Search results for "Radiation Exposure"
showing 10 items of 40 documents
Single-centre experience and preliminary Results of intravascular ultrasound in endovascular aneurysm repair
2019
Background Intravascular ultrasound (IVUS) has been introduced as diagnostic adjunct to provide new insights into the diagnosis and therapy of vascular disease. Herein, we compared the outcomes of conventional endovascular aneurysm repair (EVAR) and EVAR with IVUS in patients presenting with infrarenal abdominal aortic aneurysm using a propensity-matched cohort. Methods From May 2013 to August 2017, 221 patients were retrospectively analyzed. Of that, 122 patients were eligible for inclusion and underwent propensity score matching. Perioperative mortality and morbidity, renal function impairment, endoleak incidence, mean contrast medium usage, operative time, radiation exposure (including f…
Radiation exposure in biliary procedures performed to manage anastomotic strictures in pediatric liver transplant recipients: comparison between radi…
2013
The aim of this study was to estimate radiation exposure in pediatric liver transplants recipients who underwent biliary interventional procedures and to compare radiation exposure levels between biliary interventional procedures performed using an image intensifier-based angiographic system (IIDS) and a flat panel detector-based interventional system (FPDS). We enrolled 34 consecutive pediatric liver transplant recipients with biliary strictures between January 2008 and March 2013 with a total of 170 image-guided procedures. The dose-area product (DAP) and fluoroscopy time was recorded for each procedure. The mean age was 61 months (range 4–192), and mean weight was 17 kg (range 4–41). The…
Influence of a Commercial Lead Apron on Patient Skin Dose Delivered During Oral and Maxillofacial Examinations under Cone Beam Computed Tomography (C…
2017
The purpose of this paper is to investigate the impact of a commercial lead apron on patient skin dose delivered during maxillofacial CBCT in five critical regions by means of solid-state-dosimetry. Five anatomical regions (thyroid gland, left and right breast, gonads, back of the phantom torso) in an adult female anthropomorphic phantom were selected for dose measurement by means of the highly sensitive solid-state dosimeter QUART didoSVM. Ten repeated single exposures were assessed for each patient body region for a total of five commercial CBCT devices with and without a lead apron present. Shielded and non-shielded exposures were compared under the paired Wilcoxon test, with absolute an…
Improving pediatric radiation dose management using Agfa digital radiography DICOM header information
2007
Dose reduction in pediatric explorations is especially important because of children radiation sensitivity. According to this, with the aim of saving radiation exposure in future clinical practice, we have developed a technique to control delivered dose in pediatric radiographic exams. To that, a computer science program has been developed to calculate entrance skin dose (ESD) provided by AGFA radiology digital system, using the "lgM" parameter exported from Dicom files. ESD values are compared with dose limits established in regulations to detect if children are being exposed to excessive amounts of radiation during their explorations.
Radiosynthesis of 3-indolyl[1-11C]acetic acid for phyto-PET-imaging: An improved production procedure and formulation method
2014
Abstract An improved production procedure and formulation method for the carbon-11 radiolabeled phytohormone, 3-indolyl-[l- 11 C]acetic acid ([ 11 C]IAA), was developed by modifying selected original reaction parameters. This updated procedure both doubled the yield (from 25.9±6.7% ( n =12) to 61.0±0.3% ( n =10)) and increased the concentration (0.2–0.4 GBq/0.15–0.3 mL), enabling us to provide the radiotracer [ 11 C]IAA suitable for in vivo phyto-PET-imaging studies. The specific activity was improved by more than a factor of three (26.7±5.6 GBq/µmol to 82.5±36.1 GBq/µmol). The total synthesis time for both production and formulation was 81.8±3.0 min ( n =10). In addition, a streamlined sem…
A novel radiation exposure control apparatus for microwave assisted chemical reactions
2004
AbstractA radiation exposure control apparatus is used for microwave (2.45 GHz) treatment of chemical reactions in controlled and reproducible conditions. A spectrophotometer has been interfaced with the microwave set-up in order to monitor the reaction evolution in situ. Both numerical and experimental dosimetries are carried out in order to evaluate the field distribution within the sample. Finally, particular working conditions are suggested.
Protecting sensitive patient groups from imaging using ionizing radiation: effects during pregnancy, in fetal life and childhood
2019
The frequency of imaging examinations requiring radiation exposure in children (especially CT) is rapidly increasing. This paper reviews the current evidence in radiation protection in pediatric imaging, focusing on the recent knowledge of the biological risk related to low doses exposure. Even if there are no strictly defined limits for patient radiation exposure, it is recommended to try to keep doses as low as reasonably achievable (the ALARA principle). To achieve ALARA, several techniques to reduce the radiation dose in radiation-sensitive patients groups are reviewed. The most recent recommendations that provide guidance regarding imaging of pregnant women are also summarized, and the…
Efecto de la radiación ionizante persistente a bajas dosis en la angiogénesis del carcinoma renal de células claras : estudio morfométrico comparativ…
2013
La angiogénesis en el carcinoma de células renales claras (ccRCC) es un proceso influenciado por sustancias producidas en su mayoría por el tumor en respuesta a una reestructuración vascular necesaria en su etapa de crecimiento y metástasis. La exposición persistente a bajas dosis de radiación ionizante (CPLDIR) ha sido asociada a modificaciones nucleares que estimulan la proliferación celular neoplásica. Sus efectos en el proceso de neovascularización de los ccRCC han sido poco estudiados. Métodos: Estudiamos a través de un estudio morfométrico semiautomático e inmunohistoquímico, la densidad microvascular (MVD) y la expresión de factores angiogénicos en 124 pacientes con ccRCC de regiones…
Pleistocene Glaciations in Latvia
2011
Abstract During the Pleistocene the territory of Latvia was repeatedly overridden by Scandinavian ice sheets, at least from the Elsterian onwards. Extent limit of all glaciations was located far outside of Latvia. Due to vigorous erosion by subsequent glaciations the Pleistocene record is incomplete. Radiocarbon, cosmogenic nuclide and radiation exposure dating methods have been mainly used only for age determination of the upper part of the Pleistocene sequence. Decay of the Late Weichselian glaciation in Latvia is marked by five major ice-marginal zones
Applying the Anna Karenina principle for wild animal gut microbiota : temporal stability of the bank vole gut microbiota in a disturbed environment
2020
Gut microbiota play an important role in host health. Yet, the drivers and patterns of microbiota imbalance (dysbiosis) in wild animals remain largely unexplored. One hypothesised outcome of stress on animal microbiomes is a destabilised microbial community that is characterised by an increase in inter-individual differences compared with microbiomes of healthy animals, which are expected to be (i) temporally stable and (ii) relatively similar among individuals. This set of predictions for response of microbiomes to stressors is known as the Anna Karenina principle (AKP) for animal microbiomes. We examine the AKP in a wild mammal inhabiting disturbed environments by conducting a capture-mar…