6 resultados para Faults detections and localization


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The thoracic outlet syndrome is a changeable clinical syndrome caused by compression of the neurovascular bundle of the upper extremity, within the cervicoaxillary channel. From April 1980 through May 1995, 24 patients with clinical thoracic outlet syndrome were evaluated by selective arteriography. The diagnosis was confirmed in seven patients, in 14 the exam was normal and in the last three cases another arterial pathology was detected--subclavian artery occlusion, subclavian artery kinking and vertebral steal syndrome. The authors' aim is to emphasize arteriography as a diagnostic exam for thoracic outlet syndrome, very useful in the detection and localization of arterial compression. It also allows the diagnosis of other arterial entities.

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Multiparametric Magnetic Resonance Imaging has been increasingly used for detection, localization and staging of prostate cancer over the last years. It combines high-resolution T2 Weighted-Imaging and at least two functional techniques, which include Dynamic Contrast–Enhanced Magnetic Resonance Imaging, Diffusion-Weighted Imaging, and Magnetic Resonance Imaging Spectroscopy. Although the combined use of a pelvic phased-array and an Endorectal Coil is considered the state-of-the-art for Magnetic Resonance Imaging evaluation of prostate cancer, Endorectal Coil is only absolute mandatory for Magnetic Resonance Imaging Spectroscopy at 1.5 T. Sensitivity and specificity levels in cancer detection and localization have been improving with functional technique implementation, compared to T2 Weighted-Imaging alone. It has been particularly useful to evaluate patients with abnormal PSA and negative biopsy. Moreover, the information added by the functional techniques may correlate to cancer aggressiveness and therefore be useful to select patients for focal radiotherapy, prostate sparing surgery, focal ablative therapy and active surveillance. However, more studies are needed to compare the functional techniques and understand the advantages and disadvantages of each one. This article reviews the basic principles of prostatic mp-Magnetic Resonance Imaging, emphasizing its role on detection, staging and active surveillance of prostate cancer.

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Many important questions regarding pathophysiology and treatment of cerebral sinovenous thrombosis need clarification and may depend on further knowledge on the etiology, site, extension and recanalization of the thrombosis. We studied these variables in a cohort of children and adolescents from seven Portuguese Centers. We conclude from our results that the deep venous system and the superior longitudinal sinus are less frequently affected with thrombosis but have a greater potential for serious neurologic disease and for major sequelae. Non-recanalization, at least in the long term, is not an adverse prognostic factor. Extensive propagation of the thrombus from the initial site of origin seems to be common. The early identification of risk factors and their treatment coupled with an aggressive attitude towards diagnosis and treatment for thrombosis involving the deep venous system would be warranted.

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Portuguese health care system was created in 1979. It is universal and for free. Expenses are supported by the State through taxes. The modern perinatal care system started by the end of 1970. The first neonatal intensive care units were created in 1980, the Portuguese Neonatal Society in 1985 and the National Neonatal Transport System in 1987. Until the seventies of twentieth century and even during eighties there were more than 200 hospitals with deliveries, a great part without obstetrician or paediatrician, a great percentage of pregnancies had no prenatal care, there were few neonatal intensive care units and perinatal mortality rate was one of the highest in the European countries. In 1987 an Experts Committee was nominated by the Health Ministry aiming to collect and analyse data on perinatal care and to suggest improvements. The Report resulting from this work is the main document on which is based the reform. The reform was a 9 years program in 3 years stages aiming to close hospitals with less than 1500 deliveries/year, to reclassify hospitals, to create Coordinating Units between health centres and hospitals, to equip neonatal intensive and intermediate care units, to define needs of obstetricians, paediatricians and nurses for each centre and to promote specialised training in neonatology for paediatricians and nurses. Levels of perinatal care were defined as well as localization of each level of hospital according to the number of deliveries in one geographic area, geographic difficulties and existing routes and connections. Steps for opening and closure of different levels of hospitals were very well programmed. The organization, capacities, number of obstetricians, neonatologists and nurses as well as equipment for each level of care was defined. Rules for pregnant women and newborns transfer from level II to level III hospitals were also well described. A specific training is neonatology was created starting in 1990. This organization resulted in an impressive decrease in mortality rates at all levels and still it is the policy we have today.

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Objective: The epilepsies associated with the tuberous sclerosis complex (TSC) are very often refractory to medical therapy. Surgery for epilepsy is an effective alternative when the critical link between the localization of seizure onset in the scalp and a particular cortical tuber can be established. In this study we perform analysis of ictal and interictal EEG to improve such link. Methods: The ictal and interictal recordings of four patients with TSC undergoing surgery for epilepsy were submitted to independent component analysis (ICA), followed by source analysis, using the sLORETA algorithm. The localizations obtained for the ictal EEG and for the average interictal spikes were compared. Results: The ICA of ictal EEG produced consistent results in different events, and there was good agreement with the tubers that were successfully removed in three of the four patients (one patient refused surgery). In some patients there was a large discrepancy between the localization of ictal and interictal sources. The interictal activity produced more widespread source localizations. Conclusions: The use of ICA of ictal EEG followed by the use of source analysis methods in four cases of epilepsy and TSC was able to localize the epileptic generators very near the lesions successfully removed in surgery for epilepsy. Significance: The ICA of ictal EEG events may be a useful add-on to the tools used to establish the connection between epileptic scalp activity and the cortical tubers originating it, in patients with TSC considered for surgery of epilepsy.

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Clinically childhood occipital lobe epilepsy (OLE) manifests itself with distinct syndromes. The traditional EEG recordings have not been able to overcome the difficulty in correlating the ictal clinical symptoms to the onset in particular areas of the occipital lobes. To understand these syndromes it is important to map with more precision the epileptogenic cortical regions in OLE. Experimentally, we studied three idiopathic childhood OLE patients with EEG source analysis and with the simultaneous acquisition of EEG and fMRI, to map the BOLD effect associated with EEG spikes. The spatial overlap between the EEG and BOLD results was not very good, but the fMRI suggested localizations more consistent with the ictal clinical manifestations of each type of epileptic syndrome. Since our first results show that by associating the BOLD effect with interictal spikes the epileptogenic areas are mapped to localizations different from those calculated from EEG sources and that by using different EEG/fMRI processing methods our results differ to some extent, it is very important to compare the different methods of processing the localization of activation and develop a good methodology for obtaining co-registration maps of high resolution EEG with BOLD localizations.