613 research outputs found

    A new denoising technique for ultrasound images using morphological properties of speckle combined with tissue classifying parameters

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    In this paper we introduce a new speckle suppression technique for medical ultrasound images that incorporates morphological properties of speckle as well as tissue classifying parameters. Each individual speckles is located, and, exploiting our prior knowledge on the tissue classification, it is determined whether this speckle is noise or a medically relevant detail. We apply the technique on images of neonatal brains affected by White Matter Damage (leukomalacia). The results show that applying an active contour on a processed image, in order to segment the affected areas, yields a segmentation much closer to that of an expert

    PET image reconstruction using simulated annealing

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    Extraction of the atrial activity from the ECG based on independent component analysis with prior knowledge of the source kurtosis signs

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    In this work it will be shown that a contrast for independent component analysis based on prior knowledge of the source kurtosis signs (ica-sks) is able to extract atrial activity from the electrocardiogram when a constrained updating is introduced. A spectral concentration measure is used, only allowing signal pair updates when spectral concentration augments. This strategy proves to be valid for independent source extraction with priors on the spectral concentration. Moreover, the method is computationally attractive with a very low complexity compared to the recently proposed methods based on spatiotemporal extraction of the atrial fibrillation signal

    Design of Anisotropic Diffusion Hardware Fiber Phantoms

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    A gold standard for the validation of diffusion weighted magnetic resonance imaging (DW-MRI) in brain white matter (WM) is essential for clinical purposes but still not available. Synthetic anisotropic fiber bundles are proposed as phantoms for the validation of DW-MRI because of their well-known structure, their long preservability and the possibility to create complex geometries such as curved and fiber crossings. A crucial question is how the different material properties and size of the fiber phantoms influence the outcome of the DW-MRI experiment. Several fiber materials are compared in this study. The effect of surface relaxation and internal gradients on the SNR is evaluated. In addition, the dependency of the fiber density and fiber radius on the diffusion properties is investigated

    Onderzoek à la Bolognaise

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    Naar aanleiding van de Bolognaconferentie in Leuven / Louvain-la-Neuve (april 2009) wordt een update gemaakt van de impact die het Bolognaproces heeft gehad op het onderzoek (meer doctorale onderzoekers, internationale mobiliteit van onderzoekers, hervormingen van de derde cyclus - doctoral schools)
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