Cone penetration in sands is a complex process: it contains several challenges that geomechanicians face, such as large displacements, large strains, strain localization, and microscale phenomena such as particle crushing and sand fabric evolution. In order to gain a deeper understanding of the penetration process and the mechanisms controlling penetration resistance, capturing these displacement and strain fields and microscale phenomena is necessary. Furthermore, as more sophisticated theoretical models become available for the simulation of the cone penetration problem, the experimental validation of those methods becomes vital.<br><div><br></div><div>This dissertation presents a multiscale study of the cone penetration process in silica sands. The penetration problem is investigated using a combinational approach consisting of calibration chamber experiments, digital image correlation (DIC) analysis, and X-ray computed Tomography (XCT) scans. Three silica sands with different particle characteristics are used in the experimental program. These three sands have similar particle size distributions; however, they differ in particle morphologies and particle strengths. These differences allow a study of the effect of microscale sand properties on the macroscale response of the sands to the cone penetration process. The three silica sands used in this research are fully characterized using laboratory experiments to obtain particle size distributions, particle morphologies, particle crushing strengths, minimum and maximum packing densities, and critical-state friction angles. Subsequently, both dense and medium-dense samples of the three sands are compressed in a uniaxial loading device placed inside an X-ray microscope (XRM) and scanned at multiple stress levels during uniaxial compression. Results from uniaxial compression experiments indicate that: (1) the compressibility of the sands is closely tied to particle morphology and strength, and (2) the anisotropy in the orientations of interparticle contact normals generally increases with axial stress; however, this increase is limited by the occurrence of particle crushing in the sample.<br></div><div><br></div><div>Subsequently, cone penetration experiments are performed under different confinement levels on dense samples of the three sands in aspecial half-cylindrical calibration chamber equipped with DIC capabilities. For each penetration experiment, incremental displacement fields around the cone penetrometer are obtained using DIC analysis, and these incremental displacement fields are further analyzed to compute the incremental strain fields. A novel methodology is developed to obtain the shear-band patterns that develop around the penetrometer automatically. Furthermore, differences in the shear-band patterns in deep and shallow penetration environments are also investigated. Results show that strain fields tend to localize intensely near the penetrometer tip, and the shear bands tend to develop along the inclined face and near the shoulder of the penetrometer. Significant differences in the shear band patterns in deep and shallow penetration environments are also observed.<br></div><div><br></div><div>After each cone penetration experiment, a specially developed agar-impregnation technique is used to collect minimally disturbedsand samples from around the penetrometertip. These agar-impregnated sand samples are scanned in the XRM to obtain 3D tomography data, which are further analyzed to quantify particle crushing around the penetrometer tip. The results show that: (1) for a given sample density, the amount of crushing around the cone penetrometer depends on the confinement and the sand particle characteristics, (2) the level of crushing is not uniform around the penetrometer tip, with more severe crushing observed near the shoulder of the penetrometer, and (3) the regions with more severe particle crushing around the penetrometer approximately overlap with regions of high shear strain and volumetric contraction. A framework is also proposed to obtain the ratio of penetration resistance in more crushable sands to penetration resistance in less crushable sands. Furthermore, a novel resin-impregnation technique is also developed to collect undisturbedsand samples from around the penetrometer tip. The resin-impregnated sand sample collected after one of the penetration experiments is scanned in the XRM to obtain the 3D tomography data, which is then analyzed to obtain the distribution of interparticle contact normal orientations at multiple locations around the penetrometer tip. These analyses indicate that the interparticle contact normals tend to orient themselves with the incremental principal strains around the penetrometer: below the penetrometer tip, the interparticle contact normals orient vertically upwards, while closer to the shoulder of the penetrometer, the interparticle contact normals become more radially inclined.<br></div><div><br></div><div>Data presented in this dissertation on penetration resistance, incremental displacement fields, incremental strain fields, particle crushing, and interparticle contact normal orientations around the cone penetrometer are aimed to be useful to researchers working on the multiscale modeling of penetration processes in granular materials and aid in the further development of our understanding of penetration processes in sands.<br></div>

Överkäkshörntänderna erumperar normalt mellan 11 till 13 års ålder. Dessa kan dock bli retinerade och orsaka rotresorption på intilliggande incisiver. Konventionell röntgen upptäcker rotresorption i 12.5 procent av fallen, medan datortomografiundersökning (CT) upptäcker resorptioner i ungefär 50 procent av fallen. En huvudsaklig etiologisk faktor till resorptionerna är fysisk kontakt mellan den retinerade överkäkshörntanden och incisivens rot. Syftet med denna studie var att undersöka rotresorberade överkäksincisivers prognos efter förflyttning av intilliggande överkäkshörntänder. Studien inkluderade 22 patienter med totalt 31 rotresorberade överkäksincisiver. Alla patienter hade genomgått ortodontisk behandling för att förflytta de retinerade överkäkshörntänderna. Intraoral röntgen eller CT-undersökning genomfördes direkt efter avslutad behandling (T1). Uppföljning med CT genomfördes ett antal år efter avslutad behandling (T2). Alla röntgenologiska bilder från T2 jämfördes med bilderna från T1. Rotresorptionerna bedömdes avseende lokalisering och resorptionsgrad. Graden av resorption indelades i mild, måttlig och grav. Utvecklingen av resorptionerna mellan T1 och T2 bedömdes som antingen avstannad, progredierad eller minskad. Resultatet visar att 54.8 procent av resorptionerna var avstannade vid T2 jämfört med T1, 22.6 procent av resorptionerna hade progredierat, 6.5 procent av resorptionerna hade minskat och 16.1 procent av de rotresorberade incisiverna var extraherade vid T2. Alla extraherade incisiver var diagnostiserade med grav rotresorption. Sammanfattningsvis visar aktuella resultat att; (1) ungefär 50 procent av rotresorptionerna avstannade på lång sikt, (2) ungefär 20 procent av resorptionerna progredierade, (3) minskning var ovanlig och (4) incisiver med grava resorptioner direkt efter korrektion av de retinerade överkäkshörntänderna hade en dålig långtidsprognos i kombination med exempelvis trauma eller parodontit. / Maxillary canines normally erupt at the age of 11 to 13. These can however become impacted and cause root resorptions of adjacent incisors. Conventional radiography reveals root resorptions in 12.5 per cent of cases. Computed tomography (CT) reveals root resorptions in about 50 per cent of cases. A main etiological factor is physical contact between the impacted maxillary canine and the incisor root. The aim of the present study is to evaluate the prognosis of maxillary incisors with root resorptions after correction of adjacent maxillary canines. The present study includes 22 patients with a total of 31 root resorbed maxillary incisors. All patients had undergone orthodontic treatment in order to correct the impacted maxillary canines. Intraoral radiographs or CT investigations were taken immediately post treatment (T1). Follow-up examinations with CT were performed a number of years later (T2). All radiographs taken at T2 were compared with the radiographs taken at T1. The root resorptions were examined with respect to localization and degree of resorption. The degree of resorption was graded as slight, moderate and severe. The change of resorptions between T1 and T2 was evaluated as unchanged, increased or decreased. The results show that 54.8 per cent of the resorptions were unchanged at T2 compared to T1, 22.6 per cent of the resorptions increased, 6.5 per cent of the resorptions decreased and 16.1 per cent of the root resorbed incisors were extracted at T2. All extracted teeth were diagnosed having severe root resorption. In summery, the present results showed that; (1) about 50 per cent of the incisor root resorptions arrested in the long-term, (2) about 20 per cent of the resorptions increased, (3) decrease of the resorptions were rare and (4) the incisors with severe resorptions immediately after the correction of the impacted canines had a bad long-term prognosis if combined with eg. trauma or periodontitis.

X-ray computed tomography (CT) holds a critical role in current medical practice for the evaluation of patients, particularly in the emergency department and intensive care units. Expensive high resolution stationary scanners are available in radiology departments of most hospitals. In many situations however, a small, inexpensive, portable CT unit would be of significant value. Several mobile or miniature CT scanners are available, but none of these systems have the range, flexibility or overall physical characteristics of a truly portable device. The main challenge is the design of a geometry that optimally trades image quality for system size. The goal of this work has been to develop analysis tools to help simulate and evaluate novel system geometries. To test the tools we have developed, three geometries have been considered in the thesis, namely, parallel projections, clam-shell and parallel plate geometries. The parallel projections geometry is commonly used in reconstruction of images by filtered back projection technique. A clam-shell structure consists of two semi-cylindrical braces that fold together over the patient's body and connect at the top. A parallel plate structure uses two fixed flat or curved plates on either side of the patient's body and image from fixed sources/detectors that are gated on and off so as to step the X-ray field through the body. The parallel plate geometry has been found to be the least reliable of the three geometries investigated, with the parallel projections geometry being the most reliable. For the targeted application, the clam-shell geometry seems to be the solution with more chances to succeed in the short term. We implemented the Van Cittert iterative technique for the reconstruction of images from projections. The thesis discusses a number of variations on the algorithm, such as the use of the Conjugate Gradient Method, several choices for the initial guess, and the incorporation of a priori information to handle the reconstruction of images with metal inserts.

Computed tomography urography (CTU) is today the imaging method used to investigate patients with suspected urinary tract malignancy, replacing the old imaging method intravenous pyelography (IVP) about a decade ago. The downside of this shift was that the effective radiation dose to the examined patient was eight times higher for CTU compared to IVP. Based on four different studies, the present thesis focused on efforts to reduce the CTU radiation dose.   In study I, the number of cysts and solid lesions in the separate scan phases was evaluated in 57 patients undergoing four-phase CTU 1997-98. The number of scans was reduced from four to three when the nephrographic scan was abolished following study I. Study II registered the diameter of renal cell carcinoma (RCC) and the presenting symptoms in the total number of patients (n=232) diagnosed with RCC between 1997 and 2003. The results from study II showed that the critical size for RCCs to cause macroscopic hematuria was ≥ 4 cm. Study III was a dose-escalation study aimed to decide the minimal possible tube load in the unenhanced and excretory phase scans if the low dose images are reviewed together with normal dose corticomedullary phase images. Study III showed that it is possible to reduce the mean effective dose in three phase CTU from 16.2 mSv to 9.4 mSv with a combined low and normal dose CTU protocol. Study IV investigated the changes in the CTU protocol between 1997 and 2008, and the development of the effective radiation dose. Study IV clarified how the CTU protocol has changed between 1997 and 2008 and as a result the mean effective radiation dose to patients undergoing CTU in 2008 is only 39% of the effective dose in 1997.   In conclusion, the findings from the studies included in this thesis have contributed to a reduced radiation dose to patients undergoing CTU. The mean effective dose from CTU is at present only three times higher compared to that from the IVP.

Introdução: Pacientes com cardiopatia congênita submetidos ao procedimento de Fontan (PF) vêm atingindo a idade adulta com significativas consequências sistêmicas, particularmente hepáticas. Tais injúrias hepáticas podem resultar em fibrose, cirrose e nódulos hepáticos (NH), que podem ser benignos ou malignos. Porém, não há, até o momento, consenso na literatura quanto ao rastreamento desses nódulos, sobretudo acerca do início e da melhor modalidade para tal fim. Objetivo: Esse estudo objetivou (a) avaliar a frequência de NH em pacientes submetidos ao PF na ultrassonografia (USG), tomografia computadorizada (TC) e ressonância magnética (RM), assim como a concordância entre tais métodos; (b) investigar se há correlação entre a presença de NH e algumas variáveis clínicas e laboratoriais; (c) analisar se há diferença nos valores de rigidez hepática utilizando a elastografia por USG por meio da técnica acoustic radiation force impulse (ARFI) entre os pacientes com e sem NH. Métodos: Foram recrutados, prospectivamente, 49 pacientes submetidos ao PF entre agosto de 2014 e junho de 2016. Esses pacientes foram submetidos a rastreamento clínico e laboratorial de hepatopatia, e elastografia hepática por USG com ARFI, TC e RM. A concordância entre os testes foi acessada utilizando o kappa de Cohen. A correlação entre NH com as outras variáveis foi realizada com teste t de Student ou teste de Mann-Whitney para variáveis contínuas sem distribuição normal e teste qui-quadrado ou teste de Fisher para variáveis categóricas. Resultados: NH foram detectados em 3/49 (6%), 14/44 (31,8%) e 19/48 (39,6%) pacientes na USG, TC e RM, respectivamente. Houve uma concordância quase perfeita entre TC e RM na detecção de NH (kappa: 0,849, p < 0,001), porém a USG não demonstrou concordância com TC e RM (kappa: 0,006, p=0,095 e kappa: 0,083, p = 0,032, respectivamente). Nenhuma variável clínica ou laboratorial apresentou correlação significativa com a presença de NH, inclusive o tempo após o PF. Os valores de rigidez hepática no ARFI foram significativamente mais elevados nos pacientes com NH (2,64 ± 0,81 m/s vs. 1,94 ± 0,49 m/s; p=0,002) e foram um preditor significativo para NH (AUC: 0,767, p=0,002). Conclusão: Na nossa população, mais de um terço dos pacientes após o PF apresentou NH na TC ou RM, mas a USG não detectou a grande maioria dos nódulos. Nenhum dado clínico ou laboratorial apresentou correlação significativa com a presença de NH. A rigidez hepática no ARFI foi significativamente mais elevada nos pacientes com NH. Tais achados sugerem que a USG não é um método diagnóstico efetivo no rastreamento de NH, porém a elastografia por ARFI pode ser útil, orientando quais pacientes devem submetidos à TC ou RM / Background: Patients with congenital heart disease after Fontan procedure (FP) are reaching the adulthood with significant systemic consequences, particularly to the liver. Those hepatic injuries can cause liver fibrosis, cirrhosis and hepatic nodules (HN), which can be benign or malignant. Currently, there is no consensus in the literature regarding screening of HN in patients after FP concerning when to start and which is the best imaging modality indicated for it. Purpose: This study aimed (a) to evaluate the frequency of HN in patients after FP on ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI), as well as their inter-test agreement; (b) to investigate if there is any correlation between presence of HN and clinical or laboratorial variables; (c) to analyze if liver stiffness (LS) values using acoustic radiation force impulse (ARFI) on US elastography differ between patients with and without HN. Methods: We prospectively recruited 49 patients after FP from August 2014 to June 2016. These patients underwent clinical and laboratorial screening of hepatic disorders, ARFI elastography of the liver, abdominal US, CT and MRI. Intertest agreement was assessed by using weighted Cohen\'s kappa as statistics. The dependence of HN with the variables was performed using Student\'s t test or ANOVA for independent continuous variables without normal distribution; and chi-square test or Fisher\'s test for categorical variables. Results: HN were detected in 3/49 (6%), 14/44 (31.8%), and 19/48 (39.6%) patients on US, CT and MRI, respectively. There was an almost perfect agreement between CT and MRI in detecting HN (kappa: 0.849, p < 0.001); however, US had a non-significant correlation with CT and MRI (kappa: 0.006, p=0.095 and kappa: 0.083, p = 0.032, respectively). No clinical or laboratorial data had any significant correlation with the presence of HN, including time since FP. LS on ARFI was significantly higher in patients with HN (2.64 ± 0.81 m/s vs. 1.94 ± 0.49 m/s; p=0.002) and was a significant predictor of HN (AUC 0.767, p=0.002). Conclusion: In our study, more than one-third of patients after FP had HN on CT or MRI, but US did not detect the vast majority of them. No clinical or laboratorial data had any significant correlation with the presence of HN. LS on ARFI was significantly higher in patients with HN. These findings may suggest that US is not an effective imaging modality for screening of HN; however, ARFI elastography may help guiding which patients should be further imaged with CT or MRI

Introdução: a necrose da gordura epipericárdica é uma entidade caracterizada por dor torácica súbita de forte intensidade e ventilatório-dependente em indivíduos previamente hígidos, com menos de 50 casos descritos na literatura. O achado característico na tomografia computadorizada de tórax é de uma lesão arredondada com atenuação de gordura e graus variáveis de densificação dos planos adiposos adjacentes localizada na gordura epipericárdica. O tratamento é sintomático com analgésicos e as alterações radiológicas tendem a regredir em poucas semanas. O aumento do número de casos, nos últimos anos, sugere que a entidade possa ser subdiagnosticada. O objetivo do estudo foi estimar a frequência da necrose numa população e comparar dados clínicos e laboratoriais com um grupo controle. Material e Métodos: 7463 tomografias computadorizadas de tórax realizadas no pronto atendimento de um hospital quaternário, de julho de 2011 a dezembro de 2014 foram avaliadas por um radiologista na busca de imagens compatíveis com necrose da gordura epipericárdica. Vinte pacientes foram selecionados e comparados com um grupo controle pareado por idade e sexo, numa proporção de 1:5 pacientes com dor torácica atípica, que também realizaram tomografia computadorizada de tórax neste período. Os dados clínicos e laboratoriais foram comparados por meio de modelos de regressão linear e os aspectos de imagem e os relatórios das tomografias dos pacientes com a necrose foram avaliados individualmente. A frequência da NGE nos pacientes que realizaram tomografia computadorizada de tórax no pronto atendimento por dor torácica foi estimada. O estudo obteve aprovação do Comitê de Ética. Resultados: a média de idade dos pacientes com a necrose foi 42 ± 13 anos e, desses, 25% mulheres (5 pacientes). A necrose esteve presente em 2.15% dos indivíduos que realizaram tomografia de tórax por dor torácica e em 0.26% de todos os pacientes que realizaram tomografia de tórax no pronto atendimento. A lesão é mais frequente do lado esquerdo (p = 0.01, IC = 0.56-0.94) e está associada à derrame pleural ipsilateral (p=0.01, IC 0.36-0.80) e atelectasia (p=0.01, IC 0.58-0.99) (p=0.01, IC 0.36-0.80). No contexto de dor torácica não coronariana, a necrose tem maior probabilidade de ocorrer na ausência de outros sintomas (p=0.005, IC -5.83, -1.27) e com o não uso de medicamentos (p= 0.01 e IC-3.33, -0.40). A análise dos relatórios das tomografias de tórax mostrou um aumento nas taxas de diagnóstico ao longo dos anos. Conclusão: pacientes com dor torácica atípica que não fazem uso de medicamentos e não possuem outros sintomas associados na ocasião do atendimento exibem maior probabilidade de apresentar necrose da gordura epipericárdica. A incidência da necrose na população estudada foi de 2.15%. O conhecimento da entidade contribui para a melhora da taxa de diagnóstico / Introduction: Epipericardial fat necrosis is characteryzed by an acute onset of pleuritic chest pain in previously healthy patients. There are less than 50 cases described in english literature. The diagnosis is made by chest tomography and the deffinitive finding is a small ovoid fat attenuation lesion with mild to moderate surrounding strandings inside the epipericardial fat. The treatment is symptomatic, by relieving the symptoms with analgesics, and the radiological findings tend to disappear in a few weeks. There is an important raise of the diagnosis in the last years, what suggests that epipericardial fat necrosis is probably underdiagnosed. The objective of the study is to estimate the frequency of the necrosis in a group of patients and to compare clinical and laboratorial data with a control group. Material and Methods: The Ethics Committee approved this study. The 7463 chest tomography were performed in the emergency department of a quaternary hospital from July 2011 to December 2014. One radiologist read the images of all chest tomography and sought for image findings compatible with epipericardial fat necrosis. Twenty patients were diagnosed with epipericardial fat necrosis and compared with a control group paired by age and sex. The control group consisted of 100 patients with non-coronary chest pain who performed a chest tomography in the same period. The clinical and laboratorial data were compared using linear regression models. The imaging findings and the radiology reports were evaluated. The frequency of epipericardial fat necrosis in this group of patients was estimated. Results: The mean age of the necrosis group was 42 ± 13 years (25% women). Epipericardial fat necrosis was present in 2.15% of the patients who performed a chest tomography because of chest pain and in 0.26% of all patients that performed a chest tomography for any reason in the emergency department in the period. Epipericardial fat necrosis is more frequent in the left side (p = 0.01, IC = 0.56-0.94). It is associated with ipsilateral pleural effusion (p=0.01, IC 0.36-0.80) and atelectasis (p=0.01, IC 0.58-0.99). Epipericardial fat necrosis is more likely to occur in the absence of other symptoms (p=0.005, IC -5.83, -1.27) and in patients who are not in use of any medication (p= 0.01 e IC-3.33, -0.40). The radiological reports demonstrated increased rates of the diagnosis of epipericardial fat necrosis over the years. Conclusion: Patients who are in the emergency department with isolated atipical acute chest pain and are not in use of medications are more likely to have epipericardial fat necrosis. The frequency of the necrosis in this population was 2.15%. The knowledge of the entity leads to an increased rate of radiological diagnosis

O trauma é uma das principais causas de morbidade e mortalidade em uma faixa etária que compreende adolescentes e adultos jovens, em proporção dominante do sexo masculino, com grande impacto econômico e social. Dentro do complexo do trauma, o traumatismo abdominal fechado (TAF) é um evento bastante freqüente e apresenta dificuldade na avaliação e manejo, uma vez que o exame clínico apresenta baixa sensibilidade e especificidade. A detecção de hemoperitônio é um dos métodos de avaliação indireta de possíveis lesões intra-abdominais, inicialmente pela punção abdominal diagnóstica e posteriormente pela lavagem peritoneal diagnóstica, que, apesar da eficácia, apresentam inconvenientes invasividade e impossibilidade na quantificação do hemoperitônio e no estadiamento da lesão, resultando em laparotomias não-terapêuticas. Os métodos de imagem prestam utilidade na investigação de lesões intra-abdominais, como a radiografia convencional e contrastada, ultra-sonografia (US) e a tomografia computadorizada (TC), esta última o método que apresenta melhor resolutividade, porém como desvantagens o custo, acessibilidade, o uso de radiação ionizante e meio de contraste e o deslocamento do paciente até o aparelho. A US apresenta-se como alternativa na avaliação inicial destes pacientes como método não invasivo e com potencial de dano virtualmente ausente, de baixo custo, de rápida realização e portátil. Apesar disso, este método também apresenta suas limitações, como na de lesões intra-abdominais na ausência de líquido livre. Este estudo foi realizado com a finalidade de estabelecer o desempenho da US neste contexto, permitindo racionalizar o uso da TC. Com essa finalidade foram estudados 163 pacientes atendidos pelo PS-HC/FMUSP, com a realização consecutiva de US e TC. A população estudada enquadra-se no perfil usual das vítimas de trauma, sendo 83% do sexo masculino e 56% na faixa etária entre 20 e 39 anos e em 73% dos casos eram vítimas de acidentes de trânsito. Eles foram trazidos ao serviço num tempo médio de 51 minutos, na maior parte estáveis e com nível de consciência satisfatório. A US levou em média 5 minutos para ser realizada e o intervalo médio até a realização da TC foi de155 minutos. Dos 163 pacientes 31 (19%) apresentaram US positiva e 132 (81%) apresentaram US negativa. Dos mesmos 163 pacientes 33 (20,2%) apresentaram TC positiva e 130 (79,8%) apresentaram TC negativa, resultando em sensibilidade de 73%, especificidade de 95%, acurácia de 90% em prevalência de 20%, com valor preditivo positivo de 77% e valor preditivo negativo de 93%. Corrigindo quanto à detecção de líquido livre, resulta-se em sensibilidade de 64%, especificidade de 98%, acurácia de 89% em prevalência de 27,6% e valor preditivo positivo de 93% e valor preditivo negativo de 88%. Ao se considerar a evolução dos pacientes, o desempenho da US foi semelhante ao da TC. Ao se considerar a necessidade de cirurgia a US apresentou acurácia de 87%, com valor preditivo positivo de 58% e valor preditivo negativo de 94%, próximo da TC, com 91% de acurácia, 67% de valor preditivo positivo e 97% de valor preditivo negativo. 24% dos pacientes com lesões intra-abdominais não apresentavam líquido livre, registrados pela TC. O espaço hepatorrenal e a pelve são os locais mais freqüentes do encontro de líquido, sendo 74% e 67% à US e 51% e 62% à TC, respectivamente. Entre os fatores que indicaram tendência de necessidade cirúrgica destaca-se a presença de líquido no espaço hepatorrenal (14 de 20 pacientes) e somatória dos bolsões de líquido acima de 3,0 cm. A detecção de lesões em víscera parenquimatosa foi baixa: 4 casos em 33, sendo que apenas 2 deles se confirmaram. Dentre os fatores que limitam o estudo pela US estão as lesões intraparenquimatosas que não se associam a líquido livre e hematomas retroperitoneais. A experiência do examinador não influenciou no número de casos positivos ou negativos, mas notou-se uma tendência a falso-positivos em examinadores mais experientes e falso-negativos em menos experientes. Assim, a US apresenta-se como ferramenta útil na avaliação inicial de traumatismo abdominal fechado, fornecendo subsídios para avaliação clínica, que associado aos demais dados, permite determinar a conduta. / Trauma is a major cause of morbidity and mortality in an age group including from teenagers to young adults, in a male dominat proportion, resulting in great economic and social impact. Within the complex of trauma, blunt abdominal trauma (BAT) is frequent event and presents difficulty in the evaluation and management since the clinical examination shows low sensitivity and specificity. The detection of hemoperitoneum is one of the methods of evaluation of possible indirect intra-abdominal injuries, initially using direct diagnostic abdominal paracentesis and posteriorly the diagnostic peritoneal lavage, that despite the effectiveness, have drawbacks such as invasiveness and the inability of hemoperitoneum quantification and the lesion staging, resulting in non-therapeutic laparotomies. Imaging methods provide useful information in the investigation of abdominal injuries, such as conventional and contrast radiology, ultrasound (US) and computed tomography (CT), which is the best effective method, but has its own drawbacks, such as cost, accessibility, use of ionizing radiation and contrast media and the displacement of the patient to the machine. US presents itself as an alternative in the initial evaluation of these patients as noninvasive method, with lack of harmfulness, low cost, fast answer and portability. Nevertheless, this method also has its limitations, as in cases of abdominal injuries without free fluid. This study was conducted in order to establish the performance of the US in this setting, allowing to rationalise the use of CT. For this purpose we studied 163 patients treated in the ER of HC/FMUSP, with the completion of consecutive US and CT. The population fits the usual profile of trauma victims, with 83% male, 56% in the age group between 20 and 39 years and in 73% of cases victims of traffic accidents. They were brought to the service in an average time of 51 minutes, mainly stable and with satisfactory level of consciousness. US took on average 5 minutes to be performed and the average interval until CT completion was 155 minutes. 31 (19%) of 163 patients showed positive US and 132 (81%) had negative US. 33 (20.2%) of the same 163 patients had positive CT and 130 (79.8%) had negative CT, resulting in a sensitivity of 73%, specificity of 95%, accuracy of 90% in 20% prevalence, with 77% of positive predictive value and 93% of negative predictive value. Correcting the detection of free fluid, results in 64% of sensitivity 98% of specificity 89% of accuracy in 28% of prevalence, with 93% of positive predictive value and 88% of negative predictive value of 88%. Considering the evolution of the patients, US performance was similar to that of CT. Considering need for surgery the US presented accuracy of 87%, positive predictive value of 58% and negative predictive value of 94%, near CT, with accuracy of 91%, predictive value of 67% and negative predictive value of 97%. 24% of patients with abdominal injuries did not have free fluid, as recorded by CT. The hepatorrenal space and pelvis were the most frequent sites fluid finding, 74% and 67% at US and 51% and 62% at CT, respectively. Among the factors that showed a tendency for surgery requirement were the presence of fluid in hepatorrenal space (14 of 20 patients) and the sum of liquid pockets over 3.0 cm. Detection of parenchymal lesions was low: 4 cases in 33, while only 2 of them confirmed. Among the factors that limit the US study are parenchymal lesions not associated with free fluid and retroperitoneal hematomas. Examiner experience did not influence the number of negative or positive cases, but there was a tendency to false positive with most experienced examiners and false negative with less experienced. Thus, US is an useful tool in the initial evaluation of blunt abdominal trauma, providing information for clinical evaluation, which associated with other data, tailors the management.

Este estudo objetivou comparar o diagnóstico das reabsorções dentárias em dois tipos de exame: radiografia periapical e tomografia computadorizada de feixe cônico (Cone Beam). A amostra constituiu-se de 16 dentes anteriores e da descrição clínica de 20 exames tomográficos de feixe cônico. Nos dentes anteriores foram analisados as características morfológicas da raiz dentária comparando a imagem da radiografia periapical e os cortes tomográficos transversais oblíquos. Os resultados revelaram que: 1. A tomografia computadorizada de feixe cônico é um meio de diagnóstico eficiente para previsibilidade e avaliação das reabsorções radiculares. 2. Os cortes tomográficos transversais oblíquos permitem a análise das faces: vestibular e lingual do dente e, nos cortes tomográficos sagitais oblíquos obtemos a imagem das faces: mesial e distal. 3. Não há correlação entre o diagnóstico obtido em radiografia periapical e nos cortes tomográficos transversais oblíquos. / This study aimed to compare the diagnosis of tooth resorptions by two types of examinations, periapical radiography and cone beam computed tomography. The sample was composed of 16 anterior teeth and clinical description of 20 cone beam tomographies. The morphological characteristics of dental root were analyzed on anterior teeth, comparing the image on the periapical radiograph and oblique transverse tomographic sections. The results revealed that: 1. Cone beam computed tomography is an effective diagnostic method for prediction and evaluation of tooth resorptions. 2. Oblique transverse tomographic sections allow analysis of buccal and lingual aspects of teeth; oblique sagittal tomographic sections allow analysis of images of mesial and distal aspects. 3. There is no correlation between the diagnosis obtained on periapical radiographs and oblique transverse tomographic sections.

A gordura pericárdica (GP), um componente do tecido adiposo visceral, tem sido consistentemente relacionada com aterosclerose coronária na população geral. Este estudo avaliou a associação entre GP e a calcificação arterial coronária (CAC) em pacientes com doença renal crônica (DRC) não dialítica. Este é um estudo transversal post-hoc da linha de base de coorte prospectiva de 117 pacientes com DRC em seguimento ambulatorial sem doença coronária manifesta (idade, 56,8 ± 11 anos; 64% do sexo masculino; 95,1% hipertensos; 25,2% diabéticos; 15,5% com história prévia de tabagismo; e estágios 2 a 5 da DRC e ritmo de filtração glomerular estimado de 36,8 ± 18,1 ml/min). O escore de CAC, volume de GP e gordura visceral abdominal (GVA) foram medidos por tomografia computadorizada. A associação da GP, como variável contínua, com a presença de CAC foi analisada por regressão logística multivariada. CAC (escore de cálcio>0) esteve presente em 59,2% dos pacientes. Na comparação com os pacientes sem CAC, aqueles com CAC eram 10 anos mais velhos, apresentaram maior proporção de homens (78,7% versus 42,9%, p < 0.001), tiveram maior circunferência de abdominal (95,9 ± 10,7 versus 90,2 ± 13,2 centímetros, p=0,02), maior volume de GP (224,8 ± 107,6 versus 139,1 ± 85,0 cm³, p < 0,01), e maior área de GVA (109,2 ± 81,5 versus 70,2 ± 62,9 cm², p=0,01). Em análise multivariada ajustada para idade, sexo, diabetes, história de tabagismo, história de tabagismo, e hipertrofia ventricular concêntrica; GP esteve significantemente associada com a presença de CAC (OR: 1,88 95% IC: 1,03-3,43 por desvio padrão, p=0,04). GP permaneceu associada com CAC mesmo após ajuste adicional para ritmo de filtração glomerular e fósforo sérico (OR: 1,85 95% IC: 1,00 - 3,42, p=0,05). A GP está independentemente associada com CAC em pacientes com DRC não dialítica. / Pericardial fat (PF), a component of visceral adipose tissue has been consistently related to coronary atherosclerosis in the general population. This study evaluated the association between PF and coronary artery calcification (CAC) in non-dialysis dependent chronic kidney disease (CKD) patients. This is a post-hoc cross sectional analysis of the baseline of a prospective cohort of 117 outward CKD patients without manifest coronary artery disease (age, 56.9 ± 11.0 years, 64,1% males, 95.1% hypertensive, 25.2% diabetics, 15.5% ever smokers, CKD stage 2 to 5 with estimated glomerular filtration rate 36.8 ± 18.1 ml/min). CAC scores, PF volume and abdominal visceral fat (AVF) areas were measured by computed tomography. The association of PF as a continuous variable with the presence of CAC was analyzed by multivariate logistic regression. CAC (calcium score >0) was present in 59.2% patients. On the comparison with patients with no CAC, those with CAC were 10 years older on average, had a higher proportion of male gender (78.7% vs. 42.9%, p < 0.001), and had higher values of waist circumference (95.9 ± 10.7 versus 90.2 ± 13.2 cm, p=0.02), PF volumes (224.8±107.6 versus 139.1±85.0 cm³, p < 0.01) and AVF areas (109.2 ± 81.5 versus 70.2 ± 62.9 cm², p=0.01). In the multivariate analysis, adjusting for age, gender, diabetes, smoking and, left ventricular concentric hypertrophy, PF was significantly associated with the presence of CAC (OR: 1.88 95% CI: 1.03-3.43 per standard deviation, p=0.04). PF remained associated with CAC even after additional adjustments for estimated glomerular filtration rate or serum phosphorus (OR: 1.85 95% CI: 1.00-3.42, p=0.05). PF is independently associated with CAC in non-dialysis dependent CKD patients

INTRODUÇÃO: A maioria dos estudos sobre baixa massa muscular e osso envolvem populações idosas. No entanto, como o hipoestrogenismo nos primeiros anos da menopausa é capaz de modular negativamente a massa óssea e muscular, é importante compreender a interação entre músculo e osso neste período. Além disso, há uma escassez de estudos que investigam a influência potencial da massa e função muscular sobre a qualidade óssea (microarquitetura e resistência), o que poderia fornecer uma visão mais abrangente do risco de fratura nesta população. O objetivo deste artigo foi avaliar as correlações potenciais entre parâmetros musculares (massa, força e função) e microarquitetura e resistência óssea utilizando a tomografia computadorizada periférica de alta resolução (HR-pQCT) em mulheres pós-menopáusicas. MÉTODOS: Um total de 225 mulheres menopausadas saudáveis (56,4 ± 4,6 anos) foram avaliadas por questionário clínico, exames laboratoriais e composição corporal (DXA, Hologic, QDR-4500). A qualidade dos ossos (densidade, microarquitetura, porosidade cortical e resistência) foi analisada por tomografia computadorizada periférica de alta resolução (rádio distal e tíbia, XtremeCT, Scanco Medical, Brüttisellen, Suíça). A mobilidade funcional e o desempenho muscular foram medidos pela força de preensão palmar (dinamômetro do modelo JAMAR), testes de levantar e sentar em 30 segundos e teste de levantar e caminhar cronometrado. O equilíbrio foi avaliado pela Escala de equilíbrio de Berg. A correlação entre parâmetros ósseos (HR-pQCT) e desempenho muscular foi analisada pelo teste de Spearman (p < 0,05). RESULTADOS: No rádio, houve correlações positivas entre a força de preensão palmar e os parâmetros do HR-pQCT do osso trabecular (densidade mineral óssea volumétrica trabecular [Tb.vBMD]: r = 0,17, p = 0,03, espessura trabecular [Tb.Th]: r = 0,16, p = 0,04), bem como entre a força muscular e a resistência óssea (Rigidez [S]: r = 0,36, p < 0,001). Na tíbia, a massa muscular da perna esquerda foi correlacionada positivamente com o número de trabéculas [Tb.N] (r = 0,16, p < 0,001), separação trabecular [Tb.Sp]: r = - 0,15, p = 0,02), espessura cortical [Ct.Th] (r = 0,21, p = 0,01) e resistência óssea [S] (r = 0,37, p < 0,001). Não houve correlações significativas entre os parâmetros de HR-pQCT e os testes funcionais dos membros inferiores, exceto entre o equilíbrio e a Tb.vBMD na tíbia (r = 0,13, p = 0,04). Houve uma correlação negativa entre a gordura corporal total e a função muscular (teste de levantar e sentar em 30 segundos: r = - 0,21, p < 0,001, escala de equilíbrio de Berg: r = -0,21, p < 0,001). CONCLUSÃO: nas mulheres, nos primeiros anos da menopausa, a força muscular parece desempenhar um papel mais importante nos parâmetros ósseos do membro superior (rádio), enquanto a massa muscular parece exercer maior influência no osso do membro inferior (tíbia). Esses achados sugerem uma diferença na relação entre músculo e osso de acordo com os diferentes segmentos do corpo. Além disso, a correlação negativa entre gordura corporal com função e equilíbrio muscular indica que o aumento da massa gorda corporal pode conferir maior risco de quedas nesta população. Estudos longitudinais são necessários para confirmar esses dados / INTRODUCTION: Most studies on low muscle mass and bone involve elderly populations. However, because postmenopausal hypoestrogenism is able to negatively modulate bone and muscle mass, it is important to understand the interplay between muscle and bone in early menopause. In addition, there is a paucity of studies investigating the potential influence of muscle mass and function upon bone quality (microarchitecture and strength), which could provide a more comprehensive view of fracture risk in this population. The aim of this article was to assess the potential correlations between muscle parameters (mass, strength and function), and bone microarchitecture and strength using high-resolution peripheral computed tomography (HR-pQCT) in postmenopausal women. METHODS: A total of 225 healthy menopausal women (aged 56.4 ± 4.6 years) were evaluated by clinical questionnaire, laboratory and body composition (DXA, Hologic, QDR-4500). Bone quality (density, microarchitecture, strength and cortical porosity) was analyzed by high resolution peripheral computed tomography (distal radius and tibia, XtremeCT, Scanco Medical, Brüttisellen, Switzerland). Functional mobility and muscle performance were measured by hand grip strength (JAMAR model dynamometer), Timed-Stand and Timed Up & Go tests. Balance was assessed by the Berg Balance Scale. The correlation between bone parameters (HR-pQCT) and muscle performance was analyzed by the Spearman test (p < 0.05). RESULTS: At the radius, there were positive correlations between hand grip strength and trabecular bone HR-pQCT parameters (trabecular volumetric bone mineral density [Tb.vBMD]: r=0.17, p = 0.03, trabecular thickness [Tb.Th]: r=0.16, p=0.04), as well as between muscle strength and bone strength (Stiffness [S]: r = 0.36, p < 0.001). At the tibia, the left leg muscle mass was positively correlated with number of trabeculae [Tb.N] (r = 0.16, p < 0.001), trabecular separation [Tb.Sp]: r=- 0.15, p= 0.02), cortical thickness [Ct.Th] (r = 0.21, p = 0.01) and bone strength [S] (r= 0.37, p < 0.001). There were no significant correlations between HR-pQCT parameters and lower limb functional tests, except between the balance and tibial Tb.vBMD (r= 0.13, p = 0.04). There was a negative correlation between total body fat and muscle function (30-s chair test: r = -0.21, p < 0.001, balance: r = -0.21, p < 0.001). CONCLUSION: In postmenopausal women, muscle strength seems to play a more important role in the upper limb bone (radius) parameters, whereas muscle mass seems to exert a higher influence on the lower limb bone (tibia). These findings suggest a difference on relationship between muscle and bone according to distinct body segments. In addition, the negative correlation between body fat and balance/muscle function indicate that increased body fat mass might confer increased risk of falls in this population. Longitudinal studies are needed to test these assumptions