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1.
Artigo em Inglês | MEDLINE | ID: mdl-27169829

RESUMO

This work presents a computational framework to perform a systematic and comprehensive assessment of the morphometry of coronary arteries from in vivo medical images. The methodology embraces image segmentation, arterial vessel representation, characterization and comparison, data storage, and finally analysis. Validation is performed using a sample of 48 patients. Data mining of morphometric information of several coronary arteries is presented. Results agree to medical reports in terms of basic geometric and anatomical variables. Concerning geometric descriptors, inter-artery and intra-artery correlations are studied. Data reported here can be useful for the construction and setup of blood flow models of the coronary circulation. Finally, as an application example, similarity criterion to assess vasculature likelihood based on geometric features is presented and used to test geometric similarity among sibling patients. Results indicate that likelihood, measured through geometric descriptors, is stronger between siblings compared with non-relative patients. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Vasos Coronários/anatomia & histologia , Circulação Coronária , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiologia , Feminino , Humanos , Funções Verossimilhança , Masculino , Pessoa de Meia-Idade , Irmãos
2.
Braz J Med Biol Res ; 38(5): 661-7, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15917946

RESUMO

The aim of the present study was to evaluate the role of magnetic resonance imaging (MRI) for the non-invasive detection of coronary abnormalities and specifically the remodeling process in patients with coronary artery disease (CAD). MRI was performed in 10 control healthy subjects and 26 patients with angiographically proven CAD of the right coronary (RCA) or left anterior descending (LAD) artery; 23 patients were within two months of acute coronary syndromes, and 3 had stable angina with a positive test for ischemia. Wall thickness (WT), vessel wall area (VWA), total vessel area (TVA), and luminal area (LA) were measured. There were significant increases in WT (mean +/- SEM, RCA: 2.62 +/- 0.75 vs 0.53 +/- 0.15 mm; LAD: 2.21 +/- 0.69 vs 0.62 +/- 0.24 mm) and in VWA (RCA: 30.96 +/- 17.57 vs 2.1 +/- 1.2 mm(2); LAD: 19.53 +/- 7.25 vs 3.6 +/- 2.0 mm(2)) patients compared to controls (P < 0.001 for each variable). TVA values were also greater in patients compared to controls (RCA: 44.56 +/- 21.87 vs 12.3 +/- 4.2 mm(2); LAD: 31.89 +/- 11.31 vs 17.0 +/- 6.2 mm(2); P < 0.001). In contrast, the LA did not differ between patients and controls for RCA or LAD. When the LA was adjusted for vessel size using the LA/TVA ratio, a significant difference was found: 0.33 +/- 0.16 in patients vs 0.82 +/- 0.09 in controls (RCA) and 0.38 +/- 0.13 vs 0.78 +/- 0.06 (LAD) (P < 0.001). As opposed to normal controls, positive remodeling was present in all patients with CAD, as indicated by larger VWA. We conclude that MRI detected vessel wall abnormalities and was an effective tool for the noninvasive evaluation of the atherosclerotic process and coronary vessel wall modifications, including positive remodeling that frequently occurs in patients with acute coronary syndromes.


Assuntos
Doença da Artéria Coronariana/diagnóstico , Anomalias dos Vasos Coronários/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Idoso , Estudos de Casos e Controles , Doença da Artéria Coronariana/patologia , Anomalias dos Vasos Coronários/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Braz. j. med. biol. res ; 38(5): 661-667, May 2005. ilus, tab
Artigo em Inglês | LILACS | ID: lil-400965

RESUMO

The aim of the present study was to evaluate the role of magnetic resonance imaging (MRI) for the non-invasive detection of coronary abnormalities and specifically the remodeling process in patients with coronary artery disease (CAD). MRI was performed in 10 control healthy subjects and 26 patients with angiographically proven CAD of the right coronary (RCA) or left anterior descending (LAD) artery; 23 patients were within two months of acute coronary syndromes, and 3 had stable angina with a positive test for ischemia. Wall thickness (WT), vessel wall area (VWA), total vessel area (TVA), and luminal area (LA) were measured. There were significant increases in WT (mean ± SEM, RCA: 2.62 ± 0.75 vs 0.53 ± 0.15 mm; LAD: 2.21 ± 0.69 vs 0.62 ± 0.24 mm) and in VWA (RCA: 30.96 ± 17.57 vs 2.1 ± 1.2 mm²; LAD: 19.53 ± 7.25 vs 3.6 ± 2.0 mm²) patients compared to controls (P < 0.001 for each variable). TVA values were also greater in patients compared to controls (RCA: 44.56 ± 21.87 vs 12.3 ± 4.2 mm²; LAD: 31.89 ± 11.31 vs 17.0 ± 6.2 mm²; P < 0.001). In contrast, the LA did not differ between patients and controls for RCA or LAD. When the LA was adjusted for vessel size using the LA/TVA ratio, a significant difference was found: 0.33 ± 0.16 in patients vs 0.82 ± 0.09 in controls (RCA) and 0.38 ± 0.13 vs 0.78 ± 0.06 (LAD) (P < 0.001). As opposed to normal controls, positive remodeling was present in all patients with CAD, as indicated by larger VWA. We conclude that MRI detected vessel wall abnormalities and was an effective tool for the noninvasive evaluation of the atherosclerotic process and coronary vessel wall modifications, including positive remodeling that frequently occurs in patients with acute coronary syndromes.


Assuntos
Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Doença da Artéria Coronariana/diagnóstico , Anomalias dos Vasos Coronários/diagnóstico , Imageamento por Ressonância Magnética , Estudos de Casos e Controles
4.
Br J Radiol ; 77(918): 508-11, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15151973

RESUMO

Congenital coronary artery fistula is a rare disease and MRI is a promising technique that may be useful to demonstrate the coronary artery tree. We report three patients who underwent cardiac MRI to investigate right coronary artery fistulae. On clinical examination, a continuous murmur was heard along the left sternal border, and chest X-ray showed moderate cardiomegaly with enlargement of right chambers in all patients. Transthoracic Doppler echocardiography showed fistulae in two cases; the third case was not demonstrated by transthoracic or transoesophageal echocardiography. MRI demonstrated the course of the fistulous vessels in all patients. All patients underwent surgical closure of their coronary artery fistulae. MRI may show detailed anatomy of congenital coronary artery fistulae and may be useful as an additional non-invasive method in their investigation.


Assuntos
Fístula Artério-Arterial/congênito , Anomalias dos Vasos Coronários/diagnóstico , Adulto , Fístula Artério-Arterial/diagnóstico , Criança , Ecocardiografia Transesofagiana , Feminino , Sopros Cardíacos/etiologia , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Tomografia Computadorizada por Raios X
5.
Waste Manag ; 23(2): 183-91, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12623093

RESUMO

Increasingly, there are severe environmental controls in the mining industry. Because of lack of technological advances, waste management practices are severely limited. Most of the wastes in the milling industrial effluents are known to contain cyanides and it is recognized that after extraction and recovery of precious metals, substantial amounts of cyanide are delivered to tailings ponds. The toxicity of cyanide creates serious environmental problems. In this paper we describe several methods for the treatment of cyanide solutions. These include: (1) cyanide destruction by oxidation with chlorine dioxide (ClO(2)) in a Gas-Sparged Hydrocyclone (GSH) reactor; (2) destruction of cyanide by ozone (O(3)) using a stirred batch reactor, and finally, (3) the photolysis of cyanide with UV light in presence of titania sol. In all cases excellent performance were observed as measured by the extent and of the destruction.


Assuntos
Compostos Clorados/química , Corantes/química , Cianetos/química , Oxidantes Fotoquímicos/química , Óxidos/química , Ozônio/química , Titânio/química , Eliminação de Resíduos Líquidos/métodos , Mineração , Oxirredução
6.
J Magn Reson Imaging ; 13(5): 781-6, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11329201

RESUMO

We evaluated short-term effects of partial ventriculectomy on left ventricular (LV) parameters and its impact on late survival by magnetic resonance imaging (MRI). Twenty patients and 10 normal volunteers were studied, and LV volumes (EDV, ESV), ejection fraction (EF), short- and long-axis dimensions (SA, LA), wall thickness (Wth), shape (LA/SA), geometry (Wth/SA), a geometry index (Phi), and wall-motion score index (WMSI) were evaluated pre- and postoperatively. Also, we compared results and survival of patients with preoperative EF 17%. Short-term results showed significant changes (P < 0.001) in: EF (17.3 +/- 7.3% vs. 30.4 +/- 9.5%), EDV (391.9 +/- 118 vs. 272.7 +/- 90 mL); ESV (308.2 +/- 102.8 vs. 190.3 +/- 68.4 mL); SA (80.5 +/- 10.4 vs. 71.7 +/- 7.8 mm); LA/SA (1.13 +/- 0.1 vs. 1.34 +/- 0.1); Wth (8.35 +/- 0.99 vs. 9.75 +/- 1.41 mm); Wth/SA (0.10 +/- 0.01 vs. 0.14 +/- 0.02), diastolic( 0.80 +/- 0.16 vs. 0.58 +/- 0.13) and systolic (0.78 +/- 0.18 vs. 0.55 +/- 0.12) Phi; and WMSI (-2 vs. -1) (P = 0.032). The EF division showed differences in: LA/SA (1.26 +/- 0.10 vs. 1.49 +/- 0.12) (P < 0.001); Wth/SA (0.13 +/- 0.02 vs. 0.15 +/- 0.02) (P = 0.023); diastolic (0.65 +/- 0.11 vs. 0.48 +/- 0.11) and systolic (0.63 +/- 0.09 vs. 0.46 +/- 0.09) Phi (P < 0.001); and WMSI (-2 vs. -1) (P = 0.033). Finally, correlation between pre/postoperative EF showed for EF < 17%, r = 0.32 and for EF >17%, r = 0.83, which had different late survival. Our study showed significant changes on LV parameters after ventriculectomy. Patients with EF >17% showed better EF correlation between pre/postoperative values and higher survival rate. J. Magn. Reson. Imaging 2001;13:781-786.


Assuntos
Cardiomiopatia Dilatada/cirurgia , Ventrículos do Coração/cirurgia , Imageamento por Ressonância Magnética , Complicações Pós-Operatórias/diagnóstico , Disfunção Ventricular Esquerda/cirurgia , Adulto , Volume Cardíaco/fisiologia , Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/mortalidade , Feminino , Ventrículos do Coração/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Complicações Pós-Operatórias/mortalidade , Valor Preditivo dos Testes , Prognóstico , Volume Sistólico/fisiologia , Taxa de Sobrevida , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/mortalidade , Função Ventricular Esquerda/fisiologia
7.
J Hazard Mater ; 84(1): 29-41, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11376882

RESUMO

Although electrocoagulation is an evolving technology that is being effectively applied today for wastewater treatment, the paucity of scientific understanding of the complex chemical and physical processes involved is limiting future design and hindering progress. The objective of this review through a survey of the literature is to bring the chemistry and physical processes involved into perspective and to focus attention on those areas critically needing research.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Xenobióticos/química , Fenômenos Químicos , Físico-Química , Estimulação Elétrica , Poluentes da Água , Poluição da Água/prevenção & controle
8.
J Thorac Cardiovasc Surg ; 115(4): 800-7, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9576213

RESUMO

OBJECTIVE: This study reports initial results of partial left ventriculectomy performed with preservation of the mitral valve in the treatment of 27 patients with idiopathic dilated cardiomyopathy. METHODS: Patients were in New York Heart Association class III or IV. Partial ventriculectomy was performed as an isolated procedure in four patients and associated with mitral annuloplasty in 23 patients. There were four hospital deaths (14.8%) and the remaining patients were followed for 11.2 +/- 6 months. RESULTS: Decrease of left ventricular diastolic diameter (81.8 +/- 8.7 to 68.5 +/- 7.6 mm, p < 0.001) and improvement of left ventricular wall shortening (12% +/- 3.1% to 18.1% +/- 3.9%, p < 0.001) were demonstrated by echocardiography after the operation. Left ventricular radioisotopic angiography showed reduction of diastolic volume (495 +/- 124 ml to 352 +/- 108 ml, p < 0.001) and increase of ejection fraction (17.7% +/- 4.6% to 23.7% +/- 8.8%, p < 0.001). Right-sided heart catheterization demonstrated improvement of stroke index (24.3 +/- 7.7 ml/m2 to 28.3 +/- 7.6 ml/m2, p < 0.01) and decrease of pulmonary wedge pressure (23.2 +/- 8.8 mm Hg to 17 +/- 7 mm Hg, p < 0.01). Similar results were documented at 6 and 12 months of follow-up. Functional class improved from 3.6 +/- 0.5 to 1.4 +/- 0.6 (p < 0.001). However, seven patients died at midterm follow-up because of heart failure progression or arrhythmia-related events, and survival rate was 59.2% +/- 9.4% from 6 to 24 months of follow-up. CONCLUSIONS: Partial left ventriculectomy performed with preservation of the mitral valve improves left ventricular function and congestive heart failure in patients with dilated cardiomyopathy. Nevertheless, the high incidences of heart failure progression and arrhythmia-related deaths observed after this procedure preclude its wide clinical application.


Assuntos
Cardiomiopatia Dilatada/cirurgia , Disfunção Ventricular Esquerda/cirurgia , Cardiomiopatia Dilatada/mortalidade , Progressão da Doença , Feminino , Seguimentos , Ventrículos do Coração/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/cirurgia , Complicações Pós-Operatórias/mortalidade , Taxa de Sobrevida , Fatores de Tempo , Disfunção Ventricular Esquerda/mortalidade
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