Search

The purpose of this article is to estimate lens doses using over apron active personal dosemeters in interventional catheterisation laboratories (cardiology IC, neuroradiology IN and radiology IR) and to investigate correlations between occupational lens doses and patient doses. Active electronic personal dosemeters placed over the lead apron were used on a sample of 204 IC procedures, 274 IN and 220 IR (all performed at the same university hospital). Patient dose values (kerma area product) were also recorded to evaluate correlations with occupational doses. Operators used the ceiling-suspended screen in most cases. The median and third quartile values of equivalent dose Hp(10) per procedure measured over the apron for IC, IN and IR resulted, respectively, in 21/67, 19/44 and 24/54 mSv. Patient dose values (median/third quartile) were 75/128, 83/176 and 61/159 Gy cm², respectively. The median ratios for dosemeters worn over the apron by operators (protected by the ceiling-suspended screen) and patient doses were 0.36; 0.21 and 0.46 μSv Gy-1 cm-2, respectively. With the conservative approach used (lens doses estimated from the over apron chest dosemeter) we came to the conclusion that more than 800 procedures y-1 and per operator were necessary to reach the new lens dose limit for the three interventional specialties. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to report a set of experimental values of patient and staff doses in a cardiac catheterisation laboratory using the range of radiographic and geometric parameters from routine clinical practice. The data obtained will be available for validation of Monte Carlo calculations and for training purposes. They will also help optimise radiation protection for patients and staff. Experimental measurements were made with an anthropomorphic phantom, and a monoplane flat detector-based X-ray system was used for interventional cardiology procedures. Standard operational protocols used in clinical practice were applied. Around 1000 patient dose and 5000 staff dose values were measured for different operational conditions (angulations, distances, collimation and wedge filter, magnification, phantom thicknesses, using Copper absorber, etc.). Uncertainties were also estimated. Increase factors of 3-10 for patients and staff doses were measured for the different C-arm angulations. [ABSTRACT FROM AUTHOR]

The purpose of this article is to present the results of connecting the interventional radiology and cardiology laboratories of five university hospitals to a unique server using an automatic patient dose registry system (Dose On Line for Interventional Radiology, DOLIR) developed in-house, and to evaluate its feasibility more than a year after its introduction. The system receives and stores demographic and dosimetric parameters included in the MPPS DICOM objects sent by the modalities to a database. A web service provides a graphical interface to analyse the information received. During 2013, the system processed 10 788 procedures (6874 cardiac, 2906 vascular and 1008 neuro interventional). The percentages of patients requiring clinical follow-up due to potential tissue reactions before and after the use of DOLIR are presented. The system allowed users to verify in real-time, if diagnostic (or interventional) reference levels are fulfilled. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of −15 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was −9 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey. [ABSTRACT FROM AUTHOR]

Paediatric patients represent a very specific group within the radiology department. Compared to adult patients, they are more sensitive to radiation. As they are sometimes submitted to several radiology procedures, dose and image quality should be well balanced. Nowadays, only a few centres specialize in paediatric imaging, and knowledge of paediatric patient doses is, therefore, very scattered. The effect of the introduction of digital technology on paediatric patient doses remains largely undocumented. Data collected in the present survey illustrate that there is a clear need for standardisation in this domain. The proposal of a European diagnostic reference level (DRL) is quite difficult. Preliminary DRLs, based on typically 5-7 radiology centres per examination are proposed. The 'effective dose' may or may not be a very rigorous parameter, but it still remains useful nowadays to calculate a parameter that summarises the possible radiation-induced detriment to these young patients. However, conversion factors for calculation of the effective dose should be harmonised. Future studies should include an image quality evaluation study, using criteria that account for digital equipment. Data collection would be straightforward and could be performed in a systematic and automatic way if DICOM headers of digital images would include appropriate as well as relevant information for the particular case of paediatric examinations. [ABSTRACT FROM AUTHOR]

AIMS: To evaluate the influence of age on average values of pulsed tissue Doppler recorded at the septal and lateral mitral annulus in a population of healthy subjects and to propose reference values according to different age decades. METHODS AND RESULTS: Two hundred and forty-six healthy subjects (M/F = 160/86, mean age 40.9 years) underwent Doppler-echocardiography and pulsed tissue Doppler of the septal and lateral mitral annulus. S(m), E(m), A(m) peak velocities were measured at both the annular sides and average values obtained. The ratio of transmitral E peak velocity and average E(m) peak velocity (lateral E(m) + septal E(m)/2) was calculated as an index of left ventricular filling pressure. The population was divided into seven age decades: 10-19, 20-29, 30-39, 40-49, 50-59, 60-69 years and >70 years. E(m) was progressively reduced and A(m) increased with increasing age at both the annular sides as well as average values. S(m) reduction with advancing age was significant only at the lateral mitral annulus and as average values. Average E/E(m) ratio was particularly higher in the last three age decades. By multilinear regression analyses, age was the main independent predictor of average E(m), A(m) and E/E(m) ratio, while heart rate was the most important contributor to average S(m), with the additional contribution of age. CONCLUSIONS: Aging shows an independent impact on average tissue Doppler indexes of septal and lateral mitral annulus in normal subjects. Our data also provide reference values of tissue Doppler average variables for age decades. [ABSTRACT FROM AUTHOR]

Adjoint functions have been used with forward functions to compute gradients in implicit (iterative) solution methods for inverse problems in optical tomography, geoscience, thermal science and other fields, but only once has this approach been used for inverse solutions to the Boltzmann transport equation. In this paper, this approach is used to develop an inverse method that requires only angle-independent flux measurements, rather than angle-dependent measurements as was done previously. The method is applied to a simplified form of the transport equation that does not include scattering. The resulting procedure uses measured values of gamma-ray fluxes of discrete, characteristic energies to determine interface locations in a multilayer shield. The method was implemented with a Newton-Raphson optimisation algorithm and it worked very well in numerical 1-D spherical test cases. A more sophisticated optimisation method would better exploit the potential of the inverse method. [ABSTRACT FROM AUTHOR]

The efficacy of different antibiotics was compared in an experimental model of aortic valve endocarditis in rabbits, using a serotype 19 strain of Streptococcus pneumoniae resistant to penicillin (MIC 12 mg/L) and ceftriaxone (MIC 12 mg/L). The results were compared with those of a control group, which received no treatment. One hundred and nineteen animals were treated with one of the following antibiotic regimens: im procaine penicillin G at a dosage of 300,000 U/kg weight/12 h (16 animals); iv trovafloxacin, 13.3 mg/kg/12 h (31 animals); iv ceftriaxone, 75 mg/kg/24 h (21 animals); iv vancomycin, 20 mg/kg/12 h (15 animals) and im quinupristin-dalfopristin, 30 mg/kg/8 h (20 animals). All the antibiotics used in this study proved to be efficient in reducing numbers of S. pneumoniae and in increasing the percentage of aortic vegetations that were rendered sterile compared with the control group. Penicillin at the dosage used in our study was capable of achieving serum concentrations two or three times greater than the MIC, thus demonstrating its effectiveness as an antibiotic for this endocarditis model. No significant difference was observed between the effects of vancomycin, quinupristin-dalfopristin and penicillin. Vancomycin proved to be more efficient than trovofloxacin in reducing the bacterial load and increasing the numbers sterilized. There was also a tendency for this antibiotic to be more effective than ceftriaxone in reducing the bacterial load of the vegetations. There was a statistically significant correlation between the weight of the vegetations and their bacterial load. In the light of these results, vancomycin and quinupristin-dalfopristin may be considered suitable alternatives to penicillin for the treatment of penicillin-resistant S. pneumoniae endocarditis. [ABSTRACT FROM AUTHOR]

The authors conducted a mailed questionnaire survey of a 5% sample of the cohort of 20,643 people officially recognized by the Spanish government as having had toxic oil syndrome, a previously undescribed illness that was epidemic in Spain in 1981. After three mailings of a letter and questionnaire, responses for only 66% of the sample had been received. Nevertheless, responses were obtained from virtually all remaining patients (or surrogates for them in the cases of patients that had died) when they were sought by telephone. In 1981, there was clear-cut excess mortality in the cohort (standardized mortality ratio [SMR] 6.51; 95% confidence interval [CI]: 3.92-10.17). During the period January 1982 through 7 March 1988, there was no statistically significant overall mortality excess except during the period 1982-1983 among people aged < 65 years (SMR 2.26; 95% CI: 1.03-4.29). Toxic oil syndrome substantially altered the patterns of mortality among affected people. Analysis of deaths by cause among the TOS cohort will be useful for further evaluation of the long-term impact of the TOS epidemic. [ABSTRACT FROM AUTHOR]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009 [ABSTRACT FROM PUBLISHER]