Search results for "Radiation Dose"
showing 10 items of 44 documents
The peculiarities of the radiation damage accumulation kinetics in the case of defect complex formation
2020
Abstract The kinetics of radiation defect accumulation under irradiation by heavy particles is theoretically analysed under the assumption of defect complex genesis, particularly, the ones of anion and cation vacancies. The obtained analytical mathematical model and revealed peculiarities of radiation dose dependencies can be used for analysis of the experimental results for different crystalline materials for solid-state electronics and photonics.
Estimation of the committed radiation dose resulting from gamma radionuclides ingested with food
2014
The objective of the study was to estimate the value of the radiation dose absorbed in consequence of consumption of popular food products for individual age groups. Potatoes, corn and sugar beet were selected for the study. Edible parts of these plants were collected in experimental fields of the KWS Lochow Polska Sp. z o.o. seeding company in Kondratowice (Poland). On the basis of the obtained study results, it can be stated that in consequence of consumption of the selected food products, people may receive increased doses from both natural and artificial radioactive isotopes. The doses calculated for several age groups do not show any health hazards in consequence of consumption of the …
Retrospective dosimetry for Latvian workers at Chernobyl.
2001
Between 1986 and 1991 approximately 6500 Latvian inhabitants were recruited for clean-up work at the Chernobyl nuclear power plant. Their absorbed doses are usually unknown, because less than half of them had their external exposure officially documented. Clinical investigations show a high morbidity rate for these clean-up workers when compared with that of the general population. In order to understand the causes of their diseases and the impact of ionising radiation, electron spin resonance (ESR) has been used to measure the absorbed doses in human tooth enamel. The doses estimated by ESR were between two and three times higher than previously documented and are in accord with the result…
Adult exposures from MDCT including multiphase studies: first Italian nationwide survey.
2014
To evaluate the radiation dose in routine multidetector computed tomography (MDCT) examinations in Italian population.This was a retrospective multicentre study included 5,668 patients from 65 radiology departments who had undergone common CT protocols: head, chest, abdomen, chest–abdomen–pelvis (CAP), spine and cardiac. Data included patient characteristics, CT parameters, volumetric CT dose index (CTDIvol) and dose length product (DLP) for each CT acquisition phase. Descriptive statistics were calculated, and a multi-regression analysis was used to outline the main factors affecting exposure.The 75th percentiles of CTDIvol (mGy) and DLP (mGy cm) for whole head were 69 mGy and 1,312 mGy cm…
Complete written/oral information about dose exposure in CT: is it really useful to guarantee the patients' awareness about radiation risks?
2018
Aims and objectives: According to the European directive 2013/59/Euratom, starting from February 2018, the information relating to patient exposure will be part of computed tomography (CT) reports, but the impact of this information on patients has not been deeply evaluated. Aim of our study was to evaluate patients’ perception of radiation exposure related to routine CT and their understanding after communication of their dose exposure. Materials and methods: A survey, investigating patient’s knowledge of radiation dose, was given to all adult patients (> 18 years) undergoing a CT examination both before and after CT scan. The first survey was the same for all patients. After CT scan, a se…
CT exposure in adult and paediatric patients: a review of the mechanisms of damage, relative dose and consequent possible risks.
2014
An increase has been observed not only in the absolute number of CT examinations but also in the length of coverage and number of scanning phases, with the result that exposure to ionising radiation from CT is becoming an increasingly serious problem. The extent of the problem is not entirely known and cannot be adequately addressed without proper knowledge of all the phases that leads to the effective dose calculation. In light of the growing awareness of the issue of ionising radiation dose and the possible risk for the individual and the population, there is a need for radiologists, medical physicists and radiographers to play an active role in dose management. In this review, the author…
Abdominal Computed Tomography Angiography at 80kV: feasibility study.
2014
preliminary evaluation of different dose reduction algorithms in abdominal Computed Tomography Angiography (CTA) with standard scan protocols at 120kV vs. 80kV.prospective, randomized, crossover study. 60 consecutive patients who underwent CTA of the abdomen (Sensation 64, Siemens; Iomeprol 400 mgl/ml Bracco) for suspected or diagnosed Abdominal Aortic Aneurysm (AAA) were enrolled in the study. A standard 120kV/200mAs scan protocol was acquired in all patients (reference tube current modulated with Automatic Exposure Control). In each patient a second scan with 80kV/300mAs (Group 1; n. 20), 80kV/400mAs (Group 2; n. 20), 80kV/500mAs (Group 3; n. 20) was acquired. We used the same scan/recons…
Quantitative Cerebral Blood Flow Mapping in Stroke and During Mental Stimulation After Intravenous Injection of 195mAu
1985
The new short life isotope 195mAu has some suitable features for quantitative cerebral blood flow mapping. Its half-life is 30.5 s; therefore an injection can be repeated after 3 min (six half-lives) without any need for background subtraction and with the same specific activity. The calculated whole body radiation dose after three successive administrations of 25 mCi 195mAu amounts to 50 mrad. In comparison to a 99mTc pertechnetate injection it is estimated that the dose to the patients is reduced by a factor of eight (Garcia et al. 1981).
Channel Tracking Guidewire and Technique for Retrograde Approach
2020
Evaluation of the collateral circulation is critical for determining the feasibility of the retrograde approach. When assessing collateral channels it is of paramount importance to take time and review the previous angiogram carefully, for multiple potential collateral pathways, as the predominant collateral may change over time prior to the procedure. Careful review of collaterals prior to the procedure can reduce contrast and radiation dose as well as the duration of the procedure.Retrograde access to the distal vessel can be achieved via septal collaterals, epicardial collaterals (atrial channel), or (patent or occluded) coronary bypass grafts. Generally septals are used more often 65–70…
Low dose CT of the heart: a quantum leap into a new era of cardiovascular imaging.
2010
In 10 years, computed tomography coronary angiography (CTCA) has shifted from an investigational tool to clinical reality. Even though CT technologies are very advanced and widely available, a large body of evidence supporting the clinical role of CTCA is missing. The reason is that the speed of technological development has outpaced the ability of the scientific community to demonstrate the clinical utility of the technique. In addition, with each new CT generation, there is a further broadening of actual and potential applications. In this review we examine the state of the art on CTCA. In particular, we focus on issues concerning technological development, radiation dose, implementation,…