159 research outputs found
Ressonância magnética cardíaca para radioablação de fibrilação atrial: protocolo e técnicas de quantificação do volume atrial esquerdo
Gadolinium-enhanced cardiac magnetic resonance imaging: administered dose in relationship to United States Food and Drug Administration (FDA) guidelines
Gadolinium-enhanced cardiovascular magnetic resonance: administered dose in relationship to united states food and drug administration (FDA) guidelines
<p>Abstract</p> <p>Purpose</p> <p>Myocardial late gadolinium enhancement was originally validated using higher than label-recommended doses of gadolinium chelate. The objective of this study was to evaluate available evidence for various gadolinium dosing regimens used for CMR. The relationship of gadolinium dose warnings (due to nephrogenic systemic fibrosis) announced in 2008 to gadolinium dosing regimens was also examined.</p> <p>Methods</p> <p>We conducted a meta-analysis of peer reviewed publications from January, 2004 to December, 2010. Major subject search headings (MeSh) terms from the National Library of Medicine's PubMed were: contrast media, gadolinium, heart, magnetic resonance imaging; searches were limited to human studies with abstracts published in English. Case reports, review articles, editorials, MRA related papers and all reports that did not indicate gadolinium type or weight-based dose were excluded. For all included references, full text was available to determine the total administered gadolinium dose on a per kg basis. Average and median dose values were weighted by the number of subjects in each study.</p> <p>Results</p> <p>399 publications were identified in PubMed; 233 studies matched the inclusion criteria, encompassing 19,934 patients with mean age 54.2 ± 11.4 (range 9.3 to 76 years). 34 trials were related to perfusion testing and 199 to myocardial late gadolinium enhancement. In 2004, the weighted-median and weighted-mean contrast dose were 0.15 and 0.16 ± 0.06 mmol/kg, respectively. Median contrast doses for 2005-2010 were: 0.2 mmol/kg for all years, respectively. Mean contrast doses for the years 2005-2010 were: 0.19 ± 0.03, 0.18 ± 0.04, 0.18 ± 0.10, 0.18 ± 0.03, 0.18 ± 0.04 and 0.18 ± 0.04 mmol/kg, respectively (p for trend, NS). Gadopentetate dimeglumine was the most frequent gadolinium type [114 (48.9%) studies]. No change in mean gadolinium dose was present before, versus after the Food and Drug Administration (FDA) black box warning (p > 0.05). Three multi-center dose ranging trials have been published for cardiac MRI applications.</p> <p>Conclusion</p> <p>CMR studies in the peer-reviewed published literature routinely use higher gadolinium doses than regulatory agencies indicated in the package leaflet. Clinical trials should be supported to determine the appropriate doses of gadolinium for CMR studies.</p
A PROPOSAL OF A NEW SCALE TO MEASURE COMPETENCE IN MARKETING
Apesar de existirem alguns estudos que exploram as relações entre competências em marketing e performance, esta pesquisa tem como objetivo avançar no conhecimento sobre assunto. Sendo assim, cumpre os seguintes objetivos: propõe e valida uma nova escala para mensurar o construto de competência em marketing e suas dimensões no contexto brasileiro; identifica o impacto das competências em marketing individualmente na performance das organizações; avalia o impacto das competências na performance, considerando a interação entre as competências. Os resultados sugerem que as competências, quando consideradas em conjunto, têm impacto superior do que quando consideradas isoladamente, bem como hierarquiza as dimensões de competência segundo sua contribuição para a performance.The objective of this research is to understand the relation between competencies in marketing and it performance. More specifically, this paper present and validate a new scale to measure the construct competence in Marketing. Moreover, this paper identifies and evaluates the impact of marketing competences in the performance of the organization, considering the interaction among the competences. The results suggest that the competencies all together have a stronger impact if compared with the impact of each competence taken alone. In this manner, the results stress the concept of competence as the result of an integrated process. The paper also contributes with the idea that competences are valuable in relation of their contribution to the performance of the company
Myocardial T1 measurement: comparison of modified Look-Locker inversion recovery (MOLLI) and TI scout in the Multi-ethnic Study of Atherosclerosis (MESA)
The diagnosis of hypertrophic cardiomyopathy by cardiovascular magnetic resonance
Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the heart. HCM is characterized by a wide range of clinical expression, ranging from asymptomatic mutation carriers to sudden cardiac death as the first manifestation of the disease. Over 1000 mutations have been identified, classically in genes encoding sarcomeric proteins. Noninvasive imaging is central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is increasingly used to characterize morphologic, functional and tissue abnormalities associated with HCM. The purpose of this review is to provide an overview of the clinical, pathological and imaging features relevant to understanding the diagnosis of HCM. The early and overt phenotypic expression of disease that may be identified by CMR is reviewed. Diastolic dysfunction may be an early marker of the disease, present in mutation carriers prior to the development of left ventricular hypertrophy (LVH). Late gadolinium enhancement by CMR is present in approximately 60% of HCM patients with LVH and may provide novel information regarding risk stratification in HCM. It is likely that integrating genetic advances with enhanced phenotypic characterization of HCM with novel CMR techniques will importantly improve our understanding of this complex disease
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