Publications by authors named "Luiz F Avila"

Introduction: This study explores the possibility of a relationship between the sphericity degree of a target volume with the dose distribution. This relationship is evaluated based on the ratio isodose volume / target volume (IV/TV) and the metrics coverage, i.e.

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Background: Geometrical risk factors for CAD have been previously proposed before. To date, however, the effect of those factors is not conclusive, and remains as an open research field. Here, we hypothesize that some of these factors have a genetic component explaining inter-individual variability.

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Background: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB).

Objective: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy.

Methods: Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography.

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A woman (49 years) with Chagas' disease showed: ECG, right bundle-branch block and left anterior-superior fascicular block; V1 has unusual R > R', and elevated ST segment from V2 to V6 . Additional imaging revealed concomitant HCM and Chagas, which is uncommon. Overlapping of ECG findings can be explained by this rare association of diseases.

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Background: Although the release of cardiac biomarkers after percutaneous (PCI) or surgical revascularization (CABG) is common, its prognostic significance is not known. Questions remain about the mechanisms and degree of correlation between the release, the volume of myocardial tissue loss, and the long-term significance. Delayed-enhancement of cardiac magnetic resonance (CMR) consistently quantifies areas of irreversible myocardial injury.

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We report a dual-source computed tomography study of dynamic and quantitative myocardial perfusion in a 44-year-old patient with previous documented coronary artery disease. Quantitatively, the tomography showed myocardial perfusion deficit in the territories with significant coronary stenosis, confirmed by computed tomography angiography and conventional angiography. Dual-source computed tomography allowed dynamic perfusion and anatomic evaluation in a single study during the follow-up of this patient.

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Background: Endocardial fibrous tissue (FT) deposition is a hallmark of endomyocardial fibrosis (EMF). Echocardiography is a first-line and the standard technique for the diagnosis of this disease. Although late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) allows FT characterization, its role in the diagnosis and prognosis of EMF has not been investigated.

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Background: Coronary artery disease (CAD) is the major cause of death among chronic renal failure (CRF) patients. Traditional, non-invasive exams to detect CAD and to predict events have shown insufficient results in this group. CT Scan evaluation of Coronary Calcium Score (CCS) has proven to be of prognostic value for the population reporting no renal condition.

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Background: The magnetic resonance imaging (MRI) is an effective method to study hypertrophic cardiomyopathy (HCM).

Objective: To evaluate, using MRI, the parameters of systolic function, perfusion and myocardial viability in patients with HCM, comparing the groups with and without obstruction of the left ventricular outflow tract.

Methods: Twenty-one patients with a diagnosis of HCM underwent the assessment of myocardial function, viability and perfusion under stress and at rest through MRI.

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Visceral abdominal fat has been associated to cardiovascular risk factors and coronary artery disease (CAD). Computed tomography (CT) coronary angiography is an emerging technology allowing detection of both obstructive and nonobstructive CAD adding information to clinical risk stratification. The aim of this study was to evaluate the association between CAD and adiposity measurements assessed clinically and by CT.

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Background: Chronic aortic valve disease (AVD) is characterized by progressive accumulation of interstitial myocardial fibrosis (MF). However, assessment of MF accumulation has only been possible through histologic analyses of endomyocardial biopsies. We sought to evaluate contrast-enhanced magnetic resonance imaging (ce-MRI) as a noninvasive method to identify the presence of increased MF in patients with severe AVD.

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Background: Perioperative myocardial infarction (POMI) is a complication of coronary artery bypass grafting (CABG) with a potential prognostic impact. Technetium-99m pyrophosphate myocardial scintigraphy (MS) is used in the diagnosis of POMI; however it shows a limited sensitivity for subendocardial lesions. Cardiovascular magnetic resonance imaging (CMRI), in turn, has a high accuracy in the detection of myocardial necrosis.

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Background: Two-dimensional axial and manually-oriented reformatted images are traditionally used to analyze coronary data provided by multidetector-row computed tomography angiography (MDCTA). While apparently more accurate in evaluating calcified vessels, 2D methods are time-consuming compared with automated 3D approaches. The purpose of this study was to evaluate the performance of a modified automated 3D approach (using manual vessel isolation and different window and level settings) in a population with high calcium scores who underwent coronary half-millimeter 16-detector-row CT angiography (16 x 0.

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Objective: To show the real value of cardiac magnetic resonance imaging (CMRI) in the evaluation of patients with symptomatic chronic aortic valve disease.

Methods: Seventy patients--35 with aortic stenosis (AoS) and 35 with aortic regurgitation (AoR) with surgical indication, who underwent preoperative echocardiogram (ECHO) and CMRI to assess ventricular function, volumes, and left ventricular mass index using cine magnetic resonance imaging, were studied.

Results: No statistically significant difference was observed between the AoS and AoR groups when ECHO and CMRI variables were compared.

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Objectives: We sought to investigate whether myocardial delayed enhancement (MDE) by magnetic resonance imaging (MRI) could quantify myocardial fibrosis (MF) in patients with Chagas' heart disease (CHD), thus defining the severity of the disease.

Background: Myocardial fibrosis secondary to ischemic disease can be imaged using MDE. Advanced CHD is characterized by progressive MF.

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Objective: To assess the mechanisms that may be involved in the evolution of right and left ventricular dysfunction in patients with chronic obstructive pulmonary disease (COPD).

Methods: Magnetic resonance imaging was used in 11 control patients (group C) and 27 patients with COPD, who were divided into 2 groups, COPDc and COPDs, according to the presence or absence of right ventricular dysfunction, respectively. Doppler echocardiography was used for assessing the degree of pulmonary hypertension.

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Objective: The goals of this study were to determine the prevalence of hypertension and recoarctation in operated children and teenagers and to integrate clinical and imaging technique data.

Methods: One hundred thirteen infants and children (ages 14 years or less) were retrospectively divided into 3 groups according to the age at operation and the surgical technique: 79 underwent resection with end-to-end anastomosis; 14 had patch enlargement; 13 had subclavian flap aortoplasty; and 7 had other techniques performed. The mean age at operation was 3.

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