Segmentation of liver, its vessels and lesions from CT images for surgical planning

<p>Abstract</p> <p>Background</p> <p>Cancer treatments are complex and involve different actions, which include many times a surgical procedure. Medical imaging provides important information for surgical planning, and it usually demands a proper segmentation, i.e., the identification of meaningful objects, such as organs and lesions. This study proposes a methodology to segment the liver, its vessels and nodules from computer tomography images for surgical planning.</p> <p>Methods</p> <p>The proposed methodology consists of four steps executed sequentially: segmentation of liver, segmentation of vessels and nodules, identification of hepatic and portal veins, and segmentation of Couinaud anatomical segments. Firstly, the liver is segmented by a method based on a deformable model implemented through level sets, of which parameters are adjusted by using a supervised optimization procedure. Secondly, a mixture model is used to segment nodules and vessels through a region growing process. Then, the identification of hepatic and portal veins is performed using liver anatomical knowledge and a vein tracking algorithm. Finally, the Couinaud anatomical segments are identified according to the anatomical liver model proposed by Couinaud.</p> <p>Results</p> <p>Experiments were conducted using data and metrics brought from the liver segmentation competition held in the Sliver07 conference. A subset of five exams was used for estimation of segmentation parameter values, while 15 exams were used for evaluation. The method attained a good performance in 17 of the 20 exams, being ranked as the 6^thbest semi-automatic method when comparing to the methods described on the Sliver07 website (2008). It attained visual consistent results for nodules and veins segmentation, and we compiled the results, showing the best, worst, and mean results for all dataset.</p> <p>Conclusions</p> <p>The method for liver segmentation performed well, according to the results of the numerical evaluation implemented, and the segmentation of liver internal structures were consistent with the anatomy of the liver, as confirmed by a specialist. The analysis provided evidences that the method to segment the liver may be applied to segment other organs, especially to those whose distribution of voxel intensities is nearly Gaussian shaped.</p

Effects of 3-beta-diol, an androgen metabolite with intrinsic estrogen-like effects, in modulating the aquaporin-9 expression in the rat efferent ductules

BACKGROUND: Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP) play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT) in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol), once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. METHODS: To test this hypothesis, adult male rats were submitted to surgical castration followed by estradiol, DHT or 3-beta-diol replacement. Changes in AQP9 expression in the efferent ductules were investigated by using immunohistochemistry and Western blotting assay. RESULTS: Data show that, after castration, AQP9 expression was significantly reduced in the efferent ductules. 3-beta-diol injections restored AQP9 expression, similar to DHT and estradiol. The results were confirmed by Western blotting assay. CONCLUSION: This is the first evidence that 3-beta-diol has biological activity in the male reproductive tract and that this androgen metabolite has estrogen-like activity in the efferent ductules, whose major function is the reabsorption of luminal fluid

Prescrição Inapropriada em Idosos numa Enfermaria de Medicina Interna

INTRODUCTION: Polypharmacy is often observed in elderly patients and is associated with an increased risk of adverse drug reactions, side effects and interactions. Clinicians should be alert to inappropriate drug prescribing and reduce polypharmacy. MATERIAL AND METHODS: Observational, longitudinal, retrospective and descriptive study in an internal medicine ward in a Portuguese hospital. Polypharmacy was defined as the use of five or more different medicines. The purpose of this study was to describe the prevalence of polypharmacy and inappropriate prescribing at admission and discharge in an internal medicine ward, according to deprescribing.org guidelines/algorithms. A total of 838 consecutive patients were admitted between January and July 2017. All patients were aged under 65 years old, and those who died before discharge were excluded. Patients' medications were reviewed from a medical database at hospital admission and discharge. We examined whether patients were taking anticoagulants, proton pump inhibitors, benzodiazepines, antipsychotics and/or antihyperglycemic medication. RESULTS: A total of 483 patients were included, mean age was 79.2 ± 8.0 years, and 42% of patients were male. Median number of medications at admission and discharge was six. Polypharmacy was present in more than 70% of admitted patients. Proton pump inhibitors were the most common inappropriate prescription at discharge (17.2%). DISCUSSION: This study demonstrated a low use of inappropriate medicine (11.2% - 17.2%) in older people discharged from hospital, when compared to other studies. CONCLUSION: Our study shows that polypharmacy is present in more than 70% of elderly admitted patients. Nevertheless, the drug inappropriateness rate was not significantly affected by polypharmacy at both admission and discharge, being overall lower than published data.Introdução: A polimedicação é observada nos doentes idosos e está associada a um maior risco de reações adversas, efeitos secundários e interações. Os clínicos devem atentos à prescrição inapropriada e à redução da polimedicação. Material e Métodos: Estudo observacional, longitudinal, retrospetivo e descritivo, realizado numa enfermaria de medicina interna num hospital português. Definimos a polimedicação como o uso de cinco ou mais medicamentos. O objetivo foi descrever a prevalência da polimedicação e a prescrição inapropriada, na admissão e alta, de acordo com as guidelines/algoritmos definidos em deprescribing. org. Admitimos 838 doentes entre janeiro e julho de 2017. Excluímos todos aqueles com idade inferior a 65 anos e óbitos. A medicação dos doentes foi revista a partir da base de dados hospitalar, à admissão e à data de alta. Examinámos se os doentes estavam a tomar anticoagulantes, inibidores da bomba de protões, benzodiazepinas, antipsicóticos e/ou anti hiperglicémicos. Resultados: Incluímos 483 doentes, com média de idade de 79,2 ± 8,0 anos, e 42% dos quais eram homens. A mediana da medicação à admissão e à alta foi seis. A polimedicação estava presente em mais de 70% dos doentes admitidos. Os inibidores da bomba de protões foram a classe mais inapropriadamente prescrita à data de alta (17,2%). Discussão: Demonstrámos um uso reduzido de fármacos inapropriados (11,2% - 17,2%) nos idosos, à alta hospitalar, quando comparado com outros estudos. Conclusão: Demonstrámos que a polimedicação estava presente em mais de 70% dos idosos admitidos. Contudo, a taxa de prescrição inapropriada não afetou significativamente a polimedicação na admissão e na alta, sendo inferior aos dados publicados.info:eu-repo/semantics/publishedVersio

Externally validated model predicting gait independence after stroke showed fair performance and improved after updating

ObjectiveTo externally validate recent prognostic models that predict independent gait following stroke.Study design and settingA systematic search identified recent models (ResultsThree prognostic models met our criteria, all with high Risk of Bias. Validation data was only available for the Australian model. This model used National Institute of Health Stroke Scale (NIHSS) and age to predict independent gait, using Motor Assessment Scale (MAS) walking item. For validation, Scandinavian Stroke Scale (SSS) was a proxy for NIHSS, and Functional Independence Measure (FIM) locomotion item was a proxy for MAS. The Area Under the Curve was 0.77 (0.74-0.80) and had good calibration in the validation dataset. Adjustment of the intercept and regression coefficients slightly improved discrimination. By adding paretic leg strength, the model further improved (AUC 0.82).ConclusionExternal validation of the Australian model with proxies showed fair discrimination and good calibration. Updating the model by adding paretic leg strength further improved model performance

Hypoglycemia in elderly diabetic patients: experience in a diabetes unit

Introdução: Assiste-se atualmente a uma evolução paralela do envelhecimento da população e da prevalência crescente de Diabetes Mellitus. Os indivíduos idosos estão particularmente susceptíveis à ocorrência de episódios de hipoglicemia, responsáveis por uma morbimortalidade significativa nesta população. Os objetivos do estudo foram a avaliação da incidência de doentes diabéticos com episódios de hipoglicemia na população de idosos seguidos na Unidade Integrada de Diabetes (UID) do HFF e caracterizar, comparativamente, a população de idosos com e sem episódios de hipoglicemia. Materiais e métodos: Estudo observacional, longitudinal, retrospetivo, descritivo, consistindo na análise de variáveis demográficas, clínicas e laboratoriais constantes em processo clínico informático Soarian®, num período de um ano, procedendo-se a análise estatística dos mesmos. Resultados: Em 2013 mais de metade dos doentes seguidos na UID eram idosos, tendo-se verificado episódios de hipoglicemia em 22,6%. A maioria dos doentes com episódios de hipoglicemia (CH) tratava-se de doentes com mais de 75 anos e tinha um tempo de evolução de doença superior a 5 anos, com uma média de tempo de evolução de 17,5 anos. A presença de complicações microvasculares foi objetivada em mais de metade destes doentes (51,2%) sendo que 47,8% apresentavam complicações macrovasculares. A HbA1C média era de 7,8%, tendo apresentado, ao longo do ano, uma descida média de 0,6%. A maioria (71,7%) dos doentes CH estava medicado com insulina, mais de metade destes (54,3%) medicados com insulina com pico de ação, tratando-se de proporções significativamente superiores às objetivadas nos doentes sem episódios de hipoglicemia (SH). Relativamente ao uso de antidiabéticos orais, 26,1% estavam medicados com sulfonilureias. Conclusão: Este estudo vem reiterar a necessidade de individualização e adequação de objetivos de cuidados na população idosa e com mais comorbilidades, assumindo alvos glicémicos mais permissivos e esquemas terapêuticos com menor risco associado de hipoglicemia.info:eu-repo/semantics/publishedVersio

Neuro-Behçet: a clinical exercise

Behçet disease is a recurrent systemic vasculitis of unknown etiology, that involves vessels of nearly all sizes and types. Because of this, disease manifestations can occur at many sites throughout the body. Central nervous system (CNS) involvement may be parenchymal or nonparenchymal and has a global prevalence that ranges from 3% to 10%. Main signs of CNS involvement are pyramidal and those resulting from brain stem lesions. Aseptic meningitis, mental changes, sphincter disturbances, pseudobulbar syndrome, and deep sensory abnormalities may be seen. Analysis of cerebrospinal fluid, computed tomography (CT), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and brain angiography offer assistance in the diagnosis. The course of disease can be primary progressive, secondary progressive or have a relapsing-remitting profile. Boluses of methylprednisolone for three days followed by cyclophosphamide are the treatment of choice. This papers discusses these aspects of neuro-Behcet on the basis of complex clinical cas