Characterising the eos slot-scanning system with the effective detective quantum efficiency
In this study, the EOS system was characterised using the eDQE in imaging conditions similar to those used in clinical practice: with phantoms of different widths placed in the X-ray beam, for various incident air kerma and tube voltages corresponding to the phantom thickness. Scatter fractions in EOS images were extremely low, around 2 % for all configurations. Maximum eDQE values spanned 9–14.8 % for a large range of air kerma at the detector plane from 0.01 to 1.34 µGy. These figures were obtained with non-optimised EOS setting but still over-performed most of the maximum eDQEs recently assessed for various ...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Clavel, A. H., Monnin, P., Letang, J. M., Verdun, F. R., Darbon, A. Tags: Paper Source Type: research
System upgrade on philips allura fd20 angiography systems: effects on patient skin dose and static image quality
Fluoroscopically guided procedures might be highly irradiating for patients, possibly leading to skin injuries. In such a context, every effort should be done to lower patient exposure as much as possible. Moreover, patient dose reduction does not only benefit to the patient but also allows reducing staff exposure. In this framework, Philips Healthcare recently introduced a system upgrade for their angiography units, called ‘AlluraClarity’. The authors performed air kerma rate measurements for all available fluoroscopy modes and air kerma per frame measurements for the digital subtraction angiography protocols,...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Ryckx, N., Sans-Merce, M., Meuli, R., Zerlauth, J.-B., Verdun, F. R. Tags: Paper Source Type: research
Iterative scatter correction for grid-less bedside chest radiography: performance for a chest phantom
In conclusion, the experiment demonstrates quantitatively that software-based scatter correction allows restoring the image contrast of a non-grid image in a manner comparable with an antiscatter grid. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Mentrup, D., Jockel, S., Menser, B., Neitzel, U. Tags: Paper Source Type: research
Comparison of wireless detectors for digital radiography systems: image quality and dose
The purpose of this study was to compare dose and image quality of wireless detectors for digital chest radiography. Entrance dose at both the detector (EDD) and phantom (EPD) and image quality were measured for wireless detectors of seven different vendors. Both the local clinical protocols and a reference protocol were evaluated. In addition, effective dose was calculated. Main differences in clinical protocols involved tube voltage, tube current, the use of a small or large focus and the use of additional filtration. For the clinical protocols, large differences in EDD (1.4–11.8 µGy), EPD (13.9–80.2 &m...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Mourik, J. E. M., van der Tol, P., Veldkamp, W. J. H., Geleijns, J. Tags: Paper Source Type: research
A phantom for determination of calibration coefficients and minimum detectable activities using a dual-head gamma camera for internal contamination monitoring following radiation emergency situations
The purpose of this study was to derive calibration coefficients (in terms of cps kBq–1) and minimum detectable activities, MDA, (in terms of kBq and corresponding dose rate) for the dual head gamma camera part of an SPECT/CT-instrument when used for in vivo internal contamination measurements in radiation emergency situations. A cylindrical-conical PMMA phantom with diameters in the range of 7–30 cm was developed in order to simulate different body parts and individuals of different sizes. A series of planar gamma camera investigations were conducted using an SPECT/CT modality with the collimators removed for ...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Ören, U., Andersson, M., Rääf, C. L., Mattsson, S. Tags: Paper Source Type: research
Can an energy-compensated solid-state x-ray detector be used for radiation protection applications at higher photon energies?
The objective of this study was to investigate the characteristics of a solid-state detector commonly available at hospitals for parallel use as a real-time personal radiation monitor following radiation emergency situations. A solid-state detector probe with an inherent filtration (R100, RTI Electronics AB, Mölndal, Sweden) was chosen for evaluation. The energy dependence and the linearity in signal response with kerma in air were examined, and the detector was exposed to both X-ray beams using a conventional X-ray unit with effective photon energies ranging between 28.5 and 48.9 keV and to gamma rays 1.17 and 1.3...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Ören, U., Herrnsdorf, L., Gunnarsson, M., Mattsson, S., Rääf, C. L. Tags: Paper Source Type: research
Eye lens dosimetry for fluoroscopically guided clinical procedures: practical approaches to protection and dose monitoring
Doses to the eye lenses of clinicians undertaking fluoroscopically guided procedures can exceed the dose annual limit of 20 mSv, so optimisation of radiation protection is essential. Ceiling-suspended shields and disposable radiation absorbing pads can reduce eye dose by factors of 2–7. Lead glasses that shield against exposures from the side can lower doses by 2.5–4.5 times. Training in effective use of protective devices is an essential element in achieving good protection and acceptable eye doses. Effective methods for dose monitoring are required to identify protection issues. Dosemeters worn adjacent to th...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Martin, C. J. Tags: Paper Source Type: research
Retrospective estimation of patient dose-area product in thoracic spine tomosynthesis performed using volumerad
In conclusion, the previously developed method of retrospectively estimating the DAP in chest tomosynthesis can be applied to thoracic spine tomosynthesis. (Source: Radiation Protection Dosimetry)
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Bath, M., Söderman, C., Svalkvist, A. Tags: Paper Source Type: research
Effective dose to patients from thoracic spine examinations with tomosynthesis
The purposes of the present work were to calculate the average effective dose to patients from lateral tomosynthesis examinations of the thoracic spine, compare the results with the corresponding conventional examination and to determine a conversion factor between dose-area product (DAP) and effective dose for the tomosynthesis examination. Thoracic spine examinations from 17 patients were included in the study. The registered DAP and information about the field size for each projection radiograph were, together with patient height and mass, used to calculate the effective dose for each projection radiograph. The total ef...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Svalkvist, A., Söderman, C., Bath, M. Tags: Paper Source Type: research
Individualised calculation of tissue imparted energy in breast tomosynthesis
The imparted energy to the glandular tissue in the breast (glandular imparted energy, GIE) is proposed for an improved assessment of the individual radiation-induced risk resulting from X-ray breast imaging. GIE is computed from an estimation of the quantity and localisation of glandular tissue in the breast. After a digital breast tomosynthesis (DBT) acquisition, the volumetric glandular content (volumetric breast density, VBD) is computed from the central X-ray projection. The glandular tissue distribution is determined by labelling the DBT voxels to ensure the conservation of the VBD. Finally, the GIE is calculated by M...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Geeraert, N., Klausz, R., Muller, S., Bloch, I., Bosmans, H. Tags: Paper Source Type: research
Improved planar kidney activity concentration estimate by the posterior view method in 177lu-dotatate treatments
The aims of this study were to determine how different background regions of interest (ROIs) around the kidney represent true background activity in over- and underlying tissues in 177Lu-DOTA-octreatate (177Lu-DOTATATE) treatments and to determine the influence of the background positions on the kidney activity concentration estimates by the conjugate view (ConjV) and posterior view (PostV) methods. The analysis was performed in single-photon emission computed tomography (SPECT) images of 20 patients, acquired 24 h post injection of a 177Lu-DOTATATE treatment, by a computer algorithm that created planar images from the SPE...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Magnander, T., Svensson, J., Bath, M., Gjertsson, P., Bernhardt, P. Tags: Paper Source Type: research
Organ doses and effective dose for five pet radiopharmaceuticals
Diagnostic investigations with positron-emitting radiopharmaceuticals are dominated by 18F-fluorodeoxyglucose (18F-FDG), but other radiopharmaceuticals are also commercially available or under development. Five of them, which are all clinically important, are 18F-fluoride, 18F-fluoroethyltyrosine (18F-FET), 18F-deoxyfluorothymidine (18F-FLT), 18F-fluorocholine (18F-choline) and 11C-raclopride. To estimate the potential risk of stochastic effects (mainly lethal cancer) to a population, organ doses and effective dose values were updated for all five radiopharmaceuticals. Dose calculations were performed using the computer pr...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Andersson, M., Johansson, L., Mattsson, S., Minarik, D., Leide-Svegborn, S. Tags: Paper Source Type: research
Patient dose assessment after interventional cardiology procedures: a multi-centric approach to trigger optimisation
As the number and complexity of fluoroscopically guided interventions increase, a serious effort has to be put on the optimisation of the X-ray dose delivered to the patient. In order to set up this optimisation process, the clinical practice for a given cardiology centre has to be analysed with relevant statistical power and compared with the data at local or national level. Data from 8 Swiss cardiology centres for 10 different vascular and heart rhythm procedures have been collected. The collected dose indicators were, when available, cumulated air kerma, cumulated dose-area product, fluoroscopy time and the number of im...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Ryckx, N., Goy, J.-J., Stauffer, J.-C., Verdun, F. R. Tags: Paper Source Type: research
Verification of indicated skin entrance air kerma for cardiac x-ray-guided intervention using gafchromic film
The aim of this work was to verify the indicated maximum entrance surface air kerma (ESAK) using a GE Innova IGS 520 imaging system during cardiac interventional procedures. Gafchromic XR RV3 films were used for the patient measurements to monitor the maximum ESAK. The films were scanned and calibrated to measure maximum ESAK. Thermoluminescent dosemeters were used to measure the backscatter factor from an anthropomorphic thorax phantom. The measured backscatter factor, 1.53, was in good agreement with Monte Carlo simulations but higher than the one used by the imaging system, 1.20. The median of the ratio between indicate...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Nilsson Althen, J., Sandborg, M. Tags: Paper Source Type: research
Patient doses in computed tomography examinations in two regions of the russian federation
Computed tomography (CT) is often a justified diagnostic tool, but is also associated with high exposure of the patients. Due to the rapid increase in the number of CT units and thus the availability of CT examinations in Russia, there is a growing need for optimisation within this field. In order to develop proper optimisation procedures for CT, the two regions St. Petersburg and Belgorod of Russia were chosen, representing an urban and a rural region, respectively. In 2014, a survey was conducted of the parameters applied in CT examinations in these regions, and the results show that the highest effective doses were obse...
Source: Radiation Protection Dosimetry - June 6, 2016 Category: Radiology Authors: Chipiga, L., Bernhardsson, C. Tags: Paper Source Type: research
