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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Avaliação ultrassonográfica ao duplex Doppler colorido da varicocele / Doppler sonographic evaluation of varicoceles

Correa, André Luiz 14 May 2010 (has links)
INTRODUÇÃO: A varicocele é a dilatação das veias do plexo pampiniforme do testículo. A associação entre a varicocele e a infertilidade é diagnosticada em 20 a 40% dos homens inférteis. Atualmente, o estudo ultrassonográfico da varicocele é realizado com o paciente na posição supina antes e durante a realização de Valsalva, levando-se em consideração o diâmetro das veias (> 0,20cm), e a presença de refluxo maior que 1, segundo ao estudo Doppler espectral. OBJETIVO: A) Propor uma nova metodologia na avaliação ultrassonográfica da varicocele. B) Avaliar a concordância dos achados no exame ultrassonográfico com Doppler colorido dos vasos dos plexos pampiniformes e as alterações no espermograma na infertilidade masculina. C) Avaliar a correlação entre o diâmetro de um dos vasos dos plexos pampiniformes e as alterações no espermograma na infertilidade masculina. MÉTODOS: Foram examinados 266 pacientes, provenientes do setor de reprodução humana do Hospital das Clínicas da Universidade de São Paulo (HCUSP), por meio de duplex Doppler colorido, inicialmente com o paciente em decúbito dorsal e posteriormente, após 5 minutos de espera, na posição ortostática, realizando as medidas dos diâmetros transversais dos plexos pampiniforme nas duas posições, tanto em repouso como em Valsalva. Ao estudo pulsado foi considerado refluxo patológico apenas quando persistia por mais de 1 segundo, com uma velocidade superior que 2 cm/s. Estes pacientes também foram submetidos a analise seminal. RESULTADOS: Em relação à metodologia de realização do exame, observou-se aumento no diâmetro do plexo pampiniforme apenas com a variação da posição de cerca de 18% à direita e 5,9% à esquerda, bem como aumento na detecção do refluxo venoso na posição ortostática, de 23% à direita e 6,8% à esquerda. Observou-se também correlação direta entre as alterações no espermograma com o refluxo venoso, 65% à direita e 86% à esquerda, o mesmo não ocorrendo com o diâmetro do plexo pampiniforme. CONCLUSÕES: A) O exame de ultrassongrafia com Doppler colorido deve ser realizado na posição ortostática, após um período de latência de no mínimo cinco minutos, com condições ambientais confortáveis e manobra de esforço. B) Houve concordância significativa entre o refluxo venoso nos plexos pampiniformes e as alterações do espermograma. C) Não há correlação significativa entre o diâmetro de um dos vasos dos plexos pampiniformes e o espermograma / INTRODUCTION: Varicocele is the dilatation of the veins of the pampiniform plexus of the testicle. The association between varicocele and infertility is diagnosed in 20 to 40% of the infertile men. Currently, in the ultrasound study of varicocele, the diameter of the veins is carried through with the patient in the supine position, before and during the Valsalva maneuver, taking the diameter of the veins consideration (> 0,20cm), and a more than 1 second bigger presence of reflux according to spectral Doppler study. OBJECTIVE: A) To consider a new methodology in the ultrasonographic evaluation of varicocele. B) To evaluate the agreement of the findings in the colorful Doppler ultrasonographic examination of the pampiniform plexus vases with the alterations in the spermogram in masculine infertility. C) To evaluate the correlation between the diameter of one the pampiniform plexus vases and the alterations in the spermogram in the masculine infertility. METHODS: 266 patients from the reproduction sector human being of the Hospital of the Clinics of the University of São Paulo (HCUSP) had been examined, by means of colorful duplex-Doppler, initially with the patient in dorsal decubitus and later, after 5 minutes, in the orthostatic position, carrying through the transversal measures of the diameter of the pampiniform plexus in the two positions, in rest and in Valsalva. To the pulse study reflux was considered pathological only when persisted for more than 1 second, with speed superior to 2 cm/s. These patients were also submitted to seminal analysis. RESULTS: Regarding the methodology of accomplishment of the examination, an increase in the diameter of pampiniform plexus was noted only with the variation of the examination position, about 18% to the right and 5,9% to the left, as well as an increase in the detection of venous reflux in the orthostatic position, 23% to right and 6,8% to the left. It was also detected a correct correlation between variations in the spermogram and the venous reflux, 65% to the right and 86% to the left, the same not occurring with the diameter of pampiniform plexus. CONCLUSIONS: A) The colorful Doppler ultrasound examination must be carried through in the orthostatic position, after a period of latency of at least five minutes, with comfortable environement conditions and effort maneuver. B) A significant accordance between the pampiniform plexus venous reflux and the alterations of the spermogram. C) It does not have significant correlation between the diameter of one of the pampiniform plexus vases and the spermogram
52

Associação entre características tomográficas do osso temporal e a qualidade da janela transtemporal com o ultrassom transcraniano colorido em pacientes com AVC e AIT: estudo observacional analítico / Association between tomographic characteristics of the temporal bone and transtemporal window quality with transcranial color Doppler ultrasound in patients with stroke or transient ischemic attack: analytical and observational study

Brisson, Rodrigo Tavares 09 May 2018 (has links)
Introdução: O ultrassom transcraniano colorido (UTCC) é uma técnica ultrassonográfica que incorpora a imagem do parênquima cerebral à avaliação do fluxo sanguíneo dos vasos do polígono de Willis. Uma de suas maiores limitações é a necessidade de uma janela transtemporal adequada para insonação transcraniana, o que está ausente em cerca de 5-44% dos pacientes. A hiperostose da escama temporal tem sido fortemente associada a falência de janela transtemporal. Objetivamos neste estudo observacional analítico, avaliar a relação entre a a qualidade da janela transtemporal determinada com o UTCC e as características do osso temporal determinada com a tomografia computadorizada de crânio (TC). Materiais e métodos: Trata-se de estudo retrospectivo, analítico, observacional com avaliação de registros médicos onde foram incluídos para análise um total de 187 pacientes com acidente vascular cerebral ou AIT admitidos na Unidade de Emergência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto entre Julho de 2014 e Janeiro de 2015 que realizaram UTCC e TC de acordo com o protocolo institucional. Classificamos a qualidade das janelas dos pacientes com um escore validado em nosso serviço. A análise da espessura e densidade do osso temporal nos exames de TC foi realizada de forma cega para os demais dados clínicos e ultrassonográficos. Resultados: Ausência de Janela temporal bilateral foi encontrada em 21,93% dos pacientes da amostra e destes pacientes (78,05%) foram do sexo feminino p value < 0,0001. A média de idade dos pacientes com presença de Janela temporal foi de 59,9±13,9 anos e as medias de idade dos pacientes sem janela temporal foi de 70,5±12,7 anos com p value <0,001. A área sob a curva ROC para acurácia diagnóstica na detecção de ausência de janela a partir da espessura da escama temporal foi de 0,8232 (0,7504; 0,896) e para o ponto de corte de espessura da escama temporal na ROI de 2,23mm encontramos uma sensibilidade de 0,878 e especificidade de 0,537; Em uma regressão logística univariada, obtivemos que para cada 1 mm de aumento na espessura do osso temporal, obtivemos Odds Ratio (OR) de 4,16 em não se obter janela transtemporal pelo UTCC. Em uma regressão logística multivariada, a espessura da escama temporal em mm (OR : 3,04; IC95%: 1,73-5,35; p: 0,001) idade (OR de 1,07; IC95%: 1,03-1,11; p: 0,003) sexo feminino (OR: 5,99 IC95%:2,09-17,15; p: 0,009) se associaram com ausência da janela transtemporal e a presença de pneumatização óssea na escama do osso temporal (OR: 7,90; IC95%: 1,94-32,04; p: 0,003) se associou com presença da janela transtemporal. Discussão e conclusão: Em concordância com estudos prévios de DTC, os resultados encontrados com a técnica de UTCC sugerem que mulheres idosas possuem maior espessura da escama temporal e por consequência maior taxa de falência de janela transtemporal. Maior espessura do osso temporal e presença de pneumatização do osso temporal são fatores independentes que aumentam a chance de falência de janela transtemporal. A partir da espessura do osso temporal é possível prever a falência de janela transtemporal e assim identificar pacientes elegíveis para a realização do UTCC ou DTC / Introduction: Transcranial color Doppler ultrasound (TCDU) is an ultrasonographic technique that incorporates the image of the cerebral parenchyma to evaluate blood flow in the vessels of the Willis polygon. One of its major limitations is the need for a transtemporal window suitable for transcranial insonation, which is absent in about 5-44% of patients. Hyperostosis of the temporal scale has been strongly associated with transtemporal window failure. In this analytical observational study, we aimed to evaluate the association between the quality of the transtemporal window determined with the TCDU and the characteristics of the temporal bone determined by cranial computed tomography (CT). Materials and methods: This was a retrospective, analytical, observational study with evaluation of medical records where a total of 187 patients with stroke or TIA admitted to the Emergency Unit of the Hospital das Clínicas of the Medical School of Ribeirão Preto between July 2014 and January 2015 who underwent TCDU and CT according to the institutional protocol. We rated the quality of patients\' windows with a score validated at our service. Analysis of temporal bone thickness and density on CT scans was performed blindly for other clinical and ultrasonographic data. Results: Absence of bilateral temporal window was found in 21.93% of the patients in the sample and of these patients 78.05% were female p value <0.0001. The mean age of the patients with presence of temporal window was 59.9 ± 13.9 years and the mean age of patients without temporal window was 70.5 ± 12.7 years with p value <0.001. The area under the ROC curve for diagnostic accuracy in the detection of window absence, from the thickness of the temporal bone, was 0.8232 IC 95% (0.7504; 0.896) and for the cutoff point of the temporal scale thickness at ROI of 2.23mm we found a sensitivity of 0.878 and Specificity of 0.537; In a univariate logistic regression, we found that for each 1 mm of increase in temporal bone thickness, there was an odds ratio (OR) of 4.16 of not being able to obtain a transtemporal window by the TCDU. In a univariate logistic regression, we found that for each 1 mm increase in thickness of the temporal bone, obtained odds ratio (OR) of 4.16 to not obtain transtemporal window by the TCDU. In a multivariate logistic regression, the thickness in mm of the temporal scale (OR: 3.04; 95% CI: 1.73 to 5.35; p: 0.001), age (OR 1.07; 95% CI: 1,03 to 1.11, p: 0.003), being female (OR 5.99 95% CI: 2.09 to 17.15, P: 0.009) were associated with the absence of the transtemporal window, and the presence of bone pneumatized scale in the temporal region (OR: 7.90; 95% CI: 1.94 to 32.04, P: 0.003) was associated with the absence of the transtemporal window. Discussion and conclusion: In agreement with previous TCD studies, we have found that older women have a greater thickness of temporal scales and, consequently, a higher rate of transtemporal window failure on TCDU. From temporal bone thickness it is possible to predict transtemporal window failure and therefore to predict those patients with acute stroke that are suitable for UTCC or TCD exams.
53

Associação entre características tomográficas do osso temporal e a qualidade da janela transtemporal com o ultrassom transcraniano colorido em pacientes com AVC e AIT: estudo observacional analítico / Association between tomographic characteristics of the temporal bone and transtemporal window quality with transcranial color Doppler ultrasound in patients with stroke or transient ischemic attack: analytical and observational study

Rodrigo Tavares Brisson 09 May 2018 (has links)
Introdução: O ultrassom transcraniano colorido (UTCC) é uma técnica ultrassonográfica que incorpora a imagem do parênquima cerebral à avaliação do fluxo sanguíneo dos vasos do polígono de Willis. Uma de suas maiores limitações é a necessidade de uma janela transtemporal adequada para insonação transcraniana, o que está ausente em cerca de 5-44% dos pacientes. A hiperostose da escama temporal tem sido fortemente associada a falência de janela transtemporal. Objetivamos neste estudo observacional analítico, avaliar a relação entre a a qualidade da janela transtemporal determinada com o UTCC e as características do osso temporal determinada com a tomografia computadorizada de crânio (TC). Materiais e métodos: Trata-se de estudo retrospectivo, analítico, observacional com avaliação de registros médicos onde foram incluídos para análise um total de 187 pacientes com acidente vascular cerebral ou AIT admitidos na Unidade de Emergência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto entre Julho de 2014 e Janeiro de 2015 que realizaram UTCC e TC de acordo com o protocolo institucional. Classificamos a qualidade das janelas dos pacientes com um escore validado em nosso serviço. A análise da espessura e densidade do osso temporal nos exames de TC foi realizada de forma cega para os demais dados clínicos e ultrassonográficos. Resultados: Ausência de Janela temporal bilateral foi encontrada em 21,93% dos pacientes da amostra e destes pacientes (78,05%) foram do sexo feminino p value < 0,0001. A média de idade dos pacientes com presença de Janela temporal foi de 59,9±13,9 anos e as medias de idade dos pacientes sem janela temporal foi de 70,5±12,7 anos com p value <0,001. A área sob a curva ROC para acurácia diagnóstica na detecção de ausência de janela a partir da espessura da escama temporal foi de 0,8232 (0,7504; 0,896) e para o ponto de corte de espessura da escama temporal na ROI de 2,23mm encontramos uma sensibilidade de 0,878 e especificidade de 0,537; Em uma regressão logística univariada, obtivemos que para cada 1 mm de aumento na espessura do osso temporal, obtivemos Odds Ratio (OR) de 4,16 em não se obter janela transtemporal pelo UTCC. Em uma regressão logística multivariada, a espessura da escama temporal em mm (OR : 3,04; IC95%: 1,73-5,35; p: 0,001) idade (OR de 1,07; IC95%: 1,03-1,11; p: 0,003) sexo feminino (OR: 5,99 IC95%:2,09-17,15; p: 0,009) se associaram com ausência da janela transtemporal e a presença de pneumatização óssea na escama do osso temporal (OR: 7,90; IC95%: 1,94-32,04; p: 0,003) se associou com presença da janela transtemporal. Discussão e conclusão: Em concordância com estudos prévios de DTC, os resultados encontrados com a técnica de UTCC sugerem que mulheres idosas possuem maior espessura da escama temporal e por consequência maior taxa de falência de janela transtemporal. Maior espessura do osso temporal e presença de pneumatização do osso temporal são fatores independentes que aumentam a chance de falência de janela transtemporal. A partir da espessura do osso temporal é possível prever a falência de janela transtemporal e assim identificar pacientes elegíveis para a realização do UTCC ou DTC / Introduction: Transcranial color Doppler ultrasound (TCDU) is an ultrasonographic technique that incorporates the image of the cerebral parenchyma to evaluate blood flow in the vessels of the Willis polygon. One of its major limitations is the need for a transtemporal window suitable for transcranial insonation, which is absent in about 5-44% of patients. Hyperostosis of the temporal scale has been strongly associated with transtemporal window failure. In this analytical observational study, we aimed to evaluate the association between the quality of the transtemporal window determined with the TCDU and the characteristics of the temporal bone determined by cranial computed tomography (CT). Materials and methods: This was a retrospective, analytical, observational study with evaluation of medical records where a total of 187 patients with stroke or TIA admitted to the Emergency Unit of the Hospital das Clínicas of the Medical School of Ribeirão Preto between July 2014 and January 2015 who underwent TCDU and CT according to the institutional protocol. We rated the quality of patients\' windows with a score validated at our service. Analysis of temporal bone thickness and density on CT scans was performed blindly for other clinical and ultrasonographic data. Results: Absence of bilateral temporal window was found in 21.93% of the patients in the sample and of these patients 78.05% were female p value <0.0001. The mean age of the patients with presence of temporal window was 59.9 ± 13.9 years and the mean age of patients without temporal window was 70.5 ± 12.7 years with p value <0.001. The area under the ROC curve for diagnostic accuracy in the detection of window absence, from the thickness of the temporal bone, was 0.8232 IC 95% (0.7504; 0.896) and for the cutoff point of the temporal scale thickness at ROI of 2.23mm we found a sensitivity of 0.878 and Specificity of 0.537; In a univariate logistic regression, we found that for each 1 mm of increase in temporal bone thickness, there was an odds ratio (OR) of 4.16 of not being able to obtain a transtemporal window by the TCDU. In a univariate logistic regression, we found that for each 1 mm increase in thickness of the temporal bone, obtained odds ratio (OR) of 4.16 to not obtain transtemporal window by the TCDU. In a multivariate logistic regression, the thickness in mm of the temporal scale (OR: 3.04; 95% CI: 1.73 to 5.35; p: 0.001), age (OR 1.07; 95% CI: 1,03 to 1.11, p: 0.003), being female (OR 5.99 95% CI: 2.09 to 17.15, P: 0.009) were associated with the absence of the transtemporal window, and the presence of bone pneumatized scale in the temporal region (OR: 7.90; 95% CI: 1.94 to 32.04, P: 0.003) was associated with the absence of the transtemporal window. Discussion and conclusion: In agreement with previous TCD studies, we have found that older women have a greater thickness of temporal scales and, consequently, a higher rate of transtemporal window failure on TCDU. From temporal bone thickness it is possible to predict transtemporal window failure and therefore to predict those patients with acute stroke that are suitable for UTCC or TCD exams.
54

Diagnosis, microemboli detection and hemodynamic monitoring of intracranial atherosclerosis by transcranial Doppler in the ischemic stroke. / CUHK electronic theses & dissertations collection

January 2008 (has links)
Early deterioration and long-term recurrence were common after stroke or transient ischemic attach (TIA), however, it is unclear whether they were correlated with active embolization and the consequent new cerebral infarct in acute phase. By employing TCD and diffusion weighted imaging (DWI), we studied the significance of the progression of MES and infarcts during acute phase on the clinical outcomes. We found that the disappearance of MES was correlated with better improvement on day 7 of recruitment; for the long-term outcome, occurrence of exacerbating infarct tended to predict recurrent stroke. Treatment aiming to reduce MES and prevent infarct exacerbation in acute phase may improve the prognosis after stroke. / Finally, one study was performed to assess the changes of hemodynamic parameters after stenting of severe stenosis in the MCA. We aimed to investigate whether TCD can reflect the lumen changes after revascularization and detect hyperperfusion. The findings showed that the velocity of stented MCA in most patients normalized within 24 hours after procedure, but the role of TCD in detecting restenosis in long run needed to be verified; no one suffered from hyperperfusion during the period of our study. The long-term outcomes of patients with normalized velocity versus those with persistently high velocity needed to be further studied. Apart from the velocity changes, changes of the collateral flow after intervention may also be an important part of hemodynamic changes. (Abstract shortened by UMI.) / It was suggested that anti-platelet therapy can reduce the MES, but little was known about the efficacy of low molecular weight heparin (LMWH) although in theory LMWH can reduce the red fibrin-dependent thromboemboli. As a sub-analysis of Fraxiparine in Ischemic Stroke (FISS)-tris study, our study did not show advantages of LMWH in eliminating MES compared with aspirin. / Previous studies showed the accuracy of TCD in diagnosis of middle cerebral artery (MCA) stenosis was variable and the positive predictive value (PPV) was less than 50% in a recent report. One of the important reasons was that most criteria were based on the velocity-only method, ignoring other non-velocity information. Thus, we tried to establish new diagnostic criteria by means of designing an assessment form which integrated more characteristics apart from the velocity acceleration. A composite score for each MCA was calculated according to following parameters in the form: Velocity Scale (score 0-6 for peak systolic velocities&lt;140 to &ge;300cm/s), Hemodynamic Scale (score 0-5 for focal or diffuse velocity increase; score 0-6 for differences between bilateral MCA; score 17 for damping velocity), Spectrum Scale (score 0-2 for normal spectrum, turbulence and musical murmurs). Our results showed that compared with the previously reported criteria, the score calculated from the assessment form yielded much more balanced accuracy against magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). However, the composition of the assessment form was only based on personal experience and need to be further modified. Multicenter studies with large sample size are also needed to confirm the advantages of this new method. / Second, we performed three studies to investigate the relationship between the progression of MES and the short or long-term outcome and the relationship between MES and different treatments. / Hao, Qing. / Adviser: Ka Sing Wong. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3419. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 155-181). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
55

Neuronavigation-Guided Transcranial Ultrasound: Development towards a Clinical System and Protocol for Blood-Brain Barrier Opening

Wu, Shih-Ying January 2016 (has links)
Brain diseases including neurological disorders and tumors remain undertreated due to the challenge in accessing the brain, and blood-brain barrier (BBB) restricting drug delivery, which also profoundly limits the development of pharmacological treatment. Focused ultrasound (FUS) with acoustic agents including microbubbles and nanodroplets remains as the only method to open the BBB noninvasively, locally, and transiently to assist drug delivery. For an ideal medical system to serve a broad patient population, it requires precise and flexible targeting with simulation to personalize treatment, real-time monitoring to ensure safety and effectiveness, and rapid application, as repetitive pharmacological treatment is often required. Since none of current systems fulfills all the requirements, here we designed a neuronavigation-guided FUS system with protocol assessed in in vivo mice, in vivo non-human primates, and human skulls from in silico preplanning, online FUS treatment and real-time acoustic monitoring and mapping, to post-treatment assessment using MRI. Both sedate and awake non-human primates were evaluated with total treatment time averaging 30 min and 3-mm targeting accuracy in cerebral cortex and subcortical structures. The FUS system developed would enable transcranial FUS in patients with high accuracy and independent of MRI guidance.
56

The Detection of Cognitive Activity within a System-paced Dual-state Selection Paradigm Using a Combination of fNIRS and fTCD Measurements

Faress, Ahmed 22 November 2012 (has links)
Functional neuroimaging techniques such as near-infrared spectroscopy (NIRS) have been studied in brain-computer interface (BCI) development. Previous research has suggested that the addition of a second brain-monitoring modality may improve the accuracy of a NIRS-BCI. The objective of this study was to determine whether the classification accuracies achievable by a multimodal BCI, which combines NIRS and transcranial Doppler ultrasonography (TCD) signals, can exceed those attainable using a unimodal NIRS-BCI or TCD-BCI. Nine able-bodied subjects participated in the study. Simultaneous measurements were made with NIRS and TCD instruments while participants were prompted to perform a verbal fluency task or to remain at rest, within the context of a block-stimulus paradigm. In five of nine (55.6%) participants, classification accuracies with the NIRS-TCD system were significantly higher (p<0.05) than with NIRS or TCD systems alone. Our results suggest that multimodal neuroimaging may be a promising approach towards improving the accuracy of future BCIs.
57

The Detection of Cognitive Activity within a System-paced Dual-state Selection Paradigm Using a Combination of fNIRS and fTCD Measurements

Faress, Ahmed 22 November 2012 (has links)
Functional neuroimaging techniques such as near-infrared spectroscopy (NIRS) have been studied in brain-computer interface (BCI) development. Previous research has suggested that the addition of a second brain-monitoring modality may improve the accuracy of a NIRS-BCI. The objective of this study was to determine whether the classification accuracies achievable by a multimodal BCI, which combines NIRS and transcranial Doppler ultrasonography (TCD) signals, can exceed those attainable using a unimodal NIRS-BCI or TCD-BCI. Nine able-bodied subjects participated in the study. Simultaneous measurements were made with NIRS and TCD instruments while participants were prompted to perform a verbal fluency task or to remain at rest, within the context of a block-stimulus paradigm. In five of nine (55.6%) participants, classification accuracies with the NIRS-TCD system were significantly higher (p<0.05) than with NIRS or TCD systems alone. Our results suggest that multimodal neuroimaging may be a promising approach towards improving the accuracy of future BCIs.
58

Prevalencia de ovario poliquístico en adolescentes sanas y en adolescentes con antecedentes de pubarquía precoz. Nuevas aportaciones de la ecografía tridimensional

Conde Cuevas, Nuria 27 April 2012 (has links)
La hipótesis principal del estudio es que la morfología del ovario poliquístico (MOPQ) es una marcador precoz del síndrome del ovario poliquístico (SOPQ) ya en la adolescencia. Para ello se ha diseñado un estudio descriptivo y prospectivo comparando la prevalencia de MOPQ en dos grupos de adolescentes con riesgo diferente de presentar SOPQ en la edad adulta: adolescentes sanas y adolescentes con antecedente de pubarquia precoz (PP). En la actualidad se sabe que un 50% de las adolescentes con antecedente de PP desarrollarán a partir de la menarquia el SOPQ Las hipótesis secundarias han sido: un mayor peso al nacimiento (PN) se correlaciona con mayor frecuencia de MOPQ. Y la hormona antimulleriana (AMH) es un marcador de MOPQ. La MOPQ se define según los criterios del 2003 de Balen: uno o dos de los ovarios tienen un volumen mayor a 10cc y/o ≥12 folículos. Se han aplicado estos criterios utilizando la ecografía bidimensional (2D) y la tridimensional (3D), usando en este caso el sistema VOCAL-delineación manual. También se ha estudiado la vascularización con el Doppler espectral y el power Doppler tridimensional, ya que clásicamente se ha considerado que el ovario con MOPQ está más vascularizado. Se han reclutado 21 adolescentes con PP y 41 sanas. Los dos grupos presentan una edad de la menarquia, un peso al nacimiento y un IMC similar. La prevalencia de MOPQ en adolescentes con historia de PP es similar a la de la población sin PP: 28,6% vs 17,1% respectivamente, cuando se explora con ecografía bidimensional; 52,4% vs 41,5% respectivamente, cuando se explora con ecografía tridimensional. No hay diferencias en el PN entre las adolescentes con y sin MOPQ (diagnosticada con ecografía bidimensional o tridimensional). Cuando la MOPQ se diagnostica con la ecografía bidimensional, los niveles de hormona antimulleriana son similares entre las adolescentes con y sin MOPQ. Sin embargo, cuando la MOPQ se diagnostica con ecografía tridimensional, los niveles de hormona antimulleriana son más elevados en el grupo de adolescentes con morfología de ovario poliquístico. Se han comparado los resultados obtenidos con la ecografía bidimensional y tridimensional. El volumen ovárico de las adolescentes medido con ecografía tridimensional es mayor que cuando se mide con ecografía bidimensional En las adolescentes con PP existe una correlación lineal directa entre el volumen ovárico medido con ecografía bidimensional y el peso al nacimiento. No existen diferencias en la vascularización ovárica (medida con Doppler bidimensional o tridimensional) entre las adolescentes con y sin PP. Tampoco existen diferencias en la vascularización ovárica (medida con Doppler bidimensional o tridimensional) entre las adolescentes con y sin MOPQ. / The main hypothesis is that polycystic ovarian morphology (POM) is an early marker of polycystic ovary syndrome (POS) in adolescence. It has been designed a prospective descriptive study comparing the prevalence of POM into two groups of adolescents with different risk in presenting POS in adulthood: healthy adolescents and adolescents with a history of precocious pubarche (PP). Today we know that 50% of adolescents with a history of PP will develop POS. The secondary hypotheses are: a higher birth weight (BW) correlates with increased frequency of POM. And Antimullerian Hormone (AMH) is a marker of POM. The POM is defined by the criteria of Balen, 2003: one or two of the ovaries have a volume greater than 10cc and / or ≥ 12 follicles. It has been applied these criteria using two-dimensional (2D) and three-dimensional (3D) ultrasound, using in this case the VOCAL system-manual-delineation. Increased ovarian stromal blood flow has been considered to be a parameter to assist in the ultrasound diagnosis of POM. We have studied the ovarian stromal blood flow with the color Doppler and with the three-dimensional power Doppler imaging. It has been recruited 21 adolescents with PP and 41 healthy subjects. The two groups have similar age at menarche, birth weight and body mass index. POM prevalence in adolescents with a history of PP is similar to that of the population without PP: 28.6% vs. 17.1% respectively, with 2D ultrasound, 52.4% vs 41.5% respectively, with 3D ultrasound. No differences are found in BW among adolescents with and without POM. When POM is diagnosed by B-scan, AMH levels are similar between adolescents with and without POM. However, when POM is diagnosed by 3D ultrasound, AMH levels are higher in adolescents with POM. Ovarian volume measured by three-dimensional ultrasound is higher than when measured by two-dimensional ultrasound. There are no differences in ovarian vascularization (measured by two-dimensional color Doppler or three-dimensional power Doppler) among adolescents with and without PP. There are no differences in ovarian vascularization (measured by two-dimensional color Doppler or three-dimensional power Doppler) among adolescents with and without POM.
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Evaluación del flujo sanguíneo periférico mediante ultrasonografía duplex-doppler en caballos con laminitis

Aguirre Pascasio, Carla Natali 20 February 2009 (has links)
Objetivos: Evaluar mediante la técnica ultrasonográfica duplex-Doppler (UTD) el flujo sanguíneo de la arteria digital palmar en caballos sanos, con enfermedades que predisponen a laminitis y conlaminitis clínica.Animales: Cuarenta y dos caballos distribuidos en tres grupos: Nuevecaballos sanos (Grupo I), diecinueve caballos con enfermedades quepredisponen a laminitis (Grupo II) y catorce caballos con laminitis clínica(Grupo III). El grupo de caballos enfermos y el grupo de caballos conlaminitis fueron subdivididos en subgrupos (A y B) en función de laexistencia o no de pulso digital (Grupo II) y de cambios radiológicos en latercera falange (Grupo III).Conclusiones y Relevancia clínica: La morfología del espectro Dopplerde la arteria digital palmar junto con el diámetro del vaso, el VF, la ITV y elTAC son los parámetros que más se modifican en caballos con pulsodigital con enfermedades que predisponen a laminitis y laminitis clínica. / To evaluate palmar digital artery blood flow by transcutaneous duplex Doppler ultrasonography (TDU) in healthy horses, horses with diseases those predispose to laminitis and horses with overt laminitis. Animals: Forty-two horses classified in three groups: Nine healthy horses (Group I), nineteen horses with diseases those predispose to laminitis (Group II) and fourteen horses with overt laminitis (Group III). The group of ill horses and the group of horses with overt laminitis were subdivided in subgroups (A and B) depending on the presence of digital pulse (Group II) and the existence of radiological changes in the third phalanx (Group III). Conclusions and Clinical Relevance: Doppler spectrum blood flow patters of the palmar digital artery together with diameter, VF, ITV and TAC are the more significant parameters in horses with digital pulse and diseases that predispose to laminitis and in horses with overt
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Software analytical tool for assessing cardiac blood flow parameters /

Kumar, Hemant. January 2001 (has links)
Thesis (M.Eng. (Hons.)) -- University of Western Sydney, 2001. / Bibliography : leaves [185]-195 (v. 1).

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