REDUCING PELVIS RADIOGRAPH EXPOSURE IN CHILDREN USING A DOSE SIMULATION X-RAY RESEARCH SOFTWARE.

Pelvis radiography is a frequent X-ray examination. The objective of our study was to determine the minimum dose to be delivered without reducing the quality. We included 60 children having a pelvis X-ray in four groups that were equally represented by weight ranges. A software simulated, for each radiograph, six additional simulated photonic noise images corresponding to 100, 80, 64, 50, 40 and 32% of the initial dose. The 360 radiographs were blindly scored by two radiologists using a semi-quantitative Likert scale. There was no significant difference in scoring between the reference radiograph and simulated radiographs at 80% of the dose in children between 0 and 15 kg and over 35 kg. Inter-observer reproducibility was moderate to very good. Pelvis X-ray doses might be reduced by 20% in children in our institution. Software that produces simulated X-ray with decreasing dose might be a useful tool for an optimization process.

A Dose Simulation X-Ray Software: An Innovating Tool to Reduce Chest Radiograph Exposure in Children.

PURPOSE: Chest radiography is one of the most frequent x-ray examinations performed on children. Reducing the delivered dose is always a major task. The objective of our study was to determine the minimum dose to be delivered while maintaining the image quality of chest radiographs, using dose reduction simulation software. MATERIALS AND METHODS: We included 60 children who had had a chest radiography in 5 groups established according to the diagnostic reference levels equitably represented by weight ranges. The software simulated for each radiograph 6 additional simulated photonic noise images corresponding to 100%, 80%, 64%, 50%, 40%, and 32% of the initial dose. The 360 radiographs were blindly scored by 2 radiologists, according to the 7 European quality criteria and a subjective criterion of interpretability, using a semiquantitative visual Lickert scale. RESULTS: There was no significant difference in scoring between the reference radiograph (100%) and simulated radiographs at 80% of the dose in children between 5 and 20 kg, 50% of the dose in children between 20 and 30 kg, and between simulated radiographs at 40% of the dose in children over 30 kg. Interobserver reproducibility was moderate to excellent. CONCLUSION: Chest radiography dose might be reduced by 20% in children between 5 and 20 kg, 50% in children between 20 and 30 kg, and 60% in children over 30 kg, without any difference in the image quality appreciation. Software that produced simulated x-ray with decreasing delivered dose is an innovating tool for an optimization process.

Factors associated with influenza vaccination failure and severe disease in a French region in 2015.

Current influenza vaccination strategy is based on limited analyses of circulating strains and has some drawbacks, as illustrated during the 2014-2015 season with the circulation of A(H3N2) viruses belonging to divergent genetic subgroups. We reasoned that these strains, poorly neutralized in vitro, may have been associated with vaccination failure and more severe diseases. We conducted a study on a continuous series of 249 confirmed influenza infections. Incidence was three fold greater than in the previous three years. Most isolates were A(H3N2) viruses (78%) and clustered in subgroups 3C.2a (57%) and 3C.3b (43%). We identified 23 non-synonymous mutations that had already been identified during previous seasons at low frequencies, except mutation Q197H, present in 26% of 3C.3b isolates. We identified lung disorder, tobacco smoking and A(H1N1)pdm09 infection as risk factor of severe influenza disease. In contrast, young age (< 5 years), A(H3N2) infection and initial admission to an emergency department were associated with a better outcome of influenza infection.