Magnetic resonance study of the pineal region: normal pineal gland, simple cysts

A magnetic resonance imaging (MRI) study of the normal pineal gland and pineal simple cysts was performed in 762 cases. A fine section technique (maximum 3 millimeters) enabled most of the times the identifying of a normal pineal in addition to demonstrating that a pineal without any cyst shows an isointense signal in Tl and T2 which, in turn, is enhanced following gadolinium. The measure of the normal pineal was of about 6.1 millimeters in its diameter length. Pineal simple cysts were observed in a 2.6% frequency in relation to the whole series (762 cases); however reaches 6.1% when only the visualized pineals were considered (329 cases). Also, it was found out that simple cysts were not correlated to age or gender. Simple cysts characteristics are: dimension less or equal to 20 millimeters; absence of expansive effect; similar signal to that of the cerebrospinal fluid; absence of cyst growth.Realiza-se um estudo por ressonância magnética da pineal normal e dos cistos simples da pineal e estabelece-se um protocolo para estudo da região pineal analisando-se 762 exames. A utilização da técnica com cortes finos (3 milímetros no máximo) identifica a pineal normal na maioria das vezes (84,4%) e demonstra que a pineal normal, sem cistos, apresenta sinal isointenso em Tl e T2 com realce após a injeção de gadolínio, medindo em média 6,1 milímetros no seu maior diâmetro. Os cistos simples da pineal aparecem com frequência de 2,6% em relação a toda a série (762 casos) elevando-se essa frequência para 6,1% se forem consideradas somente as pineais visiblizadas (329 casos). Os cistos simples não se correlacionam nem com a idade nem com o sexo e os cistos sintomáticos são raros. Os critérios para diagnóstico diferencial dos cistos simples versus tumores da região da pineal são: dimensões menores ou iguais a 20 milímetros; espessura da parede abaixo de 2 milímetros; ausência de efeito expansivo; sinal igual ao líquido cefalorraquidiano e ausência de crescimento dos cistos.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Diagnóstico por ImagemUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Serviço de NeurorradiologiaUniversidade Paris-Sul Centro Hospitalar Universitário de BicêtreUNIFESP, EPM, Depto. de Diagnóstico por ImagemUNIFESP, EPM, Serviço de NeurorradiologiaSciEL

Análise da melhor alternativa terapêutica para malformações arteriovenosas durais intracranianas

The material for this research consisted of 93 patients with dural arteriovenous malformations (DAVMs) who were studied retrospectively with regards to therapeutic success and failure, who had undergone either neurosurgery, or embolization or a combination of both methods and whose disease was located in the cavernous sinus, the superior sagittal sinus, the transverse-sigmoid sinus of the anterior fossa and the tentorium. Thus, it was possible to arrive at the following conclusions: treatment of the DAVMs must be indicated, jointly, by an interventionist neuroradiologist and a neurosurgeon; DAVMs of the transverse-sigmoid sinus were better treated when a combination of both methods was used; DAVMs of the tentorium were also better treated with a combined method; the endovascular method ensured only a 50% chance of therapeutic success for DAVMs of the superior sagittal sinus; DAVMs of the cavernous sinus are better treated when the endovascular method was used with a transvenous approach, relative to the transarterial approach.O material utilizado consistiu de 93 pacientes portadores de malformações arteriovenosas durais (MAVDs) estudados retrospectivamente em relação ao sucesso e ao fracasso terapêutico submetidos aos métodos neurocirúrgico ou endovascular ou, ainda, combinação entre ambos, em que a doença se localizou nas regiões do seio cavernoso, do seio sagital superior, do seio transverso-sigmóide, da fossa anterior e do tentório. As conclusões foram as seguintes: o tratamento das MAVDs deve ser indicado pelo neurorradiologista intervencionista e pelo neurocirurgião, conjuntamente; as MAVDs do seio transverso-sigmóide foram melhor tratadas através do método combinado; as MAVDs do tentório foram melhor tratadas através do método combinado; as MAVDs do seio sagital superior tratadas por método endovascular asseguraram apenas 50% de sucesso terapêutico; as MAVDs do seio cavernoso são melhor tratadas por método endovascular empregando-se a via transvenosa quando comparadas com a via transarterial.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)Institute of GoiâniaUniversity of São PauloUNIFESP, EPMSciEL

Outpatient percutaneous treatment of deep venous malformations using pure ethanol at low doses under local anesthesia

INTRODUCTION: Venous malformations are the most frequent vascular malformation. Deep venous malformations are located in subcutaneous tissue or in the muscles. Percutaneous sclerotherapy is the treatment of choice, and the use of ethanol at low doses has not yet been described. OBJECTIVE: To analyze the results of treating Deep venous malformations patients with low doses of ethanol. METHODS: Thirty-nine patients treated between July 1995 and June 2007 were followed up prospectively over a median period of 18 months. Twenty-nine were female (74.4%) and 10 were male (25.6%), with ages ranging from 11 to 59 years (median of 24 years). All of the lesions affected limbs, and the main symptom reported was pain (97.4%). Each patient underwent fortnightly alcohol application sessions under local anesthesia on an outpatient basis. The lesions were classified into three groups according to size using nuclear magnetic resonance imaging: small, up to 3 cm (4 patients); medium, between 3 and 15 cm (27 patients); and large, greater than 15 cm (8 patients). RESULTS: The symptoms completely disappeared in 14 patients (35.9%) and improved in 24 (61.5%). The lesion size reduced to zero in 6 patients (15.4%) and decreased in 32 (82%). The median number of sessions was 7. There were no complications in 32 patients (82%), while 3 presented local paresthesia (7.7%), 2 superficial trombophlebites (5.1%), 1 skin ulcer (2.6%), and 1 case of hyperpigmentation (2.6%). CONCLUSION: Outpatient treatment for Deep venous malformations patients using ethanol at low doses was effective, with a low complication rate

Perimedullary arteriovenous fistulas in children: report on six cases

Background Perimedullary arteriovenous fistulas (PMAVFs) are rare spinal lesions and even more uncommon in children. Objective The aim of this study was to document rare occurrences of this type of arteriovenous malformation in six children treated at our institution. Methods The clinical data, radiological findings, and treatment in six cases of PMAVFs were reviewed. Six patients with PMAVFs were managed at our institution over a 5-year period. The patients (four girls and two boys), ranging in age from 6 to 15 years, presented with initially fluctuating, and eventually permanent and progressive, sudden-onset paraparesis, sensory disturbances, and sphincter dysfunction. The duration of symptoms before diagnosis ranged from 1 week to 13 years. Results All the patients underwent magnetic resonance imaging and spinal selective angiography, which demonstrated the characteristic imaging of an arteriovenous fistula. Embolization of the arteriovenous fistula was initially attempted in three patients with successful occlusion of the fistula in two. For the remaining cases, open surgery was performed, with complete occlusion of the fistula. There was no morbidity, regardless of the treatment performed. All the patients experienced neurological improvement after treatment. Conclusions No specific clinical or radiological characteristic of PMAVFs in the pediatric population was observed when our series was compared with a general series. Early diagnosis and timing of the therapeutic intervention seemed to avoid the development of irreversible ischemic myeloradiculopathy and prevented hemorrhage. Treatment for PMAVFs is difficult to standardize because these are extremely rare lesions with different angioarchitecture configurations

A Schwarz-based domain decomposition method for the dispersion equation

International audienceWe propose a Schwarz-based domain decomposition method for solving a dispersion equation consisting on the linearized KdV equation without the advective term, using simple interface operators based on the exact transparent boundary conditions for this equation. An optimization process is performed for obtaining the approximation that provides the method with the fastest convergence to the solution of the monodomain problem

Planeamento Fiscal nas operações relativas a instrumentos financeiros derivados e a sua tributação

Mestrado em FiscalidadeEsta dissertação tem por objetivo a análise e um estudo sobre o planeamento fiscal no âmbito das Operações relativas a instrumentos financeiros derivados (doravante referido como "IFD") e a sua tributação em sede de IRS, salientando-se a importância da função e objectivo da cobertura de risco, nos termos do artigo 49.º do CIRC. De facto, trata-se de um tema actual e de grande relevância, no âmbito de um contexto económico e fiscal a nível internacional, sobre o qual muito tem sido debatido e discutido, acerca das causas nefastas, devido a um planeamento fiscal abusivo, resultando numa concorrência fiscal prejudicial e no impacto da actual crise financeira mundial. Neste trabalho, prentende-se, em primeiro lugar, efectuar uma breve e sucinta distinção entre evasão e fraude fiscais, com alusão à liberdade de gestão fiscal, os respectivos deveres de comunicação e as normas anti-abuso, enquanto balizas e barreiras ao planeamento fiscal, com vista a combater-se os mais variados e complexos esquemas de planeamento fiscal abusivo. Sem olvidar, que os instrumentos legislativos de reacção contra os comportamentos fiscais abusivos, que têm em vista evitar uma utilização abusiva das leis fiscais, tendo em conta as formas inadequadas de negócios jurídicos realizados por razões de ordem fiscal, tais como a simulação em matéria fiscal, a fraude à lei e negócios indirectos, onde nestes últimos, estão enquadrados os IDF1. Em segundo lugar, visa-se definir e caracterizar alguns IFD - os swaps, futuros e opções (incluindo-se nestes os warrants) - efectuando uma abordagem à tributação directa dos IFD no sistema fiscal português e angolano, tendo em conta as recentes alterações fiscais, nesta matéria, efectuadas em ambos os sistemas fiscais, mencionando a utilização dos mesmos como instrumentos de planeamento fiscal, assim como a possibilidade de utilização de paraísos fiscais, de forma lícita ou evasiva. Com efeito, tendo em conta o fenómeno da globalização económica que se tem manifestado, trata-se de uma matéria com grande complexidade, dada a sua problemática em termos fiscais, atendendo à «dinâmica do mercado de capitais e a oferta diversificada de instrumentos financeiros derivados»2.The aim of this dissertation is the analysis and study of tax planning in operations related to derivatives financial instruments (henceforth referred to as "DFI") and its taxation on personal income tax, highlighting the importance of the purpose and function of hedging in risk, in accordance with article 49 of the Corporate Income Tax Code. In fact, this is a current topic and of great relevance, in the context of economic and tax at an international level, on which much has been debated and discussed about the damaging effects due to abusive tax planning, resulting in harmful tax competition and the impact of the current global financial crisis. Firstly, in this work, I intend to make a brief and succinct distinction between tax avoidance and tax fraud, with reference to fiscal management freedom, their communication duties and the anti-abuse rules, as landmarks and barriers to tax planning, in order to combat the most varied and complex abusive tax planning schemes. The legislative instruments of the reaction against abusive tax behaviors, with order to avoid an abusive use of tax laws, relatively the inadequate forms of legal transactions, performed for fiscal order reasons, such as the simulation in tax matters, legis fraus and indirect business which integrate DFI. Secondly, the objective is to define and characterize some DFI - swaps, futures and options (including the warrants) - performing an approach of the DFI direct taxation in the portuguese and angolan tax system, taking into account the recent tax changes in this area, carried out in both tax systems, mentioning their utilization as tax planning instruments, as well as the possible use of tax havens, lawfully or evasively. Indeed, taking into account the economic globalization phenomenon which has manifested itself, it's a matter of great complexity, given its problematic in fiscal terms, given the dynamics of the capital market and the diversity offer of DFI