Encontrados 35 documentos, a visualizar página 1 de 4
Breast skin-line detection using dynamic programming
Silva, C. A.; Lima, C. S.; Correia, J. H.In this paper, we present a novel method to extract the breast skin-line based on dynamic programming. Skin-line extraction is an important preprocessing step in CAD systems; however, it is a challenging problem due to the presence of noise, underexposed regions, which results in a low contrast area near the skin-air interface, and artifacts such as labels. Our proposal utilizes the stroma edge to constrain sea...
Multiscale texture descriptors for automatic small bowel tumors detection in ca...
Barbosa, Daniel; Roupar, Dalila; Lima, C. S.Conventional endoscopic exams do not allow the entire visualization of the gastrointestinal (GI) tract. Push enteroscopy (PE) is an effective diagnostic and therapeutic procedure, although it only allows exploration of the proximal small bowel (Pennazio et al., 1995). Simultaneously, convetional colonoscopy is limited at the terminal ileum. Therefore, prior to the wireless capsule endoscopy era, the sma...
Small bowel tumors detection in capsule endoscopy by gaussian modeling of color...
Martins, Maria M.; Barbosa, Daniel; Ramos, Jaime; Lima, C. S.This paper is concerned with the classification of tumoral tissue in the small bowel by using capsule endoscopic images. The followed approach is based on texture classification. Texture descriptors are derived from selected scales of the Discrete Curvelet Transform (DCT). The goal is to take advantage of the high directional sensitivity of the DCT (16 directions) when compared with the Discrete Wavelet Transfo...
Detection of small bowel tumors in endoscopic capsule images by modeling non-ga...
Barbosa, Daniel; Ramos, Jaime; Tavares, Adriano; Lima, C. S.This paper presents an approach to the automatic detection of small bowel tumors by processing endoscopic capsule images. The most significant texture information is selected by using wavelet processing and captured in the image domain from an appropriate synthesized image. Co-occurrence matrices are used to derive texture descriptors by modeling second order statistics of color image levels. These descriptors ...
Non-stationary biosignal modelling
Lima, C. S.; Tavares, Adriano; Correia, J. H.; Cardoso, Manuel J.; Barbosa, DanielSignals of biomedical nature are in the most cases characterized by short, impulse-like events that represent transitions between different phases of a biological cycle. As an example hearth sounds are essentially events that represent transitions between the different hemodynamic phases of the cardiac cycle. Classical techniques in general analyze the signal over long periods thus they are not adequate to mode...
Evidence of distributed subpial T2* signal changes at 7T in multiple sclerosis ...
Mainero, C.; Lima, C. S.; Cohen-Adad, J.; Greve, D.; Radding, A.; Benner, T.; Kinkel, R. P.; Fischl, B.; Rosen, B. R.Subpial lesions are the most frequent type of cortical lesion in multiple sclerosis (MS), and are thought to be closely associated with poor clinical outcome. Neuropathological studies report that subpial lesions may come in two major types: they may appear as circumscribed, focal lesions, or extend across multiple adjacent gyri leading to a phenomenon termed “general subpial demyelination” [1]. The in vivo eva...
Comparison of blood neoangiogenesis and lymphatic vascularization in colorectal...
Moreira,L.R.; Schenka,A.A.; Latuf Filho,P.; Lima,C.S.P.; Trevisan,M.A.S.; Vassallo,J.Blood and lymphatic vessel proliferation is essential for tumor growth and progression. Most colorectal carcinomas develop from adenomas (adenoma-carcinoma sequence) in a process due to accumulation of molecular genetic alterations. About 5% of adenomatous polyps are expected to become malignant, but data on the differential angiogenic patterns of these lesions in patients with and without concomitant cancer ar...
Wireless capsule endoscopic frame classification scheme based on higher order s...
Barbosa, Daniel; Ramos, Jaime; Lima, C. S.The gastrointestinal (GI) tract is a long tube, prone to all kind of lesions. The traditional endoscopic methods do not reach the entire GI tract. Wireless capsule endoscopy is a diagnostic procedure that allows the visualization of the whole GI tract, acquiring video frames, at a rate of two frames per second, while travels through the GI tract, propelled by peristalsis. These frames possess rich information a...
Automatic detection of small bowel tumors in capsule endoscopy based on color c...
Barbosa, Daniel; Correia, J. H.; Ramos, Jaime; Lima, C. S.Traditional endoscopic methods do not allow the visualization of the entire Gastrointestinal (GI) tract. Wireless Capsule Endoscopy (CE) is a diagnostic procedure that overcomes this limitation of the traditional endoscopic methods. The CE video frames possess rich information about the condition of the stomach and intestine mucosa, encoded as color and texture patterns. It is known for a long time that human p...
A multi-scale comparison of texture descriptors extracted from the wavelet and ...
Barbosa, Daniel; Correia, J. H.; Lima, C. S.Traditional endoscopic methods do not reach the entire Gastrointestinal (GI) tract. Wireless Capsule Endoscopy (CE) is a diagnostic procedure that allows the visualization of the whole GI tract, acquiring video frames, at a rate of two frames per second, while travels through the GI tract, resulting in huge amounts of data per exam. These frames possess rich information about the condition of the stomach and in...
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