530 resultados para angiography


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The hypothesis that large fluctuations in weight during young adulthood are associated with the degree of coronary artery disease was investigated by comparing patterns of weight change of patients with angiographically defined diseased or normal arteries. Participants (n = 823) were selected from men and women aged 40-74 years who had undergone angiography at North Carolina Baptist Hospital during 1987-88. Weight history from age 20 to 40 was assessed with a mailed questionnaire. Per cent prevalence of "yo-yo dieting" adjusted for age, race, and coronary disease risk factors in patients who had 0, 1, 2, 3, or more than 3 diseased arteries was 8.6, 8.8, 3.7, 5.6 and 7.1 per cent respectively (p = 0.313). These results do not support the research hypothesis. However, since the results may have been confound by neuroticism, they should not be interpreted as strong evidence against this hypothesis. ^

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En la fisiopatología del síndrome coronario agudo (SCA) sin evidencia de lesión ateromatosa oclusiva, podría participar un estado de hipertrombogenicidad sanguínea, generado por factores trombogénicos sistémicos, como los factores de riesgo cardiovascular y los que intervienen en el balance coagulación-anticoagulación, fibrinolisis y formación de fibrina. Objetivo: Estudiar y comparar los factores trombogénicos sistémicos en pacientes con SCA y cinecoronariografía (CCG) normal y patológica.

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PURPOSE: To describe and follow cotton wool spots (CWS) in branch retinal vein occlusion (BRVO) using multimodal imaging. METHODS: In this prospective cohort study including 24 patients with new-onset BRVO, CWS were described and analyzed in color fundus photography (CF), spectral domain optical coherence tomography (SD-OCT), infrared (IR) and fluorescein angiography (FA) every 3 months for 3 years. The CWS area on SD-OCT and CF was evaluated using OCT-Tool-Kit software: CWS were marked in each single OCT B-scan and the software calculated the area by interpolation. RESULTS: 29 central CWS lesions were found. 100% of these CWS were visible on SD-OCT, 100% on FA and 86.2% on IR imaging, but only 65.5% on CF imaging. CWS were visible for 12.4 ± 7.5 months on SD-OCT, for 4.4 ± 3 months and 4.3 ± 3.4 months on CF and on IR, respectively, and for 17.5 ± 7.1 months on FA. The evaluated CWS area on SD-OCT was larger than on CF (0.26 ± 0.17 mm(2) vs. 0.13 ± 0.1 mm(2), p < 0.0001). The CWS area on SD-OCT and surrounding pathology such as intraretinal cysts, avascular zones and intraretinal hemorrhage were predictive for how long CWS remained visible (r(2) = 0.497, p < 0.002). CONCLUSIONS: The lifetime and presentation of CWS in BRVO seem comparable to other diseases. SD-OCT shows a higher sensitivity for detecting CWS compared to CF. The duration of visibility of CWS varies among different image modalities and depends on the surrounding pathology and the CWS size.

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PURPOSE: To report the case of a patient with recurrent, acute posterior multifocal placoid pigment epitheliopathy. To the best of our knowledge, this is the longest documented course with the greatest number of recurrences reported. METHODS: Observational case report of one patient. A 27-year-old otherwise healthy male patient presented with recurrence of new scotomata over 15 years. Fundus photography, fluorescein angiography, indocyanine green angiography, fundus autofluorescence, and optical coherence tomography documented his clinical course. RESULTS: Over the course of 15 years, the patient developed 11 symptomatic (5 imaging-documented) recurrences of acute, posterior multifocal placoid pigment epitheliopathy affecting both eyes. Each episode manifested with new subjective scotomata and new lesions noted on imaging. Symptoms mostly resolved after each episode, and visual outcome remained excellent (20/20 in the right eye and 20/25 left eye at the last follow-up). CONCLUSION: Although typically monophasic, acute posterior multifocal placoid pigment epitheliopathy can rarely present with a recurrent course over a prolonged period of time and should be considered as a diagnosis in patients presenting with recurrent visual symptoms and new placoid lesions on imaging. In recurrent cases, visual recovery may still remain excellent.

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A semi-automatic segmentation algorithm for abdominal aortic aneurysms (AAA), and based on Active Shape Models (ASM) and texture models, is presented in this work. The texture information is provided by a set of four 3D magnetic resonance (MR) images, composed of axial slices of the abdomen, where lumen, wall and intraluminal thrombus (ILT) are visible. Due to the reduced number of images in the MRI training set, an ASM and a custom texture model based on border intensity statistics are constructed. For the same reason the shape is characterized from 35-computed tomography angiography (CTA) images set so the shape variations are better represented. For the evaluation, leave-one-out experiments have been held over the four MRI set.

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A physiological examination of mice harboring a null allele at the aryl hydrocarbon (Ah) locus revealed that the encoded aryl hydrocarbon receptor plays a role in the resolution of fetal vascular structures during development. Although the aryl hydrocarbon receptor is more commonly studied for its role in regulating xenobiotic metabolism and dioxin toxicity, a developmental role of this protein is supported by the observation that Ah null mice display smaller livers, reduced fecundity, and decreased body weights. Upon investigating the liver phenotype, we found that the decrease in liver size is directly related to a reduction in hepatocyte size. We also found that smaller hepatocyte size is the result of massive portosystemic shunting in null animals. Colloidal carbon uptake and microsphere perfusion studies indicated that 56% of portal blood flow bypasses the liver sinusoids. Latex corrosion casts and angiography demonstrated that shunting is consistent with the existence of a patent ductus venosus in adult animals. Importantly, fetal vascular structures were also observed at other sites. Intravital microscopy demonstrated an immature sinusoidal architecture in the liver and persistent hyaloid arteries in the eyes of adult Ah null mice, whereas corrosion casting experiments described aberrations in kidney vascular patterns.

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INTRODUÇÃO: Durante procedimentos endovasculares, estão presentes os riscos relacionados ao uso dos contrastes iodados, tais como a nefropatia por contraste, uma vez que é fundamental o emprego de um meio de contraste para a obtenção das imagens radiológicas vasculares. A injeção intravascular de gás CO2 purificado é reconhecidamente uma alternativa relativamente mais segura ao contraste iodado, contudo, seu manuseio artesanal pode também trazer dificuldades técnicas e riscos aos pacientes. Para contemplar estas questões, foi desenvolvido o protótipo de um injetor intravascular de CO2 medicinal, microprocessado, dedicado à obtenção de imagens angiográficas. OBJETIVOS: Realizar os testes de viabilidade técnica inicial do protótipo em modelo in vivo. MÉTODOS: Realizar a angioplastia da artéria renal esquerda de 10 porcos, divididos em 2 grupos: Grupo 1 (n=5) injeção de contraste iodado, Grupo 2 (n=5) injeção de CO2 através do protótipo. Monitorização clínica e laboratorial dos animais no pré, intra e pós-operatório, com exames de função renal na véspera e 48h após os procedimentos e 3 gasometrias arteriais seriadas no intra-operatório. Observação clínica foi mantida por 48h no pós- operatório. RESULTADOS: Os procedimentos de angioplastia com CO2 foram realizados com sucesso técnico de 100%, sem necessidade de complementação com injeção de contraste iodado no Grupo 2. Não foram identificadas falhas no protótipo em funcionamento. Não foram identificadas alterações clínicas ou radiológicas sugestivas de contaminação por ar ambiente do sistema de CO2 e nem alterações laboratoriais nos animais. As imagens angiográficas obtidas no Grupo 2 foram consideradas, numa avaliação subjetiva, relativamente inferiores às imagens obtidas no Grupo 1. DISCUSSÃO: A qualidade inferior de imagem no Grupo 2 pode ser atribuída ao equipamento de fluoroscopia utilizado, com software desatualizado em relação aos equipamentos atuais, que incluem pré-configurações para angiografia com CO2; no entanto, ainda assim todos os procedimentos propostos no Grupo 2 foram realizados com sucesso técnico, o que nos leva a classificar as imagens deste grupo 2 como satisfatórias. O manuseio do aparelho mostrou-se ágil e eficiente, com a programação dos parâmetros sendo realizada com facilidade através do visor \"touch screen\", comparativamente superior ao método artesanal de injeção de CO2 com seringas em selo d\'água. CONCLUSÕES: O protótipo do aparelho injetor intravascular de CO2 funcionou de forma adequada durante os testes e as imagens obtidas permitiram a compleição com sucesso dos procedimentos. Portanto, os resultados positivos obtidos sugerem que o equipamento é tecnicamente viável

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The purpose of this paper is to conduct a review of studies on cystoid macular edema published in the last seven years. Cystoid macular edema is a major cause of loss of visual acuity. It is the final common pathway of many diseases and can be caused by numerous processes including inflammatory, vascular, adverse drug reactions, retinal dystrophy or intraocular tumors. These processes disrupt the blood-retinal barrier, with fluid extravasation to the macular parenchyma. Imaging tests are essential for both detection and monitoring of this pathology. Fluorescein angiography and autofluorescence show the leakage of liquid from perifoveal vessels into the tissue where it forms cystic spaces. Optical coherence tomography is currently the gold standard technique for diagnosis and monitoring. This allows objective measurement of retinal thickness, which correlates with visual acuity and provides more complete morphological information. Based on the underlying etiology, the therapeutic approach can be either surgical or medical with anti-inflammatory drugs. We found that disruption of the blood-retinal barrier for various reasons is the key point in the pathogenesis of cystoid macular edema, therefore we believe that studies on its treatment should proceed on this path.

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Purpose: To characterize the relationship between fundus autofluorescence (FAF), Optical Coherence Tomography (OCT) and immunohistochemistry (IHC) over the course of chronic retinal degeneration in the P23H rat. Methods: Homozygous albino P23H rats, Sprague–Dawley (SD) rats as controls and pigmented Long Evans (LE) rats were used. A Spectralis HRA OCT system was used for scanning laser ophthalmoscopy (SLO) imaging OCT and angiography. To determine FAF, fluorescence was excited using diode laser at 488 nm. A fast retina map OCT was performed using the optic nerve as a landmark. IHC was performed to correlate with the findings of OCT and FAF changes. Results: During the course of retinal degeneration, the FAF pattern evolved from some spotting at 2 months old to a mosaic of hyperfluorescent dots in rats 6 months and older. Retinal thicknesses progressively diminished over the course of the disease. At later stages of degeneration, OCT documented changes in the retinal layers, however, IHC better identified the cell loss and remodeling changes. Angiography revealed attenuation of the retinal vascular plexus with time. Conclusion: We provide for the first time a detailed long-term analysis of the course of retinal degeneration in P23H rats using a combination of SLO and OCT imaging, angiography, FAF and IHC. Although, the application of noninvasive methods enables longitudinal studies and will decrease the number of animals needed for a study, IHC is still an essential tool to identify retinal changes at the cellular level.

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Purpose: The P23H rhodopsin mutation is an autosomal dominant cause of retinitis pigmentosa (RP). The degeneration can be tracked using different anatomical and functional methods. In our case, we evaluated the anatomical changes using Spectral-Domain Optical Coherence Tomography (SD-OCT) and correlated the findings with retinal thickness values determined by immunocytochemistry.Methods: Pigmented rats heterozygous for the P23H mutation, with ages between P18 and P180 were studied. Function was assessed by means of optomotor testing and ERGs. Retinal thicknesses measurements, autofluorescence and fluorescein angiography were performed using Spectralis OCT. Retinas were studied by means of immunohistochemistry. Results: Between P30 and P180, visual acuity decreased from 0.500 to 0.182 cycles per degree (cyc/deg) and contrast sensitivity decreased from 54.56 to 2.98 for a spatial frequency of 0.089 cyc/deg. Only cone-driven b-wave responses reached developmental maturity. Flicker fusions were also comparable at P29 (42 Hz). Double flash-isolated rod-driven responses were already affected at P29. Photopic responses revealed deterioration after P29.A reduction in retinal thicknesses and morphological modifications were seen in OCT sections. Statistically significant differences were found in all evaluated thicknesses. Autofluorescence was seen in P23H rats as sparse dots. Immunocytochemistry showed a progressive decrease in the outer nuclear layer (ONL), and morphological changes. Although anatomical thickness measures were significantly lower than OCT values, there was a very strong correlation between the values measured by both techniques.Conclusions: In pigmented P23H rats, a progressive deterioration occurs in both retinal function and anatomy. Anatomical changes can be effectively evaluated using SD-OCT and immunocytochemistry, with a good correlation between their values, thus making SD-OCT an important tool for research in retinal degeneration.

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We report a clinical case of renovascular disease, probably linked to fibromuscular dysplasia, in a 12 months old boy with severe arterial hypertension with target-organ damage, highlighting the radiological approach. Initial investigation included renal ultrasound that showed normal sized kidneys, with normal cortical echogenicity on the right and focally increased echogenicity of the posterior aspect of the left kidney, forming a mass-like lesion. Magnetic resonance imaging excluded renal tumor, which was confirmed by ultrasound guided biopsy. A doppler ultrasonography was also performed suggesting a right renal artery stenosis and decreased flow to the posterior aspect of the left kidney. Angiography with diagnostic and therapeutic intention was performed: right renal artery stenosis was detected and transluminal ballon dilation was performed; the left renal artery bifurcated precociously and the branch that irrigated the posterior part of the kidney had a stenosis which was also successfully dilated. After the intervention good blood pressure control with antihypertensive drugs was achieved, which was not possible before the angiographic procedure. The authors underline various methods of imaging used to accurately diagnose renovascular disease and the usefulness of interventional radiology treatment for this disease in very young children.

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Les artéfacts métalliques entraînent un épaississement artéfactuel de la paroi des tuteurs en tomodensitométrie (TDM) avec réduction apparente de leur lumière. Cette étude transversale prospective, devis mesures répétées et observateurs avec méthode en aveugle, chez 24 patients consécutifs/71 tuteurs coronariens a pour objectif de comparer l’épaisseur de paroi des tuteurs en TDM après reconstruction par un algorithme avec renforcement des bords et un algorithme standard. Une angiographie coronarienne par TDM 256 coupes a été réalisée, avec reconstruction par algorithmes avec renforcement des bords et standard. L’épaisseur de paroi des tuteurs était mesurée par méthodes orthogonale (diamètres) et circonférentielle (circonférences). La qualité d’image des tuteurs était évaluée par échelle ordinale, et les données analysées par modèles linéaire mixte et régression logistique des cotes proportionnelles. L’épaisseur de paroi des tuteurs était inférieure avec l’algorithme avec renforcement des bords comparé à l’algorithme standard, avec les méthodes orthogonale (0,97±0,02 vs 1,09±0,03 mm, respectivement; p<0,001) et circonférentielle (1,13±0,02 vs 1,21±0,02 mm, respectivement; p<0,001). Le premier causait moins de surestimation par rapport à l’épaisseur nominale comparé au second, avec méthodes orthogonale (0,89±0,19 vs 1,00±0,26 mm, respectivement; p<0,001) et circonférentielle (1,06±0,26 vs 1,13±0,31 mm, respectivement; p=0,005) et diminuait de 6 % la surestimation. Les scores de qualité étaient meilleurs avec l’algorithme avec renforcement des bords (OR 3,71; IC 95% 2,33–5,92; p<0,001). En conclusion, la reconstruction des images avec l’algorithme avec renforcement des bords génère des parois de tuteurs plus minces, moins de surestimation, et de meilleurs scores de qualité d’image que l’algorithme standard.

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BACKGROUND Contrast-enhanced (ce) fluid-attenuated inversion recovery magnetic resonance imaging (FLAIR MRI) has recently been shown to identify leptomeningeal pathology in multiple sclerosis. OBJECTIVE To demonstrate leptomeningeal enhancement on three-dimensional (3D) FLAIR in a case of Susac's syndrome. METHODS Leptomeningeal enhancement was correlated with clinical activity over 20 months and compared to retinal fluorescein angiography. RESULTS The size, number, and location of leptomeningeal enhancement varied over time and generally correlated with symptom severity. The appearance was remarkably similar to that of retinal vasculopathy. CONCLUSION Ce 3D FLAIR may aid in diagnosis and understanding of pathophysiology in Susac's syndrome and may serve as a biomarker for disease activity.

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PURPOSE The purpose of this study was to identify SD-OCT changes that correspond to leakage on fluorescein (FA) and indocyanine angiography (ICGA) and evaluate effect of half-fluence photodynamic therapy (PDT) on choroidal volume in chronic central serous choroidoretinopathy (CSC). METHODS Retrospective analysis of patients with chronic CSC who had undergone PDT. Baseline FA and ICGA images were overlaid on SD-OCT to identify OCT correlates of FA or ICGA hyperfluorescence. Choroidal volume was evaluated in a subgroup of eyes before and after PDT. RESULTS Twenty eyes were evaluated at baseline, of which seven eyes had choroidal volume evaluations at baseline and 3 months following PDT. SD-OCT changes corresponding to FA hyperfluorescence were subretinal fluid (73%), RPE microrip (50%), RPE double-layer sign (31%), RPE detachment (15%), and RPE thickening (8%). ICGA hyperfluoresence was correlated in 93% with hyperreflective spots in the superficial choroid. Choroidal volume decreased from 9.35 ± 1.99 to 8.52 ± 1.92 and 8.04 ± 1.7 mm(3) (at 1 and 3 months post PDT, respectively, p ≤ 0.001). CONCLUSIONS We identified specific OCT findings that correlate with FA and ICGA leakage sites. SD-OCT is a valuable tool to localize CSC lesions and may be useful to guide PDT treatment. Generalized choroidal volume decrease occurs following PDT and extends beyond PDT treatment site.

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Thesis (Ph.D.)--University of Washington, 2016-06