995 resultados para Selective imaging


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RESUMO: pela contracção involuntária de grupos musculares de extensão variável, originando movimentos involuntários e posturas anómalas, por vezes dolorosas. O tratamento convencional consiste em injecções localizadas de toxina botulínica, podendo, em casos refractários, estar indicado o tratamento por estimulação cerebral profunda. A neurobiologia da distonia focal primária permanece incompletamente compreendida. Os estudos de neuro-imagem estrutural e funcional revelam alterações subtis da anatomia e funcionamento do estriado e das vias cortico-basais, com destaque para o aumento do volume, da actividade metabólica e da neuroplasticidade do putamen e de áreas corticais motoras, pré-motoras e sensitivas. O conjunto destas alterações aponta para uma disrupção da regulação inibitória de programas motores automáticos sustentados pelo estriado e pelas vias ortico-subcorticais. Nos últimos anos tem crescido o interesse pelas manifestações psiquiátricas e cognitivas da distonia (estas últimas muito pouco estudadas). Tem despertado particular interesse a possível associação entre distonia focal primária e perturbação obsessivo-compulsiva (POC), cuja neurobiologia parece notavelmente sobreponível à da distonia primária. Com efeito, os estudos de neuro-imagem estrutural e funcional na POC revelam consistentemente aumento do volume e actividade do estriado e do córtex órbito-frontal, apontando mais uma vez para uma disfunção do controlo inibitório, no estriado, de programas comportamentais e cognitivos automáticos. Objectivos: 1. Explorar a prevalência e intensidade de psicopatologia em geral, e de psicopatologia obsessivo-compulsiva em particular, numa amostra de indivíduos com distonia focal primária; 2. Explorar a ocorrência, natureza e intensidade de alterações do funcionamento cognitivo numa amostra de indivíduos com distonia focal primária; 3. Investigar a associação entre a gravidade da distonia focal, a intensidade da psicopatologia, e a intensidade das alterações cognitivas. Metodologia: Estudo de tipo transversal, caso-controlo, observacional e descritivo, com objectivos puramente exploratórios. Casos: 45 indivíduos com distonia focal primária (15 casos de blefaroespasmo, 15 de cãibra do escrivão, 15 de distonia cervical espasmódica), recrutados através da Associação Portuguesa de Distonia. Critérios de inclusão: idade = 18; distonia focal primária pura (excluindo casos de distonia psicogénica possível ou provável de acordo com os critérios de Fahn e Williams); Metabolismo do cobre e Ressonância Magnética Nuclear sem alterações. Controlos doentes: 46 casos consecutivos recrutados a partir da consulta externa do Hospital Egas Moniz: 15 doentes com espasmo hemifacial, 14 com espondilartropatia cervical, 17 com síndrome do canal cárpico. Controlos saudáveis: 30 voluntários. Critérios de exclusão para todos os grupos: Mini-Mental State Examination patológico, tratamento actual com anti-colinérgicos, antipsicóticos, inibidores selectivos da recaptação da serotonina, antidepressivos tri- ou tetracíclicos. Avaliação: Avaliação neurológica: história e exame médico e neurológico completos. Cotação da gravidade da distonia com a Unified Dystonia Rating Scale. Avaliação psicopatológica: Symptom Check-List-90-Revised; entrevista psiquiátrica de 60 minutos incluindo a Mini-International Neuropsychiatric Interview (MINI), versão 4.4 (validada em Português), complementada com os módulos da MINI Plus versão 5.0.0 para depressão ao longo da vida e dependência/ abuso do álcool e outras substâncias ao longo da vida; Yale-Brown Obsessive-Compulsive Symptom Checklist e a Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Avaliação neuropsicológica: Wisconsin Card Sorting Test (WCST; flexibilidade cognitiva); Teste de Stroop (inibição de resposta); Block Assembly Test (capacidade visuo-construtiva); Teste de Retenção Visual de Benton (memória de trabalho visuo-espacial). Análise estatística:os dados foram analisados com a aplicação informática SPSS for Windows, versão 13. Para a comparação de proporções utilizaram-se o teste do Chi-quadrado e o teste de Fisher. Para a comparação de variáveis quantitativas entre dois grupos utilizou-se o teste t de Student ou o teste U de Mann-Whitney (teste de Wilcoxon no caso de amostras emparelhadas). Para comparações de médias entre três grupos recorreu-se à Análise de Variância a um factor (variáveis de intervalo e de rácio), ou ao teste de Kruskal-Wallis (variáveis ordinais). Para o estudo da associação entre variáveis foram utilizados os coeficientes de correlação de Pearson ou de Spearman, a análise de correlações canónicas, a análise de trajectórias e a regressão logística. Adoptou-se um Alpha de 0.05. Resultados: Os doentes com distonia focal primária apresentaram uma pontuação média na Y- -BOCS significativamente superior à dos dois grupos de controlo. Em 24.4% dos doentes com distonia a pontuação na Y-BOCS foi superior a 16. Estes doentes eram predominantemente mulheres, tinham uma maior duração média da doença e referiam predominantemente sintomas obsessivo-compulsivos (SOC) de contaminação e lavagem. Os dois grupos com doença crónica apresentaram pontuações médias superiores às dos indivíduos saudáveis nas escalas de ansiedade, somatização e psicopatologia geral. Os doentes com distonia tratados com toxina botulínica apresentaram pontuações inferiores às dos doentes não tratados nas escalas de ansiedade generalizada, fobia, somatização e depressão, mas não na Y-BOCS. Sessenta por cento dos doentes com distonia apresentavam pelo menos um diagnóstico psiquiátrico actual ou pregresso. O risco de apresentar um diagnóstico psiquiátrico actual era menor nos doentes tratados com toxina botulínica, aumentando com a gravidade da doença. A prevalência de POC foi 8,3% e a de depressão major 37,7%. No WCST e na Prova de Benton, os doentes com distonia focal primária demonstraram um desempenho inferior ao de ambos os grupos de controlo, cometendo sobretudo erros perseverativos. Os doentes com distonia e pontuação na Y-BOCS > 16 cometeram mais erros e respostas perseverativas no WCST do que os restantes doentes com distonia. As análises de correlações e de trajectórias revelaram que nos doentes com distonia a gravidade da distonia foi, juntamente com a idade e a escolaridade, o factor que mais interagiu com o desempenho cognitivo. Discussão: o nosso estudo é o primeiro a descrever, nos mesmos doentes com distonia focal primária, SOC significativos e alterações cognitivas. Os nossos resultados confirmam a hipótese de uma associação clínica específica entre distonia focal primária e psicopatologia obsessivo-compulsiva. Confirmam igualmente que a distonia focal primária está associada a um maior risco de desenvolver morbilidade psiquiátrica ansiosa e depressiva. O tratamento com toxina botulínica reduz este risco, mas não influencia os SOC. Entre os doentes com distonia, os que têm SOC significativos poderão diconstituir um grupo particular com maior duração da doença (mas não uma maior gravidade), predomínio do sexo feminino e predomínio de SOC de contaminação e limpeza. Em termos cognitivos, os indivíduos com distonia focal primária apresentam défices significativos de flexibilidade cognitiva (particularmente acentuados nos doentes com SOC significativos) e de memória de trabalho visuo-espacial. Estes últimos devem-se essencialmente a um défice executivo e não a uma incapacidade visuo-construtiva ou visuo-perceptiva. A disfunção cognitiva não é explicável pela psicopatologia depressiva nem pela incapacidade motora, já que os controlos com doença periférica crónica tiveram um desempenho superior ao dos doentes com distonia. No seu conjunto os nossos resultados sugerem que os SOC que ocorrem na distonia focal primária constituem uma das manifestações clínicas da neurobiologia desta doença do movimento. O predomínio de sintomas relacionados com higiene e o perfil disexecutivo de alterações cognitivas–perseveração e dificuldades executivas de memória de trabalho visuo-espacial – apontam para a via cortico-basal dorso-lateral e para as áreas corticais que lhe estão associadas como estando implicadas na tripla associação entre sintomas motores, obsessivo-compulsivos e cognitivos. Conclusões: A distonia focal primária é um síndrome neuropsiquiátrico complexo com importantes manifestações não motoras, nomeadamente compromisso cognitivo do tipo disexecutivo e sintomas obsessivo-compulsivos. Clinicamente estas manifestações representam necessidades de tratamento que vão muito para além da simples incapacidade motora, devendo ser activamente exploradas e tratadas.-------------- ABSTRACT: Introduction: primary focal dystonia is an idiopathic movement disorder that manifests as involuntary, sustained contraction of muscular groups, leading to abnormal and often painful postures of the affected body part. Treatment is symptomatic, usually with local intramuscular injections of botulinum toxin. The neurobiology of primary focal dystonia remains unclear. Structural and functional neuroimaging studies have revealed subtle changes in striatal and cortical-basal pathway anatomy and function. The most consistent findings involve increased volume and metabolic activity of the putamen and of motor, pre-motor and somato-sensitive cortical areas. As a whole, these changes have been interpreted as reflecting a failure of striatal inhibitory control over automatic motor programs sustained by cortical-basal pathways. The last years have witnessed an increasing interest for the possible non-motor – mainly psychiatric and cognitive – manifestations of primary focal dystonia. The possible association of primary focal dystonia with obsessive-compulsive disorder (OCD) has raised particular interest. The neurobiology of the two disorders has indeed remarkable similarities: structural and functional neuroimaging studies in OCD have revealed increased volume and metabolic activity of the striatum and orbital-frontal cortex, again pointing to a disruption of inhibitory control of automatic cognitive and behavioural programs by the striatum. Objectives: 1. To explore the prevalence and severity of psychopathology – with a special emphasis on obsessive-compulsive symptoms (OCS) – in a sample of patients with primary focal dystonia;2. To explore the nature and severity of possible cognitive dysfunction in a sample of patients with primary focal dystonia; 3. To explore the possible association between dystonia severity, psychiatric symptom severity, and cognitive performance, in a sample of patients with primary focal dystonia. Methods: cross-sectional, case-control, descriptive study. Cases: forty-five consecutive, primary pure focal dystonia patients recruited from the Portuguese Dystonia Association case register (fifteen patients with blepharospasm, 15 with cervical dystonia and 15 with writer’s cramp). Inclusion criteria were: age = 18; primary pure focal, late-onset dystonia (excluding possible or probable psychogenic dystonia according to the Fahn & Williams criteria); normal copper metabolism and Magnetic Resonance Imaging. Diseased controls: forty-six consecutive subjects from our hospital case register (15 patients with hemi-facial spasm; 14 with cervical spondilarthropathy and cervical spinal root compression; 17 with carpal tunnel syndrome). Healthy controls were 30 volunteers.Exclusion criteria for all groups: Mini-Mental State Examination score below the validated cut-off for the Portuguese population (<23 for education between 1 and 11 years; <28 for education >11 years); use of anti-cholinergics, neuroleptics, selective serotonin reuptake inhibitors, triciclic or tetraciclic antidepressants. Assessment: neurological assessment: complete medical and neurological history and physical examination; dystonia severity scoring with the Unified Dystonia Rating Scale. Psychiatric assessment:Symptom Check-List-90-Revised; 60 minute-long psychiatric interview, including Mini-International Neuropsychiatric Interview (MINI), version 4.4 (validated Portuguese version), extended with the sections for life-time major depressive disorder and life-time alcohol and substance abuse disorder from MINI-Plus version 5.0.0; Yale-Brown Obsessive-Compulsive Symptom Checklist and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Cognitive assessment: Wisconsin Card Sorting Test (WCST; cognitive set-shifting ability); Stroop Test (response inhibition); Block Assembly Test(visual-constructive ability); Benton’s Visual Retention Test (visual-spatial working memory). Statistic analysis: Data were analyzed with SPSS for Windows version 13. Proportions were compared using Chi-Square test, or Fisher’s exact test when appropriate. Student’s t-test or Mann-Whitney’s U test (or Wilcoxon’s teste in the case of matched samples) were used for two-group comparisons. P-values were corrected for multiple comparisons. One-way ANOVA with Bonferroni post-hoc analysis (interval data), or the Kruskal-Wallis Test (ordinal data), were used for three-group comparisons. Associations were analysed with Pearson’s or Spearman’s correlation coefficients, canonical correlations, path analysis and logistic regression analysis. Alpha was set at 0.05. Results: Dystonia patients had higher Yale-Brown Obsessive-Compulsive Symptom scores than both control groups. 24.4% of primary dystonia patients had a Y-BOCS score > 16. These patients were predominantly women; they had longer disease duration, and showed a predominance of hygiene-related OCS. The two groups with chronic disease had higher anxiety, somatization and global psychopathology scores than healthy subjects. Primary dystonia patients undergoing treatment with botulinum toxin had lower anxiety, phobia, somatization and depression scores than their untreated counterparts, but similar Y-BOCS scores. Sixty percent of primary dystonia patients had at least one lifetime psychiatric diagnosis. The odds of having a currently active psychiatric diagnosis were lower in botulinum toxin treated patients, and increased with dystonia severity. The prevalence of OCD was 6.7%, and the lifetime prevalence of major depression was 37.7%. Primary dystonia patients had a lower performance than the two control groups in both the WCST and Benton’s Visual Retention Test, mainly due to an excess of perseveration errors. Primary dystonia patients with Y-BOCS score > 16 had much higher perseveration error and perseveration response scores than dystonia patients with Y-BOCS = 16. Correlation and path analysis showed that, in the primary dystonia group, dystonia severity, along with age and education, was the main factor influencing cognitive performance. Discussion: our study is the first description ever of concomitant significant OCS and cognitive impairment in primary dystonia patients. Our results confirm that primary dystonia is specifically associated with obsessive-compulsive psychopathology. They also confirm that primary focal dystonia patients are at a higher risk of developing anxious and depressive psychiatric morbidity. Treatment with botulinum toxin decreases this risk, but does not influence OCS. Primary focal dystonia patients with significant OCS may constitute a particular subgroup. They are predominantly women, with higher disease duration (but not severity) and a predominance of hygiene related OCS.In terms of cognitive performance, primary focal dystonia patients have significant deficits involving set-shifting ability and visual-spatial working memory. The latter result from an essentially executive deficit, rather than from a primary visual-constructive apraxia or perceptual deficit. Furthermore, cognitive flexibility difficulties were more prominent in the subset of primary dystonia patients with significant OCS. The cognitive dysfunction found in dystonia patients is not attributable to depressive psychopathology or motor disability, as their performance was significantly lower than that of similarly impaired diseased controls. Our results suggest that OCS in primary focal dystonia are a direct, primary manifestation of the motor disorder’s neurobiology. The predominance of hygiene-related symptoms and the disexecutive pattern of cognitive impairment – set-shifting and visual-spatial working memory deficits – suggest that the dorsal-lateral cortical-basal pathway may play a decisive role in the triple association of motor dysfunction, OCS and cognitive impairment. Conclusions: primary focal dystonia is a complex neuropsychiatric syndrome with significant non- -motor manifestations, namely cognitive executive deficits and obsessive-compulsive symptoms.Clinically, our results show that PFD patients may have needs for care that extend far beyond a merely motor disability and must be actively searched for and treated.

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Multiparametric Magnetic Resonance Imaging has been increasingly used for detection, localization and staging of prostate cancer over the last years. It combines high-resolution T2 Weighted-Imaging and at least two functional techniques, which include Dynamic Contrast–Enhanced Magnetic Resonance Imaging, Diffusion-Weighted Imaging, and Magnetic Resonance Imaging Spectroscopy. Although the combined use of a pelvic phased-array and an Endorectal Coil is considered the state-of-the-art for Magnetic Resonance Imaging evaluation of prostate cancer, Endorectal Coil is only absolute mandatory for Magnetic Resonance Imaging Spectroscopy at 1.5 T. Sensitivity and specificity levels in cancer detection and localization have been improving with functional technique implementation, compared to T2 Weighted-Imaging alone. It has been particularly useful to evaluate patients with abnormal PSA and negative biopsy. Moreover, the information added by the functional techniques may correlate to cancer aggressiveness and therefore be useful to select patients for focal radiotherapy, prostate sparing surgery, focal ablative therapy and active surveillance. However, more studies are needed to compare the functional techniques and understand the advantages and disadvantages of each one. This article reviews the basic principles of prostatic mp-Magnetic Resonance Imaging, emphasizing its role on detection, staging and active surveillance of prostate cancer.

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The hypoglossal nerve is a pure motor nerve. It provides motor control to the intrinsic and extrinsic tongue muscles thus being essential for normal tongue movement and coordination. In order to design a useful imaging approach and a working differential diagnosis in cases of hypoglossal nerve damage one has to have a good knowledge of the normal anatomy of the nerve trunk and its main branches. A successful imaging evaluation to hypoglossal diseases always requires high resolution studies due to the small size of the structures being studied. MRI is the preferred modality to directly visualize the nerve, while CT is superior in displaying the bony anatomy of the neurovascular foramina of the skull base. Also, while CT is only able to detect nerve pathology by indirect signs, such as bony expansion of the hypoglossal canal, MRI is able to visualize directly the causative pathological process as in the case of small tumors, or infectious/inflammatory processes affecting the nerve. The easiest way to approach the study of the hypoglossal nerve is to divide it in its main segments: intra-axial, cisternal, skull base and extracranial segment, tailoring the imaging technique to each anatomical area while bearing in mind the main disease entities affecting each segment.

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The use of multiparametric magnetic resonance imaging (mp-MRI) for prostate cancer has increased over recent years, mainly for detection, staging, and active surveillance. However, suspicion of recurrence in the set of biochemical failure is becoming a significant reason for clinicians to request mp-MRI. Radiologists should be able to recognize the normal post-treatment MRI findings. Fibrosis and atrophic remnant seminal vesicles after prostatectomy are often found and must be differentiated from local relapse. Moreover, brachytherapy, external beam radiotherapy, cryosurgery, and hormonal therapy tend to diffusely decrease the signal intensity of the peripheral zone on T2-weighted images (T2WI) due to the loss of water content, consequently mimicking tumor and hemorrhage. The combination of T2WI and functional studies like diffusion-weighted imaging and dynamic contrast-enhanced improves the identification of local relapse. Tumor recurrence tends to restrict on diffusion images and avidly enhances after contrast administration either within or outside the gland. The authors provide a pictorial review of the normal findings and the signs of local tumor relapse after radical prostatectomy, external beam radiotherapy, brachytherapy, cryosurgery, and hormonal therapy.

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Severe chronic kidney disease may lead to disturbances, such as hyperphosphatemia, increased secretion of fibroblast growth factor -23 (FGF -23) and vitamin D deficiency. These may increase plasmatic levels of parathyroid hormone, and decrease plasmatic levels of calcium. Altogether, these may contribute to the development of secondary hyperparathyroidism, and to abnormalities in mineral metabolism. Kidney transplantation is the best option to improve longevity and quality of life in end -stage chronic kidney disease patients. Vitamin D deficiency has been associated with cardiovascular disease, which is the leading cause of death in chronic kidney disease. Therefore, diagnosing this deficiency may be pivotal for minimizing mortality in chronic kidney disease, because pharmacological treatments for this deficiency may be prescribed. Calcitriol is indicated for the treatment of vitamin D deficiency, both in chronic kidney disease and in kidney transplanted patients. However, calcitriol may increase the plasmatic levels of calcium and phosphorous, which can lead to vascular calcifications, that have been associated with cardiovascular mortality. Selective vitamin D receptor activators are indicated for the treatment of vitamin D deficiency in chronic kidney disease. These have the advantage of being associated with lower increases of plasmatic levels of calcium and phosphorous. These drugs also seem to have additional effects that may minimise patient morbidity and mortality, especially due to potentially reducing cardiovascular events. Unfortunately, there are few studies about the use of these drugs in kidney transplanted patients. Here we present a review about the physiology of vitamin D, the consequences of its deficiency in chronic kidney disease and in kidney transplanted patients, and about the diagnosis and treatment of this deficiency. Finally, we discuss the new line of research about the efficacy and safety of selective vitamin D receptor activators in kidney transplanted patients.

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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

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We report the findings of abdominal ultrasound and magnetic resonance imaging observed in a patient with advanced schistosomiasis mansoni. A 25-year-old man with hepatosplenic schistosomiasis and variceal bleeding confirmed by upper endoscopy was submitted to abdominal ultrasound and magnetic resonance imaging. During surgery for portal hypertension, a liver biopsy was taken and the diagnosis of Symmers' fibrosis was confirmed. magnetic resonance imaging scans gave more precise information about the gallbladder, periportal thickening and abdominal venous system than did the ultrasound.

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Breast cancer is the most common type of cancer among women all over the world. An important issue that is not commonly addressed in breast cancer imaging literature is the importance of imaging the underarm region—where up to 80% of breast cancer cells can metastasise to. The first axillary lymph nodes to receive drainage from the primary tumour in the breast are called Sentinel Node. If cancer cells are found in the Sentinel Node, there is an increased risk of metastatic breast cancer which makes this evaluation crucial to decide what follow-up exams and therapy to follow. However, non-invasive detection of cancer cells in the lymph nodes is often inconclusive, leading to the surgical removal of too many nodes which causes adverse side-effects for patients. Microwave Imaging is one of the most promising non-invasive imaging modalities for breast cancer early screening and monitoring. This novel study tests the feasibility of imaging the axilla region by means of the simulation of an Ultra-Wideband Microwave Imaging system. Simulations of such system are completed in several 2D underarm models that mimic the axilla. Initial imaging results are obtained by means of processing the simulated backscattered signals by eliminating artefacts caused by the skin and beamforming the processed signals in order to time-align all the signals recorded at each antenna. In this dissertation several image formation algorithms are implemented and compared by visual inspection of the resulting images and through a range of performance metrics, such as Signal-to-Clutter Ratio and FullWidth Half Maximum calculations. The results in this study showed that Microwave Imaging is a promising technique that might allow to identify the presence and location of metastasised cancer cells in axillary lymph nodes, enabling the non-invasive evaluation of breast cancer staging.

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Diffusion Kurtosis Imaging (DKI) is a fairly new magnetic resonance imag-ing (MRI) technique that tackles the non-gaussian motion of water in biological tissues by taking into account the restrictions imposed by tissue microstructure, which are not considered in Diffusion Tensor Imaging (DTI), where the water diffusion is considered purely gaussian. As a result DKI provides more accurate information on biological structures and is able to detect important abnormalities which are not visible in standard DTI analysis. This work regards the development of a tool for DKI computation to be implemented as an OsiriX plugin. Thus, as OsiriX runs under Mac OS X, the pro-gram is written in Objective-C and also makes use of Apple’s Cocoa framework. The whole program is developed in the Xcode integrated development environ-ment (IDE). The plugin implements a fast heuristic constrained linear least squares al-gorithm (CLLS-H) for estimating the diffusion and kurtosis tensors, and offers the user the possibility to choose which maps are to be generated for not only standard DTI quantities such as Mean Diffusion (MD), Radial Diffusion (RD), Axial Diffusion (AD) and Fractional Anisotropy (FA), but also DKI metrics, Mean Kurtosis (MK), Radial Kurtosis (RK) and Axial Kurtosis (AK).The plugin was subjected to both a qualitative and a semi-quantitative analysis which yielded convincing results. A more accurate validation pro-cess is still being developed, after which, and with some few minor adjust-ments the plugin shall become a valid option for DKI computation

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INTRODUCTION: There is no study relating magnetic resonance imaging (MRI) to ultrasound (US) findings in patients with Schistosomiasis mansoni. Our aim was to describe MRI findings inpatients with schistosomal liver disease identified by US. METHODS: Fifty-four patients (mean age 41.6±13.5years) from an area endemic for Schistosomiasis mansoni were selected for this study.All had US indicating liver schistosomal fibrosis and were evaluated with MRI performed witha 1.5-T superconducting magnet unit (Sigma). RESULTS: Forty-seven (87%) of the 54 patientsshowing signs of periportal fibrosis identified through US investigation had confirmed diagnosesby MRI. In the seven discordant cases (13%), MRI revealed fat tissue filling in the hilar periportalspace where US indicated isolated thickening around the main portal vein at its point of entryto the liver. We named this the fatty hilum sign. One of the 47 patients with MRI evidence ofperiportal fibrosis had had his gallbladder removed previously. Thirty-five (76.1%) of the other46 patients had an expanded gallbladder fossa filled with fat tissue, whereas MRI of the remainingeleven showed pericholecystic signs of fibrosis. CONCLUSIONS: Echogenic thickening of thegallbladder wall and of the main portal vein wall heretofore attributed to fibrosis were frequentlyidentified as fat tissue in MRI. However, the gallbladder wall thickening shown in US (expandedgallbladder fossa in MRI) is probably secondary to combined hepatic morphologic changes inschistosomiasis, representing severe liver involvement.

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Although cryptococcal infections begin in the lungs, meningoencephalitis is the most frequently encountered manifestation of cryptococcosis among individuals with advanced immunosuppression. As the infection progresses along the Virchow-Robin spaces, these structures may become dilated with mucoid material produced by the capsule of the organism. We report a case of a 24-year-old man with cryptococcal meningoencephalitis in which magnetic resonance imaging showed clusters of gelatinous pseudocysts in the periventricular white matter, basal ganglia, mammillary bodies, midbrain peduncles and nucleus dentatus with a soap bubble appearance.