Orientador: Francisco Haiter Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T19:01:13Z (GMT). No. of bitstreams: 1 Brasil_DanieliMoura_M.pdf: 14824425 bytes, checksum: 3057ff676ccce0f70d5ed273ef3ffed8 (MD5) Previous issue date: 2015 / Resumo: O objetivo deste estudo foi avaliar a influência da morfologia craniofacial em volumes e áreas transversais das vias aéreas superiores. Para isso, foram utilizadas 74 imagens por Tomografia Computadorizada de Feixe Cônico (TCFC) e 74 fotografias faciais em perfil lateral, que pertenciam aos mesmos pacientes, sendo 38 do sexo masculino e 36 do sexo feminino, com idades entre 18 e 56 anos (32,8 ± 1,8). As imagens foram selecionadas a partir de um arquivo de exames de pacientes atendidos em uma Clínica de Radiologia. Um radiologista experiente classificou a amostra em tipos esqueléticos ântero-posteriores (classe II e classe III) empregando a análise cefalométrica de Steiner e a medida AO-BO de Jacobson; e em padrões verticais (braquifacial, mesofacial e dolicofacial) utilizando a análise cefalométrica de Ricketts. A análise facial de perfil foi realizada para cada paciente. Medidas de volume total, de nasofaringe e de orofaringe e ainda de cinco áreas transversais ao longo das vias aéreas superiores foram realizadas, utilizando o software Insight ITK-SNAP 2.4.0®. Os resultados foram submetidos à análise estatística, em que o teste Mann-Whitney foi utilizado para analisar a influência do sexo e dos tipos esqueléticos ântero-posteriores nas variáveis do estudo, o teste Kruskal-Wallis foi aplicado para verificar a existência de relação entre os padrões verticais e as variáveis; o teste de Correlação de Spearman foi utilizado para analisar a possível correlação entre as medidas dentro dos padrões esqueléticos ântero-posteriores, dentro dos padrões verticais e dentro das variáveis da análise facial e as demais medidas propostas pelo estudo. Os resultados mostraram que o tipo esquelético ântero-posterior e o padrão vertical da face não influenciaram no volume das vias aéreas superiores; a área transversal na região de palato mole (PM) mostrou-se significativamente maior para classe III; o terço superior da face apresentou correlação negativa com as medidas da faringe e o terço médio da face mostrou correlação positiva com a área transversal PM. Concluiu-se que os padrões faciais não influenciaram no volume da faringe e que a observação fotográfica do perfil facial foi capaz de mostrar tendências de correlações entre terços da face e vias aéreas superiores / Abstract: The aim of this study was to evaluate the influence of craniofacial morphology in volumes and cross-sectional areas of the upper airway. For this 74 Cone Beam Computed Tomography (CBCT) images and 74 facial photographs in side profile were used, which belonged to the same patients, 38 males and 36 females, aged between 18 and 56 years (32.8 ± 1.8). The images were selected from a file examination of patients seen in a Radiology Clinic. An experienced radiologist classified the sample into anteroposterior skeletal types (class II e class III) using Steiner¿s analysis and the AO-BO measure Jacobson; and into vertical groups (brachyfacial, mesofacial and dolichofacial) using Ricketts¿ analysis. The facial profile analysis was performed for each patient. Measurement of volume and of five cross-sectional areas of upper airway were performed using Insight ITK-SNAP 2.4.0®. The data was subjected to statistical analysis, the Kruskal-Wallis test was used to verify the existence of a relationship between the vertical groups and other variables analyzed in the study. The Mann-Whitney test was used to analyze the influence of gender and anteroposterior skeletal types in the variables. Spearman Correlation test was used to analyze the possible correlation between measurements within vertical groups; within the anteroposterior skeletal types; and within variables of facial analysis, and other measures proposed by the study. Results showed that the anteroposterior skeletal type and the vertical pattern did not influence the volume of the upper airway; soft palate (SP) cross-sectional area was significantly greater in type class III; the upper facial third was negatively correlated with measures of the pharynx, and the middle facial third had positive correlation with the SP cross-sectional area. It was concluded that facial patterns do not influence the pharynx volumes. The photographic observation of the facial profiles is able to show trends of correlations between thirds of the face and upper airway / Mestrado / Radiologia Odontologica / Mestra em Radiologia Odontológica

Orientador: José Dirceu Ribeiro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T23:03:29Z (GMT). No. of bitstreams: 1 Oliveira_PricilaMaraNovaisde_D.pdf: 1258403 bytes, checksum: 7846e1b92c8fe1c6ba25524109c50608 (MD5) Previous issue date: 2015 / Resumo: Introdução: Estudos recentes indicam que a espirometria não é uma ferramenta sensível para avaliar a função pulmonar em pacientes com fibrose cística (FC). A tomografia computadorizada de alta resolução (TCAR) de tórax é considerada o padrão ouro para avaliação do dano estrutural pulmonar nesses pacientes. Já a capnografia volumétrica (VCap) tem demonstrado ser uma ferramenta promissora na avaliação da homogeneidade da ventilação pulmonar. No nosso conhecimento não existem estudos comparando esses exames. Por isso o objetivo desse estudo foi avaliar e comparar os testes de VCap, espirometria e TCAR pontuada pelo escore de Bhalla modificado na avaliação da doença pulmonar em crianças e adolescentes com FC. Método: Realizou-se avaliação transversal e longitudinal de pacientes com FC de ambos os sexos fora de exacerbação pulmonar aguda. A VCap e espirometria foram realizadas no mesmo dia. A TCAR foi obtida na avaliação de rotina realizada por esses pacientes e as imagens foram pontuadas por 2 avaliadores através do escore de Bhalla modificado. Os resultados da VCap e espirometria foram correlacionados com o escore de TCAR. Os resultados obtidos pelo grupo de pacientes com espirometria normal e alterada foram comparados. Além disso, a progressão da doença pulmonar foi avaliada e comparada através dos três exames realizados. Resultados: A tese é apresentada no formato de três artigos. No capitulo 1, realizou-se uma revisão da literatura sobre VCap. No capítulo 2, realizou-se um estudo transversal com 41 pacientes com FC com idade média de 13,8 anos. O escore de TCAR médio foi 20,64 (6,5-33,5) e 14 pacientes (34,1%) tiveram espirometria normal. O índice capnográfico (KPIv) apresentou correlação com o escore de TCAR (r=0,52; p=0,001), VEF1% (r=-0,70; p<0,001) e FEF25-75% (r=-0,65; p<0,001). Porém o FEF25-75% demonstrou maior correlação com o escore de TCAR (r= -0,65; p<0,001).O KPIv e o slope III (SIII) da VCap foram maiores nos pacientes com espirometria alterada (p=0,01 e p=0,04, respectivamente). No capítulo 3, realizou-se um estudo longitudinal com 23 pacientes avaliados pelas ferramentas propostas. Tanto a espirometria, quanto o escore da TCAR e a VCap demonstraram piora da doença pulmonar no período estudado. A variação anual do escore de TCAR (+7,38%) foi maior do que a variação do KPIv (+0,32%), do FEF25-75% (-5,71%) e do VEF1% (4,39%). Pacientes com comprometimento leve da função pulmonar apresentaram maior declínio do VEF1 e menor aumento da pontuação do escore de TCAR quando comparados aos moderados e graves (p=0,02). Conclusão: A VCap é uma ferramenta útil na monitorização das doenças pulmonares em crianças e adolescentes com FC. O KPIv derivado da Vcap correlaciona-se com o escore de TCAR e espirometria. Porém, o escore de TCAR se correlaciona melhor com a espirometria do que com a VCap. Mais estudos são necessários para avaliar a habilidade do SIII e KPIv para discriminar pacientes com espirometria normal e alterada. A espirometria, VCap e TCAR detectaram piora da doença pulmonar nos pacientes avaliados. Porém, a variação anual do escore de TCAR foi maior do que a piora da função pulmonar medida pela espirometria e da homogeinidade da ventilação avaliada pela VCap. A espirometria apresentou maior declínio nos pacientes classificados como leves, enquanto o escore de TCAR variou mais em pacientes com comprometimento moderado/grave. Nossos resultados reforçam o caráter complementar das ferramentas testadas na avaliação funcional e estrutural da doença pulmonar / Abstract: Introduction: Recent studies have indicated that spirometry is not a sensitive tool to evaluate lung disease in cystic fibrosis (CF) patients. High-resolution computed tomography (HRCT) is considered the gold standard to evaluate structural lung disease. Volumetric capnography (VCap) is a promising clinical tool used to evaluate ventilation homogeneity. In our knowledge, there is no study comparing those tools. Therefore, our study aimed to evaluate and to compare the spirometry test, with VCap, and HRCT punctuated by modified Bhalla score in children and adolescents with CF. Methods: It were conducted a cross-sectional and a longitudinal study of CF patients from both genders out of acute pulmonary exacerbation. They performed VCap and spirometry in a single test occasion. HRCT was obtained in routine evaluation and images were punctuated by 2 observers with modified Bhalla score. VCap and spirometry results were correlated with HRCT scores. Patients¿ groups with normal and abnormal spirometry were compared. Besides, the progression of lung disease was assessed and compared between those three exams. Results: The thesis is presented in three papers format. In chapter 1, we presented a review of VCap. In chapter 2, we presented the cross-sectional study with 41 CF patients with mean age of 13.8 years. HRCT score mean was 20.64 (6.5-33.5) and 14 patients (34.1%) had normal spirometry values. Capnographic index (KPIv) was correlated with the HRCT score (r=0.52; p=0.001), FEV1% (r=-0.70; p<0.001), and FEF25-75% (r=-0.65; p<0.001). Although, FEF25-75% showed stronger correlation with the HRCT score (r= -0.65; p<0.001). KPIv and slope III (SIII) from VCap were higher in patients with abnormal than normal spirometry (p=0.01 and p=0.04 respectively). In chapter 3, we presented the longitudinal study of 23 patients testes with all tests proposed. Spirometry, HRCT score, and VCap demonstrated deterioration of lung disease during the period studied. The annual variation rate of HRCT score (+7.38%) was higher than KPIv (+0.32%), FEF25-75% (-5.71%), and FEV1% (4.39%). Patients with mild lung function had higher decline of FEV1% and less improvement in HRCT score when compared to patients with moderated and severe lung disease (p=0.02). Conclusions: VCap is a useful tool in monitoring lung disease in children and adolescents with CF. KPIv from VCap correlates with HRCT score and spirometry. Still, the HRCT score correlates better with spirometry than with VCap. Further studies are needed to assess the ability of SIII and KPIv to discriminate between patients with normal and abnormal spirometry. Spirometry, VCap and HRCT were able to detect deterioration in lung disease. Although, the annual variation rate of HRCT score were higher than functional decline evaluated by spirometry and ventilation inhomogeneity assessed by VCap. Spirometry had higher annual rate decline in patients with mild lung function, while HRCT score had higher improvement in moderate/severe patients. Our results reinforce the complementary role of those tested tools in functional and structural evaluation of lung disease / Doutorado / Saude da Criança e do Adolescente / Doutora em Ciências

Orientador: Luciana Asprino / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T07:59:26Z (GMT). No. of bitstreams: 1 Santaella_GustavoMachado_M.pdf: 1130922 bytes, checksum: 73dd73d086d83d2c9e2fa04c5f9cd294 (MD5) Previous issue date: 2015 / Resumo: Os fótons de raios X são atenuados quando atravessam materiais, e isso afeta diretamente os valores dos tons de cinza da imagem. No presente estudo teve-se como objetivos avaliar a utilização de diferentes materiais como simuladores de tecidos moles e avaliar a influência dos tecidos moles nos tons de cinza em imagens de tomografia computadorizada de feixe cônico (TCFC). Para isso, foram utilizadas três cabeças humanas com os tecidos moles formolizados presentes e submetidas à aquisição de imagens de TCFC para determinação do grupo padrão-ouro. Posteriormente, as cabeças foram descarnadas e novamente tomografadas, com e sem a utilização de diferentes materiais simuladores de tecidos moles, seguindo o mesmo protocolo de aquisição. Quatro diferentes materiais foram testados, acrílico, água, cera utilidade e poliestireno expandido (EPS), utilizados isoladamente ou em combinação, totalizando 6 grupos de teste (sem simulador, com caixa de EPS de 2 cm de espessura, com acrílico com 0,5 cm de espessura, com caixa de EPS com cera de 1 cm de espessura, com caixa de EPS com cera de 1 cm de espessura e água no interior, e com caixa de EPS com água no interior). Um único avaliador selecionou oito regiões de interesse quadrangulares, sendo em maxila e mandíbula e incluindo dentes e ossos alveolares, e realizou as mensurações de todos os valores dos tons de cinza dos pixels das regiões. As medianas desses valores foram utilizadas para comparação pelos testes de Friedman e Dunn. Os resultados mostraram que os grupos testados não apresentaram diferenças estatisticamente significantes em comparação com o grupo padrão-ouro, com exceção dos grupos que envolveram água no interior das caixas. O EPS com 2 cm de espessura, associado ou não a uma camada de cera utilidade de 1 cm, e o acrílico com 0,5 cm de espessura foram os simuladores que forneceram imagens mais semelhantes às imagens do padrão-ouro. A água não se mostrou eficaz como simulador de tecidos moles. Os tecidos moles não influenciaram nos valores de tons de cinza mensurados na imagem de TCFC / Abstract: X-ray photons suffer attenuation as they pass through materials of different compositions, and this directly affects the values of the image grayscale. This study aimed to test the usefulness of different materials as soft tissue simulators and evaluate the influence of soft tissues on grayscale values in cone beam computed tomography (CBCT). Three human heads with formalin fixed soft tissues were obtained and CBCT images were acquired to determine the gold standard group. The heads were stripped and tomographic images reacquired with and without the use of different materials for soft tissue simulation, following the same acquisition protocol. Four different materials were tested, acrylic, water, utility wax and expanded polystyrene (EPS), and these were used singly or in combination, with a total of 6 test groups (no simulator, with EPS box 2 cm thick, with 0.5 cm thick acrylic, EPS box with 1 cm thick wax, EPS box with 1 cm thick wax and water inside, and EPS box with water inside). A single evaluator selected the eight quadrangular regions of interest, being in the maxilla and mandible and including teeth and alveolar bone, and performed the measurements of all the pixel grayscale values of the regions. The median of these values were used for comparison by Friedman's and Dunn's tests. The results showed that the tested groups showed no statistically significant differences compared to the gold standard group, with the exception of groups involving water inside the boxes. The EPS 2 cm thick, associated or not with a 1 cm layer of utility wax, and the 0.5 cm thick acrylic were the simulators that provided images more similar to the gold standard images. The water was not effective as a soft tissue simulator. The soft tissues did not influence the values of the CBCT image grayscale measured / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica

Low-velocity impact damage in IM7/977-3 carbon fiber reinforced polymer (CFRP) composites was investigated using 3D computed tomography (CT). 32-ply IM7/977-3 symmetric cross-ply composites were impacted at different impact energy levels and with different impactors (DELRIN® resin flat-ended cylindrical and tool steel hemispherical strikers) using an Instron 8200 Dynatup drop-weight impact machine. The impact energies were chosen to produce slightly visible damage, characterized by short cracks on the impacted surface and little delamination on the non-impacted surface (29.27 J), and barely visible damage, characterized by indentation on the impacted surface but no visible delamination on the back surface of the specimens (20.77 J). Internal damage was assessed using the Zeiss METROTOM 1500 industrial CT scanning system, and CT images were reconstructed using VGStudio MAX and the MyVGL 2.2 viewer. To determine the extent of the damage zone, impacted 152.4 mm square composite plates were initially scanned. As the relatively large specimen size did not allow for evaluation of internal cracks and isolation of delamination at ply interfaces, smaller specimens that enclosed the damaged region (45 mm square plates) were cut out and imaged. The CT scan results showed that volume of the impact damage zone had a generally positive correlation with impact energy, maximum load, and maximum deflection, but that the relationship was generally weak. Absence of a definite correlation between damage volume and impact energy was unexpected, as the difference in the impact energy was up to 30%.

Introduction: Root resorption is an undesired but frequent side effect of orthodontic treatment. Several studies have already aimed to evaluate the performance of CBCT on this topic. However, none have addressed the peculiarities of the most common daily orthodontic scenario. The aim of the study was to evaluate the influence of CBCT scans on the diagnosis of artificial external root resorption in the apical third of anterior teeth. Materials and methods: One hundred extracted human anterior teeth were randomly assigned to 2 uneven groups (51 as the control and 49 as the experimental group). A limited area of the apical third of the root of the teeth of the experimental group was selected and a buffer solution was used to induce tooth subsurface demineralization. Before CBCT image acquisition, each tooth was coated with an approximately 0.3 mm thick layer of utility wax to simulate the radiographic appearance of the periodontal space and placed into an empty mandibular anterior socket of a partially edentulous dry human mandible. The mandible was placed into a polystyrene box filled with water prior to the CBCT examination to simulate soft-tissue attenuation and scattering. The CBCT images were obtained on an i-CAT unit (i-CAT Next Generation, Imaging Sciences International, Hatfield, PA) according to three protocols: (I) half scan (180°), 0.40 mm voxel size; (II) full scan (360°), 0.40 mm voxel size; and (III) full scan (360°), 0.125 mm voxel size. The 300 resultant CBCT DICOM volumes were imported into InVivo software (InVivo5, Anatomage, San Jose, CA) for evaluation by three blinded, previously calibrated observers using a five-point confidence rating scale. Cohen’s kappa was used to calculate observers’ agreement. The diagnostic values of sensitivity (Sn), specificity (Sp) and accuracy (Ac) were performed by pooling observer responses for every image modality. Receiver operating characteristic (ROC) were built and the areas under the curve (AUC) were calculated. The Sn, Sp and Ac values were compared by Cochran’s Q test. The AUC values were compared by Mann-Whitney U test. Results: The observers’ agreement ranged from 0.63 to 0.71, which was interpreted as a substantial agreement. Protocol III (0.125 mm voxel size) displayed the highest Sn (81.63 %), Ac (80.67%) and AUC (0.807). There were statistically significant differences between protocol III and the other two protocols (p < 0.001). The specificity of protocol I (84.97 %) was greater than that of protocols II (69.93 %) and III (79.74 %); however statistically significant difference was only found between protocols I and II (p = 0.005). Conclusion: Although there was no difference in accuracy between the degrees of rotation (half and full scan) within the same voxel size (0.4 mm), there was a considerable difference between those and the smallest voxel size (0.125 mm). In fact, it may be suggested that a more dedicated, high resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22316号 / 医博第4557号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 溝脇 尚志, 教授 松田 秀一, 教授 安達 泰治 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Articular cartilage is a highly organized, anisotropic tissue lining the ends of bones within synovial joints. Composed primarily of water, collagens, proteoglycans and chondrocytes which synergistically give rise to the tissue's mechanical and tribological properties. Fluid pressurization and resistance to fluid flow within the porous extracellular matrix of cartilage, coupled with the low hydraulic permeability of the tissue endow the tissue with a viscoelastic response to loading and aid to reduce the coefficient of friction between articulating surfaces, with the pressurized fluid supporting 95% of applied loads. Experiencing millions of articulations throughout an average lifetime, articular cartilage possesses distinct biotribological properties. These require effective lubrication, mediated by the synergistic interaction between fluid and boundary lubricants, to provide a low coefficient of friction and prevent wear at the cartilage surface. Osteoarthritis is the progressive deterioration of articular cartilage and synovial joint structure and function, leading to softer and wear prone tissue on account of altered biochemical composition of the extracellular matrix. Plain radiography remains the most accessible tool and the current standard of care to visualize musculoskeletal diseases and injuries (e.g., osteoarthritis), but cannot directly visualize soft tissues or cartilage, and diagnoses are based solely on boney changes, which occur in the later stages of the disease. Coupled with no way to quantitatively assess tissue health prior to irreversible deterioration, there remains no cure for osteoarthritis. Integral to OA pathology are concomitant changes in the biochemical composition of synovial fluid that result in deterioration of rheological properties, contributing to increased cartilage wear. To address both the lack of quantitative diagnosis methods and lack of chondroprotective therapies, this dissertation presents a dual faceted approach to quantitatively image articular cartilage health, coupled with lubrication strategies to improve cartilage lubrication, and preserve cartilage tissue. This dissertation describes the synthesis of tantalum oxide nanoparticles of varying surface charges for use as contrast agents for rapid, minimally invasive, non-destructive, and quantitative contrast-enhanced computed tomography to assess both the biochemical content and biomechanical integrity of articular cartilage. Ex vivo contrast enhanced computed tomography attenuation using the nanoparticle contrast agent reveals correlations between attenuation and the mechanical and biochemical properties of the tissue. The lubrication strategy described within this dissertation involves introducing a rolling ball element between two surfaces to reduce friction. In this strategy, either single, globular macromolecules or nanoparticles are employed as ball bearings between articulating surfaces to reduce friction when asperities on the surfaces are in direct contact. Rheological characterization and construction of classical Stribeck curves using the lubricant formulations reveal that introducing the rolling element reduces the coefficient of friction during boundary lubrication, while leaving the rheological properties of the base fluid intact. Ex vivo cartilage mechanical testing involving shear deformation under varying speeds and loads reveal improved biotribological performance compared to pure synovial fluid or saline.

A large proportion of dogs undergoing computed tomography are anaesthetised and receive concurrent supplementary oxygen. Both factors promote the development of pulmonary atelectasis, which may mask or mimic lung pathology and compromise image quality, which is of concern to the radiologist. The aim of the study was firstly to determine whether significant atelectasis would develop using a commonly employed anaesthetic protocol in a typical hospital setting, especially where dogs may have been anaesthetised in lateral recumbency prior to scanning. Secondly, to determine whether a change in body position to sternal recumbency would be sufficient to resolve atelectasis. Six healthy adult Beagles were anaesthetised in sternal recumbency and using a breath-hold technique, baseline helical transverse thoracic images were acquired. Dogs were then placed in either right or left lateral recumbency for 30 minutes, with scans performed at predetermined lung lobe locations and time intervals. Dogs were then repositioned in sternal recumbency for a further 20 minutes, with similar scans performed. The study was repeated two weeks later in the opposite lateral recumbency. Changes in Hounsfield units and cross-sectional area of all lung lobes were measured. Lateral recumbency did not result in true atelectasis in healthy Beagles of normal body condition. Infrequently, patchy increased attenuation, which failed to resolve completely during sternal recumbency, was visualised in the left cranial lobe during left lateral recumbency. The degree of attenuation changes in healthy Beagles was minimal, and thus if dogs were anaesthetised in lateral recumbency prior to computed tomography, this should not preclude scanning. / Dissertation (MMedVet)--University of Pretoria, 2016. / Companion Animal Clinical Studies / MMedVet / Unrestricted

Introduction: Magnetic resonance (MR) represents still the gold standard in myocardial imaging. There are some studies suggesting that the computed tomography (CT) might be a valid alternative for some patients (especially the ones who are unable to undergo MR). Aims: We had two aims. Aim number 1: To evaluate the ability of CT in the evaluation of delayed contrast enhancement (DCE) in patients with dilated cardiomyopathy. Aim number 2: To assess the possibilities of CT originally performed for a different indication in myocardial tissue characterization. Methods: Part 1: We prospectively enrolled 17 patients with dilated cardiomyopathy. All the patients underwent both cardiac CT and cardiac MR. We compared the findings of DCE on CT with the findings of DCE on MR. Part 2: We retrospectively evaluated 96 patients who underwent both CT for any indication and cardiac MR. We compared the findings of a hypodense area in the myocardium with the findings of DCE on MR. Results: Part 1: CT detected DCE in 3 patients and MR detected DCE in 6 patients. The agreement between both modalities was in v 82% cases (kappa 0.56). The sensitivity and specificity of CT were 50% and 100%, respectively and the positive predictive value was 100%. In patients with positive findings on CT, the localization of DCE was almost...

Die moderne multimodale Computertomografie (CT) beinhaltet das Schichtröntgen des Gehirns (native CT), die Darstellung der hirnversorgenden Arterien (CT-Angiografie) und die Messung der Hirndurchblutung (CT-Perfusion). Mit Hilfe dieser Untersuchungstechnik kann bei Patienten mit akutem Schlaganfall rasch die Ursache der plötzlich eingesetzten Symptome beleuchtet werden: Liegt eine Gefäßobstruktion oder eine Blutung in das Gehirn vor? Wie ausgedehnt ist die Durchblutungsstörung und wie viel Hirngewebe ist bereits beschädigt bzw. vom Untergang bedroht? Anhand dieser Informationen kann sofort eine spezifische Therapie eingeleitet werden, die es ermöglicht, die Patienten vor dauerhafter schwerer Behinderung zu bewahren bzw. die Prognose schon früh abzuschätzen. / Computed tomography (CT), including CT perfusion imaging and CT angiography, has the capacity to assess stroke pathology on a functional and morphological level and can thus provide important information about patients with acute stroke. It excludes brain haemorrhage, assesses the extent of perfusion deficit, the extent of ischemic damage, and the site and type of arterial obstruction. Ischemic brain tissue below the blood flow level of structural integrity takes up water immediately and causes a decrease in x-ray attenuation. Computed tomography thus has the specific advantage of being able to identify the brain tissue which is irreversibly injured. If CT can exclude major ischemic damage in acute stroke patients, reperfusion strategies may rescue brain function and prevent disability.