79 research outputs found
Trends of Increasing Medical Radiation Exposure in a Population Hospitalized for Cardiovascular Disease (1970-2009)
Abstract Background: High radiation doses employed in cardiac imaging may increase cancer frequency in exposed patients after decades. The aim of this study was to evaluate the relative trends in medical radiation exposure in a population hospitalized for cardiovascular disease. Methods and Results: An observational single-center study was conducted to examine 16,431 consecutive patients with heart disease admitted to the Italian National Research Council Institute of Clinical Physiology between January 1970 and December 2009. In all patients, the cumulative estimated effective dose was obtained from data mining of electronic records of hospital admissions, adopting the effective dose typical values of the American Heart Association 2009 statement and Mettler\u27s 2008 catalog of doses. Cumulative estimated effective dose per patient in the last 5 years was 22 (12-42) mSv (median, 25th-75th percentiles), with higher values in ischemic heart disease (IHD), 37 (20-59) vs non-IHD, 13 (8-22) mSv, p,0.001. Trends in radiation exposure showed a steady increase in IHD and a flat trend in non-IHD patients, with variation from 1970-74 to 2005-2009 of +155% for IHD (p,0.001) and 21% in non-IHD (NS). The relative contribution of different imaging techniques was remodeled over time, with nuclear cardiology dominating in 1970s (23% of individual exposure) and invasive fluoroscopy in the last decade (90% of individual exposure). Conclusion: A progressive increase in cumulative estimated effective dose is observed in hospitalized IHD patients. The growing medical radiation exposure may encourage a more careful justification policy regarding ionizing imaging in cardiology patients applying the two main principles of radiation protection: appropriate justification for ordering and performing each procedure, and careful optimization of the radiation dose used during each procedure
Quantification of Epicardial Fat by Cardiac CT Imaging
The aim of this work is to introduce and design image processing methods for the quantitative analysis of epicardial fat by using cardiac CT imaging
Experiences from a winter school on landscape agronomy: Stakes, difficulties, perspectives
International audienceIn the latest fifteen years, agronomic research has shown a growing interest for studies which link farm or field scale to landscape scale. Thus, agronomy is called to renew its research questions and methodologies, and as well its educational programmes. In this context, some French and Italian researchers interested in these topics, coming from different scientific fields but sharing interests on landscape scale issues in research and higher education, decided to join their efforts around a common one-week educational programme on Landscape Agronomy for undergraduate and PhD students. Their aim has been to develop a new form of knowledge transfer and application on Landscape Agronomy approaches to students of SSSA-Pisa (IT) and of the PhD School of ABIES-AgroParisTech-Paris (FR). The educational programme consisted of three phases : 1) some theoretical contributions supported by presentations on : issues regarding agriculture and farming practices at landscape level, main approaches on environmental functions of agriculture, changes in farmers practices driven by environmental questions,spatial organization of agricultural activities, role of farming in ecological dynamics, identification of complementarities among agro-environmental functions, environmental impacts of cropping systems,biodiversity influence on agro-ecosystem functions and vice-versa ; 2) two case-studies: a macro level one(at landscape scale) to analyse the role of agriculture on landscape dynamics, and a micro level one (at farm scale) to analyse farming practices and their environmental impacts ; 3) a final evaluation of the educational programme based on : contents of oral presentations on fieldwork results, global evaluation of the educational programme contents by all the participants, each individual ex-post analysis of fieldwork results. The evaluation of the students and teachers underlines benefits, requests and perspectives for education in landscape agronomy. Furthermore, this experience stimulated a collective conceptual and methodological debate that confirmed the necessity to favour and organise experience exchanges on researching and learning in landscape agronomy
Treatment of perinfarction recurrent ventricular fibrillation by percutaneous pharmacological block of left stellate ganglion
A patient suffering from an acute myocardial infarction presented on the seventh and eighth days of hospitalization recurrent episodes of ventricular fibrillation refractory to antiarrhythmic treatment. The life-threatening ventricular fibrillation was suppressed by percutaneous pharmacological block of the left stellate ganglion
Abnormal Glucose Tolerance Is Associated with a Reduced Myocardial Metabolic Flexibility in Patients with Dilated Cardiomyopathy
Dilated cardiomyopathy (DCM) is characterized by a metabolic shift from fat to carbohydrates and failure to increase myocardial glucose uptake in response to workload increments. We verified whether this pattern is influenced by an abnormal glucose tolerance (AGT). In 10 patients with DCM, 5 with normal glucose tolerance (DCM-NGT) and 5 with AGT (DCM-AGT), and 5 non-DCM subjects with AGT (N-AGT), we measured coronary blood flow and arteriovenous differences of oxygen and metabolites during Rest, Pacing (at 130 b/min), and Recovery. Myocardial lactate exchange and oleate oxidation were also measured. At Rest, DCM patients showed a reduced nonesterified fatty acids (NEFA) myocardial uptake, while glucose utilization increased only in DCM-AGT. In response to Pacing, glucose uptake promptly rose in N-AGT (from 72 ± 21 to 234 ± 73 nmol/min/g, p<0.05), did not change in DCM-AGT, and slowly increased in DCM-NGT. DCM-AGT sustained the extra workload by increasing NEFA oxidation (from 1.3 ± 0.2 to 2.9 ± 0.1 mol/min/gO2 equivalents, p<0.05), while DCM-NGT showed a delayed increase in glucose uptake. Substrate oxidation rates paralleled the metabolites data. The presence of AGT in patients with DCM exacerbates both the shift from fat to carbohydrates in resting myocardial metabolism and the reduced myocardial metabolic flexibility in response to an increased workload. This trial is registered with ClinicalTrial.gov NCT02440217
Hybrid Image Visualization Tool for 3D integration of CT coronary anatomy and quantitative myocardial perfusion PET
Purpose: Multimodal cardiac imaging by CTA and quantitative PET enables acquisition of patient-specific coronary anatomy and absolute myocardial perfusion at rest and during stress. In the clinical setting, integration of this information is performed visually or using coronary arteries distribution models. We developed a new tool for CTA and quantitative PET integrated 3D visualization, exploiting XML and DICOM clinical standards. Methods: The Hybrid Image Tool (HIT) developed in the present study included four main modules: (1) volumetric registration for spatial matching of CTA and PET datasets, (2) an interface to PET quantitative analysis software, (3) a derived DICOM generator able to build DICOM dataset from quantitative polar maps, and (4) a 3D visualization tool of integrated anatomical and quantitative flow information. The four modules incorporated in the HIT tool communicate by defined standard XML files: XML-transformation and XML MIST standards. Results: The HIT tool implements a 3D representation of CTA showing real coronary anatomy fused to PET derived quantitative myocardial blood flow distribution. The technique was validated on 16 datasets from EVINCI study population. The validation of the method confirmed the high matching between "original" and derived datasets as well as the accuracy of the registration procedure. Conclusions: Three-dimensional integration of patient-specific coronary artery anatomy provided by CTA and quantitative myocardial blood flow obtained from PET imaging can improve cardiac disease assessment. The HIT tool introduced in this paper may represent a significant advancement in the clinical use of this multimodal approach
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