se visualiza una gran tumoracion en el espacio carotideo izquierdo, la cual se biopsio obteniendo el diagnostico histologico de paraganglioma. Al realizar el estudio de extension se identifico la …
Direct flow separation strategy, to isolate no-carrier-added 90Nb from irradiated Mo or Zr targets
2016
Abstract 90Nb has an intermediate half-life of 14.6 h, a high positron branching of 53% and optimal β + emission energy of only E mean 0.35 MeV per decay. These favorable characteristics suggest it may be a potential candidate for application in immuno-PET. Our recent aim was to conduct studies on distribution coefficients for ZrIV and NbV in mixtures of HCl/H2O2 and HCl/oxalic acid for anion exchange resin (AG 1 × 8) and UTEVA resin to develop a “direct flow” separation strategy for 90Nb. The direct flow concept refers to a separation accomplished using a single eluent on multiple columns, effectively streamlining the separation process and increasing the time efficiency. Finally, we also …
Complexation des acides aminés basiques arginine, histidine et lysine avec l’ADN plasmidique en solution aqueuse : participation à la capture de radi…
2016
L’environnement chimique de l’ADN en situation biologique est complexe notam-ment en raison de la presence d’histones, proteines nucleaires, associees en quantite approximativement egales a l’ADN pour former la chromatine. Les histones possedent de nombreux radicaux basiques arginine et lysine charges positivement et dont la majorite se trouve sur les chaines emergentes, l’ADN presente quant a lui des charges negatives sur ses groupements phosphates localises tout au long de la double helice. Dans cette etude, la complexite de la structure de la chromatine nucleaire est dans un premier temps mimee en solution aqueuse par la formation de complexes entre un ADN plasmidique sonde et les trois …
Morfofisiología del diafragma torácico en las medicinas china y occidental
2016
Resumen Las autoras creen que el analisis comparativo de diversos temas entre la medicina china y la occidental supone una aportacion al progresivo —y deseado— avance hacia la mutua comprension y sinergia entre ambas disciplinas. La descripcion occidental del diafragma toracico sugiere ciertas lineas de confluencia respecto al enfoque chino: anatomicamente aportan sugerentes paralelismos las referencias de insercion muscular e inervacion del diafragma, asi como su biodinamica respiratoria, elementos coincidentes con la posicion de diversos puntos de acupuntura toracicos que presentan, ademas, posibles semejanzas en sus funciones fisiologicas reguladoras a diversos niveles, con las que la me…
Development of a fast characterization setup for radionuclide generators demonstrated by a 227Ac-based generator
2021
Abstract The development of a setup for a fast online characterization of radionuclide generators is reported. A generator utilizing the mother nuclide 227Ac sorbed on a cation exchange resin is continuously eluted by using a peristaltic pump. To allow continuous and pulse-free elution of a large volume over extended time periods a 3D-printed interface designed to remove pressure-oscillations induced by the pump was placed between pump and generator column to ensure undisturbed generator elution. The eluate of the generator is passed through a 3D printed flow cell placed inside a borehole Na(Tl)-scintillation detector for high counting efficiency. Alternatively, a HPGe detector suitable for…