A espécie asinina (E. asinus) teve sua origem há milhares de anos, se desenvolvendo a partir de um tronco comum ao do eqüino doméstico que conhecemos. Vem passando por um processo adaptativo, apresentando características distintas, quando os observamos em diversas partes do planeta. Na região nordeste do Brasil, desenvolve um papel fundamental, influenciando diretamente na renda das famílias locais. Tendo em vista o grande número de afecções locomotoras e a falta de cuidados a que estão submetidos, realizou-se um estudo anatômico e radiográfico da região distal de seus membros torácicos, buscando-se subsídios a prática clínica e cirúrgica dedicada a esses animais, bem como a compreensão de sua maior resistência a lesões locomotoras, quando comparado ao eqüino. A avaliação anatômica revelou características musculares semelhantes as já descritas para eqüinos. O exame radiográfico evidenciou lesões severas, caracterizadas por osteíte podal e áreas de reabsorção óssea e remodelamento na margem solear, associadas à rotação da falange distal. Ainda na avaliação radiográfica, caracterizaram-se os principais vasos arteriais dessa região através de técnica angiográfica. Não se observou correlação entre o ângulo de inclinação da muralha do casco e falange distal, com a área de secção transversal dos tendões dos músculos flexores. As maiores secções transversais para o tendão flexor digital superficial, profundo e interósseo, mostraram coincidência com os pontos de maior estresse articular, caracterizando, assim, a resistência dos asininos à lesões nestas estruturas em seu aparelho locomotor. / The asinine species was originated thousands of years ago from the same branch of the domestic equine. The asinine have been undergoing to a great adaptation resulting in different characteristics of each population of asinine around the world. In the northeast region of Brazil, they play an essential role in the income of the local families. Due to a large number of locomotor disorders and a lack of professional care, an anatomic and radiographic study of the distal forelimb region of the asinine was carried out in order to gather information to improve the clinical and surgical practice in this species, and to explain the less susceptibility to locomotor disorders compared to equines. The anatomical study showed that asinine have similar muscular characteristics already described for equines. The radiographic exam showed severe lesions, characterized by pedal osteitis, bone reabsorption areas and remodelling of sole margin associated to the distal phalanx rotation. The radiographic study also showed the characterization of the main arterial vessels. No significant correlation was observed between the angle of the hoof wall and the angle of the distal phalanx with the cross section area of the flexor tendons. The larger cross section areas of the superficial digital flexor tendon, deep digital flexor tendon and interosseus tendon were coincidental with the great articular stress, explaining the greater resistance of the asinines to lesions in those structures of their locomotor apparatus.

As imagens de Angiografia por Ressonância Magnética (angio-RM) e Tomografia Computadorizada (angio-TC) são ferramentas amplamente usadas em processos de quantificação vascular e no diagnóstico de doenças cardiovasculares, as quais são consideradas entre as principais causas de morte. Contudo, a análise dos vasos em larga escala a partir das imagens é dificultada, tanto pela variabilidade natural dos vasos no corpo humano, quanto pela grande quantidade de dados disponíveis. Além disso, os métodos de quantificação existentes, usualmente extraem as características a partir dos esqueletos, ou até mesmo das próprias imagens de angiografia, razão pela qual tais métodos podem fazer necessária a reanálise das imagens repetidas vezes. Com o intuito de facilitar a análise e de fornecer uma ferramenta de apoio ao diagnóstico, neste trabalho são apresentados um modelo de representação textual de redes vasculares e uma metodologia de quantificação vascular automática, que é feita a partir dessa representação. A representação é obtida a partir da segmentação de imagens volumétricas de angio-RM e angio-TC, seguida da extração de trajetórias e diâmetros de redes vasculares. Tal representação é híbrida, combinando grafos e uma sequência textual de instruções, e permite não apenas a extração de caraterísticas morfológicas da rede vascular, como também a compressão das imagens e, ainda, a reconstrução de imagens similares às imagens originais. A partir das características extraídas, foram realizados estudos comparativos entre arquiteturas vasculares, o que é feito tanto por meio do uso de imagens sintéticas, como por meio de imagens reais, imagens nas quais foi possível encontrar diferenças entre arquiteturas, além de viabilizar a caracterização de aneurismas em um indivíduo. Paralelamente, desenvolvemos um método que permite identificar similaridade entre segmentos vasculares, o que por sua vez possibilita o reconhecimento e rotulação de segmentos em um conjunto de redes vasculares. A metodologia por nós desenvolvida deve também auxiliar no desenvolvimento de processos de classificação de vasos sanguíneos, de ferramentas para o diagnóstico automático de doenças vasculares, e para a melhora de técnicas utilizadas na prática clínica. / Magnetic Resonance Angiography (angio-MR) and Computed Tomography Angiography (angio-TC) are widely used imaging techniques used for vascular quantification and the diagnosis of cardiovascular diseases, considered one of the main causes of death. Blood vessel analysis using angiographic images is intrisically difficult because of the natural human vessel variability and the large amount of information. Additionally, most quantification methods perform the analysis of entire datasets, which can be very time consuming when they need to be reanalyzed. With the aim of reducing these problems and to provide a tool to aid diagnosis, we propose a textual representation model for vascular networks and an automatic vascular quantification methodology. The representation is obtained from volumetric image segmentation of angio-MR and angio-TC, followed by the extraction of the trajectory and the blood vessel diameters. This representation is hybrid in nature, combining graphs and a sequence of textual instructions, allowing for the extraction of morphological features, image compression, and the synthesis of angiographic images. Using extracted features derived from the model, comparative studies of vascular architecture can be performed. Experiments were made using synthetic and real images, in which was possible to find structural differences that make feasible to characterize abnormalities such as aneurysms. Also, a vessel similarity identification method was developed, which makes it possible to recognize vessel segments and label them in a set of vessel networks. The proposed methodology should aid in blood vessel classification processes, automatic diagnosis of cardiovascular diseases, and allow development of methods and applications that could be used in the clinical practice.

<p>Atherosclerosis is a serious threat to public health and a major cause of morbidity and mortality. In this doctoral research, the feasibility of using whole-body magnetic resonance angiography (WBMRA) was studied as a principal aim both in patients and in an epidemiological setting. Secondary aims were to create a score for assessment of the degree of atherosclerosis with the use of WBMRA and to investigate the correlation between this score and various cardiovascular (CV) risk factors. </p><p>WBMRA was found feasible both in atherosclerotic patients and in an elderly population from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). All subjects except one completed the examination without any adverse events. A large proportion (93-99%) of the vessel segments could be evaluated and the results of a smaller comparison between WBMRA and conventional invasive x-ray angiography were reasonable regarding the assessed degree of maximum stenosis or occlusion. This indicates the safety and robustness of the WBMRA method.</p><p>Unsuspected significant vascular abnormalities were found in patients with atherosclerotic symptoms and significant vascular abnormalities were present in elderly subjects without any self-reported vascular disease. The prevalence rates of vascular abnormalities in the carotid, renal, and inflow and runoff arteries of the lower limbs were estimated in an elderly population. A total atherosclerotic score (TAS) reflecting the degree of luminal narrowing was created for the WBMRA method and was significantly related to Framingham risk score (FRS) and to the amount of abdominal visceral adipose tissue, interleukin-6, and leptin and was inversely significantly related to adiponectin. </p><p>Studies with outcome data of the PIVUS cohort are needed for further validation of the WBMRA method and to determine whether TAS can be used as an adjunct for CV risk assessment. Meanwhile, the correlation with FRS indicates that TAS could be of value for this purpose.</p>

Atherosclerosis is a serious threat to public health and a major cause of morbidity and mortality. In this doctoral research, the feasibility of using whole-body magnetic resonance angiography (WBMRA) was studied as a principal aim both in patients and in an epidemiological setting. Secondary aims were to create a score for assessment of the degree of atherosclerosis with the use of WBMRA and to investigate the correlation between this score and various cardiovascular (CV) risk factors. WBMRA was found feasible both in atherosclerotic patients and in an elderly population from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). All subjects except one completed the examination without any adverse events. A large proportion (93-99%) of the vessel segments could be evaluated and the results of a smaller comparison between WBMRA and conventional invasive x-ray angiography were reasonable regarding the assessed degree of maximum stenosis or occlusion. This indicates the safety and robustness of the WBMRA method. Unsuspected significant vascular abnormalities were found in patients with atherosclerotic symptoms and significant vascular abnormalities were present in elderly subjects without any self-reported vascular disease. The prevalence rates of vascular abnormalities in the carotid, renal, and inflow and runoff arteries of the lower limbs were estimated in an elderly population. A total atherosclerotic score (TAS) reflecting the degree of luminal narrowing was created for the WBMRA method and was significantly related to Framingham risk score (FRS) and to the amount of abdominal visceral adipose tissue, interleukin-6, and leptin and was inversely significantly related to adiponectin. Studies with outcome data of the PIVUS cohort are needed for further validation of the WBMRA method and to determine whether TAS can be used as an adjunct for CV risk assessment. Meanwhile, the correlation with FRS indicates that TAS could be of value for this purpose.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 60-62). Also available in electronic version. Access restricted to campus users.

Coronary arteries are the blood vessels supplying oxygen-rich blood to the heart muscles. Coronary artery calcium (CAC), which is the total amount of calcium deposited in these arteries, indicates the presence or the future risk of coronary artery diseases. Quantification of CAC is done by using computed tomography (CT) scan which uses attenuation of x-ray by different tissues in the body to generate three-dimensional images. Calcium can be easily spotted in the CT images because of its higher opacity to x-ray compared to that of the surrounding tissue. However, the arteries cannot be identified easily in the CT images. Therefore, a second scan is done after injecting a patient with an x-ray opaque dye known as contrast material which makes different chambers of the heart and the coronary arteries visible in the CT scan. This procedure is known as computed tomography angiography (CTA) and is performed to assess the morphology of the arteries in order to rule out any blockage in the arteries. The CT scan done without the use of contrast material (non-contrast-enhanced CT) can be eliminated if the calcium can be quantified accurately from the CTA images. However, identification of calcium in CTA images is difficult because of the proximity of the calcium and the contrast material and their overlapping intensity range. In this dissertation first we compare the calcium quantification by using a state-of-the-art non-contrast-enhanced CT scan method to conventional methods suggesting optimal quantification parameters. Then we develop methods to accurately quantify calcium from the CTA images. The methods include novel algorithms for extracting centerline of an artery, calculating the threshold of calcium adaptively based on the intensity of contrast along the artery, calculating the amount of calcium in mixed intensity range, and segmenting the artery and the outer wall. The accuracy of the calcium quantification from CTA by using our methods is higher than the non-contrast-enhanced CT thus potentially eliminating the need of the non-contrast-enhanced CT scan. The implications are that the total time required for the CT scan procedure, and the patient's exposure to x-ray radiation are reduced.

Tez (Tıpta Uzmanlık) - Süleyman Demirel Üniversitesi, Tıp Fakültesi, Kardiyoloji Anabilim Dalı, 2004. / Bibliyografya var.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 17, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, [Department of] Physics, University of Alberta. Includes bibliographical references.