Background Cutaneous metastases (CM) are a frequent finding in the follow-up of malignant tumours. Objectives CM were examined with dermoscopy, optical coherence tomography (OCT), dynamic OCT and line-field confocal OCT (LC-OCT) to describe common findings. Methods In the University Hospital Carl Gustav Carus Dresden, Germany, 18 patients with 61 CM were examined with dermoscopy. CM (n = 43, 31 melanoma metastases, two metastases of renal carcinoma, five metastases of cutaneous squamous cell carcinoma and five metastases of pleomorphic dermal sarcoma) were examined with OCT (VivoSight® Michelson Diagnostics). Additional 18 melanoma metastases were examined with LC-OCT (deepLive™; Damae Medical). Results CM were localized on the head, trunk, neck and limbs. Dermoscopy patterns were angioma-like, nevus-like nonglobular, nevus-like globular, blue nevus-like and unspecific. CM showed an ulceration, hyperkeratosis with increased entrance signal and disturbed architecture of the epidermis in OCT. In deeper metastases, the dermoepidermal junction (DEJ) was normal; in most cases it was disturbed. CM were visible as subepidermal hyporeflective roundish area, with septae, with either clear margin and shadowing or blurred margin. DOCT showed dot, coiled, serpiginous and branched vessels; there was a disarray in size and distribution and vessels were converging on the centre of the metastasis. In LC-OCT, CM showed enhanced entrance signal and disturbed architecture of a thinned epidermis, ulceration, atypical honeycomb or cobblestone pattern as well as a broken DEJ. In the dermis, a hyporeflective roundish area with clusters of hyporeflective cells with septae, clear margin and clefting or blurred margin was visible; the hyporeflective area was surrounded by bundles of connective tissue. Subepidermal vessels differentiated in size and distribution. Inflammatory, dendritic and pagetoid cells were visible. Conclusions OCT and LC-OCT may be useful tools for immediate diagnosis, localization of CM and monitoring under treatment in addition to conventional methods like ultrasound and histopathology.

Resumo: O objetivo neste estudo foi avaliar as diferenças no espaço aéreo faríngeo em crianças com diferentes padrões faciais. Foram avaliadas as tomografias computadorizadas de feixe cônico de 98 indivíduos em crescimento, com idade média de 8,9 anos, divididas por sexo e faixa etária, e subdivididas de acordo com o padrão de crescimento (horizontal, vertical normal e produtores) e tipo de má oclusão (Classe I e Classe II). Utilizando um programa tridimensional, foram analisados o volume, área sagital, menor área de seção transversal e as dimensões ântero-posteriores da faringe superior e inferior. As dimensões ântero-posterior da faringe superior e inferior foi significativamente menor em indivíduos com Classe II em crianças na faixa etária entre 9 a 11 anos e a faringe superior em foi significativamente menor em crianças na faixa etária entre 5 e 7 anos com padrão de crescimento vertical. Porém, quando a faringe foi avaliada tridimensionalmente, não foram encontradas diferenças nas demais dimensões sugerindo que diferenças no padrão vertical e no tipo de má oclusão ântero-posterior (Classe I e II) não influenciam as dimensões da faringe. Não foi encontrado dimorfismo sexual. A região de maior constrição da faringe esteve presente mais freqüentemente na orofaringe (86%). Embora as dimensões lineares possam variar entre os diferentes padrões faciais, quando avaliadas tridimensionalmente, elas não foram influenciadas pelas diferentes morfologias faciais / Abstract: The aim of this study was to assess the differences in pharyngeal airway space in children with different facial patterns. Cone-beam computed tomography records of 98 growing patients with mean age of 8.9 years divided by sex and age groups and subdivided according to growth pattern (horizontal, normal and vertical growers) and type of malloclusion (Class I and Class II) were evaluated .Using a 3-dimensional virtual program the volume, sagital area, smallest cross section area, anteroposterior dimensions of superior and inferior pharynx were obtained. The anteroposterior linear dimensions of superior and inferior pharynx in children with 9 to11 years was significant smaller in patients with Class II relationship but in 3D evaluation differences were not found suggesting that anteroposterior malocclusion do not influence pharynx dimensions. The anteroposterior linear dimensions of superior , pharynx in children with 5 to7 years was significant smaller in patients with vertical growth pattern when compared to normal growers, but in 3D evaluation differences were not found suggesting that vertical pattern do not influence pharynx dimensions. No sexual dimorphism was found. The most constricted region of pharynx were mostly found at oropharynx(96%).Although linear dimensions can vary among different facial patterns, the 3-dimensional dimensions weren't influenced by different facial morphologies / Orientador: Luiz Cesar de Moraes / Coorientador: Weber José da Silva Ursi / Banca: Jefferson Luis OshiroTanaka / Banca: Edmundo Medici Filho / Mestre

Seismic tomography is a technique for illuminating the physical dynamics of the Earth by seismic waves generated by earthquakes or explosions. In both industry and academia, the seismic exploration does not yet have the capability of imaging seismic tomography in real-time and with high resolution. There are two reasons. First, at present raw seismic data are typically recorded on sensor nodes locally then are manually collected to central observatories for post processing, and this process may take months to complete. Second, high resolution tomography requires a large and dense sensor network, the real-time data retrieval from a network of large-amount wireless seismic nodes to a central server is virtually impossible due to the sheer data amount and resource limitations. This limits our ability to understand earthquake zone or volcano dynamics. To obtain the seismic tomography in real-time and high resolution, a new design of sensor network system for raw seismic data processing and distributed tomography computation is demanded. Based on these requirements, three research aspects are addressed in this work. First, a distributed multi-resolution evolving tomography computation algorithm is proposed to compute tomography in the network, while avoiding costly data collections and centralized computations. Second, InsightTomo, an end-to-end sensor network emulation platform, is designed to emulate the entire process from data recording to tomography image result delivery. Third, a sensor network testbed is presented to verify the related methods and design in real world. The design of the platform consists of hardware, sensing and data processing components.

Introduction. Aortic stenosis is characterised both by progressive narrowing of the valve and the hypertrophic response of the left ventricle. The purpose of this thesis was to study the contribution of inflammation and calcification to valve narrowing using Positron Emission and Computed Tomography (PET/CT) and to investigate the hypertrophic response using cardiovascular magnetic resonance (CMR). Methods. PET/CT studies. Patients with aortic sclerosis and mild, moderate and severe stenosis were prospectively compared to matched control subjects. Aortic valve severity was determined by echocardiography. Calcification and inflammation in the aortic valve and coronary arteries were assessed by sodium 18-­‐fluoride (18F-­‐NaF) and 18-­‐fluorodeoxyglucose (18F-­‐FDG) uptake using PET. CMR studies. Consecutive patients with moderate or severe aortic stenosis undergoing CMR were enrolled into a registry. Patients who received gadolinium contrast were categorised into absent, mid-­‐ wall or infarct patterns of late gadolinium enhancement (LGE) by blinded independent observers. Patients follow-­‐up was completed using patient questionnaires, source record data and the National Strategic Tracing Scheme. After excluding those patients with concomitant triggers to LV remodeling, the extent and patterns of hypertrophy were investigated based upon measurements of indexed LV mass, indexed LV volume and the relative wall mass. Results. PET/CT studies. 121 subjects (20 controls; 20 aortic sclerosis; 25 mild, 33 moderate and 23 severe aortic stenosis) were studied. Quantification of tracer uptake within the valve demonstrated excellent inter-­‐observer reproducibility with no biases and limits of agreement of ±0.21 (18F-­‐NaF) and ±0.13 (18F-­‐FDG) for maximum tissue-­‐to-­‐background ratios (TBR). Activity of both tracers was higher in patients with aortic stenosis than control subjects (18F-­‐NaF: 2.87±0.82 vs 1.55±0.17; 18F-­‐ FDG: 1.58±0.21 vs 1.30±0.13; both P<0.001). 18F-­‐NaF uptake displayed a progressive rise with valve severity (r2=0.540, P<0.001) with a more modest increase observed for 18F-­‐FDG (r2=0.218; P<0.001). Amongst patients with aortic stenosis, 91% had increased 18F-­‐NaF (>1.97) and 35% increased 18F-­‐ FDG (>1.63) uptake. Increased 18F-­‐NaF uptake was also observed in the coronary arteries in a subset of patients with atherosclerosis. These patients (n=40) had higher rates of prior cardiovascular events (p=0.016) and angina (p=0.023), and higher Framingham risk scores (p=0.011). CMR studies. 143 patients (aged 68±14 years; 97 male) were followed up for 2.0±1.4 years and 27 died. Compared to those with no LGE (n=49), univariate analysis revealed that patients with mid-­‐wall fibrosis (n=54) had an eight-­‐fold increase in all-­‐cause mortality despite similar aortic stenosis severity and coronary artery disease burden. Patients with an infarct pattern (n=40) had a six-­‐fold increase. Mid-­‐wall fibrosis (HR 5.35 [95% CI 1.16-­‐24.56]; P=0.03) emerged as an independent predictor of all cause mortality by multivariate analysis. The pattern of LV remodelling was studied in 91 patients (61±21 years; 57 male) and displayed wide variation comprising normal ventricular geometry (n=11), concentric remodelling (n=11), asymmetric remodelling (n=11), concentric hypertrophy (n=34), asymmetric hypertrophy (n=14) and LV decompensation (n=10). The magnitude of the hypertrophic response was unrelated to the severity of aortic valve narrowing. Conclusions. Modern imaging techniques have provided important insights in to the pathology underlying aortic stenosis and suggest that valvular calcification and myocardial fibrosis have a key role. Both represent important potential targets for future therapeutic interventions.

No description available.

The radial velocity anomaly which affects spectroscopic observations of stars undergoing transit by a companion body is known as the Rossiter-McLaughlin effect. This effect can be used to measure the obliquities of the orbits of transiting planets. In this thesis I present a tomographic method for analysing the effect, which manifests itself in stellar spectral line-profiles. I implement this method on seven systems known to host transiting planets, and some systems with early-type host stars, for which the transit events have not yet been shown to be the result of planetary companions. Despite being well-suited to examining systems with early-type, rapidly-rotating host stars which have a more pronounced Rossiter-McLaughlin effect, I find the tomographic method is able to produce reasonable results for the system parameters of planets orbiting relatively slowly-rotating stars. I show that the method provides a significant increase in the accuracy of determinations of the stellar rotation rate and is able to better constrain values for the transit impact parameter. Though I do not confirm the existence of any new planets around early-type stars, I do use the tomographic method to reject one candidate as a stellar eclipsing binary system, and also reveal that one of the candidate host stars is a non-radial pulsator. I show that the method is able to examine systems involving stars with a range of spectral types and rotation rates.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Computed Tomography (CT) is a medical imaging modality which acquires anatomical data via the unique x-ray attenuation of materials. Yet, some clinically important materials remain difficult to distinguish with current CT technology. Spectral CT is an emerging technology which acquires multiple CT datasets for specific x-ray spectra. These spectra provide a fingerprint that allow materials to be distinguished that would otherwise look the same on conventional CT. The unique characteristics of spectral CT data motivates research into novel visualization techniques. In this thesis, we aim to provide the foundation for visualizing spectral CT data. Our initial investigation of similar multi-variate data types identified intermixing as a promising visualization technique. This promoted the development of a generic, modular and extensible intermixing framework. Therefore, the contribution of our work is a framework supporting the construction, analysis and storage of algorithms for visualizing spectral CT studies. To allow evaluation, we implemented the intermixing framework in an application called MARSCTExplorer along with a standard set of volume visualization tools. These tools provide user-interaction as well as supporting traditional visualization techniques for comparison. We evaluated our work with four spectral CT studies containing materials indistinguishable by conventional CT. Our results confirm that spectral CT can distinguish these materials, and reveal how these materials might be visualized with our intermixing framework.

No description available.

No description available.