27 research outputs found

    A Deep Learning Approach to MR-less Spatial Normalization for Tau PET Images

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    The procedure of aligning a positron emission tomography (PET) image with a common coordinate system, spatial normalization, typically demands a corresponding structural magnetic resonance (MR) image. However, MR imaging is not always available or feasible for the subject, which calls for enabling spatial normalization without MR, MR-less spatial normalization. In this work, we propose a template-free approach to MR-less spatial normalization for [18F]flortaucipir tau PET images. We use a deep neural network that estimates an aligning transformation from the PET input image, and outputs the spatially normalized image as well as the parameterized transformation. In order to do so, the proposed network iteratively estimates a set of rigid and affine transformations by means of convolutional neural network regressors as well as spatial transformer layers. The network is trained and validated on 199 tau PET volumes with corresponding ground truth transformations, and tested on two different datasets. The proposed method shows competitive performance in terms of registration accuracy as well as speed, and compares favourably to previously published results

    Concordância entre diagnósticos dermatológicos obtidos por consulta presencial e por análise de imagens digitais Agreement between dermatological diagnoses made by live examination compared to analysis of digital images

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    FUNDAMENTOS: A teledermatologia, pouco utilizada no Brasil e com iniciativas incipientes no Amazonas, necessita de estudos para demonstrar sua factibilidade e eficácia. OBJETIVOS: Avaliar a eficácia de um método assíncrono de teledermatologia, utilizando recursos tecnológicos simples e de baixo custo. MÉTODOS: Cento e setenta e quatro pacientes foram examinados por quatro dermatologistas; dois efetuaram diagnóstico presencial (A1 e A2) e dois por meio de imagens das lesões e história clínica (B1 e B2). Foi investigada a concordância entre as avaliações presenciais e por imagens. RESULTADOS: A concordância do diagnóstico principal entre os examinadores presenciais (A1 e A2) foi de 83,3% e entre os de imagens (B1 e B2), de 81%. A concordância entre o diagnóstico principal estabelecido pelo método presencial e o obtido por meio de imagens variou de 78,2% a 83,9%. CONCLUSÃO: O diagnóstico de doenças dermatológicas realizado por imagens digitais demonstrou concordância ótima quando comparado àquele realizado com a presença física do paciente.<br>BACKGROUND: Teledermatology is seldom used in Brazil, although some incipient initiatives have been implemented in the state of Amazonas. Further studies are still required to confirm the feasibility and efficacy of this diagnostic tool. OBJECTIVES: To evaluate the efficacy of an asynchronous method of teledermatology using simple, inexpensive technological resources. METHODS: One hundred and seventy-four patients were examined by four dermatologists, two clinic-based dermatologists, who diagnosed the patients following live examination (A1 and A2), and two consultant specialists in image dermatology, who reached diagnoses by examining images of the lesions and the patients' clinical histories (B1 and B2). The agreement between live examination and examination of images was evaluated. RESULTS: Agreement between the two live examiners (A1 and A2) with respect to the principal diagnosis was 83.3% compared to 81.0% between the physicians who diagnosed by examining images (B1 and B2). Agreement between the principal diagnosis established by live examination and that obtained from examining images ranged from 78.2% to 83.9%, CONCLUSION: Agreement between diagnoses of dermatological diseases reached following examination of digital images and those reached following live examination of the patient was excellent

    Advancing the Science of Community-Level Interventions

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    Community interventions are complex social processes that need to move beyond single interventions and outcomes at individual levels of short-term change. A scientific paradigm is emerging that supports collaborative, multilevel, culturally situated community interventions aimed at creating sustainable community-level impact. This paradigm is rooted in a deep history of ecological and collaborative thinking across public health, psychology, anthropology, and other fields of social science. The new paradigm makes a number of primary assertions that affect conceptualization of health issues, intervention design, and intervention evaluation. To elaborate the paradigm and advance the science of community intervention, we offer suggestions for promoting a scientific agenda, developing collaborations among professionals and communities, and examining the culture of science. (Am J Public Health. Published online ahead of print June 16, 2011:e1-e10. doi:10.2105/AJPH.2010.300113)
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