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1.
BMC Geriatr ; 23(1): 659, 2023 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833642

RESUMO

BACKGROUND: Infective endocarditis (IE) is a severe disease associated with high morbidity and mortality. Little is known about the best management of elderly patients with IE. In these patients, surgery may be challenging. Our study aimed to describe IE's features in octogenarians and to identify the independent predictors of mortality, focusing on the prognostic impact of disability. METHODS: We retrospectively analyzed 551 consecutive patients admitted to a single surgical centre with a definite diagnosis of non-device-related infective endocarditis; of these, 97 (17.6%) were older than 80 years. RESULTS: In patients under eighty, males were mostly involved with a sex ratio exceeding 2:1. This ratio was inverted in older people, where the female gender represented 53.6% of the total. Enterococci (29.8 vs. 17.4%, p = 0.005) were significantly more frequent than in younger people. Comorbidities were more frequent in elderly patients; consequently, EuroSCORE II was higher (median ± IQR 16.4 ± 21.1 vs. 5.0 ± 10.3, p = 0.001). In octogenarians, IE was more frequently left-sided (97.9 vs. 89.8%, p = 0.011). Octogenarians were more often excluded from surgery despite indication (23.7 vs. 8.1%, p = 0.001) and had higher three-year mortality (45.3 vs. 30.6%, p = 0.005) than younger patients. In elderly patients, age did not independently predict mortality, while exclusion from surgery and a high grade of disability did. CONCLUSIONS: Octogenarians with IE have specific clinical and microbiological characteristics. Older patients are more often excluded from surgery, and the overall prognosis is poor. Age per se should not be a reason to deny surgery, while disability predicts futility.


Assuntos
Endocardite Bacteriana , Endocardite , Masculino , Idoso de 80 Anos ou mais , Humanos , Feminino , Idoso , Estudos Retrospectivos , Octogenários , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/epidemiologia , Endocardite Bacteriana/cirurgia , Endocardite/diagnóstico , Endocardite/cirurgia , Endocardite/microbiologia , Prognóstico , Mortalidade Hospitalar
2.
Heart ; 109(16): 1248-1253, 2023 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-37147131

RESUMO

OBJECTIVE: The best strategy to manage patients with left-sided infective endocarditis (IE) and intermediate-length vegetations (10-15 mm) remains uncertain. We aimed to evaluate the role of surgery in patients with intermediate-length vegetations and no other European Society of Cardiology guidelines-approved surgical indication. METHODS: We retrospectively enrolled 638 consecutive patients admitted to three academic centres (Amiens, Marseille and Florence University Hospitals) between 2012 and 2022 for left-sided definite IE (native or prosthetic) with intermediate-length vegetations (10-15 mm). We compared four clinical groups: medically (n=50) or surgically (n=345) treated complicated IE, medically (n=194) or surgically (n=49) treated uncomplicated IE. RESULTS: Mean age was 67±14 years. Women were 182 (28.6%). The rate of embolic events on admission was 40% in medically treated and 61% in surgically treated complicated IE, 31% in medically treated and 26% in surgically treated uncomplicated IE. The analysis of all-cause mortality showed the lowest 5-year survival rate for medically treated complicated IE (53.7%). We found a similar 5-year survival rate for surgically treated complicated IE (71.4%) and medically treated uncomplicated IE (68.4%). The highest 5-year survival rate was observed in surgically treated uncomplicated IE group (82.4%, log-rank p<0.001). The analysis of the propensity score-matched cohort estimated an HR of 0.23 for uncomplicated IE treated surgically compared with medical therapy (p=0.005, 95% CI: 0.079 to 0.656). CONCLUSIONS: Our results suggest that surgery is associated with lower all-cause mortality than medical therapy in patients with uncomplicated left-sided IE with intermediate-length vegetations even in the absence of other guideline-based indications.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Endocardite Bacteriana , Endocardite , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Endocardite/complicações , Endocardite/cirurgia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Hospitalização , Endocardite Bacteriana/complicações , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/cirurgia
3.
BMC Infect Dis ; 22(1): 554, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715766

RESUMO

BACKGROUND: Infective endocarditis still has high mortality and invalidating complications, such as cerebral embolism. The best strategies to prevent and manage neurologic complications remain uncertain. This study aimed to identify predictors of cerebral septic embolism and evaluate the role of surgery in these patients in a real-world surgical centre. METHODS: We retrospectively analyzed 551 consecutive patients admitted to our department with a definite diagnosis of non-device-related infective endocarditis; of these, 126 (23%) presented a neurologic complication. RESULTS: Cerebral embolism was significantly more frequent in patients with large vegetations (p = 0.004), mitral valve infection (p = 0.001), and Staphylococcus aureus infection (p = 0.025). At multivariable analysis, only vegetation length was an independent predictor of cerebral embolism (HR per unit 1.057, 95% CI 1.025-1.091, p 0.001), with a best predictive threshold of 10 mm at ROC curve analysis (AUC 0.54, p = 0.001). Patients with neurologic complications were more often excluded from surgery despite an indication to it (16% vs 8%, p = 0.001). If eligible, they were treated within two weeks from diagnosis in similar proportions as patients without cerebral embolism with a similar survival rate. Predictors of mortality were hemorrhagic lesions (p = 0.018), a GCS < 14 (p = 0.001) or a severe degree of disability (p = 0.001) at presentation. The latter was the only independent predictor of mortality at multivariable analysis (HR 2.3, 95% CI 1.43-3.80, p = 0.001). CONCLUSIONS: The present study highlights the prognostic value of functional presentation and the safety of cardiac surgery, when feasible, in patients with cerebral septic embolism.


Assuntos
Embolia , Endocardite Bacteriana , Endocardite , Embolia Intracraniana , Sepse , Embolia/complicações , Endocardite/complicações , Endocardite/diagnóstico , Endocardite/cirurgia , Endocardite Bacteriana/complicações , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/terapia , Humanos , Embolia Intracraniana/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Sepse/complicações
4.
Am J Cardiol ; 175: 152-157, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35597626

RESUMO

Anorexia nervosa (AN) is a psychiatric disorder that may lead to cardiac complications. The objective of this study was to evaluate global and regional longitudinal strain changes in patients affected by AN as an early marker of myocardial damage. We prospectively enrolled 48 consecutive patients with AN and 44 age-matched and gender-matched healthy controls. In all subjects, we performed echocardiography, including global longitudinal strain (GLS) measurement. A subset of 33 patients with AN had further echocardiographic examinations during the follow-up. Compared with healthy controls, patients with AN had a greater prevalence of pericardial effusion (9 of 48 vs 0 of 44, p = 0.003), a smaller left ventricular mass (63 ± 15 vs 99 ± 30 g, p < 0.001), a lower absolute value of GLS (-18.9 ± 2.8 vs -20.2 ± 1.8%, p = 0.010) and of basal LS (-15.4 ± 6.0 vs -19.4 ± 2.6%, p < 0.001). The bull's eye mapping showed a plot pattern with blue basal areas in 18 of 48 patients with AN versus 1 of 44 controls (p < 0.001). During the follow-up, of 13 patients with blue areas in the first bull's eye mapping, 11 recovered completely, and of 20 patients with a red bull's eye at the first examination, none presented blue areas at the second one. In conclusion, GLS is significantly altered in patients with AN, and a basal blue pattern on bull's eye mapping identifies more severe cases. These changes seem to be reversible.


Assuntos
Anorexia Nervosa , Cardiopatias , Adulto , Anorexia Nervosa/complicações , Ecocardiografia , Cardiopatias/complicações , Humanos , Função Ventricular Esquerda
5.
Sci Rep ; 12(1): 6223, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35418671

RESUMO

Paper-based biosensors featuring immunoconjugated gold nanoparticles have gained extraordinary momentum in recent times as the platform of choice in key cases of field applications, including the so-called rapid antigen tests for SARS-CoV-2. Here, we propose a revision of this format, one that may leverage on the most recent advances in materials science and data processing. In particular, we target an amplifiable DNA rather than a protein analyte, and we replace gold nanospheres with anisotropic nanorods, which are intrinsically brighter by a factor of ~ 10, and multiplexable. By comparison with a gold-standard method for dot-blot readout with digoxigenin, we show that gold nanorods entail much faster and easier processing, at the cost of a higher limit of detection (from below 1 to 10 ppm in the case of plasmid DNA containing a target transgene, in our current setup). In addition, we test a complete workflow to acquire and process photographs of dot-blot membranes with custom-made hardware and regression tools, as a strategy to gain more analytical sensitivity and potential for quantification. A leave-one-out approach for training and validation with as few as 36 sample instances already improves the limit of detection reached by the naked eye by a factor around 2. Taken together, we conjecture that the synergistic combination of new materials and innovative tools for data processing may bring the analytical sensitivity of paper-based biosensors to approach the level of lab-grade molecular tests.


Assuntos
Técnicas Biossensoriais , COVID-19 , Nanopartículas Metálicas , Nanotubos , Técnicas Biossensoriais/métodos , COVID-19/diagnóstico , DNA , Ouro , Humanos , SARS-CoV-2/genética
6.
Heart Vessels ; 37(5): 895-901, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34741209

RESUMO

Most cases of infective endocarditis (IE) involve a single valve, and little is known concerning IE that simultaneously affects two valves. The involvement of more than one valve may imply more severe and extensive cardiac lesions. In these patients, surgery may be challenging. We aimed to determine the clinical characteristics, the therapeutic strategy, and the prognostic impact of double-valve IE (DVIE). We retrospectively included in the analysis that 440 consecutive patients with definite active IE in a single surgical centre. DVIE occurred in 75 of the total enrolled 440 patients (17%) and involved mostly the combination of mitral and aortic valves (N = 63, 84%). Most patients had double-native IE (N = 45, 60%). Staphylococci were less frequent in patients with double-valve than single-valve IE (SVIE). The proportion of patients undergoing valve repair among those treated surgically was higher for patients with DVIE than for SVIE (p < 0.03). Valve repair of at least one valve was associated with non-significant better survival than double replacement. DVIE was associated with higher all-cause mortality than SVIE (p < 0.013) and a higher relapse rate (p = 0.023). DVIE was not associated with a higher risk of composite non-fatal adverse events. DVIE represents a considerable proportion of overall cases of IE, mainly involving aortic and mitral valves, with a jet lesion on the mitral valve; Staphylococcus is significantly less frequent than in SVIE; DVIE is independently associated with higher mortality and relapse rate; finally, mitral valve repair is feasible in a considerable proportion of surgical cases.


Assuntos
Endocardite Bacteriana , Endocardite , Endocardite/diagnóstico , Endocardite/cirurgia , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/cirurgia , Humanos , Prognóstico , Recidiva , Estudos Retrospectivos
7.
BMC Infect Dis ; 21(1): 1010, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34579674

RESUMO

BACKGROUND: Intravenous drug abuse (IDA) is a known risk factor for infective endocarditis (IE) and is associated with frequent relapses, but its prognostic impact is still debated. The potential futility of surgery in this population is a further issue under discussion. We aimed to describe the clinical characteristics, the therapeutic strategy, and the prognosis associated with IDA in IE. METHODS: We retrospectively analysed 440 patients admitted to a single surgical centre for definite active IE from January 2012 to December 2020. RESULTS: Patients reporting IDA (N = 54; 12.2%) were significantly younger (p < 0.001) and presented fewer comorbidities (p < 0.001). IDA was associated with a higher proportion of relapses (27.8 vs. 3.3%, p < 0.001) and, at multivariable analysis, was an independent predictor of long-term mortality (HR 2.3, 95%CI 1.1-4.7, p = 0.015). We did not register multiple relapses in non-IDA patients. Among IDA patients, we observed 1 relapse after discharge in 9 patients, 2 relapses in 5 patients and 3 relapses in 1 patient. In IDA patients, neither clinical and laboratory variables nor the occurrence of even multiple relapses emerged as indicators of an adverse risk-benefit ratio of surgery in patients with surgical indication. CONCLUSIONS: IE secondary to IDA affects younger patients than those with IE not associated with IDA. Probably due to this difference, IE secondary to IDA is not associated with significantly higher mortality, whereas the negative, long-term prognostic impact of IDA emerges in multivariate analysis. Considering the good prognosis of patients with uncomplicated IE treated medically, surgery should be reserved to patients with a strict- guidelines-based indication. However, since there are no clear predictors of an unfavourable risk-benefit ratio of surgery in patients with surgical indication, all patients with a complicated IE should be operated, irrespective of a history of IDA.


Assuntos
Usuários de Drogas , Endocardite Bacteriana , Endocardite , Abuso de Substâncias por Via Intravenosa , Endocardite/tratamento farmacológico , Endocardite/epidemiologia , Humanos , Recidiva Local de Neoplasia , Estudos Retrospectivos , Fatores de Risco , Abuso de Substâncias por Via Intravenosa/complicações
8.
BMC Cardiovasc Disord ; 21(1): 186, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33858337

RESUMO

BACKGROUND: The association of infective endocarditis (IE) with spondylodiscitis (SD) was first reported in 1965, but few data are available about this issue. This study aimed to evaluate the prevalence of SD in patients with IE, and to determine the clinical features and the prognostic impact of this association. METHODS: We retrospectively analysed 363 consecutive patients admitted to our Department with non-device-related IE. Radiologically confirmed SD was revealed in 29 patients (8%). Long-term follow-up (average: 3 years) was obtained by structured telephone interviews; in 95 cases (13 of whom had been affected by SD), follow-up echocardiographic evaluation was also available. RESULTS: At univariable analysis, the combination of IE with SD was associated with male gender (p = 0.017), diabetes (p = 0.028), drug abuse (p = 0.009), Streptococcus Viridans (p = 0.009) and Enterococcus (p = 0.015) infections. At multivariable analysis, all these factors independently correlated with presence of SD in patients with IE. Mortality was similar in patients with and without SD. IE relapses at 3 years were associated with the presence of SD (p = 0.003), Staphylococcus aureus infection (p < 0.001), and drug abuse (p < 0.001) but, at multivariable analysis, only drug abuse was an independent predictor of IE relapses (p < 0.001; HR 6.8, 95% CI 1.6-29). At echocardiographic follow-up, SD was not associated with worsening left ventricular systolic function or valvular dysfunction. CONCLUSIONS: The association of IE with SD is not rare. Hence, patients with IE should be screened for metastatic infection of the vertebral column, especially if they have risk factors for it. However, SD does not appear to worsen the prognosis of patients with IE, either in-hospital or long-term.


Assuntos
Discite/epidemiologia , Endocardite/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Diabetes Mellitus/epidemiologia , Discite/diagnóstico , Discite/microbiologia , Endocardite/diagnóstico , Endocardite/microbiologia , Enterococcus/patogenicidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Prognóstico , Reinfecção , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores Sexuais , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Fatores de Tempo
9.
BMC Cardiovasc Disord ; 21(1): 28, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33435885

RESUMO

PURPOSE: Mortality in infective endocarditis (IE) is still high, and the long term prognosis remains uncertain. This study aimed to identify predictors of long-term mortality for any cause, adverse event rate, relapse rate, valvular and ventricular dysfunction at follow-up, in a real-world surgical centre. METHODS: We retrospectively analyzed 363 consecutive episodes of IE (123 women, 34%) admitted to our department with a definite diagnosis of non-device-related IE. Median follow-up duration was 2.9 years. Primary endpoints were predictors of mortality, recurrent endocarditis, and major non-fatal adverse events (hospitalization for any cardiovascular cause, pace-maker implantation, new onset of atrial fibrillation, sternal dehiscence), and ventricular and valvular dysfunction at follow-up. RESULTS: Multivariate analysis independent predictors of mortality showed age (HR per unit 1.031, p < 0.003), drug abuse (HR 3.5, p < 0.002), EUROSCORE II (HR per unit 1.017, p < 0.0006) and double valve infection (HR 2.3, p < 0.001) to be independent predictors of mortality, while streptococcal infection remained associated with a better prognosis (HR 0.5, p < 0.04). Major non-fatal adverse events were associated with age (HR 1.4, p < 0.022). New episodes of infection were correlated with S aureus infection (HR 4.8, p < 0.001), right-sided endocarditis (HR 7.4, p < 0.001), spondylodiscitis (HR 6.8, p < 0.004) and intravenous drug abuse (HR 10.3, p < 0.001). After multivariate analysis, only drug abuse was an independent predictor of new episodes of endocarditis (HR 8.5, p < 0.001). Echocardiographic follow-up, available in 95 cases, showed a worsening of left ventricular systolic function (p < 0.007); severe valvular dysfunction at follow-up was reported only in 4 patients, all of them had mitral IE (p < 0.03). CONCLUSIONS: The present study highlights some clinical, readily available factors that can be useful to stratify the prognosis of patients with IE.


Assuntos
Tratamento Conservador/efeitos adversos , Endocardite Bacteriana/terapia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Complicações Pós-Operatórias/etiologia , Transtornos Relacionados ao Uso de Substâncias/complicações , Fatores Etários , Idoso , Tomada de Decisão Clínica , Tratamento Conservador/mortalidade , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/mortalidade , Feminino , Implante de Prótese de Valva Cardíaca/mortalidade , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Valor Preditivo dos Testes , Recidiva , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Transtornos Relacionados ao Uso de Substâncias/mortalidade , Fatores de Tempo , Resultado do Tratamento
10.
Cancer Res ; 80(15): 3170-3174, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32540962

RESUMO

Quantitative analysis of biomedical images, referred to as radiomics, is emerging as a promising approach to facilitate clinical decisions and improve patient stratification. The typical radiomic workflow includes image acquisition, segmentation, feature extraction, and analysis of high-dimensional datasets. While procedures for primary radiomic analyses have been established in recent years, processing the resulting radiomic datasets remains a challenge due to the lack of specific tools for doing so. Here we present RadAR (Radiomics Analysis with R), a new software to perform comprehensive analysis of radiomic features. RadAR allows users to process radiomic datasets in their entirety, from data import to feature processing and visualization, and implements multiple statistical methods for analysis of these data. We used RadAR to analyze the radiomic profiles of more than 850 patients with cancer from publicly available datasets and showed that it was able to recapitulate expected results. These results demonstrate RadAR as a reliable and valuable tool for the radiomics community. SIGNIFICANCE: A new computational tool performs comprehensive analysis of high-dimensional radiomic datasets, recapitulating expected results in the analysis of radiomic profiles of >850 patients with cancer from independent datasets.


Assuntos
Algoritmos , Diagnóstico por Imagem , Processamento de Imagem Assistida por Computador/métodos , Radiologia , Software , Interpretação Estatística de Dados , Conjuntos de Dados como Assunto , Diagnóstico por Imagem/métodos , Diagnóstico por Imagem/estatística & dados numéricos , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Interpretação de Imagem Assistida por Computador/estatística & dados numéricos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Imageamento Tridimensional/métodos , Imageamento Tridimensional/estatística & dados numéricos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Neoplasias/diagnóstico , Neoplasias/diagnóstico por imagem , Neoplasias/epidemiologia , Tomografia por Emissão de Pósitrons/métodos , Tomografia por Emissão de Pósitrons/estatística & dados numéricos , Radiologia/métodos , Radiologia/estatística & dados numéricos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Fluxo de Trabalho
11.
Eur J Intern Med ; 78: 82-87, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32317239

RESUMO

BACKGROUND: In patients with left-sided infective endocarditis (IE) and heart failure associated with large vegetations, early surgery prevents embolic events. However, optimal timing of surgery for other indications is still unresolved particularly when the presence of large vegetations represents the sole indication. METHODS: We retrospectively analyzed 308 consecutive patients admitted to our department with definite left-sided IE. Of these patients, 243 (79%) underwent cardiac surgery (complicated IE), 34 patients with uncomplicated IE received medical treatment, 24 were not operated due to prohibitive general conditions and 7 refused surgery. Long-term follow-up was obtained by structured telephone interviews. RESULTS: During the 6-year follow-up (average 121.8 weeks ± 76), patients not operated because of general conditions or refusal had the worst prognosis, while outcome in operated patients for complicated IE was comparable to that of uncomplicated IE treated medically. Early (<2 weeks from diagnosis) surgery was associated with better survival compared to delayed surgery (HR 0.58, p = 0.23). Embolic events were detected at admission in 38% of cases; Staphylococcus Aureus etiology and vegetation size were independently associated with embolism (OR 2.4, p = 0.01; OR 1, p=0.008 respectively). CONCLUSIONS: Compared to uncomplicated medically-treated patients, complicated IE showed comparable survival when managed aggressively by surgical intervention, whereas a conservative approach was associated with an adverse prognosis. Staphylococcus Aureus infection and vegetation size were independent predictors of systemic embolism. Our data support aggressive surgical management of complicated IE patients and highlight the importance of etiological characterization in clinical decision-making.


Assuntos
Embolia , Endocardite Bacteriana , Endocardite , Endocardite/complicações , Endocardite/cirurgia , Endocardite Bacteriana/complicações , Endocardite Bacteriana/cirurgia , Humanos , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
12.
Med Phys ; 44(11): 5988-5996, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28857189

RESUMO

PURPOSE: The exposure of operators moving in the static field of magnetic resonance (MR) facilities was assessed through measurements of the magnetic flux density, which is experienced as variable in time because of the movement. Collected data were processed to allow the comparison with most recent and authoritative safety standards. METHODS: Measurements of the experienced magnetic flux density B were performed using a probe worn by volunteers moving in MR environments. A total of 55 datasets were acquired nearby a 1.5 T, 3 T, and 7 T whole body scanners. Three different metrics were applied: the maximum intensity of B, to be compared with 2013/35/EU Directive exposure limit values for static fields; the maximum variation of the vector B on every 3s-interval, for comparison with the ICNIRP-2014 basic restriction aimed at preventing vertigo effects; two weighted-peak indices (for "sensory" and "health" effects: SENS-WP, HLTH-WP), assessing compliance with ICNIRP-2014 and EU Directive recommendations intended to prevent stimulation effects. RESULTS: Peak values of |B| were greater than 2 T in nine of the 55 datasets. All the datasets at 1.5 T and 3 T were compliant with the limit for vertigo effects, whereas six datasets at 7 T turned out to be noncompliant. At 7 T, all 36 datasets were noncompliant for the SENS-WP index and 26 datasets even for the HLTH-WP one. CONCLUSIONS: Results demonstrate that compliance with EU Directive limits for static fields does not guarantee compliance with ICNIRP-2014 reference levels and clearly show that movements in the static field could be the key component of the occupational exposure to EMF in MR facilities.


Assuntos
Campos Magnéticos , Imageamento por Ressonância Magnética/instrumentação , Movimento (Física) , Exposição Ocupacional/análise , Humanos , Reprodutibilidade dos Testes
13.
Radiat Prot Dosimetry ; 163(3): 292-305, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24936022

RESUMO

In this paper, a procedure is described for the assessment of human exposure to magnetic fields with complex waveforms generated by arc-welding equipment. The work moves from the analysis of relevant guidelines and technical standards, underlining their strengths and their limits. Then, the procedure is described with particular attention to the techniques used to treat complex waveform fields. Finally, the procedure is applied to concrete cases encountered in the workplace. The discussion of the results highlights the critical points in the procedure, as well as those related to the evolution of the technical and exposure standards.


Assuntos
Campos Magnéticos , Exposição Ocupacional/análise , Saúde Ocupacional/normas , Proteção Radiológica/normas , Soldagem/instrumentação , Contagem Corporal Total/normas , Carga Corporal (Radioterapia) , Desenho de Equipamento , Análise de Falha de Equipamento/normas , Segurança de Equipamentos/normas , Europa (Continente) , Guias como Assunto , Humanos , Doses de Radiação , Soldagem/normas
14.
Prog Biophys Mol Biol ; 107(3): 456-63, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22019904

RESUMO

Portable - or "laptop" - computers (LCs) are widely and increasingly used all over the world. Since LCs are often used in tight contact with the body even by pregnant women, fetal exposures to low frequency magnetic fields generated by these units can occur. LC emissions are usually characterized by complex waveforms and are often generated by the main AC power supply (when connected) and by the display power supply sub-system. In the present study, low frequency magnetic field emissions were measured for a set of five models of portable computers. For each of them, the magnetic flux density was characterized in terms not just of field amplitude, but also of the so called "weighted peak" (WP) index, introduced in the 2003 ICNIRP Statement on complex waveforms and confirmed in the 2010 ICNIRP Guidelines for low frequency fields. For the model of LC presenting the higher emission, a deeper analysis was also carried out, using numerical dosimetry techniques to calculate internal quantities (current density and in-situ electric field) with reference to a digital body model of a pregnant woman. Since internal quantities have complex waveforms too, the concept of WP index was extended to them, considering the ICNIRP basic restrictions defined in the 1998 Guidelines for the current density and in the 2010 Guidelines for the in-situ electric field. Induced quantities and WP indexes were computed using an appropriate original formulation of the well known Scalar Potential Finite Difference (SPFD) numerical method for electromagnetic dosimetry in quasi-static conditions.


Assuntos
Computadores , Feto , Campos Magnéticos , Exposição Materna , Fontes de Energia Elétrica , Feminino , Humanos , Campos Magnéticos/efeitos adversos , Exposição Materna/efeitos adversos , Gravidez , Radiometria
15.
Radiat Prot Dosimetry ; 137(3-4): 247-51, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19841019

RESUMO

The endorsement process of the 2004/40/EC Directive (still in progress) has led to a critical analysis of the ICNIRP Guidelines, on which the directive is based. In particular, some known problems affect the applicability of the numerical techniques needed for checking compliance with limits at low frequency. A review of these open problems is presented in the paper, highlighting how such problems deal more with pre-processing and post-processing steps than with the core numerical calculation of the current density.


Assuntos
Algoritmos , Carga Corporal (Radioterapia) , Exposição Ambiental/análise , Fidelidade a Diretrizes , Guias como Assunto , Proteção Radiológica/normas , Radiometria/normas , Campos Eletromagnéticos , União Europeia , Doses de Radiação
16.
Int J Occup Saf Ergon ; 12(2): 201-15, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16790178

RESUMO

An overview of quasi-static electromagnetic dosimetry is presented. After an introductive description of quantities and standards and a quick look at experimental and analytical approaches, attention is focused on numerical dosimetry. The process that leads to the calculation of results is analyzed in its basic steps, including the representation of the human body by means of a realistic voxel phantom. The most popular numerical methods are then described. An analysis of different methods in the same framework emphasizes common features and differences. This can help in choosing a more suitable method to solve a particular problem. An example of an application is finally reported.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Exposição Ocupacional/análise , Radiometria/métodos , Relação Dose-Resposta à Radiação , Regulamentação Governamental , Guias como Assunto , Corpo Humano , Humanos , Agências Internacionais , Itália , Concentração Máxima Permitida , Modelos Estatísticos , Exposição Ocupacional/prevenção & controle , Radiação não Ionizante/efeitos adversos , Radiometria/estatística & dados numéricos
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