Uso de software como ferramenta pedagógica no processo de ensino-aprendizagem da mamografia digital

OBJETIVO: Avaliar o impacto sobre o treinamento de residentes utilizando uma ferramenta computacional dedicada à avaliação do desempenho da leitura de imagens radiológicas convencionais e digitais. MATERIAIS E MÉTODOS: O treinamento foi realizado no Laboratório de Qualificação de Imagens Médicas (QualIM). Os residentes de radiologia efetuaram cerca de 1.000 leituras de um total de 60 imagens obtidas de um simulador estatístico (Alvim®) que apresenta fibras e microcalcificações de dimensões variadas. O desempenho dos residentes na detecção dessas estruturas foi avaliado por meio de parâmetros estatísticos. RESULTADOS: Os resultados da probabilidade de detectabilidade foram de 0,789 e 0,818 para os sistemas convencional e digital, respectivamente. As taxas de falso-positivos foram de 8% e 6% e os valores de verdadeiro-positivos, de 66% e 70%, respectivamente. O valor de kappa total foi 0,553 para as leituras em negatoscópio e 0,615 em monitor. A área sob a curva ROC foi de 0,716 para leitura em filme e 0,810 para monitor. CONCLUSÃO: O treinamento proposto mostrou ser efetivo e apresentou impacto positivo sobre o desempenho dos residentes, constituindo-se em interessante ferramenta pedagógica. Os resultados sugerem que o método de treinamento baseado na leitura de simuladores pode produzir um melhor desempenho dos profissionais na interpretação das imagens mamográficas.

La nueva formación de profesionales: sobre la competencia profesional y la competencia del estudiante de enfermería.

La idea de competencia profesional está, desde hace unos años, presente en varias profesiones, entre ellas la enfermería y la medicina. La reciente publicación de trabajos y artículos sobre el tema en la literatura científica en lengua castellana demuestra la creciente implicación de los profesionales en la necesidad de aplicar, tanto desde la perspectiva asistencial como la educativa, fórmulas para crear profesionales competentes. La transformación impulsada por las directrices europeas de enseñanza superior que está experimentando el mundo universitario, ha supuesto, entre otras, la organización de las enseñanzas en función del aprendizaje y la introducción de la educación basada en las competencias del alumno. La definición de las competencias del estudiante es una tarea fundamental, que permite coordinar la formación y determinar la priorización de los objetivos de aprendizaje, tanto en pregrado como en postgrado. Es importante constatar el esfuerzo de diversas escuelas para introducir cambios en los planes de estudio y nuevas estrategias metodológicas encaminadas al objetivo de una educación basada en las competencias finales del alumno. Algunos ejemplos son los nuevos planteamientos en el diseño de programas y la introducción de estrategias como el aprendizaje basado en problemas, los practicum o los sistemas de evaluación basado en las competencias.

Evaluación de la Competencia 'aplicar los conocimientos para lograr resultados (nivel I)' en el primer curso de grado en derecho

Uno de los temas que merece ser objeto de reflexión en el nuevo marco docente diseñado en España como consecuencia de la convergencia hacia el Espacio Europeo de Educación Superior es el de la evaluación, pues ésta adquiere una nueva dimensión al colocarse el estudiante en el centro del proceso de aprendizaje y al aplicarse un enfoque docente basado en competencias y, por ello, se hace necesario replantearse su naturaleza y el diseño de todos los elementos estructurales que la configuran. El objeto de nuestro trabajo se circunscribe a la evaluación de una competencia determinada en el primer curso de grado en Derecho y a la experiencia adquirida en distintas universidades, públicas y privadas, en los primeros años de su aplicación; centrándonos, en concreto, en el caso práctico semipresencial (trabajo colaborativo) como actividad decisiva para el aprendizaje de la competencia asignada a nuestra disciplina y procedimiento óptimo para evaluar su adquisición.

Population ageing and ICT: An exploratory review of technology innovation trough digital applications

The multidimensional process of physical, psychological, and social change produced by population ageing affects not only the quality of life of elderly people but also of our societies. Some dimensions of population ageing grow and expand over time (e.g. knowledge of the world events, or experience in particular situations), while others decline (e.g. reaction time, physical and psychological strength, or other functional abilities like reduced speed and tiredness). Information and Communication Technologies (ICTs) can help elderly to overcome possible limitations due to ageing. As a particular case, biometrics can allow the development of new algorithms for early detection of cognitive impairments, by processing continuous speech, handwriting or other challenged abilities. Among all possibilities, digital applications (Apps) for mobile phones or tablets can allow the dissemination of such tools. In this article, after presenting and discussing the process of population ageing and its social implications, we explore how ICTs through different Apps can lead to new solutions for facing this major demographic challenge.

Competencia lectora y aprendizaje

En el presente trabajo se discute acerca de la construcción de la competencia lectora y se examinan las relaciones existentes entre dicha competencia y el aprendizaje. Se asume que una concepción amplia y compleja de la lectura tiene mayores posibilidades de lograr una plena alfabetización (social e individual) que una representación más restringida y simple. Estala concepción simple tiende a considerar que leer es una habilidad que se adquiere en un periodo concreto de la vida y que se aplica indistintamente a diversos textos y situaciones. Contrariamente a esta postura, se argumenta que la apropiación y el uso de la lectura en las sociedades letradas se inician muy pronto y no se acaban nunca, pues siempre es posible profundizar en la competencia lectora. Esta posición conlleva aceptar los cambios profundos que, por el impacto de las diversas situaciones y usos de la lectura en las que las personas nos vemos implicadas, se producen en la forma de ser lector a lo largo de la vida. En estas situaciones, gracias al concurso de otros, se pueden aprender las estrategias que permiten ir más allá de la lectura superficial, y posibilitan una lectura profunda, crítica, capaz de transformar la información en conocimiento. Se revisan algunos datos proporcionados por estudios internacionales de evaluación, así como las conclusiones de trabajos de investigación, que en conjunto ponen de manifiesto que la enseñanza y el aprendizaje de esta forma de lectura es menos frecuente de lo que cabría desear. Se concluye argumentando la necesidad de proyectos sociales y de centro dirigidos a fomentarla.

A comprehensive model for quantum noise characterization in digital mammography.

NlmCategory="UNASSIGNED">A version of cascaded systems analysis was developed specifically with the aim of studying quantum noise propagation in x-ray detectors. Signal and quantum noise propagation was then modelled in four types of x-ray detectors used for digital mammography: four flat panel systems, one computed radiography and one slot-scan silicon wafer based photon counting device. As required inputs to the model, the two dimensional (2D) modulation transfer function (MTF), noise power spectra (NPS) and detective quantum efficiency (DQE) were measured for six mammography systems that utilized these different detectors. A new method to reconstruct anisotropic 2D presampling MTF matrices from 1D radial MTFs measured along different angular directions across the detector is described; an image of a sharp, circular disc was used for this purpose. The effective pixel fill factor for the FP systems was determined from the axial 1D presampling MTFs measured with a square sharp edge along the two orthogonal directions of the pixel lattice. Expectation MTFs were then calculated by averaging the radial MTFs over all possible phases and the 2D EMTF formed with the same reconstruction technique used for the 2D presampling MTF. The quantum NPS was then established by noise decomposition from homogenous images acquired as a function of detector air kerma. This was further decomposed into the correlated and uncorrelated quantum components by fitting the radially averaged quantum NPS with the radially averaged EMTF(2). This whole procedure allowed a detailed analysis of the influence of aliasing, signal and noise decorrelation, x-ray capture efficiency and global secondary gain on NPS and detector DQE. The influence of noise statistics, pixel fill factor and additional electronic and fixed pattern noises on the DQE was also studied. The 2D cascaded model and decompositions performed on the acquired images also enlightened the observed quantum NPS and DQE anisotropy.

Hardcopy quality parameters to ensure structures detection at digital mammography

Objective To develop procedures to ensure consistency of printing quality of digital images, by means of hardcopy quantitative analysis based on a standard image. Materials and Methods Characteristics of mammography DI-ML and general purpose DI-HL films were studied through the QC-Test utilizing different processing techniques in a FujiFilm®-DryPix4000 printer. A software was developed for sensitometric evaluation, generating a digital image including a gray scale and a bar pattern to evaluate contrast and spatial resolution. Results Mammography films showed maximum optical density of 4.11 and general purpose films, 3.22. The digital image was developed with a 33-step wedge scale and a high-contrast bar pattern (1 to 30 lp/cm) for spatial resolution evaluation. Conclusion Mammographic films presented higher values for maximum optical density and contrast resolution as compared with general purpose films. The utilized digital processing technique could only change the image pixels matrix values and did not affect the printing standard. The proposed digital image standard allows greater control of the relationship between pixels values and optical density obtained in the analysis of films quality and printing systems.

Digital evidence, 'absence' of data and ambiguous patterns of reasoning

In this paper we discuss the use of digital data by the Swiss Federal Criminal Court in a recent case of attempted homicide. We use this case to examine drawbacks for the defense when the presentation of scientific evidence is partial, especially when the only perspective mentioned is that of the prosecution. We tackle this discussion at two distinct levels. First, we pursue an essentially non-technical presentation of the topic by drawing parallels between the court's summing up of the case and flawed patterns of reasoning commonly seen in other forensic disciplines, such as DNA and particle traces (e.g., gunshot residues). Then, we propose a formal analysis of the case, using elements of probability and graphical probability models, to justify our main claim that the partial presentation of digital evidence poses a risk to the administration of justice in that it keeps vital information from the defense. We will argue that such practice constitutes a violation of general principles of forensic interpretation as established by forensic science literature and current recommendations by forensic science interest groups (e.g., the European Network of Forensic Science Institutes). Finally, we posit that argument construction and analysis using formal methods can help replace digital evidence appropriately into context and thus support a sound evaluation of the evidence.

Reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications

Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemar's test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57%) patients. Such individuals presented with a total of 29 (41.43%) carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50) of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001) was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.

Lessons from the Digital Divide

Peer-reviewed

Evaluación del estado del arte en relación con la temática, las plataformas y la experiencia del usuario: El documental interactivo en la estrategia de la multidifusión digital

This article argues that interactive documentaries play a key role in digital multicasting strategies the author offers analysis of the latest trends in this area from three angles: the documentery subject, the support/ platform, and the user experience.