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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.
171

Determination of the Compressive Response of the Pediatric Thorax Utilizing System Identification Techniques

Icke, Kyle J. January 2014 (has links)
No description available.
172

A Genetic Algorithm Approach to Feature Selection for Computer Aided Detection of Lung Nodules

Sprague, Matthew J. January 2016 (has links)
No description available.
173

DETECTION AND QUANTIFICATION OF CORONARY CALCIUM FROMDUAL ENERGY CHEST X-RAYS: PHANTOM FEASIBILITY STUDY

Zhou, Bo January 2016 (has links)
No description available.
174

The evaluation of chest images compressed with JPEG and wavelet techniques

Wen, Cathlyn Y. 22 August 2008 (has links)
Image compression reduces the amount of space necessary to store digital images and allows quick transmission of images to other hospitals, departments, or clinics. However, the degradation of image quality due to compression may not be acceptable to radiologists or it may affect diagnostic results. A preliminary study was conducted using several chest images with common lung diseases and compressed with JPEG and wavelet techniques at various ratios. Twelve board-certified radiologists were recruited to perform two types of experiments. In the first part of the experiment, presence of lung disease, confidence of presence of lung disease, severity of lung disease, confidence of severity of lung disease, and difficulty of making a diagnosis were rated by radiologists. The six images presented were either uncompressed or compressed at 32:1 or 48:1 compression ratios. In the second part of the experiment, radiologists were asked to make subjective ratings by comparing the image quality of the uncompressed version of an image with the compressed version of the same image, and judging the acceptability of the compressed image for diagnosis. The second part examined a finer range of compression ratios (8:1, 16:1, 24:1, 32:1, 44:1, and 48:1). In all cases, radiologists were able to judge the presence of lung disease and experienced little difficulty diagnosing the images. Image degradation perceptibility increased as the compression ratio increased; however, among the levels of compression ratio tested, the quality of compressed images was judged to be only slightly worse than the original image. At higher compression ratios, JPEG images were judged to be less acceptable than wavelet-based images but radiologists believed that all the images were still acceptable for diagnosis. These results should be interpreted carefully because there were only six original images tested, but results indicate that compression ratios of up to 48:1 are acceptable using the two medically optimized compression methods, JPEG and wavelet techniques. / Master of Science
175

Sledování respiračních funkcí u pacientů po operaci hrudního koše dle Nusse / Monitoring of the Respiratory Functions in Patients after the Rib Cage Surgery according to Nuss

Svobodová, Jana January 2011 (has links)
Objective: The goal of the thesis "Monitoring of the Respiratory Functions in patients after the Rib Cage Surgery according to Nuss" was to confront the present knowledge about respiratory functions and the strength of respiratory muscles of patients with inherited pectoral deformity pectus excavatum, to compare it with my own measuring and to find out about their development after the surgical correction according to Nuss. Methodology: There were 15 patients being monitored (13 men and 3 women), who underwent spirometric and bodypletysmographic examination and the occlusal mouth pressures were determined before the surgery. The same pulmonary function tests were run in the course of 4 to 10 months (7.1 months on average) on all the patients, the control determination of mouth pressures is available for 13 of them. Results: In the entry tests, compared to adequate values the patients in this file had increased residual lung capacities (RV 142%, p=0.001; ITGV 116.2%, p=0.004; RV%TLC 133.8%, p=0.002; ITGV% 116.1%, p=0.001) at the expense of statistically lower vital lung capacity (VC 81.9%, p=0.0004) and inspiratory reserve capacity (IC 84.2%, p=0.0003), while the total lung capacity remained unaltered (TLC 99.7%, p=0.877). The obstructive parameters of these patients were significantly altered (FEV1 95.7%,...
176

Correlação clínica, funcional e radiológica em pacientes com fibrose cística / Clinical, functional and radiological correlations in cystic fibrosis patients

Stollar, Fabíola 09 August 2011 (has links)
Introdução: a variabilidade clínica da fibrose cística (FC) levou ao desenvolvimento de diferentes sistemas de escores de avaliação de sua gravidade. Como nem sempre é possível fazer a monitorizarão do paciente com exames radiológicos, tomográficos, funcionais e clínicos simultaneamente, o entendimento das correlações entre esses métodos é um ponto importante para que a equipe multiprofissional dos centros de FC selecione o método mais adequado na sua rotina de atendimento. Objetivo: avaliar a gravidade das alterações clínicas, estruturais e funcionais de uma população de pacientes com fibrose cística por meio de escores clínicos, radiológicos, tomográficos e testes funcionais e analisar as correlações, por pareamento entre os escores de Shwachman-Kulczychi (E-SK), Brasfield (E. Brasfield), Bhalla (E. Bhalla), espirometria e teste de caminhada de seis minutos (TC6M). Métodos: Estudo transversal prospectivo em pacientes com idade entre 3-21 anos. Foram realizados no mesmo dia: espirometria, TC6M, radiografia de tórax (RX), tomografia computadorizada (TC) de tórax e avaliação do estadio clínico. Utilizou-se a regressão linear (coeficiente de correlação de Spearman) para a análise das correlações entre os exames. Foi construída uma Curva ROC para avaliar o melhor ponto de corte para o valor de escore de Brasfield que indicaria a presença de bronquiectasias na TC. Resultados: 43 pacientes foram avaliados, 19F/24M, 10,5 ± 4,7 anos, com mediana de E. Bhalla, E. Brasfield e E-SK de 10, 17 e 70, respectivamente. Os valores médios (% previsto) de capacidade vital forçada (CVF), volume expiratório forçado no primeiro segundo (VEF1) e fluxo expiratório forçado entre 25 e 75 % da capacidade vital (FEF25-75%) foram, respectivamente, 70,4 ± 26, 59,2 ± 26, 47,4 ± 35,8. Houve correlações significativas entre quase todos os parâmetros estudados. Apenas não houve correlação estatisticamente significativa entre escore do teste de caminhada de seis minutos (Z-TC6M) e aprisionamento + mosaico (r = -0,35), VEF1 70% e E-SK (r = -0,04); VEF1 70% e E. Bhalla (r = -0,32), VEF1 70% e E. Brasfield (r = 0,14), VEF1 70% e Z-TC6M (r =0,14). Através da Curva ROC foi determinado o ponto de corte do escore de Brasfield de 18 como o de melhor sensibilidade (83%), especificidade (92%), valor preditivo positivo (96%) e valor preditivo negativo (71%) para detecção de bronquiectasias na TC de tórax. Conclusões: Nesta casuística de pacientes com fibrose cística houve uma ampla variação quanto à gravidade da doença quando avaliada por parâmetros clínicos, radiológicos, tomográficos e funcionais. Apesar desta variação, houve correlação significativa entre a maioria dos métodos utilizados no estudo. As correlações não foram significativas nos pacientes com função pulmonar normal ou com distúrbio ventilatório obstrutivo leve, o que pode estar relacionado a uma menor capacidade discriminatória entre os diferentes métodos quando o acometimento pulmonar é de grau leve. Nessa amostra estudada, pacientes com escore de Brasfield menor ou igual a 18, tiveram uma probabilidade de 83% de apresentar bronquiectasias na TC de tórax. O teste da caminhada de seis minutos se mostrou como um método complementar alternativo que pode ser utilizado na avaliação da gravidade dos pacientes com FC / Introduction: The clinical variability of cystic fibrosis (CF) led to the development of different scoring systems to evaluate its severity. As it is not always possible to simultaneously assess CF patient with radiography, tomography, functional tests and clinical status, understanding the correlations between these methods is important for the multidisciplinary team of CF centers to select the most suitable method in their routine attendance. Objective: To assess the severity of the clinical, structural and functional characteristics of a population of CF patients by means of clinical scores, chest radiography (CXR), chest tomography (CT) and pulmonary functional tests and to analyze the correlations between Shwachman-Kulczychi score (SK), Brasfield score (Brasfield), Bhalla score (Bhalla), spirometry and six minute walk test (6-MWT). Method: A cross-sectional and prospective study including patients aged 3-21 years-old. Spirometry, 6-MWT, CRX, CT and evaluation of clinical status were performed on the same day. Linear regression (Spearman correlation coefficient) was performed to analyze the correlations between the tests. A ROC curve was constructed to assess the best value for the Brasfield score that would indicate the presence of bronchiectasis on CT. Results: A total of 43 patients were evaluated, 19F/24M, 10.5 ± 4.7 years, with median Bhalla, Brasfield and SK scores of 10, 17 and 70, respectively. Mean values (% predicted) forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) were respectively 70.4 ± 26, 26 ± 59.2, 47.4 ± 35.8. There were significant correlations among almost all parameters studied. Only there was no statistically significant correlation between Z-6MWT and air trapping + mosaic perfusion (r = -0.35), FEV1 70% and SK (r = -0.04), FEV1 70% and Bhalla (r = -0.32), FEV1 70% and Brasfield (r = 0.14), FEV1 70% and Z-6MWT (r = 0.14). ROC curve determined that Brasfield score of 18 had the best sensitivity (83%), specificity (92%), positive predictive value (96%) and negative predictive value (71%) for detecting bronchiectasis on chest CT. Conclusions: These patients with cystic fibrosis had a wide variation in disease severity as assessed by clinical, radiographic, tomographic and functional scores. Despite this variation, there was a significant correlation between most methods used in the study. The correlations were not significant in patients with normal lung function or with mild obstructive lung disease, which may be related to a lower discriminate capacity between the different methods when pulmonary involvement is mild. In this study, patients with Brasfield score less than or equal to 18, had a probability of 83% to have bronchiectasis on chest CT. The six-minute walk test is a complementary method that can be used to assess the severity of patients with CF
177

Correlação clínica, funcional e radiológica em pacientes com fibrose cística / Clinical, functional and radiological correlations in cystic fibrosis patients

Fabíola Stollar 09 August 2011 (has links)
Introdução: a variabilidade clínica da fibrose cística (FC) levou ao desenvolvimento de diferentes sistemas de escores de avaliação de sua gravidade. Como nem sempre é possível fazer a monitorizarão do paciente com exames radiológicos, tomográficos, funcionais e clínicos simultaneamente, o entendimento das correlações entre esses métodos é um ponto importante para que a equipe multiprofissional dos centros de FC selecione o método mais adequado na sua rotina de atendimento. Objetivo: avaliar a gravidade das alterações clínicas, estruturais e funcionais de uma população de pacientes com fibrose cística por meio de escores clínicos, radiológicos, tomográficos e testes funcionais e analisar as correlações, por pareamento entre os escores de Shwachman-Kulczychi (E-SK), Brasfield (E. Brasfield), Bhalla (E. Bhalla), espirometria e teste de caminhada de seis minutos (TC6M). Métodos: Estudo transversal prospectivo em pacientes com idade entre 3-21 anos. Foram realizados no mesmo dia: espirometria, TC6M, radiografia de tórax (RX), tomografia computadorizada (TC) de tórax e avaliação do estadio clínico. Utilizou-se a regressão linear (coeficiente de correlação de Spearman) para a análise das correlações entre os exames. Foi construída uma Curva ROC para avaliar o melhor ponto de corte para o valor de escore de Brasfield que indicaria a presença de bronquiectasias na TC. Resultados: 43 pacientes foram avaliados, 19F/24M, 10,5 ± 4,7 anos, com mediana de E. Bhalla, E. Brasfield e E-SK de 10, 17 e 70, respectivamente. Os valores médios (% previsto) de capacidade vital forçada (CVF), volume expiratório forçado no primeiro segundo (VEF1) e fluxo expiratório forçado entre 25 e 75 % da capacidade vital (FEF25-75%) foram, respectivamente, 70,4 ± 26, 59,2 ± 26, 47,4 ± 35,8. Houve correlações significativas entre quase todos os parâmetros estudados. Apenas não houve correlação estatisticamente significativa entre escore do teste de caminhada de seis minutos (Z-TC6M) e aprisionamento + mosaico (r = -0,35), VEF1 70% e E-SK (r = -0,04); VEF1 70% e E. Bhalla (r = -0,32), VEF1 70% e E. Brasfield (r = 0,14), VEF1 70% e Z-TC6M (r =0,14). Através da Curva ROC foi determinado o ponto de corte do escore de Brasfield de 18 como o de melhor sensibilidade (83%), especificidade (92%), valor preditivo positivo (96%) e valor preditivo negativo (71%) para detecção de bronquiectasias na TC de tórax. Conclusões: Nesta casuística de pacientes com fibrose cística houve uma ampla variação quanto à gravidade da doença quando avaliada por parâmetros clínicos, radiológicos, tomográficos e funcionais. Apesar desta variação, houve correlação significativa entre a maioria dos métodos utilizados no estudo. As correlações não foram significativas nos pacientes com função pulmonar normal ou com distúrbio ventilatório obstrutivo leve, o que pode estar relacionado a uma menor capacidade discriminatória entre os diferentes métodos quando o acometimento pulmonar é de grau leve. Nessa amostra estudada, pacientes com escore de Brasfield menor ou igual a 18, tiveram uma probabilidade de 83% de apresentar bronquiectasias na TC de tórax. O teste da caminhada de seis minutos se mostrou como um método complementar alternativo que pode ser utilizado na avaliação da gravidade dos pacientes com FC / Introduction: The clinical variability of cystic fibrosis (CF) led to the development of different scoring systems to evaluate its severity. As it is not always possible to simultaneously assess CF patient with radiography, tomography, functional tests and clinical status, understanding the correlations between these methods is important for the multidisciplinary team of CF centers to select the most suitable method in their routine attendance. Objective: To assess the severity of the clinical, structural and functional characteristics of a population of CF patients by means of clinical scores, chest radiography (CXR), chest tomography (CT) and pulmonary functional tests and to analyze the correlations between Shwachman-Kulczychi score (SK), Brasfield score (Brasfield), Bhalla score (Bhalla), spirometry and six minute walk test (6-MWT). Method: A cross-sectional and prospective study including patients aged 3-21 years-old. Spirometry, 6-MWT, CRX, CT and evaluation of clinical status were performed on the same day. Linear regression (Spearman correlation coefficient) was performed to analyze the correlations between the tests. A ROC curve was constructed to assess the best value for the Brasfield score that would indicate the presence of bronchiectasis on CT. Results: A total of 43 patients were evaluated, 19F/24M, 10.5 ± 4.7 years, with median Bhalla, Brasfield and SK scores of 10, 17 and 70, respectively. Mean values (% predicted) forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced expiratory flow between 25 and 75% of vital capacity (FEF25-75%) were respectively 70.4 ± 26, 26 ± 59.2, 47.4 ± 35.8. There were significant correlations among almost all parameters studied. Only there was no statistically significant correlation between Z-6MWT and air trapping + mosaic perfusion (r = -0.35), FEV1 70% and SK (r = -0.04), FEV1 70% and Bhalla (r = -0.32), FEV1 70% and Brasfield (r = 0.14), FEV1 70% and Z-6MWT (r = 0.14). ROC curve determined that Brasfield score of 18 had the best sensitivity (83%), specificity (92%), positive predictive value (96%) and negative predictive value (71%) for detecting bronchiectasis on chest CT. Conclusions: These patients with cystic fibrosis had a wide variation in disease severity as assessed by clinical, radiographic, tomographic and functional scores. Despite this variation, there was a significant correlation between most methods used in the study. The correlations were not significant in patients with normal lung function or with mild obstructive lung disease, which may be related to a lower discriminate capacity between the different methods when pulmonary involvement is mild. In this study, patients with Brasfield score less than or equal to 18, had a probability of 83% to have bronchiectasis on chest CT. The six-minute walk test is a complementary method that can be used to assess the severity of patients with CF
178

Röntgen-Thorax-Aufnahmen zur radiologischen Quantifizierung des Lungenödemsbei Patienten mit Akutem Atemnotsyndrom des Erwachsenen (ARDS)

Zippler, Anke 07 May 1999 (has links)
Das ARDS gilt, trotz verschiedenster Möglichkeiten der intensivmedizinischen Therapie, immer noch als die schwerste Form einer Lungenparenchymverletzung mit einer hohen Letalität. Zu Beginn der Erkrankung zeigt sich eine große Diskrepanz zwischen zunehmender Hypoxie und blandem Röntgen-Thorax-Befund. Die Röntgen-Thorax-Aufnahme bildet somit einen wichtigen diagnostischen Bestandteil. Die Kriterien einer einfachen Durchführung, guten Reproduzierbarkeit, hohen Aussagekraft und der Möglichkeit einer Verlaufsbeurteilung machen die Röntgen-Thorax-Liegendaufnahme zu einem wichtigen Bestandteil der intensivmedizinischen Diagnostik. Untersucht wurden retrospektiv 1575 Röntgen-Thorax-Aufnahmen von 33 Patienten mit dem Krankheitsbild des ARDS. Das Patientenkollektiv setzte sich aus 14 Frauen und 19 Männern im Alter von 12 bis 63 Jahren zusammen. Die Überlebensrate des untersuchten Patientenkollektives betrug 87,9%. Pro Patient wurden durchschnittlich 48 Röntgen-Thorax-Aufnahmen (zwischen 10 und 148 Aufnahmen) angefertigt. Die Aufnahmen wurden im Hinblick auf ihre Qualität, Strahlenexposition und ihre Übereinstimmung mit klinischen Parametern untersucht. Für die Beurteilung der Inter- und Intraobservervariabilität wurden verschiedenen Untersuchern 60 Röntgen-Thorax-Aufnahmen exemplarisch zur Bewertung vorgelegt. Aufgrund der schwierigen Aufnahmebedingungen bei Intensivpatienten sind verdrehte und verkippte Röntgen-Thorax-Aufnahmen nicht zu vermeiden. Trotz dieser Qualitätseinbußen ist ihr Informationsgehalt ein wichtiges Kriterium der intensivmedizinischen Diagnose und Therapie. Die Strahlenexposition der Röntgen-Thorax-Liegendaufnahmen und der daraus zu errechnende Lebenszeitverlust sind im Hinblick auf die Schwere und die hohe Letalität der Grunderkrankung als verschwindend gering zu betrachten. Die Röntgen-Scores nach Murray, Morel, Miniati, Rommelsheim und Ostendorf sind in der Diagnostik und Verlaufsbeurteilung des ARDS weit verbreitet. Sie sind in Handhabung und Gewichtung der Veränderungen jedoch sehr unterschiedlich. Zusammenhänge zwischen klinischen Parametern konnten für alle Scores, sowie für einen neuen Score beobachtet werden. Dabei ergaben sich für alle Scores ähnliche Beziehungen. Unter Berücksichtigung der Handhabung der einzelnen Röntgen-Scores, der Inter- und Intraobservervariabilität, sowie der Übereinstimmung mit klinischen Parametern sind der Röntgen-Score nach Rommelsheim, sowie der neue Röntgen-Score für den klinischen Alltag zu empfehlen. / Radiological Quantification of Chest X-Rays of the Lung Oedema of Patients with Adult Respiratory Distress Syndrome (ARDS) The ARDS is still regarded as the most serious form of lung parenchyma injury with a high lethality in spite of various possibilities of intensive care therapies. In the beginning of the illness a high discrepancy between an increasing hypoxia and a mostly inconspicouos chest X-ray result can be observed. Therefore, the chest X-ray forms an essential part of the diagnostic basis. It is characterized by simple implementation, a good reproducibility, a high meaningfulness and the possibility to judge the course of the illness. This makes the chest X-ray very valuable for the intensive care diagnosis. 1575 chest X-rays from 33 patients with ARDS symptoms were evaluated. The patients consisted of 14 women and 19 men between 12 and 63 years of age. The overall survival rate for all patients was 87.9%. An average of 48 (ranging from 10 to 148) chest X-rays were taken per patient. They were examined with regard to quality, radiation dose and correspondence to clinical variables. In order to judge the interobserver and intraobserver variability 60 chest X-rays were evaluated by different examiners. Due to the difficult conditions while taking the chest X-rays distorted and tilted chest X-rays cannot be avoided. Despite this loss of quality their content of information is an important criterion for the intensive care diagnosis and treatment. The loss of lifetime due to the radiation dose received can be ignored compared to the severeness and the high lethality of the basic illness. The chest X-ray scores according to Murray, Morel, Miniati, Rommelsheim and Ostendorf are commonly used for diagnostic purposes and to judge the course of the ARDS. However, their handling and their weightning of changes varies a lot. Correlations between all scores, a new score and the clinical variables were observed. All scores, including the new score, showed similar relations between the score ranking and the clinical variables. Considering the handling of the different chest X-ray scores, their interobserver and intraobserver variability and their correlation to clinical variables the chest X-ray score according to Rommelsheim and the new score can be recommended for daily use.
179

Beslag eller buckla? : En studie av platta järnfragment från hallhuset i Birkas Garnison

Bäckheden, Anna January 2006 (has links)
<p>This paper deals with flat iron fragments from the Viking Age hall situated in Birkas Garrison, Adelsö parish in Uppland. The aim of the study was to identify which objects these flat fragments were originally derived from. The aim was also to discuss the function of these objects and their presence in the hall. This would hopefully increase the knowledge about the hall and the warriors who lived and worked there. In some cases the fragments form and placement in the hall has not provided enough information to classify the object from which they derived. Where it has been possible, a majority of the fragments has been interpreted as parts of chest mounts or shield buckles. The result of the analysis shows the possibility of a large chest having once stood in the southwest corner of the hall.</p>
180

Testovani embryotoxicity psychofarmak metodou CHEST / Embryotoxicity testing of psychopharmacs using the CHEST method

Pavlovič, Ondřej January 2014 (has links)
Psychotropic drugs are commonly used group of pharmaceuticals, their main effect is to alter psychic condition, including mental diseases treatment. Symptoms of mental illnesses are more and more common, theref orenumber of patients diagnosed with mental illnes, and thus using psychotropics, is growing stronger. But using psychotropics during gestation is not without risks for mother and embryo itself. However, thanks to the absence of controlled human studies, the knowledge of emrbyotoxic effects of pschotropics is limited to casuistics, reported side effects and animal experimental studies. Many of those studies suggests emrbyotoxic potential of psychotropic drugs, on the other hand, others claim their safety. The goal of this thesis is to test at least some of them, using CHEST method, that allows us to observe direct effect of unmetabolized substance on chick embryo. In this thesis we tested selected psychotropics, very common antidepressant fluoxetine (prozac) and antipsychotic drug olanzapine, for embryotoxicity, using in ovo method CHEST with chick embryos as model organism. By bypassing the maternal organism and his metabolism, this method allows to observe direct effect of unmetabolized substance on chick embryo. Results revealed embryotoxic effect of fluoxetin in dosage 10-2 and 10-3 on 3rd and...

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