In recent publications, such as Publications 117 and 120, the Commission provided practical advice for physicians and other healthcare personnel on measures to protect their patients and themselves during interventional procedures. These measures can only be effective if they are encompassed by a framework of radiological protection elements, and by the availability of professionals with responsibilities in radiological protection. This framework includes a radiological protection programme with a strategy for exposure monitoring, protective garments, education and training, and quality assurance of the programme implementation. Professionals with responsibilities in occupational radiological protection for interventional procedures include: medical physicists; radiological protection specialists; personnel working in dosimetry services; clinical applications support personnel from the suppliers and maintenance companies; staff engaged in training, standardisation of equipment, and procedures; staff responsible for occupational health; hospital administrators responsible for providing financial support; and professional bodies and regulators. This publication addresses these elements and these audiences, and provides advice on specific issues, such as assessment of effective dose from dosimeter readings when an apron is worn, estimation of exposure of the lens of the eye (with and without protective eyewear), extremity monitoring, selection and testing of protective garments, and auditing the interventional procedures when occupational doses are unusually high or low (the latter meaning that the dosimeter may not have been worn).

Purpose Recent developments in medical technology have broadened the spectrum of X-ray procedures and changed exposure practice in X-ray facilities. For this reason, diagnostic reference levels (DRLs) for diagnostic and interventional X-ray procedures were updated in 2016 and 2018, respectively. It is the aim of this paper to present the procedure for the update of the DRLs and to give advice on their practical application. Materials and Methods For the determination of DRLs, data from different independent sources that collect dose-relevant data from different facilities in Germany were considered. Seven different weight intervals were specified for classifying pediatric X-ray procedures. For each X-ray procedure considered, the 25th, 50th, and 75th percentile of the respective national distribution of the dose-relevant parameters were determined. Additionally, effective doses that correspond to the DRLs were estimated. Results In procedures with already existing DRLs before 2016, the values were lowered by circa 20 % on average. Numerous DRLs were established for the first time (9 for interventional procedures, 10 for CT examinations). Conclusion For dose optimizations even below the new national DRLs, the BfS recommends establishing local reference levels, using dose management software (particularly in CT and interventional radiology), adapting dose-relevant parameters of X-ray protocols to the individual patient size, and establishing internal radiation protection teams responsible for optimizing X-ray procedures in clinical practice. When applying good medical practice and using modern equipment, the median dose values of the nationwide dose distributions can not only be easily achieved but can even be undercut. Key Points: Citation Format

The European Directive 2013/59/Euratom requires member states of the European Union to ensure justification and optimisation of radiological procedures and store information on patient exposure for analysis and quality assurance. The EuroSafe Imaging campaign of the European Society of Radiology created a working group (WG) on “Dose Management” with the aim to provide European recommendations on the implementation of dose management systems (DMS) in clinical practice. The WG follows Action 4: “Promote dose management systems to establish local, national, and European diagnostic reference levels (DRL)” of the EuroSafe Imaging Call for Action 2018. DMS are designed for medical practitioners, radiographers, medical physics experts (MPE) and other health professionals involved in imaging to support their tasks and duties of radiation protection in accordance with local and national requirements. The WG analysed requirements and critical points when installing a DMS and classified the individual functions at different performance levels. Key Points • DMS are very helpful software tools for monitoring patient exposure, optimisation, compliance with DRLs and quality assurance. • DMS can help to fulfil dosimetric aspects of the European Directive 2013/59/Euratom. • The EuroSafe WG analyses DMS requirements and gives recommendations for users.

The average in vivo chest computed tomographic (CT) attenuation number (air = -1,000, soft tissue = 0, perflubron = +2,300 Hounsfield units [HU]) of 10 ventrodorsal-oriented lung segments was calculated to assess the distribution of gas and perflubron in 14 oleic acid lung-injured adult sheep during partial liquid ventilation (PLV, n = 7) or gas ventilation (GV, n = 7). Partial liquid ventilation was associated with a significant decrease in shunt fraction (PLV = 40 +/- 12%, GV = 76 +/- 12%, p = 0.004). Computed tomographic attenuation data during expiration (HUexp) demonstrated minimal gas aeration in GV animals in the dependent (segments 6-10) lung zones (HUexp = -562 +/- 108 for segments 1-5, HUexp = -165 +/- 104 for segments 6-10, p = 0.015). During PLV, perflubron was predominantly distributed to the dependent lung regions (HUexp = 579 +/- 338 for segments 1-5, HUexp = 790 +/- 149 for segments 6-10, p = 0.04). The ratio of the inspiratory to expiratory HU (HUinsp/exp) was greater in dependent than nondependent regions (mean HUinsp/exp segments 1-5 = 0.56, segments 6-10 = 0.81, p = 0.01), indicating that during inspiration relatively more gas than perflubron was distributed to the nondependent lung regions. We conclude that during PLV in this lung injury model, (1) gas exchange is improved when compared with gas ventilation, (2) perflubron is distributed predominantly to the dependent regions of the lung, and (3) although gas is distributed throughout the lung with each inspiration, more gas than perflubron goes to the nondependent lung regions.