7 resultados para Anatomy
em RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal
Resumo:
ABSTRACT Background: According to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Presently, the International Agency for Research on Cancer classifies formaldehyde as carcinogenic to humans (Group 1), based on sufficient evidence in humans and in experimental animals. Manyfold in vitro studies clearly indicated that formaldehyde can induce genotoxic effects in proliferating cultured mammalian cells. Furthermore, some in vivo studies have found changes in epithelial cells and in peripheral blood lymphocytes related to formaldehyde exposure. Methods: A study was carried out in Portugal, using 80 workers occupationally exposed to formaldehyde vapours: 30 workers from formaldehyde and formaldehyde-based resins production factory and 50 from 10 pathology and anatomy laboratories. A control group of 85 non-exposed subjects was considered. Exposure assessment was performed by applying simultaneously two techniques of air monitoring: NIOSH Method 2541 and Photo Ionization Detection equipment with simultaneously video recording. Evaluation of genotoxic effects was performed by application of micronucleus test in exfoliated epithelial cells from buccal mucosa and peripheral blood lymphocytes. Results: Time-weighted average concentrations not exceeded the reference value (0.75 ppm) in the two occupational settings studied. Ceiling concentrations, on the other hand, were higher than reference value (0.3 ppm) in both. The frequency of micronucleus in peripheral blood lymphocytes and in epithelial cells was significantly higher in both exposed groups than in the control group (p < 0.001). Moreover, the frequency of micronucleus in peripheral blood lymphocytes was significantly higher in the laboratories group than in the factory workers (p < 0.05). A moderate positive correlation was found between duration of occupational exposure to formaldehyde (years of exposure) and micronucleus frequency in peripheral blood lymphocytes (r = 0.401; p < 0.001) and in epithelial cells (r = 0.209; p < 0.01). Conclusions: The population studied is exposed to high peak concentrations of formaldehyde with a long-term exposure. These two aspects, cumulatively, can be the cause of the observed genotoxic endpoint effects. The association of these cytogenetic effects with formaldehyde exposure gives important information to risk assessment process and may also be used to assess health risks for exposed worker
Resumo:
This paper analyses the Portuguese stock market since it reopened in 1977, with a special focus on the evolution of the statistic and stochastic characteristics of the market return throughout this 36 year period. The market return for the period of time between 1977 and 2012 (September 28th) is estimated and then compared with the return that would have been achieved with Government bonds and treasury bills, which allows us to confirm that the hierarchy of return / risk across the different financial instruments is verified. The market risk premium for this 36 year period is also estimated and a comparison with other markets is performed, suggesting that the Portuguese markets risk has not been compensated by an adequate return. The study also examines the evolution of the Portuguese markets volatility in the 1977-2012 period and compares it with other markets, showing the existence of extremely high peaks during the first 11 years, but indicating a downwards trend throughout the whole period under analysis. Finally, the correlation between market returns for Portugal and for other countries and the degree of integration are estimated and their evolution throughout time is assessed, leading to the conclusion that the performance of the Portuguese stock market has become increasingly correlated with major European markets correlation with some markets close to 0.70 from 2000 onwards-, but that country-specific risk factors are still relevant.
Resumo:
Resumo: A hiperplasia benigna da prstata (HBP) tem elevada prevalncia nos homens entre os 50 e 79 anos de idade, sendo ubiquitria com o envelhecimento. Devido significativa morbi-mortalidade associada aos tratamentos mdicos e cirrgicos currentemente disponveis, so necessrias novas tecnologias para melhorar os resultados e minimizar o desconforto dos doentes. Recentemente, estudos preliminares de experimentao animal e em 3 doentes tratados, sugeriram a embolizao arterial prosttica selectiva (EAPS) como hiptese teraputica para a HBP. Decidimos investigar se a EAPS poderia ser um procedimento bem sucedido no tratamento da HBP gravemente sintomtica. Para tal realizmos um estudo antomo-radiolgico e clnico em 63 doentes com recurso a uma teraputica inovadora minimamente invasiva guiada pela imagem. Avalimos 126 hemiplvis com recurso a Angio-RM, Angio-TC e Angiografia Digital de Subtraco, com o intuito de definir os padres bsicos de bifurcao das artrias ilacas internas at agora apenas descritos em estudos cadavricos. Estudmos ainda o suprimento vascular arterial prosttico, identificando: 1 as artrias prostticas; 2 origem e direco; 3 os ramos intra-prostticos; 4 anastomoses com outras artrias. Em relao aos resultados anatmicos, identificmos 181 artrias prostticas, j que em 43.7% das hemiplvis existiam dois pedculos arteriais prostticos com origens independentes. A origem mais frequente foi a artria pudenda interna (39.7%), seguida do tronco comum glteo-pudendo (21%) e da artria vesical superior (18.2%). Origens menos frequentes foram a artria obturadora (12.1%), as artrias glteas inferior (3.9%)ou superior (1.7%), ramos rectais provenientes da artria mesentrica inferior (1.7%) e a artria pudenda acessria (1.7%). Identificaram-se anastomoses com as artrias adjacentes em 57.9% dos casos: com a terminao da artria pudenda interna (41.6%),artrias prostticas contra-laterais (18.2%) e homo-laterais (11.7%), com ramos rectais (15.6%) e com artrias vesicais (12.9%). Em relao ao estudo clnico tratmos 63 doentes (idades compreendidas entre 52 - 82 anos, mdia 69.5 anos) com HBP gravemente sintomtica refractria teraputica mdica h mais de 6 meses. Foi possvel avaliao aps o tratamento em 37 doentes: mdia de seguimento de 4.7 meses (variando entre 1 e 12 meses). A EAPS unilateral foi possvel em todos os doentes, com embolizao bilateral em 73% dos casos. A embolizao bilateral no foi possvel em 27% dos casos devido a tortuosidade, alteraes ateroesclerticas e pequeno calibre das artrias ilacas e/ou prostticas. Em mdia houve uma melhoria do International Prostate Symptom Score (IPSS) de 10.8 pontos, da QoL de 1.5 pontos e do Internationl Index of Erectile Function (IIEF) de 2.1 pontos. Houve uma reduo mdia do PSA de 30% (2.4 ng/mL), um aumento do pico de fluxo urinrio (Qmax) de 3.1 - 3.85 mL/s e uma reduo mdia do volume prosttico de 21% (18.5 mL). Registou-se uma complicao major: pequena rea de isqumia da parede vesical tratada cirurgicamente. Em 75% dos doentes tratados obteve-se sucesso clnico com franca melhoria dos sintomas, enquanto 25% dos doentes foram considerados insucesso clnico por se ter registado uma fraca ou ausente melhoria sintomtica aps a embolizao. Os restantes doentes tratados esto sob controlo evolutivo, pararam toda a medicao prosttica, sem qualquer caso de disfuno sexual associada com o tratamento. Este trabalho constitui o primeiro estudo anatmico descritivo in vivo das artrias prostticas, conseguido devido utilizao de tcnicas de imagem nunca usadas para este fim. O uso clnico dos dados anatmicos acima referidos permitiu a implementao de tcnicas de Radiologia de Interveno no tratatamento de uma doena de elevada prevalncia. ------------------------------- ABSTRACT: Benign prostatic hyperplasia (BPH) has high prevalence in men aged 5079 years being ubiquitous with aging. Due to significant morbi-mortality associated with currently available medical and surgical treatments, there is the need for innovative technologies to continue to improve outcomes and minimize patient discomfort and morbidity. Recently, prostatic arterial embolization (PAE) was suggested as a treatmentoption for BPH based on preliminary results from animal studies and 3 treated patients. We decided to investigate if PAE might be a successful treatment option for severely symptomatic BPH patients. We performed a clinical and anatomical-radiological study in 63 patients with the use of an inovative image-guided minimally invasive technique. We evaluated 126 pelvic sides using Angio-MR or Angio-CT and Catheter Angiography before embolisation to treat symptomatic BPH. We aimed to define the main branching patterns of the male internal iliac arteries, so far only studied in the cadaver. We also evaluated the prostatic arterial supply, identifying: 1 the prostatic arteries; 2 origin and direction; 3 intra-prostatic branches; 4 anastomoses with surrounding arteries. Regarding the anatomical study we identified 181 prostatic arteries, because in 43.7% of pelvic sides 2 separate prostatic vascular pedicles were found. The most frequent origin was the internal pudendal artery (39.7%) with the common glutealpudendal trunk (21%) and superior vesical arteries (18.2%) the next commonest. Less frequent origins were the obturator artery (12.1%), the inferior (3.9%) or superior (1.7%) gluteal arteries, rectal branches from the inferior mesenteric artery (1.7%) and the accessory pudendal artery (1.7%). There were anastomoses with the surrounding arteries in 57.9% of cases: termination of the internal pudendal artery (41.6%), contralateral prostatic arteries (18.2%), same-side prostatic arteries (11.7%), rectal branches (15.6%), and vesical arteries (12.9%).Regarding the clinical study, we treated 63 patients aged 5282 years (mean 69.5 years) who presented with symptomatic BPH refractory to medical treatment for at least 6 months. Follow-up evaluation (mean 4.7 months, range 1-12 months) was possible in 37 patients. PAE was achieved in all patients with bilateral embolization in 73%. In 27% PAE was performed unilaterally due to tortuosity, atherosclerotic changes and small size of iliac and prostatic arteries. There was a mean decrease in the IPSS of 10.8 points, a mean improvement in QoL of 1.5 points, and a mean increase in the sexual function score of 2.1 points. There was a mean PSA reduction of 30% (2.4 ng/mL), a Qmax increase of 3.1 to 3.85 mL/sec, and a mean prostate volume decrease of 21% (18.5 mL). There was one major complication: a small area of bladder wall ischemia treated by surgery. Overall, 75% of patients were considered clinical success with major improvement after PAE, while 25% of patients were considered clinical failure with little or no improvement after PAE. All remaining patients are under follow-up, stopped all prostatic medication, and reported no sexual dysfunction. This study is the first one to describe the radiological anatomy of the prostatic arteries, with the use of imaging techniques never used for this purpose before. The clinical use of the anatomical findings allowed the implementation of Interventional Radiology tehniques in the treatment of a disease with a high prevalence.
Resumo:
Considering Alan Turings challenge in Computing Machinery and Intelligence (1950) can machines play the imitation game? it is proposed that the requirements of the Turing test are already implicitly being used for checking the credibility of virtual characters and avatars. Like characters, Avatars aim to visually express emotions (the exterior signs of the existence of feeling) and its creators have to resort to emotion codes. Traditional arts have profusely contributed for this field and, together with the science of anatomy, shaped the grounds for current Facial Action Coding System (FACS) and their databases. However, FACS researchers have to improve their instruction tables so that the machines will be able, in a near future, to be programmed to carry out the operation of recognizing human expressions (face and body) and classify them adequately. For the moment, the reproductions have to resort to the copy of real life expressions, and the presente smile of avatars comes from mirroring their human users.
Resumo:
RESUMO: Na descrio deste estudo foi utilizada a terminologia anatmica da Sociedade Brasileira de Anatomia adaptada ao portugus por J. A. Esperana-Pina de acordo com o tratado Anatomia Humana da Relao. Os actuais estudos sobre hipoacusia sensorioneural implicam um grupo crescente de situaes, em que a leso se situa ao nvel da microvascularizao coclear, da que o conhecimento exacto da angiomorfologia normal se torne essencial na fase actual do conhecimento. A autora tem vindo a estudar, desde 1986, a angiomorfologia do ouvido Interno no modelo experimental, o Cobaio, utilizando vrias tcnicas microvasculares. sendo dado enfse particular neste estudo tcnica de microscopia electrnica de varrimento em moldes vasculares. Os animais usados no presente estudo pertencem espcie cavia porcellus, cobaio, por serem considerados na comunidade cientifica internacional como o melhor modelo experimental para estudo do ouvido interno, pelo facto de a morfologia coclear ser muito semelhante do Homem e por isso ser um modelo fivel para cirurgia experimental e microdisseco. Este estudo foi realizado em 100 cobaios, cavia porcellus, de ambos os sexos com peso mdio de 450g. A vascularizao do ouvido interno, no cobaio como no homem, faz-se atravs dos ramos de diviso da artria auditiva interna ou labirntica. A artria labirntica origina-se como ramo colateral da artria cerebelosa ntero-inferior a qual tem origem na artria basilar ou na artria vertebral. Embora no homem a artria auditiva interna possa tambm destacar-se da artria basilar e at da artria vertebral, no cobaio em todos os casos estudados a sua origem verificou-se sempre na artria cerebelosa ntero-inferior. A artria labirntica, ao passar abaixo do meato auditivo interno, divide-se na artria vestibular anterior e na artria coclear comum.A artria vestibular anterior dirige-se para o nervo vestibular, emite vasa nervorum para este nervo e vasculariza o utrculo e os canais semicirculares. A artria coclear comum origina dois ramos principais, a artria vestbulococlear ou vestibular posterior no cobaio, a qual se destaca junto espira basal da cclea e a artria coclear, como ramo terminal, que passa a denominar-se de artria modiolar ou espiralada, aps entrar no modolo. A artria modiolar ascende no modolo promovendo atravs dos seus ramos colaterais e dos seus ramos terminais a microvascularizao coclear, numa vascularizao de rgo de tipo terminal. Ao longo do seu trajecto verificouse de modo constante uma reduo gradual de calibre em cada uma das espiras, por emisso de ramos colaterais, sendo que o calibre da artria na base da cclea apresenta um valor que diminui gradualmente at ao pice. A artria modiolar origina em todo o seu trajecto ramos colaterais, cujo nmero diminui em valor absoluto da base para o pice: Arterolas radirias internas, arterolas de trajecto flexuoso que caminham junto s estruturas sensorioneurais da parede interna da cclea, junto ao lbio timpnico da lmina espiral ssea e na parede do prprio modolo, que se relacionam intimamente com este. As arterolas radirias internas originamse no flanco da artria modiolar espiralada. Contamse dez a doze em cada espira, extraordinariamente flexuosas desde a sua origem. As arterolas radirias internas originam como ramos colaterais, vrios grupos de arterolas de menor calibre, que vascularizam distintas regies da parede interna da cclea, as arterolas do gnglio espiral, a rede espiral interna, as arterolas de origem dos glomrulos de Schwalbe e a arterola da lmina basilar. As arterolas radirias externas importantes ramos colaterais da artria modiolar espiralada promovem a vascularizao de importantes estruturas da parede externa. Ao atingir o limite externo do ligamento espiral, as arterolas radirias externas dividemse em vrios ramos arteriolares de menor calibre, ao longo da convexidade do limite externo do ligamento espiral, originando a rede capilar ps-estriada que ocupa a poro lateral do ligamento espiral e a rede capilar ad -estriada, na sua poro mais medial em ntima relao com a estria vascular. A espira basal da cclea apresenta grande riqueza de vascularizao, com caractersticas particulares apenas a esta espira, a qual metabolicamente a mais exigente. A arterola da janela da cclea aborda a janela da cclea pela sua convexidade e divide-se numa rica rede vascular da qual emergem arterolas pr-capilares que se ramificam em capilares, os quais se dirigem em profundidade penetrando a rampa timpnica da cclea ao nvel da espira basal. Importou neste estudo verificar quais as semelhanas em termos de calibre de estruturas anlogas, na parede interna e na parede externa da cclea, com particular incidncia na rede capilar. Do estudo estatstico realizado com testes paramtricos de Tamahane e no paramtricos de Mann-Whitney, verifica-se que comparando todas as estruturas consideradas estas tm calibres diferentes, com excepo dos capilares da estria vascular e do ligamento espiral, pertencentes parede externa da cclea que tm calibres iguais aos capilares da rede espiral interna e aos capilares da parede interna da cclea, dependentes das arterolas da rede espiral interna. As redes capilares dependentes das arterolas radirias internas que vascularizam as estruturas sensorioneurais junto parede interna do modiolo so em tudo semelhantes em termos de calibre s redes capilares da parede externa da cclea, incluindo os capilares da estria vascular. Esta particularidade traduz num rgo com vascularizao de tipo terminal,um mecanismo de controlo do fluxo sanguneo coclear to importante na parede interna como na parede externa da cclea. ------------ ABSTRACT:Current studies on sensorineural hearing loss, imply a growing group of situations in which the lesion is located at the level of the cochlear microvasculature, hence the exact knowledge of normal angiomorfology becomes essential in current state of knowledge. The author has been studying since 1986, the angiomorfology of inner on the experimental model, the guinea pig, using various microvascular techniques being given particular emphasis in this study to the results of the technique of scanning electron microscopy on corrosion casts. The animals used in this study belong to the species cavia porcellus, guinea pig, to be considered in the international scientific community as the best experimental model for the study of the inner ear, the cochlear morphology is very similar to human and therefore a reliable model for experimental surgery and microdissection. This study was performed in 100 guinea pigs of both sexes with average weight of 450g. There shall be a brief description of embryology, anatomy and cochlear physiology in the light of developmental biology, regarding also the spatial location of the cochlea and the determinism of morphogenetic fields in their development and function. The cochlear transduction mechanism converts the sound wave in stimuli sound and so afferent auditory nerve fibres and deafness are closely related to the cochlear microvasculature. Cochlear ischemia is accompanied by immediate hearing loss. The different type of cochlear injury that leads to sensorineural deafness is well studied in presbycusis where an objective link with the audiometric pattern as been established. The sensory type of deafness, is closely related to the degeneracy of the organ of Corti and damage to the outer hair cells at the basal turn of the cochlea. Keeping in mind cochlear tonotopy with location of high frequency sounds at the level of the base of the cochlea, it explains the audiometric pattern with loss in high frequencies. The neural type of deafness, is characterized by neuronal loss with loss of descendant important neuronal afferents, with audiometric translation on a gradually curve with important loss of auditory discrimination. The metabolic type of deafness results in atrophy of the vascular stria, with consequent change in the potential of the endolymph by decreasing the vascular stria cells and changes in K + recycling mechanism. There is also a change in the morphology of the spiral ligament and the audiometric patern as a flattened curve with loss at all frequencies. Bearing in mind cochlear tonotopy and being characterized all types of sensorineural deafness, we may inquire to what extent the cochlear microvasculature, considering not only the cochlea as a whole but different regions of the inner wall and the outer wall of the cochlea, contributes to deafness. We analysed the entire cochlear morphology on scanning electron microscopy with particular emphasis on bone and membranous cochlea. The inner wall of the cochlea and intramodiolar structures such as the spiral ganglion, the morphology of its cell bodies and their axons are analyzed. The morphology of Cortis organ is described in detail, with description and large detail of the inner and outer hair cells. Is then presented the study of the microvasculature itself. The spiral modiolar artery is observed with the diaphanization technique and the technique of scanning electron microscopy on corrosion vascular casts. After emergence of collateral branches of the greatest importance, the radiating internal and external arterioles, the modiolar artery gives rise to its terminal branches, the arterioles of the cochear apex. Arterial vasa vasorum and vasa nervorum are displayed with a great detail, which was not yet described in such detail in previous microvascular studies. The arterial radiating arterioles originate in the flank of the spiral modiolar artery in number of ten to twelve in each loop, and they vascularize through their branches the inner wall cochlear sensorineural structures located in the modiolus as the spiral ganglion and structures near the organ of Corti. Their caliber is above 20 m on the basal turn and in the second loop it decreases to values between 12 and 20 m, decreasing progressively to the apex of the cochlea.They arise near the modiolus or on their way in the spiral lamina forming vascular loops, and divide without presenting vascular constrictions in their divisions, originating new vascular loops of lower caliber. Internal ratiating arterioles originate as collateral branches several groups of smaller caliber arterioles, which vascularize distinct regions of the inner wall of the cochlea namely, the arterioles of the spiral ganglion, the internal spiral network, the arterioles of origin of the glomeruli of Schwalbe and the arterioles of the basilar membrane. The glomeruli of Schwalbe play an important functional role as relay-stations, in hemodynamic terms, to control the cochlear microvasculature. External radiating arterioles have their origin in the spiral modiolar artery, they are directed towards the outer wall of the cochlea and run through the roof of the scala vestibuli. Above the insertion of Reissners membrane on the external wall the external radiating arterioles originate the spiral ligament arterioles, which vascularize the spiral ligament, they divide into several arteriolar branches of smaller caliber, along the convexity of the outer edge of the spiral ligament. The connective tissue of the spiral ligament forms a mesh with supporting function of the highly specialized epithelium, where pericytes were identifiable. Next to its base there is the microvascular network of stria vascularis. The adstriated vascular network which is divided into a capillary network, the capillary network of stria vascularis. The stria vascularis, the only vascularized epithelium of the human body, plays an important role, forming an haemato-labyrintine barrier to assure labyrinthine endocochlear potential and transport of ions, essential for the mechanism of transduction of external hair cells. The cochlear basal turn has a special feature on its external wall, the region of the windows, the round windows giving access to scala tympani and the oval window thatleads into scala vestibuli, and so it is metabolic demanding. For their role in cochlear tonotopy the sensorineural structures and those of the external wall of the cochlea, are particularly vulnerable to hypoxia. Although the complementarity of all the techniques was important for three- -dimensional reconstruction of the microvasculature of the cochlea, the scanning electron microscopy technique, especially when we used the system Semafore was fundamental to perform precise morphometric mesures regarding all vascular structures.Regarding the capillaries of the inner and outer wall of the cochlea networks this technique allowed their characterization in morphometric terms. To conclude the capillaries of the inner wall and of the external wall of the cochlea have similar size. So although located at different cochlear regions, with a different functional role, in cochlear physiology these networks consist of capillaries of similar caliber. It seems to translate a cochlear blood flow control mechanism that is so important in the inner wall as in and the external wall of the cochlea to provide for in inner ear homeosthasia.
Resumo:
The Gallus gallus (chicken) embryo is a central model organism in evolutionary developmental biology. Its anatomy and developmental genetics have been extensively studied and many relevant evolutionary implications have been made so far. However, important questions regarding the developmental origin of the chicken skull bones are still unresolved such that no solid homology can be established across organisms. This precludes evolutionary comparisons between this and other avian model systems in which skull anatomy has evolved significantly over the last millions of years.(...)
Resumo:
RESUMO: Os mais recentes mtodos de neuro imagem tal como a Ressonncia Magntica (RM) permitiram obter imagens detalhadas do crebro humano in vivo. Essas imagens revelam, muitas vezes, achados imprevistos face ao padro normal, com elevada propenso para os indivduos idosos e franca coexistncia com fatores de risco vascular, como caracterstica dum processo de envelhecimento normal. Embora na ltima dcada tenham surgido vrias publicaes sobre este assunto, ele continua ainda pouco explicado. Um pouco por todo o mundo tm emergido os programas de preveno da doena e promoo da sade desenvolvidos pela Sade Pblica suportadas sobretudo pelo avano das tecnologias mdicas que resultaram, entre outros impactos, num crescimento da populao idosa. Estima-se, em 2030, uma composio demogrfica com 20% de indivduos acima dos 65 anos. Neste contexto, a doena microvascular cerebral a causa mais frequente de comprometimento cognitivo vascular no idoso sendo as caractersticas senescentes na imagem por RM do tipo leses isqumicas da Substncia Branca (Leukoaraiosis) e enfartes lacunares (Status lacunar), atrofia cerebral, gliose e acumulao excessiva de ferro nos ncleos da base. Esta tese, considerando a linha de investigao de que deriva Cincias da Vida - especializao em Medicina Clinica - Biotecnologia, rene e reflete sobre trs vertentes ligadas RM e interdependentes em relao a uma problemtica comum. A primeira trata da caracterizao da Tecnologia por Ressonncia Magntica existente em Portugal, a qual inclui uma avaliao exploratria da aplicao da tcnica de Difuso Anisotrpica nos estudos cerebrais. As dimenses analticas estudadas foram a Tecnolgica, Sociodemogrfica e Econmica. Na recolha de dados recorreu-se a vrias fontes de informao e a uma metodologia exploratria faseada, validada pela triangulao dos resultados. A sua anlise obedeceu a critrios de estratificao e agrupamento segundo as mesmas dimenses analticas. Otimizao da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco crebro-vascular A segunda descreve o estudo antomo radiolgico que recaiu sobre parmetros de quantificao assente na temtica do crebro do idoso em cadver segundo uma metodologia experimental aplicada s mtricas da difuso por RM. Na terceira, e ltima, apresentado o estudo tcnico - radiolgico para avaliao e otimizao da imagem ponderada em difuso em estudos clnicos associados ao crebro do idoso The Usual Brain Aging ou Envelhecimento Cerebral Normal, com base metodolgica assente nos critrios e indicadores estabelecidos pelo Estudo de Imagem de Roterdo (Rotterdam Scan Study - RSS). Como principais resultados obteve-se que no existem em Portugal estruturas para avaliao dos equipamentos pesados ou Agncia de Avaliao das Tecnologias da Sade para desenvolver o importante papel da produo de estudos comparativos entre os equipamentos disponveis no mercado, a relao preo-qualidade e a sua afetao s necessidades clnico-epidemiolgicas. Constatou-se que a implementao de equipamentos de RM est fortemente assente em critrios econmicos carecendo de recomendaes e diretivas para o uso racionalizado destas tecnologias. Quanto a dados quantitativos conclumos que a maioria dos equipamentos est instalada em instituies privadas (80,2%); a intensidade de campo magntico mais frequente [1,5T] com 119 equipamentos; os equipamentos esto instalados maioritariamente nos distritos de Lisboa (55 unidades) e do Porto (39 unidades); o rcio mdio de equipamentos por habitante em Portugal de 1 para 65 195 habitantes; a amplitude de gradientes com maior expresso na amostra 30-39mT/m; a maioria dos equipamentos foi instalada no intervalo temporal [2009-2012] com 59 equipamentos; apenas 6 instituies desenvolvem investigao clinica e a maioria das bobinas para estudos de crnio so do tipo Array. O estudo de otimizao da tcnica da difuso revelou, quanto avaliao dos valoresb, que os mais baixos (b=500 s/mm2 e b=1000 s/mm2), apresentam maior IS e SNR sendo esta uma boa medida referente qualidade de imagem, no entanto, os valores-b mais elevados (b=2000 s/mm2) apresentam maior CNR e CR, face aos anteriores, o Otimizao da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco crebro-vascular que apesar de proporcionar inferior detalhe anatmico e consequentemente inferior qualidade de imagem, num encfalo normal, pode auxiliar na interpretao e apresentar vantagens na identificao de leses microvasculares sempre que persistirem dvidas em relao ao diagnstico diferencial de doena microvascular do tipo status lacunar ou Hiperintensidades da Substncia Branca. As alteraes deste parmetro so particularmente refletidas nas diferenas da avaliao da qualidade de imagem na regio fronto-calos Conclumos da avaliao quantitativa da concentrao mdia de ferro (26Fe) em todas as faixas etrias que os ncleos da base que apresentam maior concentrao so, por ordem decrescente: Substncia Nigra, Globus Pallidus, Putamen, Tlamo, Ncleo Rubro e Ncleo Caudado; que existe uma predominncia na concentrao de ferro (26Fe) no hemisfrio esquerdo e que os indivduos do gnero masculino apresentam mais ferro (26Fe) que os do gnero feminino nas faixas etrias [30-40[, [40-50[ e [50-60[. Como principal concluso do estudo da concentrao mdia de ferro em relao idade destacamos que a concentrao mdia de ferro (26Fe) superior nos grupos etrios superiores, logo aumenta com a idade, sobretudo na Substncia Nigra e no Ncleo Lenticular. No estudo tcnico-radiolgico encontrmos evidncias do aumento da difusibilidade da gua na substncia branca subcortical dos sujeitos idosos comparativamente aos mais jovens. Uma relao idntica foi avaliada nos tlamos. O aumento relacionado com a idade parece ser predominantemente observado em doentes com mais de 65 anos de idade o que pode refletir alteraes estruturais ligeiras associados ao envelhecimento normal. Os resultados indicam que a anlise quantitativa das imagens ponderadas em difuso fornece informaes, sobre a estrutura do crebro, as quai s no esto disponveis apenas por inspeo visual, tanto nas imagens ponderadas em difuso como em outras sequncias de aplicao clnica de rotina. Para fazer face s desvantagens dos sistemas de quantificao das HSB os quais so dispendiosos, complexos, requererem tecnologia e formao especficas, recomendamos que a aplicao automatizada GUIAL, desenvolvida ao longo do nosso trabalho de utilizao elementar e prtica para que seja introduzida nos sistemas de aquisio de imagem por RM com o fim de integrar o processamento de imagem nos indivduos portadores de fatores de risco vascular. A avaliao do ADC, nesta amostra, permitiu concluir que a variao desta varivel explicada estatisticamente pela existncia da condio clnica de status lacunar em ambos os hemisfrios ou por outras palavras, o status lacunar influencia o valor de ADC. Embora uma pequena percentagem da variao do ADC seja explicada pelo gnero, o ADC nos homens foi superior ao das mulheres o que no nos surpreende, pois so tambm os homens onde a frequncia de doena microvascular se revelou mais expressiva. Os valores do ADC, globalmente, entre os hemisfrios cerebrais no mostraram alteraes exceto na SB entre os idosos e no idosos. A SB da regio frontal mostrou valores diminudos na anisotropia e isotropia face s restantes reas anatmicas. Os estudos indicam que na idade avanada existe uma maior predisposio para suscetibilidades de estrutura com status de desconexo. A classificao das HSB foi superior em indivduos mais velhos e com status lacunar, e em menor quantidade (inferior rating de classificao) nos indivduos idosos sem status lacunar. As alteraes volumtricas foram mais frequentes no homem do que na mulher, presumivelmente devido associao com a elevada classificao de status lacunar. Um aumento do ndice de Evan correspondeu, neste estudo, ao aumento das HSB, diminuio do volume cerebral total, expanso ventrculo-sulcal frontal e ao aumento da medida do ngulo caloso. Estes resultados foram agravados pela classificao elevada de status lacunar nos indivduos que apresentaram indcios de doena de pequenos vasos, com manifesto aumento dos espaos de Virchow-Robin,enfartes lacunares ou HSB. Esses resultados foram mais expressivos no gnero masculino do que no feminino revelando uma maior vulnerabilidade sobretudo na atrofia frontal nos homens. Por sua vez as dimenses do Corpo Caloso tornaram-se reduzidas devido compresso dos ventrculos laterais e terceiro ventrculo. Estes indicadores tiveram expresso particularmente nos indivduos com mais de 65 anos. ---------------------------------------------------------------------------------------------ABSTRACT: The latest neuroimaging methods, such as Magnetic Resonance Imaging (MRI), have enabled detailed images of in vivo human brain. These images reveal often unexpected findings related to the normal pattern, with high predisposition for the elderly people with forthright coexistence with vascular risk factors such as characteristics of a normal aging process. Although it has been, in the last decade, several publications on this subject, it is still little explained. All over the world have emerged disease prevention programs and health promotion developed by the Public Health sector, supported mainly by the advancement of medical technologies that have resulted, among other impacts, in a growing of the elderly population. It is estimated, in 2030, a demographic composition with 20% o people over 65 years. In this context, microvascular disease is the most common cause of cognitive vascular impairment in the elderly and senescent characteristics in the MRI trough ischemic lesions of the white matter (Leukoaraiosis) and lacunar infarcts (lacunar status), cerebral atrophy, gliosis and iron accumulation in the basal ganglia in excess.This thesis, considering the research line that stems - Life Sciences - specialization in Clinical Medicine, Biotechnology, gathers and reflects on three aspects linked to MR, interdependent and related to a common problem. The first deals with the Magnetic Resonance Technology characterization in Portugal, which includes an exploratory evaluation of the implementation of Anisotropic Diffusion technique in brain studies. The analytical dimensions studied were the Technologic, Socio-demographic and Economics. Collecting data was supported by different sources of information and was applied an exploratory methodology whose results were validated by triangulation. The research method was grouped and stratified criteria under the same analytical dimensions. The second describes the anatomical study - which was focused on radiological measurement parameters, based on the brains specimen under an experimental methodology applied to MRI diffusion metrics. Radiological evaluation and optimization of the weighted image diffusion in clinical studies were associated with the brain of the elderly "The Usual Brain Aging" with methodological basis based on established criteria and indicators by Rotterdam Scan Study (RSS). The main results obtained reveal the inexistence frameworks in Portugal for evaluation of equipments or Agency of Health Technology to produce studies comparing the equipment available on the market, the value for money and its allocation to clinical and epidemiological needs. It was found that the implementation of MRI equipment is strongly based on economic criteria lacking recommendations and guidelines for the rationalized use of these technologies. As the quantitative data we conclude that most of the scanners are located in private clinical institutions (80,2%); the most frequent magnetic field intensity is [1.5T] with 119 scanners; the scanners are mainly installed in Lisbon (55 units) and Porto (39 units) districts; the average ratio of equipment per capita in Portugal is 1 to 65 195 people; the gradient power with higher expression in the sample is 30-39mT / m;most of the scanners were installed in the years range [2009-2012 years] with 59 equipment; only 6 clinical placements develop clinical research and the most coils for brain studies are of Array type. The optimization study of diffusion technique revealed, as the assessment of the bvalues, the lower (b = 500 s / mm2 and b = 1000 s / mm 2), promotes an increase in the SI and SNR being this measure related to a higher image quality, however the highest b values (b = 2000 s / mm 2) have a higher CNR (Contrast to Noise-Ratio) and CR (Contrast Ratio), compared to the previous ones. This may provide less anatomical details and, thus, ower image quality, of a normal brain, however can help the interpretation and have advantages in identifying microvascular injuries when doubts persist regarding the differential diagnosis of microvascular disease of lacunar or WMH (White Matter Hyperintensities) status type. Changes on this parameter are Otimizao da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco crebro-vascular particularly reflected in the differences of image quality evaluation in the frontocallosum anatomical area. We conclude from the quantitative assessment of the average concentration of iron (26Fe), in all age groups to the basal ganglia, that the higher concentrations are, in descending order: Nigral Substantia, Globus pallidus, Putamen, Thalamus, Rubio nucleus and Caudate nucleus; that there is a predominance in the concentration of iron (26Fe) in the left hemisphere and that male gender show higher iron (26Fe) level tha females, in the age groups [30-40 [[40-50 [and [50- 60 [. Regarding a main conclusion of the mean concentration study of iron, in terms of age we point out that the average concentration of iron (26Fe) is higher among older groups and increases with age, especially in Nigral Substantia and Lenticular Nucleus. On the technical and radiological study we found evidence of an increased in water /diffusivity in the ubcortical white matter of the elderly compared with younger subjects. A similar relationship was assessed in the Thalamus. The increase agerelated seems to be predominantly observed in patients over 65 years which may reflect minor structural changes associated with normal aging. The results indicate that quantitative analysis of diffusion weighted imaging can provide information about the structure of the brain which is not reached only by visual inspection or standard sequences applied in clinical routine. To address the disadvantages the systems of quantification of WMH which the authors state that are costly, complex, require specific technology and training, we recommend that the automated application GUIAL, developed over our work is basic and practical to use and to be introduced in MR image systems acquisition in order to integrate image processing in patients with vascular risk factors. The evaluation of the ADC showed that its variation is statistically explained by the existence of the medical condition of lacunar status, in both hemispheres, or in other words, the lacunar status influences the ADC value. Although a small percentage of the ADC variation is explained by gender, the ADC in men was higher than women which Otimizao da anisotropia fronto-calosa e [RM 1,5T] no idoso normal e com risco crebro-vascular do not surprise us, since they are also men where the frequency of microvasculardisease has proved more significant. The values of ADC, overall, between the cerebral hemispheres showed no changes but were different in WM among the elderly and non-elderly subjects.The WM's forehead showed decreased values in anisotropy and isotropy face the other anatomical areas. The studies indicate that in old age there is a greater tendency to higher susceptibility to disconnection- status framework. The classification of WMH was higher in elderly people and lacunar status, and fewer (lower classification rating) in the elderly without lacunar status. volumetric changes were more frequent in men than in women, most probably because of its association with high lacunar status rating. An increase of Evan index corresponded, in this study, to an increase in WMH, to a decreased of total brain volume, to a ventricle sulcal frontal and callous angle expansion. These results were wound up by high ranking of lacunar status in subjects who had small vessel disease, clear increase in spaces of Virchow-Robin, lacunar infarctions or WMH. These results were more significant in males than in females revealing vulnerability particularly in the frontal atrophy in men. In turn the size of Corpus Callosum because reduced due to the compression of the lateral and third ventricles. These indicators had expression particularly in individuals over 65 years.
