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1.
IEEE Trans Pattern Anal Mach Intell ; 44(1): 143-153, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-32750834

RESUMO

The susceptibility of super paramagnetic iron oxide (SPIO) particles makes them a useful contrast agent for different purposes in MRI. These particles are typically quantified with relaxometry or by measuring the inhomogeneities they produced. These methods rely on the phase, which is unreliable for high concentrations. We present in this study a novel Deep Learning method to quantify the SPIO concentration distribution. We acquired the data with a new sequence called View Line in which the field map information is encoded in the geometry of the image. The novelty of our network is that it uses residual blocks as the bottleneck and multiple decoders to improve the gradient flow in the network. Each decoder predicts a different part of the wavelet decomposition of the concentration map. This decomposition improves the estimation of the concentration, and also it accelerates the convergence of the model. We tested our SPIO concentration reconstruction technique with simulated images and data from actual scans from phantoms. The simulations were done using images from the IXI dataset, and the phantoms consisted of plastic cylinders containing agar with SPIO particles at different concentrations. In both experiments, the model was able to quantify the distribution accurately.


Assuntos
Aprendizado Profundo , Algoritmos , Compostos Férricos , Imageamento por Ressonância Magnética
2.
Nutrients ; 11(9)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500172

RESUMO

A healthy dietary pattern and high quality nutrient intake reduce atherosclerotic cardiovascular disease risk. Red wine grape pomace (RWGP)-a rich natural source of dietary fiber and antioxidants-appears to be a potential functional food ingredient. The impact of a dietary supplementation with RWGP flour was evaluated in atherogenic diet-fed SR-B1 KO/ApoER61h/h mice, a model of lethal ischemic heart disease. SR-B1 KO/ApoER61h/h mice were fed with atherogenic (high fat, cholesterol, and cholic acid, HFC) diet supplemented with: (a) 20% chow (HFC-Control), (b) 20% RWGP flour (HFC-RWGP), or (c) 10% chow/10% oat fiber (HFC-Fiber); and survival time was evaluated. In addition, SR-B1 KO/ApoER61h/h mice were fed for 7 or 14 days with HFC-Control or HFC-RWGP diets and plasma lipid levels, inflammation, oxidative damage, and antioxidant activity were measured. Atherosclerosis and myocardial damage were assessed by histology and magnetic resonance imaging, respectively. Supplementation with RWGP reduced premature death, changed TNF-α and IL-10 levels, and increased plasma antioxidant activity. Moreover, decreased atheromatous aortic and brachiocephalic plaque sizes and attenuated myocardial infarction and dysfunction were also observed. These results suggest that RWGP flour intake may be used as a non-pharmacological therapeutic approach, contributing to decreased progression of atherosclerosis, reduced coronary heart disease, and improved cardiovascular outcomes.


Assuntos
Antioxidantes/administração & dosagem , Aorta/metabolismo , Doenças da Aorta/prevenção & controle , Aterosclerose/prevenção & controle , Suplementos Nutricionais , Frutas/química , Isquemia Miocárdica/prevenção & controle , Miocárdio/metabolismo , Estresse Oxidativo , Extratos Vegetais/administração & dosagem , Vitis/química , Ração Animal , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Aorta/patologia , Doenças da Aorta/sangue , Doenças da Aorta/genética , Doenças da Aorta/patologia , Aterosclerose/sangue , Aterosclerose/genética , Aterosclerose/patologia , Biomarcadores/sangue , Dieta Aterogênica , Modelos Animais de Doenças , Feminino , Mediadores da Inflamação/sangue , Interleucina-10/sangue , Lipídeos/sangue , Masculino , Camundongos Knockout para ApoE , Isquemia Miocárdica/sangue , Isquemia Miocárdica/genética , Isquemia Miocárdica/patologia , Miocárdio/patologia , Extratos Vegetais/sangue , Extratos Vegetais/isolamento & purificação , Placa Aterosclerótica , Receptores Depuradores Classe B/deficiência , Receptores Depuradores Classe B/genética , Fator de Necrose Tumoral alfa/sangue
3.
Cardiovasc Intervent Radiol ; 36(1): 128-32, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22547030

RESUMO

PURPOSE: We present our experience with embolization of incompetent pelvic veins (IPV) in women with recurrence of varicose veins (VV) in lower limbs, as well as symptoms of pelvic congestion syndrome (PCS), after first surgery. In addition, we evaluated the effects of embolization in decreasing the symptoms of VV before surgery as well as its effects on PCS symptoms. MATERIALS AND METHODS: We included 10 women who had consulted a vascular surgeon because of recurrent VV in lower limbs after surgery. All of these patients were included in the study because they also had symptoms of PCS, probably due to IPV. In patients who had confirmed IPV, we performed embolization before a second surgery. VV and PCS were assessed before and at 3 months after embolization (before the second surgery) using a venous clinical severity score (VCSS) and a visual analog pain scale (VAS), respectively. Patients were controlled between 3 and 6 months after embolization. Paired Student t test analysis was used for comparing data before and after embolization. RESULTS: Fifteen vein segments in 10 women were suitable for embolization. There was a significant (p < 0.001) decrease of VCSS after embolization, and recurrence of VV was not detected within a period of 6 months. There was also significant (p < 0.01) relief of chronic pelvic pain related to PCS evaluated using VAS at 3 months after embolization. CONCLUSION: Embolization decreases the risk of VV recurrence after surgery and also improves PCS symptoms in women with VV in lower limbs and IPV.


Assuntos
Embolização Terapêutica/métodos , Dor Pélvica/terapia , Pelve/irrigação sanguínea , Varizes/terapia , Insuficiência Venosa/terapia , Adulto , Cateterismo Periférico/métodos , Estudos de Coortes , Feminino , Seguimentos , Humanos , Extremidade Inferior/diagnóstico por imagem , Medição da Dor , Seleção de Pacientes , Dor Pélvica/diagnóstico por imagem , Pelve/diagnóstico por imagem , Flebografia/métodos , Estudos Prospectivos , Recidiva , Medição de Risco , Índice de Gravidade de Doença , Síndrome , Resultado do Tratamento , Varizes/diagnóstico por imagem , Veias , Insuficiência Venosa/diagnóstico por imagem
4.
Rev. méd. Chile ; 140(12): 1535-1543, dic. 2012. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-674024

RESUMO

Background: Visceral fat accumulation is associated with the development of metabolic diseases. Anthropometry is one of the methods used to quantify it. aim: to evaluate the relationship between visceral adipose tissue volume (VAT), measured with magnetic resonance imaging (MRI), and anthropometric indexes, such as body mass index (BMI) and waist circumference (WC), in type 2 diabetic patients (DM2). Patients and Methods: Twenty four type 2 diabetic patients aged 55 to 78 years (15 females) and weighting 61.5 to 97 kg, were included. The patients underwent MRI examination on a Philips Intera® 1.5T MR scanner. The MRI protocol included a spectral excitation sequence centered at the fat peak. The field of view included from L4-L5 to the diaphragmatic border. VAT was measured using the software Image J®. Weight, height, BMI, WC and body fat percentage (BF%), derived from the measurement offour skinfolds with the equation of Durnin and Womersley, were also measured. The association between MRIVAT measurement and anthropometry was evaluated using the Pearson's correlation coefficient. Results: Mean VAT was 2478 ± 758 ml, mean BMI29.5 ± 4.7 kg/m², and mean WC was 100 ± 9.7 cm. There was a poor correlation between VAT, BMI (r = 0.18) and WC (r = 0.56). Conclusions: BMI and WC are inaccurate predictors of VAT volume in type 2 diabetic patients.


Assuntos
Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antropometria , /patologia , Gordura Intra-Abdominal/patologia , Imageamento por Ressonância Magnética/métodos , Fatores de Risco , Software , Estatísticas não Paramétricas , Circunferência da Cintura
5.
Radiology ; 250(2): 551-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19188323

RESUMO

UNLABELLED: Institutional review board approval and signed informed consent were not needed, as medical images included in public databases were used in this study. The purpose of this study was to improve the detection of microcalcifications on mammograms and lung nodules on chest radiographs by using the dynamic cues algorithm and the motion and flickering sensitivity of the human visual system (HVS). Different sets of mammograms from the Mammographic Image Analysis Society database and chest radiographs from the Japanese Society of Radiological Technology database were presented statically, as is standard, and in a video sequence generated with the dynamic cues algorithm. Nine observers were asked to rate the presence of abnormalities with a five-point scale (1, definitely not present; 5, definitely present). The data were analyzed with receiver operating characteristic (ROC) techniques and the Dorfman-Berbaum-Metz method. The video sequence generated with the dynamic cues algorithm increased the rate of detection of microcalcifications by 10.2% (P = .002) compared with that obtained with the standard static method, as measured by the area under the ROC curve. Similar results were obtained for lung nodules, with an increase of 12.3% (P = .0054). The increase in the rate of correct detection did not come just from the image contrast change produced by the algorithm but also from the fact that image frames generated with the dynamic cues algorithm were put together in a video sequence so that the motion sensitivity of the HVS could be used to facilitate the detection of low-contrast objects. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/250/2/551/DC1.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Sinais (Psicologia) , Neoplasias Pulmonares/diagnóstico por imagem , Mamografia , Radiografia Torácica , Percepção Visual/fisiologia , Algoritmos , Humanos , Curva ROC
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