Emission of fluorescent x-radiation from non-lead based shielding materials of protective clothing: a radiobiological problem?

The aim of this study was to investigate the effectiveness of different shielding materials in protective clothing using dicentric frequency in human peripheral lymphocytes as a marker of radiation-induced damage. Blood samples from a healthy donor were exposed to 70 kV x-rays behind shielding materials lead (Pb), tin/antimony (Sn + Sb) and bismuth barrier/tin/tungsten (Bi + Sn + W) with the same nominal lead equivalent value of 0.35 mm lead.

[Interhospital transport of intensive care patients in Lower Saxony : statewide need-based and effective management].

Background: Since 2007 interhospital transport of intensive care patients in Lower Saxony appertains to the performance requirements of emergency medical services. Against this background the Working Group for Evaluation of Intensive Care Transport (Arbeitsgemeinschaft Evaluation Intensivverlegung) was established. This group formulated standardized definitions for the requirements of intensive care transport vehicles and a federal statewide monitoring of intensive care transport was implemented to analyze if simultaneously on-call intensive care transport systems (intensive care helicopter and ground based mobile intensive care units) can be deployed need-based and efficiently.

Enhanced yield of chromosome aberrations after CT examinations in paediatric patients.

Purpose: To determine whether computed tomography (CT) could enhance the chromosome aberration yields in paediatric patients.

Material And Methods: Blood samples were taken before and after CT scans from 10 children for whom the medical justifications for CT examinations were accidental injuries and not diseases as investigated in earlier studies. Chromosome analysis was carried out in lymphocytes by fluorescence plus Giemsa (FPG) staining exclusively in metaphases of the first cell cycle in vitro.

[Out-of-hospital airway management in northern Germany. Physician-specific knowledge, procedures and equipment].

Background: Out-of-hospital airway management confronts emergency medical teams with complex challenges. To date no specific data are available on the qualifications of emergency physicians (EPs) and the quality of emergency equipment in northern Germany.

Materials And Methods: This study surveyed individual EPs at regional emergency dispatch centres about their personal knowledge and skills, and the procedures and equipment used in out-of-hospital airway management.

The sensitivity of the alkaline comet assay in detecting DNA lesions induced by X rays, gamma rays and alpha particles.

Experiments were designed and performed in order to investigate whether or not the different cellular energy deposition patterns of photon radiation with different energies (29 kV, 220 kV X rays; Co-60, Cs-137-gamma-rays) and alpha-radiation from an Am-241 source differ in DNA damage induction capacity in human cells. For this purpose, the alkaline comet assay (single cell gel electrophoresis) was applied to measure the amount of DNA damage in relation to the dose received. The comet assay data for the parameters '% DNA in the tail' and 'tail moment' for human peripheral lymphocytes did not indicate any difference in the initial radiation damage produced by 29 kV X rays relative to the reference radiations, 220 kV X rays and the gamma rays, whether for the total mean dose range of 0-3 Gy nor in the low-dose range.

Fluoroscopic radiation exposure of the kyphoplasty patient.

Kyphoplasty (KP) is a minimally invasive technique for the percutaneous stabilisation of vertebral fractures. As such, this technique is highly dependent upon intraoperative fluoroscopic visualisation. In order to assess the range of radiation doses that patients are typically subjected to, 60 consecutive procedures using simultaneous bilateral fluoroscopy were analysed with respect to exposure time (ET).

RADIUS--closing the circle on the assessment of imaging performance.

The RADIUS (Radiological Imaging Unification Strategy) project addresses the assessment of image quality in terms of both physical and clinically relevant measures. The aim is to unify our understanding of both types of measure as well as the numerous underlying factors that play a key role in the assessments of imaging performance. In this way it is expected to provide a solid basis for the improvement in radiological safety management, where not only radiation risks are considered but also diagnostic risks of incorrect clinical outcomes (i.

Average glandular dose conversion coefficients for segmented breast voxel models.

For 8 voxel models of a compressed breast (4-7 cm thickness and two orientations for each thickness) and 14 radiation qualities commonly used in mammography (HVL 0.28-0.50 mm Al), tissue dose conversion coefficients were calculated for a focus-to-film distance of 60 cm using Monte Carlo methods.

A high-resolution voxel phantom of the breast for dose calculations in mammography.

Though mammography is one of the most sensitive methods to detect breast cancer, the benefit of the mammography screening programmes is still not clearly proven. One of the reasons is the radiation dose delivered by the examinations. Simulations of the radiation transport based on realistic breast phantoms are a useful tool to estimate the dose for the risk relevant parenchymal tissue.

Clinical evaluation of a new set of image quality criteria for mammography.

The European Commission (EC) quality criteria for screen-film mammography are used as a tool to assess image quality. A new set of criteria was developed and initially tested in a previous study. In the present study, these criteria are further evaluated using screen-film mammograms that have been digitised, manipulated to simulate different image quality levels and reprinted on film.

Measurement of the initial levels of DNA damage in human lymphocytes induced by 29 kV X rays (mammography X rays) relative to 220 kV X rays and gamma rays.

Experiments using the alkaline comet assay, which measures all single-strand breaks regardless of their origin, were performed to evaluate the biological effectiveness of photons with different energies in causing these breaks. The aim was to measure human lymphocytes directly for DNA damage and subsequent repair kinetics induced by mammography 29 kV X rays relative to 220 kV X rays, 137Cs gamma rays and 60Co gamma rays. The level of DNA damage, predominantly due to single-strand breaks, was computed as the Olive tail moment or percentage DNA in the tail for different air kerma doses (0.

[Is the lead-equivalent suited for rating protection properties of lead-free radiation protective clothing?].

Purpose: Currently, lead-free x-ray-protective clothing is classified by the European production standard EN 61 331-3. To evaluate protective effects of lead-free materials according to this standard, the certifying offices as well as customers solely refer to the lead equivalent (LE). The LE of lead-free protective clothing, however, depends on the tube voltage (energy spectrum).

Thermoluminescence dosimetric properties of a new thin beta detector (LiF:Mg, Cu, P; GR-200F) in comparison with highly sensitive Al2O3:C beta dosimeters.

There is an increasing need for efficient beta detectors to fulfil ICRU recommendations for new quantities especially in the field of medical physics and retrospective dosimetry. The thermoluminescence properties of thin LiF:Mg, Cu, P (GR-200F) tapes produced in 1998 by Sange Company, People's Republic of China, are investigated and compared with those of highly sensitive thin Al2O3:C beta detectors as regards their applicability in the detection of low energy photons and beta particles. The radiation dose response, minimum detectable dose, reproducibility of measurements and effect of residual signal at low dose are assessed for the possible low level beta dosimetry use.

Skill dependence of radiation exposure for the orthopaedic surgeon during interlocking nailing of long-bone shaft fractures: a clinical study.

Introduction: The objective of this clinical trial was to determine whether there is a skill dependence for the total amount of radiation exposure to orthopaedic surgeons caused by fluoroscopy during intramedullary fracture fixation.

Materials And Methods: Surgical teams were assigned to either the 'Senior group' or the 'Junior group' according to their professional qualification and clinical appointment. Twenty-two long-bone shaft fractures were stabilized with intramedullary nails.

Influence of the characteristic curve on the clinical image quality of lumbar spine and chest radiographs.

The "European Guidelines on Quality Criteria for Diagnostic Radiographic Images" do not address the choice of the film characteristic (H&D) curve, which is an important parameter for the description of a radiographic screen-film system. The image contrast of clinical lumbar spine and chest radiographs was altered by digital image processing techniques, simulating images with different H&D curves, both steeper and flatter than the original. The manipulated images were printed on film for evaluation.

Re-evaluation of the RBE of 29 kV x-rays (mammography x-rays) relative to 220 kV x-rays using neoplastic transformation of human CGL1-hybrid cells.

Neoplastic transformation of human CGL1-hybrid cells was examined after exposure to 29 kV x-rays (mammography x-rays) and conventional 220 kV x-rays. The study was designed to repeat, under well-defined irradiation and culture conditions, an earlier investigation by Frankenberg et al. (Radiat Res, 2002), and to assess the validity of the high RBE values of 29 kV x-rays that had been reported.

An adaptive algorithm for the detection of microcalcifications in simulated low-dose mammography.

This paper uses the task of microcalcification detection as a benchmark problem to assess the potential for dose reduction in x-ray mammography. We present the results of a newly developed algorithm for detection of microcalcifications as a case study for a typical commercial film-screen system (Kodak Min-R 2000/2190). The first part of the paper deals with the simulation of dose reduction for film-screen mammography based on a physical model of the imaging process.

Enhanced values of the RBE and H ratio for cytogenetic effects induced by secondary electrons from an X-irradiated gold gurface.

The low-energy secondary electrons emerging from the entrance surface of an X-irradiated gold foil increase the dose to cells in contact with or at micrometer distances from this surface (Radiat. Res. 150, 92-100, 1998).

The influence of different technique factors on image quality of chest radiographs as evaluated by modified CEC image quality criteria.

The Commission of the European Communities (CEC) research project "Predictivity and optimisation in medical radiation protection" addressed fundamental operational limitations in existing radiation protection mechanisms. The first part of the project aimed at investigating (1) whether the CEC image quality criteria could be used for optimization of a radiographic process and (2) whether significant differences in image quality based on these criteria could be detected in a controlled project with well known physical and technical parameters. In the present study, chest radiographs on film were produced using healthy volunteers.

Detection of elevated RBE in human lymphocytes exposed to secondary electrons released from X-irradiated metal surfaces.

Regulla, D., Panzer, W., Schmid, E.

Backscatter factors for mammography calculated with Monte Carlo methods.

The objective of this study is to establish a comprehensive set of backscatter factors for mammography based on the exposure model proposed by the European Protocol on Dosimetry in Mammography. The Monte Carlo calculated backscatter factors (BSFs) presented in this study are for various exposure conditions encountered in mammographic practice as well as in calibration procedures. The data demonstrate the variation of the BSF as a function of the exposure parameters, hence enabling a better match with calibration conditions and, at the same time, reviewing the BSF data already recommended by the European Protocol.

Endovascular irradiation from beta-particle-emitting gold stents results in increased neointima formation in a porcine restenosis model.

Background: Recent studies have shown that ionizing radiation reduces neointima formation after balloon angioplasty and stent implantation in experimental models of restenosis and first clinical trials. The objective of this study was to determine the dose distribution of a new beta-particle-emitting radioactive gold stent and to evaluate the dose-dependent vascular response in the coronary overstretch pig model.

Methods And Results: Sixteen Göttinger minipigs underwent placement of 11 nonradioactive and 36 beta-particle-emitting stents with activity levels of 10.