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Yoshimaru, Eriko Suzanne. "Magnetic Resonance Imaging Techniques for Rodent Pulmonary Imaging." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293388.
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Magnetic Resonance Imaging (MRI) is a safe and widely used diagnostic imaging method that allows in vivo observation of anatomy and characterization of tissues. MRI provides a method to monitor patients without invasive measures, making it suitable for both diagnostics and longitudinal monitoring of various pathologies. A notable example of this is the work carried out by the Alzheimer's Disease Neuroimaging Initiative (ADNI), which utilizes imaging, including multiple MRI techniques, to monitor disease progression in AD patients and evaluates treatment responses and prevention strategies. Similarly, MRI has been extensively used in evaluating diseases in a variety of animal models. In order to detect subtle anatomical changes over time, small differences in MR images must be accurately extracted. Furthermore, to ensure that the extracted differences are due to anatomical changes rather than equipment variance, it becomes essential to monitor and to assess the MRI system stability. In the first chapter of the dissertation, a method for monitoring pre-clinical MRI system performance is discussed. The technique developed during the study provides a fast and simple method to monitor pre-clinical MRI systems but also has applications for all areas of MRI. The second chapter describes the development of a 3D UTE MRI method for pulmonary imaging in freely breathing mice. The development of the 3D UTE sequence for pulmonary MRI has demonstrated its ability to collect images without noticeable motion artifacts and with appreciable signal from the lung parenchyma. Furthermore, images at two distinct respiratory phases were reconstructed from a single data set, providing functional information of the rodents' lungs. Finally, in the third chapter, 3D ¹⁹F UTE MRI is evaluated for imaging in vivo distributions of perfluorocarbon (PFC) nanoemulsions for measuring pulmonary inflammation. Building upon the development of pulmonary imaging, fluorinated contrast agents made from PFCs were used to target immune cells in response to pulmonary pathology. Both 3D ¹H and ¹⁹F UTE MRI were used to acquire pulmonary images of mouse models documented to have pulmonary pathology. Even though the mice had confirmed elevation in alveolar macrophage counts, no visible ¹⁹F signal accumulation within the pulmonary tissue was observed with MRI.
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Saba, Tarek Sami. "The assessment of pulmonary haemodynamics with magnetic resonance imaging in pulmonary hypertension." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/29346.
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In this thesis we set out to investigate whether anatomical and blood flow measurements made with MRI can detect and quantify raised pulmonary artery pressure at cardiac catheterisation. We then looked to see whether MRI has any advantages over Doppler echocardiography, the current gold standard non-invasive investigation. We enrolled twenty-eight subjects who were undergoing cardiac catheterisation and Doppler echocardiography for investigation of suspected pulmonary hypertension at the Scottish Pulmonary Vascular Unit between September 1999 and March 2001. We used MRI to measure right and left ventricular mass, volume, and wall thickness, and aortic and pulmonary artery diameter. We calculated a novel ventricular mass indeed by dividing right ventricular mass by left ventricular mass. We then performed a flow quantification in the right pulmonary artery to measure mean and peak velocity of blood flow, acceleration time and ejection time, and calculated the ratio of acceleration time over ejection time. Finally we attempted to study the changes in these variables following straight leg raising exercise. In summary, we have shown that anatomical measurements made in the cardiopulmonary circulation with MRI can be used to estimate pulmonary artery pressure with greater accuracy than doppler echocardiography. These estimates are likely to be more reliable than those provided by echocardiography, and may also give a measure of the recent burden of pulmonary vascular disease. An analogy may be made with the use of glycosylated haemoglobin instead of glucose in diabetes; pulmonary artery pressure fluctuates on a minute by minute basis whereas anatomical measurements reflect sustained changes in pulmonary haemodynamics. Furthermore, we have shown that MRI measurements of blood flow are sensitive and specific indicators of pulmonary hypertension, and can be used to study exercise-related changes in blood flow.
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Schuessler, Thomas Florian. "Advances in pulmonary monitoring and thoracic imaging." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34444.
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The high incidence of pulmonary disease in critically ill patients necessitates new and improved techniques for pulmonary monitoring and thoracic imaging. To investigate pulmonary monitoring techniques using pressure and flow signals, I developed a comprehensive computational model of subjects breathing spontaneously or with the support of an assist-ventilator. The model was used to quantitatively assess measurement techniques for dynamic intrinsic positive end-expiratory pressure (PEEP$ rm sb{i})$ and inspiratory work of breathing. The results demonstrate that some means of correction for both expiratory muscle activity and cardiogenic oscillations on esophageal pressure is necessary if dynamic PEEP$ rm sb{i}$ and work of breathing are to be measured accurately on-line. I also conclude that the discrepancies between static and dynamic PEEP$ rm sb{i}$ are caused by heterogeneity of the expiratory flow limitation. An adaptive filter to reduce the cardiogenic oscillations on esophageal pressure was developed and validated in a computer simulation. In four intensive care patients, the adaptive filter markedly attenuated the apparent cardiogenic oscillations and reduced the standard deviation of the measured PEEP$ rm sb{i}$ by 57%. Investigation of the interactions between patients and a pressure support ventilator using the computer model confirmed our present understanding of patient-ventilator asynchrony and indicated that patient and ventilator form a highly nonlinear dynamic system, so that the optimal ventilator settings most likely vary between patients and with time. In the second part of this thesis, I investigated the importance of inaccuracies in conventional Finite Elements for thoracic Electrical Impedance Tomography (EIT) imaging. Augmenting the number of first-order Finite Elements did not efficiently reduce these inaccuracies. A computer simulation suggested that the accuracy of the forward solution needs to be improved by at least 30 dB before useful
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Schuessler, Thomas F. "Advances in pulmonary monitoring and thoracic imaging." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ30376.pdf.
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Van, Tassel Lora. "Imaging Evaluation of the Solitary Pulmonary Nodule." Thesis, The University of Arizona, 2012. http://hdl.handle.net/10150/221418.
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A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine.An estimated 150,000 solitary pulmonary nodules (SPNs) are identified at chest radiography each year, making it important for physicians to understand how to characterize them and evaluate patients for potential malignancy. We performed an extensive literature search to identify risk factors, characteristics of SPNs, and available technologies used to identify and evaluate these nodules through a comprehensive literature search. Additionally, we present evidence-based management schemes for incidentally identified nodules. CONCLUSIONS: A number of features visible at thoracic CT are useful for determining whether an SPN is benign or malignant. FDG PET/CT plays an important role in the diagnosis and management of lung cancer and is an increasingly valuable tool for the characterization and management of SPNs. Unlike CT and MRI imaging, PET provides metabolic activity of a nodule. The information provided by PET/CT imaging allows for both morphological and anatomical characteristics as well as physiological data in the form of metabolism within the nodule itself. The information gained from PET is extremely useful for directing patient management and may obviate the need for invasive diagnostic procedures.
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Johns, Christopher. "Improving the diagnostic pathway of pulmonary hypertension using cardio-pulmonary magnetic resonance imaging." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/20207/.
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Whilst pulmonary hypertension is a relatively uncommon condition, it is associated with a poor quality of life and poor survival. It is therefore important that we correctly identify patients who suffer from pulmonary hypertension, assess the underlying cause (an essential step for treatment) and seek those who are at risk of death. Current guidelines centre on right heart catheterisation as the recommended tool to answer these important clinical questions. Since it was first described in the mid-1950s, there have been significant improvements in the survival of patients with pulmonary hypertension, mainly due to the introduction of vasodilator therapies and surgical procedures. There have been parallel improvements in imaging technologies, the most tangible of which is cardiac MRI, allowing time resolved assessment of cardiac structure and function. Despite these improvements in non-invasive methodologies, there remains heavy reliance upon invasively measured pressures and flow for the diagnosis, phenotyping and assessment of risk in patients with pulmonary hypertension. The aim of this PhD thesis is to evaluate, and hopefully increase, the role of cardio pulmonary vascular MRI in the non-invasive assessment of pulmonary hypertension. I show that cardiac MRI metrics, particularly when combined in a regression model, are able to predict mean pulmonary arterial pressure. Such models are able to identify with reasonable accuracy the presence of pulmonary hypertension in patients referred to a tertiary referral centre. The role of cardio-pulmonary MRI in the assessment of the underlying group of pulmonary hypertension, such as chronic thrombo-embolic pulmonary hypertension and PH-left heart disease, is then explored as identification of patients who may respond to PH specific therapy is an important step. Finally, the role of MRI in the assessment of prognosis, concentrating specifically on patients with PH left heart disease and PH in patients with chronic obstructive pulmonary disease is assessed.
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McLeod, Karen A. "Intravascular ultrasound and magnetic resonance imaging of the pulmonary arteries in pulmonary hypertension." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/28597.
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The main aim of this thesis is to describe the changes which are detectable on intravascular ultrasound and magnetic resonance imaging in patients with pulmonary hypertension and to determine whether these imaging modalities could be of use for the clinical assessment of the condition. Intravascular ultrasound was performed in 10 young adults with Eisenmenger's Syndrome and 4 infants with pulmonary hypertension secondary to a left to right shunt. Vasodilator studies were performed in 5 of the patients with Eisenmenger's. The vessel wall appeared as a single echogenic layer in all patients making it difficult to define or measure medial thickness with certainty. Morphological changes of intimal hypertrophy and atherosclerosis were evident in patients with Eisenmenger's whereas in the infants the intima appeared thin and smooth, typical of normal artery. The technique gave excellent definition of the vessel lumen allowing continuous measurement of changes in luminal dimensions in response to vasodilators. MRI of the pulmonary arteries was performed in 11 patients with Eisenmenger's and 6 normal controls. In patients with pulmonary hypertension the pulmonary arteries were found to be dilated with reduced distensibility when compared with normals. Calculations of Qp:Qs by MRI in patients with systemic to pulmonary shunts and pulmonary hypertension did not correlate well with values from cardiac catheterisation in all patients. In conclusion, magnetic resonance imaging was found to have limited role in the assessment of pulmonary hypertension but with new technical developments could become a non-invasive method of studying pulmonary hypertension in the future. The morphological changes detectable by intravascular ultrasound tend to be in severe disease only but the technique provides a unique method of studying pulmonary vascular reactivity in life.
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Wang, Lei. "FDG-PET imaging of pulmonary vascular remodelling in PAH." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/58197.
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Pulmonary artery hypertension (PAH) is a disease of progressive pulmonary vascular remodelling characterised by dysregulated proliferation and inflammation. With increasing acceptance that glucose metabolism is perturbed in proliferating and inflammatory cells in PAH, the present thesis took interest in the application of molecular 18F-2-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) imaging, widely used in the oncology clinic, in the assessment of PAH patients. Our hypothesis is that FDG-PET imaging can be used as a potential tool for the in vivo assessment of pulmonary vascular remodelling and evaluation of anti-remodelling therapies in PAH. In the first part of the thesis, a clinical applicable dynamic FDG-PET acquisition protocol with kinetic Patlak analysis was assessed in idiopathic PAH (IPAH) patients and PAH associated with systemic lupus erythematosus (SLE-PAH) patients for detection and quantification of lung FDG uptake. Mean lung FDG uptake was increased in both IPAH and SLE-PAH patients compared to that in healthy controls. There was heterogeneity of lung FDG uptake within PAH population, which aligns with our current understanding of the complex and regional pathology in PAH. Lung FDG uptake of SLE-PAH patients significantly correlated with SLE disease activity markers. In the following in vivo FDG-PET study, treatments with liraglutide and tacrolimus significantly attenuated the increased pulmonary artery pressure and right heart hypertrophy, as well as pulmonary vascular muscularisation and inflammatory cell infiltration in monocrotaline-induced PAH rat models, accompanied by a decreased lung FDG uptake. These data support further evaluation of the use of FDG-PET as a potential tool for evaluating these therapies in clinical trials. We learnt that FDG-PET imaging lacks specificity to differentiate proliferation from inflammation as an underlying disease process. Future development of other PET tracer may help to identify a marker that interrogates the pulmonary pathology of interest.
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Walvick, Ronn P. "Magnetic Resonance Imaging of Neural and Pulmonary Vascular Function." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-dissertations/372.
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"Magnetic resonance imaging (MRI) has emerged as the imaging modality of choice in a wide variety experimental and clinical applications. In this dissertation, I will describe novel MRI techniques for the characterization of neural and pulmonary vascular function in preclinical models of disease. In the first part of this dissertation, experimental results will be presented comparing the identification of ischemic lesions in experimental stroke using dynamic susceptibility contrast (DSC) and a well validated arterial spin labeling (ASL). We show that DSC measurements of an index of cerebral blood flow are sensitive to ischemia, treatment, and stroke subregions. Further, we derived a threshold of cerebral blood flow for ischemia as measured by DSC. Finally, we show that ischemic lesion volumes as defined by DSC are comparable to those defined by ASL. In the second part of this dissertation, a methodology of visualizing clots in experimental animal models of stroke is presented. Clots were rendered visible by MRI through the addition of a gadolinium based contrast agent during formation. Modified clots were used to induce an experimental embolic middle cerebral artery occlusion. Clots in the cerebral vasculature were visualized in vivo using MRI. Further, the efficacy of recombinant tissue plasminogen activator (r-tPA) and the combination of r-tPA and recombinant annexin-2 (rA2) was characterized by clot visualization during lysis. In the third part of this dissertation, we present results of the application of hyperpolarized helium (HP-He) in the characterization of new model of experimental pulmonary ischemia. The longitudinal relaxation time of HP-He is sensitive to the presence of paramagnetic oxygen. During ischemia, oxygen exchange from the airspaces of the lungs to the capillaries is hindered resulting in increased alveolar oxygen content which resulted in the shortening of the HP-He longitudinal relaxation time. Results of measurements of the HP-He relaxation time in both normal and ischemic animals are presented. In the final part of this dissertation, I will present results of a new method to measure pulmonary blood volume (PBV) using proton based MRI. A T1 weighted, inversion recovery spin echo sequence with cardiac and respiratory gating was developed to measure the changes in signal intensity of lung parenchyma before and after the injection of a long acting intravascular contrast agent. PBV is related to the signal change in the lung parenchyma and blood before and after contrast agent. We validate our method using a model of hypoxic pulmonary vasoconstriction in rats."
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Miele, Amy Caroline. "Comparative pulmonary fibrosis : imaging fibroproliferation in donkey and man." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/17885.
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Pulmonary fibrosis is a chronic and debilitating condition that proposes several challenges to both veterinary and medical clinicians. Despite considerable research, many fibrotic lung diseases remain elusive in terms of aetiology, pathogenesis and treatment. Furthermore, progress is hindered by the lack of a translatable animal model with durable and persistent fibrosis. Asinine Pulmonary Fibrosis (APF) is a spontaneous syndrome of aged donkeys with high prevalence (35%). No previous detailed characterisation of APF has been performed and disease diagnosis remains a challenge. APF was studied with regard to clinical, pathological and molecular features and the suitability of this condition as a model for a rare fibrotic lung disease in humans known as pleuroparenchymal fibroelastosis (PPFE) was assessed. In addition, target activatable optical imaging reagents for the real time detection of two key molecular markers of fibrosis: matrix metalloproteinases (MMPs) and lysyl oxidases (LOXF) were evaluated in spontaneous ex vivo models of fibrosis. Such reagents may be used alongside fibred confocal fluorescence microscopy (FCFM), a relatively noninvasive and cutting edge diagnostic tool, to detect and monitor fibroproliferation in animals and man. Whole lungs were collected from 32 aged donkeys at routine necropsy. Gross examination revealed pulmonary fibrosis in 19 donkeys (APF cases), while 13 (controls) had grossly normal lungs. HRCT images and histology sections were reviewed independently and blindly for each of the lungs. Ten of 19 APF lungs were categorised as being ‘consistent with’ PPFE according to previously defined histological and imaging criteria. All 10 PPFE-like lungs had marked pleural and subpleural fibrosis, predominantly within the upper lung zone, with accompanying intra-alveolar fibrosis and elastosis. An activatable Smartprobe for the detection of LOXF, TWB-219, was synthesised by The Bradley Group, Department of Chemistry (UoEDC). The probe was based on a tandem amine oxidation and β-elimination mechanism, resulting in signal amplification detected at the 488nm wavelength. The probe showed increased fluorescence in the presence of diamine oxidase as well as on incubation with aged human lung tissue cell-free homogenate as determined by a fluorescent plate reader. This signal amplification could be inhibited by β-aminopropionitrile, a recognised LOX inhibitor as well as by an in-house inhibitor specific to LOX. An evolutionary family of MMP probes with varying cleavage sequences and structures, synthesised by the UoEDC, was evaluated at each stage of progression with regard to signal to noise ratio, sensitivity and specificity. Probes were tested against recombinant enzymes from the MMP family as well as neutrophil elastase and plasmin. Signal amplification was also assessed on incubation with human and ovine ex vivo lung tissue. The final ‘lead’ MMP probe, SVC-186, was cleaved by MMP-2, -9 and -13. Signal amplification was also seen following incubation with both human and ovine tissue with significant inhibition in the presence of the pan- MMP inhibitor, marimastat. In conclusion, APF is an emerging condition of aged donkeys that shares key pathological and imaging features with human PPFE. Diagnosis of APF and other fibrotic lung conditions across species remains a challenge to veterinary and medical professionals. As such, optical imaging tools may provide dynamic, real time information on the presence and progression of fibroproliferation in the lung. TWB- 219 and SVC-186 produce a detectable increase in fluorescent signal at the 488nm wavelength when activated by LOXF and MMPs respectively. These probes have been shown to function in human ex vivo tissue as assessed by FCFM.
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Rajaram, Smitha. "Imaging in pulmonary hypertension : the role of MR and CT." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/6959/.
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Pulmonary hypertension (PH) is a debilitating disease with many causes that has a significant impact on quality of life and results in premature death. Until recently imaging has only played an adjunctive role to primary diagnostic modalities such as echocardiography and right heart catheterization in identifying these patients. The advent of newer imaging techniques and developments in hardware has opened up a new scope for imaging. CT offers excellent structural detail while MRI provides superb functional information without the risk of radiation. These modalities now offer a robust and in-depth diagnostic approach for the investigation of patients with suspected pulmonary hypertension. This document explores the role of MR and CT imaging methods in investigating patients with pulmonary vascular disease and different aspect of lung disease. In particular, subgroups of pulmonary hypertension associated with unique morphological changes have been closely scrutinized. In this work the value of MR angiography in patients suspected with chronic thromboembolic pulmonary hypertension or unexplained PH has been explored and in the same subgroup of patients, the role of 3D MR lung perfusion as a diagnostic tool has also been demonstrated. This research has also shown that the thoracic CT offers valuable prognostic information and imaging characteristics in patients with each of the major subcategories of pulmonary arterial hypertension. Furthermore, the diagnostic accuracy and prognostic significance of MR and CT indices for the detection of PH in patients with connective tissue disease associated with PH has been highlighted. Finally, the feasibility and diagnostic quality of MRI to identify structural parenchymal lung changes have also been analysed and this study demonstrates the potential clinical utility of imaging high risk patients with MRI in longitudinal studies thereby avoiding the hazards of radiation exposure.
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Swift, Andrew J. "Developing the role of magnetic resonance imaging in pulmonary hypertension." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/3216/.
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Jasinowodolinski, Dany. "Estudo da perfusão pulmonar por angiotomografia computadorizada em pacientes com hipertensão pulmonar." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5150/tde-01122014-144947/.
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Introdução: A hipertensão arterial pulmonar (HAP) é uma doença grave da circulação pulmonar, cujo diagnóstico e cuja avaliação funcional dependem do cateterismo cardíaco direito. A tomografia de dupla energia (TCDE), por meio da técnica de decomposição de materiais, permite obter um mapa de Iodo do parênquima pulmonar, que pode ser avaliado de forma qualitativa e quantitativa, e pode ser útil na avaliação da HAP. Objetivos: Avaliar a distribuição de Iodo no parênquima pulmonar, comparando com marcadores hemodinâmicos, marcadores de gravidade e com grupo-controle normopressórico. Métodos: Pacientes com HAP, acompanhados na Unidade de Circulação Pulmonar (InCor-HCFMUSP), foram avaliados por angiotomografia das artérias pulmonares (angioTC) como parte de sua rotina diagnóstica, em modo de dupla energia. O grupo-controle foi composto por pacientes com suspeita clínica de tromboembolismo pulmonar (TEP), com angioTC negativa para TEP e com ecocardiograma normal. Foram avaliadas as concentrações de Iodo no pulmão (mg/mL) por meio de 8 regiões de interesse redondas com 1 cm2 de área, distribuídas ao longo do eixo ântero-posterior do pulmão direito, em 3 níveis predeterminados. Foram obtidas, também, as medidas do ventrículo direito (VD), ventrículo esquerdo (VE), razão VD/VE, diâmetros da aorta (AO) e artéria pulmonar (AP). O realce da artéria pulmonar por meio da TCDE (PAenh) também foi obtido. Os resultados foram comparados entre os grupos, e correlacionados no grupo HAP com parâmetros hemodinâmicos invasivos e marcadores de gravidade. Resultados: O grupo HAP foi composto por 21 pacientes, com idade média de 42 anos, 47,6% em classe funcional I/II. Houve diferença significativa nos diâmetros da AP (p<0,01), VD (p<0,01), e VE (p=0,01), entre os grupos HAP e controle. Também demonstraram diferenças significativas às relações entre os diâmetros AP/AO (p < 0,01) e VD/VE (p < 0,01), entre os grupos. Calibre da artéria pulmonar maior do que 2,9 cm e relação AP/AO maior do que 1,1 cm demonstraram sensibilidade de 90,5% e 87,5%, e especificidade de 100% para o diagnóstico de HP. A PAenh não demonstrou diferenças significativas entre os grupos HAP e controle, contudo se correlacionou significativamente com a medida do débito cardíaco no grupo HAP (r=-0,661, p=0,01). A PAPm demonstrou correlação com a relação AP/AO (r=0,676) e, também, com a relação VD/VE (r=0,679), ambas com p < 0,01. A concentração de Iodo no parênquima foi significativamente menor no grupo HAP em todos os segmentos analisados. O mapa de Iodo demonstrou gradiente progressivo da concentração de Iodo no parênquima pulmonar, de caráter ântero-posterior, em ambos os grupos, de magnitude significativamente menor no grupo HAP. Usando-se o valor de PAenh para correção das medidas de concentração de Iodo, deixa de haver diferença entre os grupos HAP e controle. Conclusões: A TCDE, além das medidas anatômicas obtidas pela técnica convencional, permitiu demonstrar a manutenção do gradiente ântero-posterior da concentração de Iodo em pacientes com HAP, sugerindo que sua menor magnitude seja determinada pelo baixo débito cardíacoBackground: Pulmonary arterial hypertension (PAH) is a severe disease of the pulmonary circulation. Right heart catheterization (RHC) is crucial for diagnosis and management of these patients. High-resolution computed tomography (CT) and CT angiography play a crucial role in the diagnostic work-up of pulmonary hypertension. Dual energy computed tomography (DECT) is a technique of acquisition of modern CT scanners that allows obtaining a computed tomography of the pulmonary arteries with low iodine dose, and providing an estimation of iodine distribution in the lungs. Although the search for non-invasive methods for evaluation of PAH is developing, data concerning application of DECT on PAH patients remain scarce. Objectives: To evaluate the iodine distribution in the lungs obtained by DECT in PAH patients and a control group and compare to the hemodynamic profile, and prognostic markers of PAH patients. Methods: 21 patients followed at the Pulmonary Circulation Unit (InCor-HCFMUSP) and submitted to CT angiography were evaluated by DECT. A matched control group was composed by patients routinely referred to CT angiography to rule out pulmonary embolism with negative results and also a normal echocardiogram obtained at the same day. Eight circular 1cm2 ROIs were placed along the anteroposterior axis, at the middle of the right lung and at predetermined levels to measure the Iodine concentration in the lungs. Measurements of the pulmonary artery (PA), ascending aorta (AO), right ventricle (RV) and left ventricles (LV) were obtained, as well as enhancement of the PA (PAenh). Results were compared to the control group, and correlated with hemodynamic parameters in the PAH group. Results: PAH patients averaged 42 y/o, female/male ratio of 7/1, NYA functional classes I/II. Statistically significant differences between PAH patients and controls were found regarding measurements of PA (p < 0,01), RV (p < 0,01), LV (p=0,01), PA/AO (p < 0,01) and RV/LV (p < 0,01). PA diameter greater than 2,9 cm and PA/AO ratio greater 1,1 were diagnostic for pulmonary hypertension with sensitivity/specifity of 90,5%/100% and 87,5%/100%. PAenh showed no statistical difference between PAH patients and controls . A characteristic anteroposterior Iodine concentration gradient was found in all subjects, both PAH patients showed lower Iodine concentration diffusely (p < 0,01). When corrected by PAenh, Iodine gradients showed no statistical difference between PAH patients and controls. PAenh correlates with cardiac output (r=-0,661), and mPaP correlates with PA/AO ratio (r=0,676), RV/LV ratio VD/VE ratio (r=0,679), and p<0,01. Conclusion: Anteroposterior Iodine concentration gradient is preserved in PAH in comparison with controls, but with lower magnitude. This difference was corrected through the multiplication of individual Iodine measurements by PAenh, suggesting that this could be explained by lower blood flow to the lungs of PAH patients. PAenh correlates with cardiac output, mean pulmonary arterial pressure correlates with PA/AO and RV/LV in PAH patients. DECT provided conventional anatomic measurements and allowed the characterization of preserved anteroposterior Iodine gradients in PAH patients, with decreased magnitude in comparison with controls, that could be atributed to a lower CO of these patients
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Nilsson, Tage. "Pulmonary embolism : validation of diagnostic imaging methods in the clinical setting /." Stockholm : Karolinska institutets bibl, 2002. http://diss.kib.ki.se/2002/91-7349-346-5.
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Blyth, Kevin G. "Magnetic resonance imaging of the right ventricle in human pulmonary hypertension." Thesis, Connect to e-thesis, 2008. http://theses.gla.ac.uk/248/.
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Thesis (MD.) - University of Glasgow, 2007.MD. thesis submitted to the Faculty of Medicine, Division of Cardiovascular and Medical Sciences, 2007. Includes bibliographical references. Print version also available.
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Karmouty, Quintana Harry. "Experimental pulmonary disease assessed non-invasively by magnetic resonance imaging (MRI)." Thesis, King's College London (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437768.
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Neal, Mary Agnes. "19F-MRI of inhaled perfluoropropane for quantitative imaging of pulmonary ventilation." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3963.
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MRI of exogenous imaging agents offers a safely repeatable modality to assess regional pulmonary ventilation. A small number of studies have validated the safety and potential utility of 19F imaging of inhaled thermally polarised perfluoropropane. However, the relative scarcity of signal in restrictive breath hold length acquisition times inhibits translation of this technique to clinical application. This work presents methods used to maximise the attainable image quality of inhaled perfluoropropane. Novel quantitative measures of ventilation and perfusion have been investigated and discussed. A preliminary healthy volunteer study was conducted to verify the efficacy of the imaging technique and to assess perfluoropropane wash-in and wash-out rates. Quantitative assessment of the suitability of four RF coil designs was performed, comparing power efficiency with loading and signal homogeneity within the sensitive volume of each coil. The 3D spoiled gradient echo sequence was simulated, accounting for the power performance of the chosen birdcage coil design, for calculation of acquisition parameter values required to achieve the highest SNR in a fixed acquisition period for 19F-MRI of inhaled perfluoropropane. Studies on resolution phantoms and healthy volunteers assessed the performance of the optimised imaging protocol, in combination with a compressed sensing technique that permitted up to three-fold acceleration. Two novel lung-representative phantoms were fabricated and used to investigate the behaviour of the MR properties of inhaled perfluoropropane with changing structural and magnetic environments. Finally, a method for lengthening the T2* of inhaled perfluoropropane by susceptibility matching the alveolar tissue to the inhaled gas by intravenous injection of a highly paramagnetic contrast agent is presented. Initial development work was conducted in phantoms and rodents before translation to healthy volunteers. This technique offers the potential to concurrently acquire images reflecting both pulmonary ventilation and perfusion.
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Stecker, Ian. "Optimizing Quantitative Methods in Murine Pulmonary Imaging with UTE 1H MR." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592135581719325.
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Conway, Joy Helen. "The assessment of intra-pulmonary deposition of aerosols using multi-modality imaging." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242562.
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Namati, Eman, and eman@namati com. "Pre-Clinical Multi-Modal Imaging for Assessment of Pulmonary Structure, Function and Pathology." Flinders University. Computer Science, Engineering and Mathematics, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20081013.044657.
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In this thesis, we describe several imaging techniques specifically designed and developed for the assessment of pulmonary structure, function and pathology. We then describe the application of this technology within appropriate biological systems, including the identification, tracking and assessment of lung tumors in a mouse model of lung cancer.
The design and development of a Large Image Microscope Array (LIMA), an integrated whole organ serial sectioning and imaging system, is described with emphasis on whole lung tissue. This system provides a means for acquiring 3D pathology of fixed whole lung specimens with no infiltrative embedment medium using a purpose-built vibratome and imaging system. This system enables spatial correspondence between histology and non-invasive imaging modalities such as Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET), providing precise correlation of the underlying 'ground truth' pathology back to the in vivo imaging data. The LIMA system is evaluated using fixed lung specimens from sheep and mice, resulting in large, high-quality pathology datasets that are accurately registered to their respective CT and H&E histology.
The implementation of an in vivo micro-CT imaging system in the context of pulmonary imaging is described. Several techniques are initially developed to reduce artifacts commonly associated with commercial micro-CT systems, including geometric gantry calibration, ring artifact reduction and beam hardening correction. A computer controlled Intermittent Iso-pressure Breath Hold (IIBH) ventilation system is then developed for reduction of respiratory motion artifacts in live, breathing mice. A study validating the repeatability of extracting valuable pulmonary metrics using this technique against standard respiratory gating techniques is then presented.
The development of an ex vivo laser scanning confocal microscopy (LSCM) and an in vivo catheter based confocal microscopy (CBCM) pulmonary imaging technique is described. Direct high-resolution imaging of sub-pleural alveoli is presented and an alveolar mechanic study is undertaken. Through direct quantitative assessment of alveoli during inflation and deflation, recruitment and de-recruitment of alveoli is quantitatively measured. Based on the empirical data obtained in this study, a new theory on alveolar mechanics is proposed.
Finally, a longitudinal mouse lung cancer study utilizing the imaging techniques described and developed throughout this thesis is presented. Lung tumors are identified, tracked and analyzed over a 6-month period using a combination of micro-CT, micro-PET, micro-MRI, LSCM, CBCM, LIMA and H&E histology imaging. The growth rate of individual tumors is measured using the micro-CT data and traced back to the histology using the LIMA system. A significant difference in tumor growth rates within mice is observed, including slow growing, regressive, disappearing and aggressive tumors, while no difference between the phenotype of tumors was found from the H&E histology. Micro-PET and micro-MRI imaging was conducted at the 6-month time point and revealed the limitation of these systems for detection of small lesions ( < 2mm) in this mouse model of lung cancer. The CBCM imaging provided the first high-resolution live pathology of this mouse model of lung cancer and revealed distinct differences between normal, suspicious and tumor regions. In addition, a difference was found between control A/J mice parenchyma and Urethane A/J mice normal parenchyma, suggesting a 'field effect' as a result of the Urethane administration and/or tumor burden. In conclusion, a comprehensive murine lung cancer imaging study was undertaken, and new information regarding the progression of tumors over time has been revealed.
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Livieratos-Petratos, George N. "Neural networks for computer aided diagnosis of pulmonary images in nuclear medicine." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295017.
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Brewis, Melanie J. "Imaging right ventricular function to predict outcome in patients treated for pulmonary hypertension." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/7888/.
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Pulmonary arterial hypertension (PAH) is a rare but devastating disorder of the pulmonary vasculature characterised pathologically by progressive intimal obliteration and vascular remodelling leading to increased pulmonary vascular resistance (PVR) and elevation in pulmonary arterial pressure (PAP), and clinically by functional impairment from breathlessness and ultimately death from right ventricular failure. Whilst the initial insult occurs in the pulmonary circulation, it is increasing recognised that survival relates to the ability of the right ventricle (RV) to adapt to this increased afterload. Despite a number of therapeutic advances in recent years, long-term survival remains poor, quality of life impaired by functional limitation and progression to RV failure often inevitable. In contrast, pulmonary hypertension (PH) related to chronic lung disease is relatively common, but is usually mild in severity with largely preserved RV function. The development of PH is however associated with greater functional impairment and worse survival and at present other than referral for lung transplantation there are no therapeutic options. Severe PH associated with lung disease is relatively rare, but shares many of the characteristics with PAH with more severe RV dysfunction and significant morbidity and mortality. It is also increasingly recognised in data from large PH registries, that increasing overlap exists between the two conditions, and what represents PAH with co-morbid lung disease (and therefore should receive specific PAH therapies) and what is PH secondary to lung disease (and therefore should not) increasingly muddied. What is clear is the critical role the RV plays in determining outcome in PH, but despite this studies on the impact of current therapies on RV function are few, and improvement or preservation of RV function is not an accepted clinical endpoint in pharmaceutical trials. Current methods of monitoring patient response to therapies are suboptimal, such as the established and commonly employed six minute walk distance (6MWD). The complex anatomy of the RV makes assessment of its function by modalities such as echocardiogram difficult. The development of simple, reproducible measures of RV function will both improve monitoring of PH patients but also facilitate acceptance of routine assessment of RV function in both clinical practice and pharmaceutical trials, and hopefully establish the optimal approach to RV dysfunction in PAH. Cardiac magnetic resonance imaging (CMR) is particularly suited to interrogating RV function, and has recently been established in the literature to provide prognostic significance in a number of disease states including PAH. At present, however, it is unclear what the optimal method of assessing RV function is, with a number of indices assessed by varying modalities associated with prognosis and therapeutic response in PAH. Recently research interest has developed in the potential utility of RV-arterial coupling in PH. From physiological principles, this metric of RV function has potential superiority over commonly employed indices such as RVEF or right atrial pressure (RAP) as it is less preload dependent. Its clinical use however is limited due to the need for instantaneous pressure-volume loops at varying levels of load in its derivation. It is however possible to estimate non-invasively by CMR. The aim of the work described by this thesis was to provide clarity on the optimal method of determining and monitoring RV dysfunction in PAH patients, and contrast this to patients with severe PH associated with lung disease treated with PAH therapies, where the aetiology of PH differs and utility of CMR to characterise RV function has not been explored. In chapter 3 PAH therapies given to severe PH/lung disease patients resulted in improvements in 6MWD (average ∆6MWD 24m, p=0.032), and NTproBNP (average ∆NTproBNP -396pg/mL, p=0.008), but to a lesser extent than IPAH patients. CMR imaging demonstrated that RV dysfunction (assessed by RV ejection fraction (RVEF), stroke volume (SV) and increased RV volumes) was prevalent, predicted prognosis in both conditions, and could be used to detect PH in lung disease by either measures of pulmonary vascular stiffness (relative area change of main pulmonary artery – RAC MPA) or RV mass (RVM). In Chapter 4, invasive pressure (Ees/Ea-P) and non-invasive volume (SV/ESV) estimates of RV-arterial coupling (determined by right heart catheterisation and CMR) were compared to other metrics of RV function in normal subjects, PAH and PH associated with lung disease patients as prognostic variables. Severe PH/lung disease patients displayed impaired RV adaptation in comparison to IPAH subjects, Ees/Ea-P 1.07 versus 1.37mmHg/mL, p=0.020. RV-arterial coupling estimated by the pressure method did not predict survival, but when estimated by the volume method (SV/ESV) did. Both RVEF and SV/ESV were independent predictors of outcome (HR 0.958, p=0.006 and HR 0.329, p=0.002 respectively). Invasive measures of RV function therefore provided no prognostic advantage over the more patient acceptable CMR. Finally in chapter 5, improvement in RV-arterial coupling assessed by CMR (SV/ESV) was seen after commencing PAH therapy (0.461 to 0.616, p=0.036). Survival was poorer in those with a fall in either RVEF or SV/ESV during therapy, with no superiority of either method of determining prognosis (Logrank p=0.002 for both). Change in RV function poorly related to change in 6MWD but closely related to change in NTproBNP. ∆NTproBNP but not ∆6MWD was an independent predictor of survival (HR 1.622 p=0.024 and HR 0.995 p=0.129 respectively) and therefore a useful monitoring tool of RV function and therapy response for the clinic. The results described in this thesis therefore suggest that RV function to predict outcome in patients with PH during treatment follow up is best determined by CMR imaging of RVEF or SV/ESV, with no clear benefit of re-evaluating invasive haemodynamics or pressure estimates of RV-arterial coupling.
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Liu, Yifei. "A Correlative Workflow for Imaging Murine Extracellular Matrix to Determine Pulmonary Valve Biomechanics." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619095019644309.
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Jose, Arun. "Value of Baseline Cardiac Magnetic Resonance Imaging for Predicting Adverse Outcomes in Treatment-naive Pulmonary Hypertension Patients." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1560866307524617.
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ISHIGAKI, TAKEO, MITSUHIKO HIROSE, KIYOKO NAKAMURA, MITSURU IKEDA, KENGO ITO, and NICOLAS MILLA. "FUNDAMENTAL AND CLINICAL EVALUATION OF CHEST COMPUTED TOMOGRAPHY IMAGING IN DETECTABILITY OF PULMONARY NODULE." Nagoya University School of Medicine, 1994. http://hdl.handle.net/2237/16074.
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Cederlund, Kerstin. "Radiological imaging of pulmonary emphysema : preoperative evaluation of candidates for lung volume reduction surgery /." Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-195-0.
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Sauret, Veronique. "Topology and morphology of pulmonary anatomical features for aerosol deposition applications using medical imaging." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342803.
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Lee, Namheon. "Assessment of Pulmonary Insufficiency using Energy-Based Endpoints and 4D Phase Contrast MR Imaging." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384865927.
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Crawley, Stephen F. "Cardiac magnetic resonance imaging in the diagnosis and determination of outcome of pulmonary hypertension." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7431/.
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Pulmonary hypertension (PH) is a rare but serious condition that causes progressive right ventricular (RV) failure and death. PH may be idiopathic, associated with underlying connective-tissue disease or hypoxic lung disease, and is also increasingly being observed in the setting of heart failure with preserved ejection fraction (HFpEF). The management of PH has been revolutionised by the recent development of new disease-targeted therapies which are beneficial in pulmonary arterial hypertension (PAH), but can be potentially harmful in PH due to left heart disease, so accurate diagnosis and classification of patients is essential. These PAH therapies improve exercise capacity and pulmonary haemodynamics, but their overall effect on the right ventricle remains unclear. Current practice in the UK is to assess treatment response with 6-minute walk test and NYHA functional class, neither of which truly reflects RV function. Cardiac magnetic resonance (CMR) imaging has been established as the gold standard for the evaluation of right ventricular structure and function, but it also allows a non-invasive and accurate study of the left heart. The aims of this thesis were to investigate the use of CMR in the diagnosis of PH, in the assessment of treatment response, and in predicting survival in idiopathic and connective-tissue disease associated PAH. In Chapter 3, a left atrial volume (LAV) threshold of 43 ml/m2 measured with CMR was able to distinguish idiopathic PAH from PH due to HFpEF (sensitivity 97%, specificity 100%). In Chapter 4, disease-targeted PAH therapy resulted in significant improvements in RV and left ventricular ejection fraction (p < 0.001 and p = 0.0007, respectively), RV stroke volume index (p < 0.0001), and left ventricular end-diastolic volume index (p=0.0015). These corresponded to observed improvements in functional class and exercise capacity, although correlation coefficients between Δ 6MWD and Δ RVEF or Δ LVEDV were low. Finally, in Chapter 5, one-year and three-year survival was worse in CTD-PAH (75% and 53%) than in IPAH (83% and 74%), despite similar baseline clinical characteristics, lung function, pulmonary haemodynamics and treatment. Baseline right ventricular stroke volume index was an independent predictor of survival in both conditions. The presence of LV systolic dysfunction was of prognostic significance in CTD-PAH but not IPAH, and a higher LAV was observed in CTD-PAH suggesting a potential contribution from LV diastolic dysfunction in this group.
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Kannan, Arun, Chithra Poongkunran, Mahendran Jayaraj, and Rajesh Janardhanan. "Role of Strain Imaging in Right Heart Disease: A Comprehensive Review." Elmer, 2014. http://hdl.handle.net/10150/621330.
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Advances in the imaging techniques of the heart have fueled the
interest in understanding of right heart pathology. Recently, speckle
tracking echocardiography has shown to aid in understanding various
right heart diseases and better management. Its role is well established
in diagnosing right heart failure, pulmonary artery hypertension,
arrhythmogenic right ventricular dysplasia and congenital
heart disease. We review the basic mechanics of speckle tracking
and analyze its role in various right heart conditions.
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Wang, Maisie S. "Ultra-high resolution imaging and artery-vein separation of blood pool contrast-enhanced MRA /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8094.
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Stone, Ian. "Effects of COPD and its treatment on cardiovascular structure and function assessed through advanced imaging techniques." Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/23199.
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Significant cardiovascular morbidity and mortality exists in chronic obstructive pulmonary disease independent of traditional risk factors. A number of different hypotheses exist to explain this association including the contribution arterial stiffness and lung hyperinflation. Non-invasive cardiovascular imaging and assessment are ideal methods through which this relationship can be further studied although a number of the techniques have yet to be validated in COPD. In this thesis we aimed to achieve a number of goals. First, we aimed to assess the reproducibility and level of agreement between different measures of arterial stiffness in stable hyperinflated COPD. Second, we hoped to establish the utility of 3 different measurement techniques for measuring intrinsic cardiac function in stable hyperinflated COPD. Third, in a case-control study we compared surrogates of cardiovascular risk in hyperinflated COPD patients and a group matched for cardiovascular risk with normal lung function. Finally, we sought to understand the impact of pharmacologically reducing lung hyperinflation on cardiovascular structure, function and arterial stiffness. We have firstly demonstrated that non-invasive measures of arterial stiffness are reproducible in stable hyperinflated COPD. Secondly, we have established the level of agreement and reproducibility of three different CMR techniques for measuring intrinsic myocardial function which will provide important information for the powering of future CMR studies in COPD. Thirdly, we have shown that surrogates for cardiovascular outcomes are adversely affected in COPD compared to a group matched for global cardiovascular risk, suggesting that current scoring systems may be suboptimal in risk prediction in COPD. Finally, we have demonstrated that pharmacological lung deflation has consistent and physiologically plausible beneficial effects on cardiac structure, function and the pulmonary vasculature. Whether intrinsic myocardial function can be modulated through prolonged periods of lung deflation is as yet unverified and should be the focus of future clinical trials.
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Jardim, Carlos Viana Poyares. ""Avaliação da distensibilidade da artéria pulmonar através da ressonância magnética e sua relação com a resposta ao teste agudo com vasodilatador em pacientes com hipertensão arterial pulmonar"." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/5/5150/tde-12092005-103213/.
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A hipertensão arterial pulmonar idiopática é uma doença que acomete os vasos arteriais pulmonares, determinando o aumento da resistência vascular pulmonar levando à deterioração hemodinâmica. Avaliamos se a distensibilidade da artéria pulmonar avaliada pela ressonância magnética se correlaciona à resposta ao teste agudo com vasodilatador em pacientes com hipertensão pulmonar. Houve diferença significativa de distensibilidade da artéria pulmonar em pacientes respondedores e não-respondedores. Após a análise dos dados por uma curva ROC, a distensibilidade de 10% distinguiu a população de respondedores de não-respondedores com 100% de sensibilidade e 56% de especificidadePulmonary arterial hypertension is characterized by an increase in pulmonary vascular resistance, eventually leading to hemodynamic failure. We assessed whether pulmonary artery distensibility (evaluated by magnetic resonance) correlated with acute vasodilator test response. A statistically significant difference was found in terms of pulmonary artery distensibility in responders and non-responders. A ROC curve showed that 10% distensibility could discriminate responders from non-responders with 100%sensitivity and 56% specificity
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Wielopolski, Piotr Alfred. "Three-dimensional magnetic resonance imaging of the pulmonary vascular system with rapid gradient echo acquisitions." Case Western Reserve University School of Graduate Studies / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1060277751.
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Unglert, Carolin [Verfasser]. "Quantitative optical coherence tomography for imaging healthy and emphysematous pulmonary alveoli in vivo / Carolin Unglert." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2014. http://d-nb.info/1050912241/34.
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Matin, Tahreema Nihad Hashmi. "Functional lung assessment using hyperpolarised xenon gas magnetic resonance imaging." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:61e77bfb-67d9-4221-b246-4a5cd66b5144.
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Purpose Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality worldwide. The standard method for assessing lung function in COPD is spirometry, which provides global lung function information but is a poor predictor of disability and quality of life. The overall aim of this thesis is to develop utility of hyperpolarised xenon gas magnetic resonance imaging (HP 129Xe-MRI) as a technique to evaluate regional lung function. Methods Studies were approved by the National Research Ethics Service (NRES). Eleven volunteers and 25 patients with COPD underwent HP 129Xe-MRI, pulmonary function tests (PFTs) and quantitative computerised tomography (QCT). Gravitational-dependent gradients of HP 129Xe-MRI were compared between prone and supine postures in healthy volunteers. Lobar quantification of HP 129Xe-MRI was completed in COPD patients, who also underwent time-resolved HP 129Xe-MRI and HP 129Xe-MRI pre- and post-salbutamol to determine feasibility of detecting regional delayed ventilation and post-intervention change. The relationship between study measures was assessed using Pearson's correlation coefficient. Results HP 129Xe-MR ventilation gradients were more marked in the supine than prone posture in healthy volunteers, whereas diffusion-weighted gradients were more uniform. HP 129Xe-MRI was successfully quantified according to pulmonary lobes and correlated with lobar lung anatomy (QCT) and global functional transfer capability (TLCO) (r=-0.61, p<0.005). Delayed ventilation was observed with time-resolved breath-hold HP 129Xe-MRI. Differential regional ventilation change was detected with HP 129Xe-MRI post-salbutamol. Conclusion These data demonstrate technical optimisation of HP 129Xe-MRI in healthy volunteers and COPD patients. Successful generation of lobar HP 129Xe-MRI parameters offers an automated analysis method that can be adopted into the clinical workflow. Finally proof-of-principle data have identified roles for HP 129Xe-MRI in evaluating regional treatments and assessing therapeutic response. Future work will evaluate the role of HP 129Xe-MRI in patient selection for lung volume reduction therapy and as a surrogate end-point in drug development studies.
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Soerensen, Dennis Dam. "Optimization and Analysis of The Total Cavo-Pulmonary Connection." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10444.
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Single Ventricle congenital heart defects with cyanotic mixing between systemic and pulmonary circulations afflict 2 per 1000 live births. The total cavo-pulmonary connection (TCPC), where the superior and inferior vena cavae are sutured to the left and right pulmonary arteries, is the current procedure of choice. It is believed that reducing the fluid mechanical power losses in the TCPC will relieve strain on the single functional ventricle. It is hypothesized that a proposed idealized TCPC design, decreases power losses to a level below that of any other TCPC designs, while providing other advantages and increased flexibility. Physical models with slightly different geometries of the proposed design were created, and in vitro experiments carried out with particle image velocimetry (PIV), phase contrast magnetic resonance imaging (PC-MRI), and control volume flow analysis at physiological flow rates. Computational fluid dynamics (CFD) was used for numerical studies of the same geometries as in the physical models. Power losses were calculated using the control volume method and the viscous power dissipation function. The latter method incorporated registration of high-resolution PC-MRI velocity vectors to tetrahedral meshes followed by inverse interpolation of the vectors onto the meshes. Detailed flow structures were analyzed. Results show that the new design is more energy efficient than any other idealized models.
Furthermore, a tool was developed to extract flow and vessel information from PC-MRI datasets obtained from patients with Fontan connections. The tool utilized a display algorithm, which was developed for optimal noise detection in PC-MRI images. This enabled accurate segmentation. Comparing PC-MRI images before and after this accurate segmentation showed that the standard deviations of the pixels at the perimeter of the segmented vessel were statistically significantly smaller after the segmentation in 94.1% of the datasets investigated.
The developed tool was able to extract flow, flow in the quadrants of vessels, area of the segmented vessel, velocities and pulsatility indices. The velocity vectors were exported for use as CFD boundary conditions in models reconstructed from patient anatomies. A database was created with patient PC-MRI data from approximately 140 patients, which is probably the largest database in the world.
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Al, Jefairi Nora. "Leads to improve atrial fibrillation ablation, catheters, imaging and mapping guidance." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0834/document.
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La fibrillation auriculaire (FA) est la forme la plus fréquente d'arythmie cardiaque chez l’Homme. L'isolement des veines pulmonaires (VP) par radiofréquence (RF) est le traitement de référence pour les patients atteints de fibrillation auriculaire paroxystique (FAP) réfractaire symptomatique malgré le traitement médicamenteux. L’isolation des VP fonctionne très bien pour traiter les FA paroxystiques mais elle a un rôle limité dans le traitement des patients atteints de FA persistante (FAPs). La FA persistante est en effet plus complexe, en raison du développement dans l'oreillette gauche (OG) d’un substrat arythmogène résultant d’un remodelage électrique et anatomique. Ce substrat maintient la FA et nécessite donc des ablations supplémentaires dans l’OG (en dehors des veines pulmonaires). Les récidives de fibrillation auriculaire sont principalement dues à la reconnexion électrique des veines pulmonaires. C’est un phénomène fréquent, qui limite le succès de la procédure à long terme. Certaines séries rapportent de 20 à 50% de récidive, avec un impact important pour le patient, et pour le système de santé puisque générant des hospitalisations et des procédures répétées. L'ablation point par point utilisant un cathéter d’ablation à électrode unique peut être techniquement complexe. De ce fait, les lésions transmurales, contiguës et pérennes sont parfois difficiles et longues à réaliser, expliquant pour une part les taux élevés de reconnexion. Par conséquent, de nouveaux types de cathéters d’ablation ont été développés. On citera par exemple : les cathéters ballons de cryoablation, les cathéters d’ablation circulaire à électrodes multiples (PVAC et nMARQ), sont maintenant disponibles et ont pour but la création de lésions complètes et continues. Cependant, le ballon de cryoablation a des limites, notamment dans sa capacité à s'adapter à la variabilité anatomique des VP et pour l'ablation des sites extra-veineux. La conséquence est qu’un cathéter d’ablation supplémentaire doit être utilisé pour l’ablation des sites extra-veineux ce qui rend la procédure plus complexe et coûteuse. L’absence d'irrigation du cathéter PVAC augmente sans doute le risque de complications thromboemboliques. Le cathéter nMARQ en revanche est un cathéter circulaire irrigué qui, en plus de son rôle dans l’isolation des VP, permet l'ablation de substrat en dehors des veines pulmonaires. Par ailleurs, les outils de cartographie et d'imagerie cardiaques sont de plus en plus couramment utilisés pour planifier et guider l'ablation de FA. On citera la cartographie électroanatomique invasive (Carto®3) et non invasive (ECVUETM), la tomodensitométrie (TDM) et l'imagerie par résonance magnétique (IRM). Nous avons émis l'hypothèse que différentes stratégies et technologies pourraient améliorer la procédure et les résultats de l’isolation des VP en produisant de meilleures lésions et en permettant une visualisation directe des lésions. Nous avons donc évalué le rôle du cathéter circulaire irriguée pour la cartographie et l’ablation (nMARQ) dans la FAP et la FAPs avec ou sans guidage non invasif par ECGi. Nous nous sommes également intéressés à l’analyse en IRM des lésions produites par ce cathéter lors de l’isolation des veines pulmonaires. À cette fin, les données de l’isolation des VP ont été obtenues et traitées de manière aiguë et à 3 mois. Le suivi clinique a été évalué à 1 an. La thèse se compose de 3 parties : Partie 1 : Comment améliorer l'isolation des veines pulmonaires chez les patients atteints de fibrillation auriculaire paroxystique ? Partie 2 : Cathéter circulaire multiélectrodes et ablation de fibrillation auriculaire persistante. Partie 3 : Rôle de l'imagerie par résonance magnétique dans l'évaluation de la reconnexion des veines pulmonaires après l'isolement des veines pulmonaires ?Atrial fibrillation (AF) is the most common form of cardiac arrhythmia in Humans. Pulmonary vein isolation (PVI) by radiofrequency (RF) ablation is the mainstay treatment for patients with symptomatic and drug refractory paroxysmal atrial fibrillation (PAF) as ectopic beats (triggers) from pulmonary veins (PVs) initiate AF, however PVI alone had limited role in treating patients with persistent atrial fibrillation (PsAF), due to additional involvement in left atrium (LA) by electrical and anatomical remodeling, creating more complex substrate (fibrosis) that maintain AF and therefore necessitate non-PV sites ablation to modify the arhythmogenic substrate. Atrial fibrillation recurrence mainly due to pulmonary vein (PV) electrical reconnection is common and remains the current issue that limits long term procedural success and generates extra costs due to repeated hospital admissions and repeated procedures. Point by point ablation using single tip catheter can be challenging, complex and time consuming, enhancing electrical reconnection as stable lesions are difficult to achieve. To overcome these limitations, new type of catheters such as balloon (cryoablation) and multi-electrode circular ablation catheters like PVAC and nMARQ, are now available. However, cryoablation balloon is limited by inability to adapt to anatomic PV variability and to ablate non-PV sites. This means that an additional ablation catheter has to be used for non-PV targets, and it certainly adds to the costs. The PVAC catheter lacks of irrigation increases the risk of thromboembolic complications. On contrary, nMARQ is an irrigated circular ablation catheter which in addition to its role in PVI, allows for non-PV/LA substrate ablation. Cardiac mapping and imaging tools are now commonly used to plan and guide AF ablation, such as invasive (Carto 3) and noninvasive (ECVUE) electroanatomic mapping (EAM), computed tomography (CT) and magnetic resonance imaging (MRI), respectively. We hypothesized that different strategies and technologies could improve PVI procedure and outcome by producing better lesions and by allowing for direct visualization of lesions. We therefore, assessed the role of circular, irrigated mapping and ablation catheter (nMARQ) in PAF and PsAF with or without noninvasive ECGi guidance, and advanced imaging technologies (MRI) after PVI. For that purpose, PVI data were obtained and processed acutely and at 3 months. Clinical follow up was evaluated at 1 year. The thesis consists of 3 parts: Part 1: How to improve pulmonary vein isolation lesion formation in patients with paroxysmal atrial fibrillation? Part 2: Circular catheter and persistant atrial fibrillation ablation. Part 3: The role for magnetic resonance imaging in assessing pulmonary vein reconnection after pulmonary vein isolation?
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Akinyi, Teckla G. "An Affordable Open-Source Small Animal MR and Hyperpolarized Gas Compatible Ventilator: Feasibility in preclinical imaging." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1490354672385997.
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Blé, François-Xavier Frossard Nelly Beckmann Nicolau. "Lung magnetic resonance imaging as a non-invasive alternative to assess experimental pulmonary diseases in small rodents." Strasbourg : Université Louis Pasteur, 2008. http://eprints-scd-ulp.u-strasbg.fr:8080/996/01/BLE_FrancoisX2_2007.pdf.
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Blé, François-Xavier. "Lung magnetic resonance imaging as a non-invasive alternative to assess experimental pulmonary diseases in small rodents." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/BLE_Francois-Xavier_2007.pdf.
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L’imagerie par résonance magnétique est capable de détecter le contenu en eau des tissus biologiques et ainsi d’estimer localement et de manière non invasive l’infiltration d’eau et/ou la sécrétion de fluides et/ou la densification tissulaire. Dans les maladies pulmonaires comme l’asthme, les bronchopathies chroniques obstructives ou la fibrose, la fuite plasmatique, la sécrétion de mucus et l’épaississement des tissus du poumon composent parmi les signes pathologiques majeurs qui contribuent directement à l’amoindrissement de la fonction pulmonaire. Ces caractéristiques sont, en outre, bien conservées dans les modèles expérimentaux de maladies pulmonaires chez le petit rongeur. Un intérêt particulier est porté vers le développement et l’utilisation de modèles chez la souris qui a fourni, en parallèle des avancées en matière de génie génétique et de biologie molécuaire, un pertinent support in vivo pour l’investigation et la compréhension des maladies pulmonaires. De nos jours, les méthodes de routine employées pour l’évaluation de l’état pathologique des poumons dans ces modèles sont terminales, ou ne fournissent qu’une estimation globale de la fonction des voies respiratoires sans information d’ordre spatial. Ainsi, nous avons mis au point une méthode utilisant l’IRM afin de détecter différents signes pathologiques induits dans un modèle d’asthme chez la souris. Lors de cette thèse, nous avons démontré et validé la pertinence de l’IRM dans la détection et le suivi de signaux associés à la fuite plasmatique et aux sécrétions de mucus dans les voies aériennes, qui sont deux caractéristiques majeures de la réponse inflammatoire suite à la provocation allergénique. Afin de valider de façon plus approffondie nos observations, nous avons démontré l’utilité de la méthode dans une étude pharmacologique. Nous avons choisi d’étudier la pharmacologie du sphingosine-1-phosphate (S1P) car de récentes publications indiquaient l’implication de ce médiateur endogène dans les mécanismes inflammatoires et dans le maintien de la perméabilité des tissus. Dans deux études examinant les effets (i) de l’agoniste général du S1P, le FTY720 et (ii) de l’antagoniste sélectif du S1P2, le JTE013, l’incidence de la fuite plasmatique dans la détection des signaux IRM a été mise en évidence dans notre modèle d’inflammation pulmonaire chez la souris et a été confirmée par histologie et par analyse du lavage broncho-alvéolaire. De plus, la technique ayant été précédemment mise au point chez le rat, durant les travaux de thèse nous avons progressé dans les investigations concernant l’utilisation de l’IRM du poumon pour cette espèce. Ainsi, nous sommes parvenus à détecter de façon sélective et à suivre la progression des sécrétions de mucus par IRM en utilisant un agent de contraste spécifique dans un modèle d’hypersécrétion de mucus induite par endotoxine chez le rat. En outre, nous avons également démontré les capacités de l’IRM dans l’estimation et le suivi de l’hydratation des sécrétions des voies aériennes. En effet, dans un modèle non-inflammatoire chez le rat, la formation de signaux IRM liés à la présence de fluide a été induite par l’instillation d’une solution hypertonique et accrue de manière dose dépendente par l’administration de différents composés agissant directement ou indirectement sur les canaux sodiques épithéliaux (ENaC), responsables de la régulation du niveau d’hydratation du liquide de surface des voies aériennes. Ces études ont été menées avec succés chez le rat dans la perspective d’un futur transfert chez la souris permettant d’utiliser des animaux transgéniques. Enfin, nous avons en partie validé l’utilisation de l’IRM dans un modèle moins aigü de fibrose induite par bléomycine chez la souris. Ce modèle a été choisi pour sa capacité à reproduire les caractéristiques globales de la fibrose pulmonaire humaine ainsi que pour sa facilité à être mis en place. Dans cette étude, nous avons été capable de localiser et de suivre par IRM la course des signaux liés aux composantes inflammatoire et fibrotique incluant la fuite plasmatique, la sécrétion de mucus et l’épaississement des tissus qui ont été confirmées par analyse histologique des poumons. En résumé, ce travail a permis d’apporter la preuve que l’IRM peut contribuer de façon significative à la recherche dans le domaine des maladies pulmonaires chez le petit rongeur. Les résultats obtenus soutiennent que l’utilisation de l’IRM, comme un outil non-invasive et fournissant des informations d’ordre spatial et temporel, peut être envisagée en complément et/ou en remplacement des méthodes pratiquées aujourd’hui pour l’évaluation de modèles expérimentaux chez le petit rongeurMagnetic resonance imaging (MRI) is able to detect water content in the biological tissue and thus to non-invasively assess on a regional basis infiltrated water and/or secreted fluids and/or tissue densification. In pulmonary diseases such as asthma, chronic obstructive pulmonary diseases or fibrosis, plasma exudation, mucus secretion and thickening of the lung tissue constitute hallmarks of the pathological status that directly contribute to functional impairment. These features are well conserved in experimental pulmonary disease models in the small rodents. A particular interest is given to murine models that have provided, in parallel to the technological progress in genetic engineering and molecular biology, a reliable in vivo support for lung disease understanding and investigation. Nowadays, routine methods used to evaluate disease state of the lung in these models are either terminal or gives functional estimation of the global airways. Therefore, we have set up a method using MRI technique to non-invasively depict different hallmarks occurring in a murine model of asthma. In this thesis, we have demonstrated that proton MRI provides a relevant mean to assess and follow signals associated with the plasma leakage and mucus secretions in the lung, which are both important features of the inflammatory response following allergenic provocation. To further confirm these findings, we have also validated in this model the effect of pharmacological tools. We chose to study sphingosine-1-phosphate (S1P) pharmacology on the basis of recent publications indicating a possible implication of this endogenous mediator in inflammation and lung barrier integrity in models of asthma. In two studies examining the effects of the general S1P agonist FTY720 and of the S1P2 antagonist JTE013, the incidence of plasma leakage on fluid signal detection was highlighted in our murine model of airway inflammation and confirmed by histology and BAL fluid analyses. Additionally, since the technique had been previously set up in the rat, we extended the knowledge in this species. In this regard, we achieved the selective detection and monitoring of mucus dynamics by MRI with the use of a specific contrast agent in a model of endotoxin-induced mucus hypersecretion. Besides, we also demonstrated the capabilities of MRI to follow the hydration of airway secretions. In this non-inflammatory model, the formation of MRI fluid signals were induced by hypertonic saline instillation and dose-dependently enhanced by different compounds that interact directly or indirectly with epithelial Na+ channel (ENaC), a major regulator of airway surface liquid hydration. These studies have been successfully performed in the rat with the perspective of future translation to murine models for transgenic application. Finally, we have partially validated the application of this technique to a less acute model, the murine bleomycin-induced fibrosis. This model has been chosen regarding its admitted relevance to mimic global characteristics of human pulmonary fibrosis in addition to its simplicity to be set up. In this study, we have been able to follow by MRI the course of edematous, mucous and/or fibrotic features in correlation with histological findings. In summary, the present work is bringing evidence of possible contributions of MRI in pulmonary disease investigations in mouse and rat, and postulates for its use to complete and/or replace the methods used nowadays to evaluate experimental murine models
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McLure, Lindsey Elizabeth Robertson. "The role of cardiac magnetic resonance imaging in the assessment of right ventricular function in pulmonary hypertension." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6884/.
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Pulmonary hypertension (PH) is a rare disease of the pulmonary arteries. It is characterised by vascular proliferation and remodelling resulting in a progressive increase in pulmonary vascular resistance and right ventricular failure. The functional capacity of the right ventricle is the major prognostic determinant in PH, and death usually results from right ventricular failure. Although recent therapeutic advances have improved the short-to-medium term outlook of PH patients, early death due to right ventricular failure remains inevitable in many patients. The imperative role of RV performance in the clinical status and long- term outcome in PH patients is evident. Evaluation of right ventricular function is essential in the management of patients with pulmonary hypertension. Current methods of assessment of PH patients are suboptimal. The right ventricle is difficult to assess due to its position and geometry. Recent developments in imaging techniques, such as cardiac magnetic resonance (CMR) imaging and echocardiography, have improved our understanding of the structure and function of the right ventricle. Assessment of RV function is complex and no single measurement is generally accepted in clinical practice. The experimental work performed in this thesis aimed to improve our understanding of RV function in PH patients and to provide clarity in the role of CMR in the non-invasive assessment and monitoring of pulmonary hypertension patients. A non-invasive measurement of stroke volume would be beneficial to monitor disease progression in pulmonary hypertension patients. Chapter 3 demonstrated that cardiac magnetic resonance imaging provided non-invasive measurements of stroke volume that were as accurate as those obtained by thermodilution measured during right heart catheterisation. Inert gas rebreathing using photoacoustic analysis also provided accurate non-invasive measurements of stroke volume. Chapter 4 compared two patient groups: idiopathic pulmonary arterial hypertension (IPAH) and pulmonary hypertension associated with connective tissue disease (CTDPAH). We clarified that there was no significant differences in RV structure and performance between these two distinct patient groups to account for the poorer prognosis in the CTDPAH group. Treatments for PH are always expensive, sometimes invasive and carry significant side effects. It is imperative that we are able to assess the patient’s response to therapy in a clinically meaningful, accurate and non-invasive manner. The importance of escalating therapy if a patient does not respond to initial treatment has been emphasised in recently published guidelines. Current monitoring techniques have acknowledged limitations and are suboptimal. Chapter 5 presents the results obtained from my contribution to the prospective, longitudinal multinational EURO-MR study. Longitudinal CMR examination identified significant improvements in cardiac function with the introduction of disease-targeted therapy. Baseline and 4 months post therapy CMR scans were compared. It is anticipated that CMR could be a useful monitoring technique for patients with pulmonary hypertension.
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Boulate, David. "L'évaluation du ventricule droit dans l'hypertension pulmonaire." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS500/document.
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L’insuffisance cardiaque droite est la première cause de mortalité des patients atteints d’hypertension pulmonaire (HP). Au début de la maladie, le ventricule droit (VD) opère un remodelage permettant une adaptation à l’augmentation des résistances vasculaires pulmonaires. Au cours de cette adaptation, les caractéristiques morphologiques, fonctionnelles et myocardiques se modifient. L’analyse de ces modifications peut s’appliquer en clinique au niveau du dépistage, de l’évaluation pronostique et du suivi des patients atteints d’HP. Néanmoins, la physiopathologie du passage d’un état compensé à un état décompensé reste à élucider de même que l’identification de nouvelles cibles thérapeutiques ou l’élaboration de méthodes non-invasives d’évaluation du VD restent à développer. L’objectif de cette thèse était d’évaluer un moyen de dépistage de l’HP en échographie cardiaque et d’étudier la physiopathologie de la défaillance ventriculaire droite sur un cœur droit remodelé. Un large rappel des notions d’anatomie, d’embryologie et de physiologie nécessaires à la compréhension des paramètres d’évaluation du VD a été réalisé, puis des études originales publiées et en cours ont été présentées.Une première étude s’est intéressée au dépistage échocardiographique d’une HP chez des patients avec une pathologie pulmonaire avancée. Nous avons montré que la dilatation de l’oreillette droite, du VD et certains paramètres fonctionnels étaient liés à une HP. Lorsque la fuite tricuspidienne était quantifiable (chez 52% des patients), l’évaluation d’autres paramètres du VD n‘améliorait pas le dépistage d’une HP. La présence de paramètres du VD anormaux chez les patients dont la fuite tricuspidienne n’était pas quantifiable n’améliorait pas le dépistage ; 20% des patients sans HP présentaient une dilatation du VD. Une validation extrinsèque chez l’animal avec une obstruction vasculaire pulmonaire modérée et progressive confirmait que la dilatation du VD était un des paramètres les plus précoces quantifiable lors du développement d’une HP. Le développement d’indices non-invasifs du VD plus spécifique d’une l’HP est nécessaire.Une seconde étude, nous avons caractérisé les modifications du VD au cours d’une insuffisance cardiaque droite aigue survenant dans le cadre d’une HP dans une nouveau modèle animal. Le VD était évalué avec des paramètres de courbes pression-volume, d’échocardiographie, de cathétérisme cardiaque droit et par des biomarqueurs circulants. L’analyse anatomopathologique et protéique du VD, environ 3 heures après la restauration hémodynamique, retrouvait des lésions d’ischémie sous-endocardiques et sous-épicardiques et des stigmates d’activation d’autophagie. Nous avons retrouvé des lésions sous-endocardiques du VD similaires chez 5 patients avec une HP ayant bénéficié d’une transplantation cardiopulmonaire dans un contexte de défaillance hémodynamique. Des données préliminaires suggèrent que ces lésions sont associées aux défaillances rénales et hépatiques et à une altération de la survie après transplantation cardiopulmonaire.En conclusion, certains signes de remodelage du VD peuvent être présents chez des patients avec des pathologies pulmonaires avancés en l’absence d’HP, ce qui limite leur intérêt pour le diagnostic non-invasif d’une HP. A l’autre extrémité du spectre de sévérité d’une HP, nous avons modélisé pour la première fois une insuffisance cardiaque droite aigue dans un modèle animal d’HP. Nous avons démontré pour la première fois que des lésions ischémiques pouvaient se développer dans le VD en quelques heures malgré l’induction d’une restauration hémodynamique avec de la dobutamine. Ces données apportent un rationnel fort pour l’évaluation des lésions tissulaires du VD à l’aide de biomarqueurs circulant en pratique clinique dont les applications restent à établirRight heart failure is the leading cause of mortality in patients with pulmonary hypertension (PH). At early stage of PH the right ventricle (RV) remodels to adapt to the increased pulmonary vascular resistances. This adaptation is characterized by morphological, functional and myocardial changes. The evaluation of these changes may be applied for screening, prognosis evaluation and follow-up of patients with PH. However, the pathophysiology of the transition from adaptive to maladaptive phenotypes remains unclear; and identification of RV therapeutic targets and noninvasive methods for its evaluation remains to developed. The aim of this thesis was to evaluate non-invasive screening of PH with echocardiography and to study the pathophysiology of acute right heart failure in the setting of chronic PH by performing precise phenotyping of a new large animal model. A wide review of anatomic, embryologic and physiologic concepts was performed to help for the understanding of parameters of RV evaluation; then published and ongoing original studies were presented.In a first study, we investigated PH screening with echocardiography in patients with advanced lung disease. In this study, we showed that enlargement of the RV and of the right atrium, as well as function parameters of the RV were associated with PH. When the tricuspid regurgitation was available (52% of cases), RV morphology and function parameters did not improve PH diagnosis. Abnormal RV morphology and function without available tricuspid regurgitation provided moderate detection value; whereas 20% of patients without PH presented enlargement of the RV. In a large animal model with progressive increase in pulmonary artery mechanical obstruction, enlargement of the RV was the earliest RV parameter associated with PH development. This study highlights the need for more specific RV indices of PH.In a second study we investigated right ventricular changes in a new large animal model of acute right heart failure occurring on chronic PH; a situation associated with around 40% mid term mortality or transplantation. We characterized right ventricular changes during acute volume and pressure overload and after hemodynamic restauration in a large animal model of chronic thromboembolic PH. The RV was evaluated with parameters derived from pressure-volume loops, echocardiography, right heart catheterism and with circulating biomarkers. Pathological and proteins content analyzes of the RV around 3 hours after hemodynamic restauration showed acute subendocardial and subepicardial focal ischemic lesions as well as signs of autophagy activation. We found similar ischemic lesions in RV of 5 patients who underwent a heart-lung transplantation for PH in the setting of hemodynamic compromise. Preliminary data suggest that these lesions are associated with end-organ injury and poor overall survival after heart-lung transplantation in patients with PH.In conclusion, abnormal echocardiographic right heart metrics may be observed in patients with advanced lung disease without PH limiting their use for PH screening in this population. This highlight the need for more specific right heart metrics associated with PH. At the other extreme of the spectrum of PH severity, we described for the first time a large animal model of acute right heart failure in chronic PH. We reproduced and described the main morphological and functional features observed in acute right heart failure on PH and we showed for the first time that acute right ventricular ischemic lesions may develop within few hours despite hemodynamic restauration with dobutamine. These data provide a strong rational to develop specific biomarkers to evaluate tissue lesions of the right ventricle and determine their clinical implications
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Sweers, Lynelle. "The scintigraphic evaluation of the pulmonary perfusion pattern of dogs hospitalised with babesiosis." Diss., Electronic thesis, 2007. http://upetd.up.ac.za/thesis/available/etd-05082008-153547/.
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Tonelotto, Bruno Francisco de Freitas. "Determinação da PEEP ideal e avaliação de atelectasia pulmonar com o uso da ultrassonografia durante intraoperatório de cirurgias eletivas." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5152/tde-27022019-151124/.
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Introdução: A atelectasia intraoperatória ocorre imediatamente após a indução anestésica e pode ser detectada por ultrassom pulmonar (LUS). No entanto, até o momento o LUS não é utilizado para avaliar a hiperdistensão pulmonar. Neste estudo, descreveu-se um método para detectar hiperdistensão pulmonar usando LUS. A tomografia de impedância elétrica (TIE) foi a referência para comparação dos métodos. Métodos: Dezoito (18) pacientes, com 63 ± 6 anos de idade, com pulmões normais, submetidos à cirurgia abdominal inferior. O TIE foi calibrado, realizada a indução anestésica, intubação e ventilação mecânica. Para reverter a atelectasia posterior, realizou-se uma manobra de recrutamento alveolar com o uso de pressão expiratória final positiva (PEEP) 20 cmH20 e pressão aérea do platô 40 cmH2O durante 120 segundos. A titulação PEEP foi então obtida com valores descendentes: 20, 18, 16, 14,12,10, 8, 6 e 4 cmH2O. Os dados de ultrassom e TIE foram coletados em cada nível PEEP e interpretados por dois observadores independentes. O número de linhas H foi contado usando um filtro especial. O teste de correlação de Spearman e a curva ROC foram utilizados para comparar os dados do LUS e TIE. Resultados: O número de linhas H aumentou linearmente com PEEP: de 3 em PEEP 4 cmH2O a 10 em PEEP 20 cmH2O. Cinco linhas H foram o limiar para a detecção de hiperdistensão pulmonar, definida como hiperdistensão na TIE >= 24,5%. A área sob a curva ROC foi 0,947 (IC 95% 0.901-0.976). Conclusão: O LUS intraoperatório detectou hiperdistensão pulmonar em valores descendentes de PEEP. A presença de cinco ou mais linhas H podem ser consideradas como indicando hiperdistensão pulmonarPurpose: Intraoperative atelectasis occurs immediately after anaesthetic induction and can be detected by lung ultrasound (LUS). However, LUS is considered as unable to assess pulmonary hyperinflation. In this study, we propose a method to detect pulmonary hyperinflation using LUS. Electrical impedance tomography (EIT) was the reference method. Methods: We included 18 patients, 63 ± 6-year old, with normal lungs, undergoing lower abdominal surgery. The following protocol was used: EIT was calibrated, followed by anaesthetic induction, intubation and mechanical ventilation. To reverse posterior atelectasis, a recruitment maneuver - positive end-expiratory pressure (PEEP) 20 cmH20 and plateau airway pressure 40 cmH2O during 120 sec was performed. PEEP titration was then obtained during a descending trial: 20, 18, 16, 14,12,10, 8, 6 and 4 cmH2O. Ultrasound and EIT data were collected at each PEEP level and analyzed by two independent observers. The number of H lines was counted using a special filter. Spearman correlation test and ROC curve were used to compare LUS and EIT data. Results: The number of H lines increased linearly with PEEP: from 3 at PEEP 4 cmH2O to 10 at PEEP 20 cmH2O. Five H lines was the threshold for detecting pulmonary hyperinflation, defined as a mean decrease in maximum EIT compliance >= 24,5 %. The area under the ROC curve was 0.947 (CI 95% 0.901-0.976). Conclusion: Intraoperative transthoracic LUS can detect pulmonary hyperinflation during a PEEP descending trial. Five or more H lines can be considered as indicating pulmonary hyperinflation in normally aerated lung regions
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Santos, Vitor Vasquez dos. "Semi-quantificação cintilográfica de defeitos perfusionais em portadores de Doença Falciforme. Comparação com sintomas clínicos." Botucatu, 2019. http://hdl.handle.net/11449/182321.
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Orientador: Sonia Marta MoriguchiResumo: Introdução: A doença falciforme (DF) é a doença monogênica herdada mais comum no mundo. Acometimentos cardiopulmonares de caráter progressivo associados à vaso oclusão e fenômenos embólicos assim como, as exacerbações de sintomas respiratórios são causas recorrentes de internações nessa população. A cintilografia de perfusão é método de imagem sensível e consagrado para avaliação hipoperfusão pulmonar, notadamente em processos embólicos. A semi-quantiticação da porcentagem de obstrução vascular de perfusão (POVF) apresenta relação segura com a angiografia. Objetivo: 1) Verificar a correlação entre os sintomas clínicos (Classes funcionais) versus Porcentagem de defeitos perfusionais (POVF%) em portadores de DF e 2) Verificar a associação entre POVF% e espirometria, avaliada pela porcentagem da capacidade vital forçada do predito (CVF%). Casuística e Metodologia Trata-se de estudo transversal observacional descritivo de 22 portadores de Doença Falciforme (DF), com coleta retrospectiva de dados clínicos e de espirometria, no período de 2017-2019 e semi-quantificação da cintilografia de perfusão pulmonar (POVF%), CF de I a IV e CVF% Análise estatística descritiva e inferenciais (Coeficiente de correlação – CC), com nível de significância com p<0,05. Resultados: Foram observados cinco subtipos de DF: SS (n=13), BSB0 (n=04), SS+alfatalassemia (n=02), SS+ fetal elevada (n=02) e SC (n=1). A cintilografia de perfusão pulmonar foi sensível identificando defeitos perfusionais em 91% da ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: INTRODUCITON: Sickle cell disease (SCD) is the most common inherited monogenic disease in the world. Cardiopulmonary complications of a progressive character, associated with vessel occlusion and embolic phenomena, such as, exacerbations of respiratory symptoms are recurrent causes of hospitalization in this population. Perfusion scintigraphy is a sensitive and conspicuous imaging method for evaluating pulmonary hypoperfusion, especially in embolic processes. The semi-quantification of the percentage of vascular perfusion obstruction (POVF) presents a safe relationship with angiography. Objective: 1) To verify the correlation between clinical symptoms (functional classes- FC) versus percentage of perfusion defects (POVF%) in patients with CSD and 2) to verify the association between POVF% and spirometry, evaluated by the percentage of forced vital capacity predicted VCF%). MATERIALS AND METHODOLOGY This was a descriptive, observational cross-sectional study of 22 patients with SCD, with retrospective collection of clinical data and spirometry data for the period 2017-2019 and semi-quantification of pulmonary perfusion scintigraphy (POVF%) , FC from I to IV and VCF% Descriptive and inferential statistical analysis (Coefficient of correlation - CC), with level of significance with p <0.05. Results: Five subtypes of SCD: SS (n = 13), BSB0 (n = 04), SS + alphatassemia (n = 02), high fetal SS + (n = 02) and SC (n = 1) were observed. Pulmonary perfusion scintigraphy was sensitive b... (Complete abstract click electronic access below)
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Yaroshenko, Andriy [Verfasser], Franz [Akademischer Betreuer] [Gutachter] Pfeiffer, and Axel [Gutachter] Haase. "X-ray dark-field imaging for diagnosis of pulmonary disorders / Andriy Yaroshenko. Betreuer: Franz Pfeiffer. Gutachter: Axel Haase ; Franz Pfeiffer." München : Universitätsbibliothek der TU München, 2015. http://d-nb.info/1103658328/34.
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Varghese, Juliet Jaison. "A Magnetic Resonance Imaging Method to Non-Invasively Measure Blood Oxygen Saturation." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1471622211.
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Citro, Lucas Abraham. "High-field Cardiac Magnetic Resonance Imaging in Small Animal Models of Cardiovascular Disease." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365082830.
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Ding, Kai. "Registration-based regional lung mechanical analysis." Thesis, University of Iowa, 2008. http://ir.uiowa.edu/etd/20.
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