Synthtic OCT Data for image processing performance testing

The use of synthetic images is needed for testing the performance of image processing methods in order to establish a ground truth to test performance metrics. However, these synthetic images do not represent real applications. The aim of this paper is to build a mathematical model to obtain a synthetic noise-free image mimicking a real Optical Coherence Tomography (OCT) B-scan or volume from the human retina, in order to establish a ground truth for filtering performance metrics in this context. Moreover we also suggest a method to add speckle noise to this image based on the speckle noise of the given OCT volume. In this way we establish a replicable method to obtain a ground truth for image processing performance metrics that actually mimics a real case.FCTFEDERProgram COMPET

Improved adaptive complex diffusion despeckling filter

Despeckling optical coherence tomograms from the human retina is a fundamental step to a better diagnosis or as a preprocessing stage for retinal layer segmentation. Both of these applications are particularly important in monitoring the progression of retinal disorders. In this study we propose a new formulation for a well-known nonlinear complex diffusion filter. A regularization factor is now made to be dependent on data, and the process itself is now an adaptive one. Experimental results making use of synthetic data show the good performance of the proposed formulation by achieving better quantitative results and increasing computation speed.Fundação para a Ciência e TecnologiaFEDERPrograma COMPET

Ocular fundus Imaging: from structure to function

Imaging the ocular fundus, namely the retina, to detect and/or monitor changes over time from the healthy condition is of fundamental importance to assess onset and disease progression and is a valuable tool to understand the basic mechanisms of ocular diseases. Current trends point to the need for less or non-invasive approaches, to the need for detailed (higher spatial and temporal resolution) imaging systems and to the quantification as opposed to qualitative classification of any findings. In this work we present a snapshot of our research by presenting two examples of technical development aiming to obtain structural and function information from the human retina, in vivo, using non-invasive techniques, namely optical coherence tomography imaging. Based on our experience and developed work, we are now starting to bridge the gap to brain imaging as the eye is only the starting point of vision.FCTFEDERProgram COMPET

Dinâmica entre a alimentação habitual, anemia e segurança alimentar entre estudantes de Saúde no Amazonas

The aim of this work was to approach the dynamic between the usual food habit and the presence of iron deficiency anemia in students of health courses (Medicine, Dentistry and Nursing) from the Universidade do Estado do Amazonas (UEA), future professionals that deal with health education. At the beginning of the study, subjects were submitted to a questionnaire about their food habits (24-hour feeding recall and food frequency), use of medications, health history and demographic factors, and blood was collected for hemoglobin and iron study, and anthropometric data. 22 out of the 114 enrolled students have completed the survey - 64% females and 36% males; the mean age 19.8 and 26.2 years, respectively; anemia was detected in 18.2% of participants. Understanding of nutrition education is an essential, important and decisive factor for health and food safety

Correlação entre hipertrigliceridemia e estenose carotídea em pacientes com acidente vascular cerebral isquêmico

Introduction: Cerebrovascular disease has a multifactorial etiology, depending on genetic predisposition and environmental elements related to diet and lifestyle. Like arterial hypertension and diabetes, dyslipidemia is also considered an important risk factor, and the control of hypercholesterolemia has for some time been a target for the treatment and prevention of atherosclerosis, including carotid stenosis and, consequently, ischemic stroke. On the other hand, there are few studies associating hypertriglyceridemia with the degree of carotid artery disease. Objective: To correlate hypertriglyceridemia, carotid stenosis and ischemic stroke in patients with stroke diagnosis. Material and methods: The study was cross-sectional, retrospective, with a quantitative-descriptive approach, and analyzed the medical records of 100 patients diagnosed with ischemic stroke. Sociodemographic data, risk factors, clinical signs and symptoms, as well as complementary tests were analyzed. Critical carotid stenosis was considered when equal to or greater than 70% and hypertriglyceridemia when values were greater than 150 mg/dl. Result: The mean age was 69.6 years, most were female (54%), motor deficits (79%) and language deficits (63%) predominated. The most common risk factor was systemic arterial hypertension (79%). It was observed that 38% had hypercholesterolemia and 35% had hypertriglyceridemia. Critical carotid stenosis was present in 9.21%, all of this subgroup had hypertriglyceridemia (p=0.008 and odds-ratio=3.7). Conclusion: The study concluded that there is a positive association between hypertriglyceridemia, carotid stenosis and stroke.Introdução: a doença cerebrovascular tem etiologia multifatorial, dependendo de predisposição genética e elementos ambientais relacionados à dieta e ao estilo de vida. Assim como a hipertensão arterial e o diabetes, a dislipidemia também é considerada um fator de risco importante. O controle da hipercolesterolemia há algum tempo é alvo do tratamento e da prevenção da aterosclerose, inclusive da estenose carotídea e consequentemente de acidente vascular cerebral isquêmico (AVCi). Por outro lado, há poucos estudos associando a hipertrigliceridemia com o grau de doença carotídea. Objetivo: fazer a correlação entre hipertrigliceridemia e estenose carotídea em pacientes com AVCi. Metodologia: estudo transversal, retrospectivo, com abordagem quantitativa-descritiva. Analisou-se prontuários de 100 pacientes com diagnóstico de AVCi, além de dados sociodemográficos, fatores de risco, sinais e sintomas clínicos, assim como exames complementares. Considerou-se estenose crítica da carótida aquela igual ou maior que 70% e hipertrigliceridemia se valores maiores que 150 mg/dl. Resultado: a média de idade dos pacientes foi de 69,6 anos. A maioria era do sexo feminino (54%), predominava déficit motor (79%) e de linguagem (63%). O fator de risco mais encontrado foi hipertensão arterial sistêmica (79%). Observou-se que 38% tinham hipercolesterolemia e 35% tinham hipertrigliceridemia. Estenose crítica de carótida esteve presente em 9,21% e todos desse subgrupo apresentavam hipertrigliceridemia (p=0,008 e odds-ratio=3,7). Conclusão: existe uma associação positiva entre hipertrigliceridemia, estenose de carótida e acidente vascular encefálico

Adaptive complex diffusion noise despeckling for 3D OCT Data

Purpose: To demonstrate the performance of a recently proposed despeckling filter when extended to 3D in OCT data. Methods: A new formulation for a complex diffusion filter was recently proposed [1] being adaptive in time and adjusting parameters to data, facilitating diffusion in the vitreous and reducing it in the retina to preserve tissue information. This new formulation outperformed, both quantitatively and qualitatively, currently existing filters, while at the same time was computationally more efficient attaining the same despeckling level in 34% of the computing time. We have now extended it to perform 3D OCT despeckling achieving a significant improvement in noise removal. We have resorted to a mathematical based synthetic OCT scan in order to assess quantitative results in 3D. In addition, we have applied this 3D filter to a set of 72 eye scans, from healthy volunteers (20), diabetic retinopathy (20), cystoid macular edema (2), age-related macular degeneration (20) and choroidal neo-vascularization (10), who underwent high-definition Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) using macular cube protocols (200x200x1024 and/or 512x128x1024). Results: The extension from 2D to 3D of this adaptive complex diffusion filter proved to be beneficial by achieving an increased level of noise reduction while simultaneously better preserving fundamental information. These facts are supported from well known metrics (e.g. MSE-mean squared error, ENL-effective number of looks and CNR-contrast-to-noise ratio) for the synthetic OCT scan and from the assessment made by 3 retina specialist who graded qualitatively the output of the 2D and 3D filters. Conclusions: These findings demonstrate this new formulation and its extension to 3D is beneficial for human analysis of OCT data and suggest it might be an important tool for automated data processing as in segmentation of retinal structures. [1] Bernardes R, Maduro C, Serranho P, Araújo A, Barbeiro S, Cunha-Vaz J. Improved adaptive complex diffusion despeckling filter. OPTICS EXPRESS 18(23):24048-24059, 2010.FCT, FEDER, COMPET

Synthetic volume from real optical coherence tomography data

Purpose: To build a mathematical model to mimic a real OCT b-scan/volume without noise, in order to establish a ground truth for image processing performance metrics. Methods: Current image processing techniques (eg. despeckling filtering methods) with application to optical coherence tomography (OCT) rely on the respective qualitative evaluation of its results. Quantitative approaches are reduced to using synthetic images which consists of an homogeneous background and a set of abstract objects, eg. cubes and spheres. In this work, we suggest a mathematical model to address this issue by creating a synthetic b-scan/volume based on any real OCT data scan, that can be used as ground truth for processing methods testing. Eye scans of healthy volunteers and eyes of patients with age-related macular degeneration and diabetic retinopathy were used following Cirrus OCT (Carl Zeiss Meditec, Dublin, CA, USA) scans using both the 200x200x1024 and the 512x128x1024 Macular Cube Protocols. Each of these eye scans was processed in order to extract required parameters. For healthy subjects, only the segmentation of the inner limiting membrane (ILM) and the retinal pigment epithelium (RPE) are needed, though for pathologic eyes, the segmentation of other structures to be preserved might also be needed. In each segmented region, OCT data is surface fitted using appropriate basis functions. Results: A total of 45 scans were processed resulting in the synthetic data representing the major characteristics of the respective real OCT scans. These results have been used for testing the performance of an improved complex diffusion despeckling method proposed by some of the authors. Conclusions: This process allows to automatically compute a synthetic OCT scan mimicking a real one. In this way, this process makes it possible to quantify the result of any processing (eg. filtering) by providing adequate synthetic data as ground truth.FCT, Feder e Compet

MATEMÁTICA BÁSICA INSTRUMENTAL: UMA FORMAÇÃO CONTINUADA DE SERVIDORES

O presente trabalho visa a apresentar o curso de extensão Matemática Básica Instrumental, de proponência e coordenação pedagógica de um servidor técnico-administrativo em educação da Escola Politécnica, da Universidade Federal do Rio de Janeiro. Realizado na modalidade de educação a distância (EaD) e contando, em sua equipe, com outros dois servidores lotados nessa mesma unidade acadêmica, trata-se de uma formação continuada para servidores públicos, com abrangência nacional, que tem como objetivo principal oportunizar ao participante o redimensionamento de seus conhecimentos e competências matemáticos, bem como o aperfeiçoamento de sua habilidade para mobilizá-los de forma a contribuir para a sua qualidade de vida e, consequentemente, para o atendimento dos interesses institucionais. Iniciada sua oferta em 2015 via Subcoordenação de Formação Profissional, da Pró-Reitoria de Pessoal (PR-4), e passando, a partir de 2016, a integrar o Programa de Formação Continuada de Servidores Públicos – PROFOS, da Pró-Reitoria de Extensão (PR-5) da UFRJ, o curso é composto por 7 (sete) Módulos semanais, com carga horária total de 60 horas, nos quais são discutidos conceitos matemáticos que abrangem áreas como Aritmética, Geometria, Matemática Financeira e Estatística. Em 2019, inauguramos um segundo curso, intitulado “Matemática Básica Instrumental – Parte II” onde, além de aprofundarmos a discussão sobre os referidos temas e conceitos, ampliamos o escopo conceitual abordando também temas como Proporcionalidade, Funcionalidade e Probabilidade. Com suas atividades desenvolvidas na Plataforma EAD UFRJ, o processo avaliativo se dá de forma contínua, por meio dos seguintes instrumentos: 1. Fórum Virtual, o espaço de interação e discussão sobre o tema, dentro de uma perspectiva dialógica, problematizadora e de construção de conhecimentos de forma colaborativa; 2. Tarefa Semanal, composta por situações-problema contextualizadas, onde os conceitos matemáticos discutidos na semana são mobilizados e aplicados; e 3. Trabalho Final, abordando todos os temas discutidos no curso, a ser produzido e encaminhado pelos participantes no último Módulo. Os dados analisados por este trabalho são oriundos da Autoavaliação e da Avaliação do Curso, que os participantes são convidados a realizar, no último Módulo, respondendo a um formulário online. Apoiando-nos na análise de conteúdo de Bauer (2002), os dados mostraram que há uma satisfação geral com o curso, no entanto, sugerem a necessidade de alguns ajustes, especificamente no tocante a ampliação do seu tempo de duração e aos prazos para a realização das atividades.