Does digital imaging decrease patient dose? A pilot study and review of the literature

The potential for decreasing patient dose is one of the main arguments for the justification of the cost of digital imaging equipment. However, the literature review with respect to patient doses using digital imaging modalities, presents conflicting results. During this study, patients' entrance surface doses were measured for three simple radiographic examinations, in European centres equipped with a computed radiography digital system. Results showed that doses between centres varied from 30% for chest LAT to 250% for chest PA examination. With the digital image quality criteria still under discussion, and with the post-processing parameters and/or image documentations varying, any dose comparisons between conventional/digital systems, as well as dose comparisons between different centre using digital units, are difficult. Clinical trials are required in order to define reference levels associated with quality of digital image necessary to address specific clinical requirements.     

Studies on the current 137Cs body burden of children in Belarus--can the dose be further reduced?

After the Chernobyl reactor accident wide areas of Belarus were contaminated with radioactive fallout. The verification and documentation of the long-term development of radiation doses is still going on. A population group of special concern are the children living in contaminated regions. The annual dose limit of 1 mSv is still exceeded in some cases, essentially due to high body burdens of (137)Cs as indicated by screening measurements with portable incorporation monitors. In this situation the evaluation of possible dose reduction measures in addition to the control of food contamination is being investigated. Special attention is given to the therapeutic application of a pectin preparation (Vitapect), for which a dose-lowering effect is presumed by Belarusian scientists. In a placebo-controlled double-blind study, several groups of contaminated children received a pectin compound named Vitapect for a two-week period during their stay in a sanatorium. For comparison the same number of control groups were given a placebo preparation. The (137)Cs body burden of the children was measured at the beginning and the end. The mean relative reduction of the specific activity within the Vitapect groups was found to be approximately 33%, whereas the specific activity of the children who received a placebo decreased only by approximately 14%, due to clean food supply. It is known that pectins chemically bind cations like caesium in the gastrointestinal tract and thereby increase faecal excretion. Theoretical calculations based on this assumption and considering metabolism processes are qualitatively consistent with the experimentally found retention of radiocaesium in the human body after pectin treatment.     

Can the HML's sliced BOMAB phantom be used in any whole body counter with a reduced number of sources?

The sliced Bottle Manikin Absorber (BOMAB) phantom was originally proposed as an alternative to a commercially available phantom, but it suffers from the disadvantage of containing over 160 sources that need to be manufactured; however, it was found that the number of slices could be reduced substantially and that two slices in the sliced phantom gave the same performance characteristics over a wide energy range as a conventional BOMAB phantom for a particular counting system. This work explores the adaptability of this phantom to another counting geometry. The response of the Human Monitoring Laboratory's whole-body counter measuring this phantom with a decreasing number of planar sources has been modelled using MCNP5 over a wide energy range (122-2754 keV). It was found that the best agreement was obtained when the phantom contained 10 sources, 1 in the mid point of each section. As this is a different result from a previous finding, any other counting geometry will have to be assessed to determine the optimum loading if the sliced phantom is to be used. Also, it is clear that this type of phantom cannot be used for an intercomparison that will encounter different counting geometries, unless it contains a full loading of sources.     

Can a renal nurse assess fluid status using ultrasound on the inferior vena cava? A cross‐sectional interrater study

Introduction: Ultrasound of the inferior vena cava (IVC‐US) has been used to estimate intravascular volume status and fluid removal during a hemodialysis session. Usually, renal nurses rely on other, imprecise methods to determine ultrafiltration. To date, no study has examined whether renal nurses can reliably perform ultrasound for volume assessment and for potential prevention of intradialytic hypotension. This pilot study aimed to determine if a renal nurse could master the skill of performing and correctly interpreting Point of Care Ultrasound on patients receiving hemodialysis. Methods: After receiving theoretical training and performing 100 training scans, a renal nurse performed 60 ultrasound scans on 10 patients. These were categorized by the nurse into hypovolemic, euvolemic, or hypervolemic through measurement of the maximal diameter and degree of collapse of the IVC. Scans were subsequently assessed for adequacy and quality by two sonologists, who were blinded to each other's and the nurse's results. Findings: The interrater reliability of 60 scans was good, with intraclass correlation 0.79 (95% confidence interval (CI) =0.63–0.87) and with a good interrater agreement for the following estimation of intravascular volume (Cohen's weighted Kappa κ_w = 0.62), when comparing the nurse to an expert sonographer. Discussion: A renal nurse can reliably perform ultrasound of the IVC in hemodialysis patients, obtaining high quality scans for volume assessment of hemodialysis patients. This novel approach could be more routinely applied by other renal nurses to obtain objective measures of patient volume status in the dialysis setting.     

How to investigate the historical roots and evolution of research fields in China? A case study on iMetrics using RootCite

Scientometrics - This paper aimed to provide an approach to investigate the historical roots and evolution of research fields in China by extending the reference spectroscopy year spectroscopy...