National Diagnostic Reference Levels for Standard Descending Thoracic Endovascular Aortic Repair and Optimisation Strategies.

OBJECTIVE: The International Commission on Radiological Protection has highlighted the large number of medical specialties that use fluoroscopy outside diagnostic imaging departments without radiation protection programmes for patients and staff. Vascular surgery is one of these specialties. Thoracic endovascular aortic repair (TEVAR) is a complicated procedure requiring radiation protection guidance and optimisation. The recent EU Basic Safety Standards Directive requires the use and periodic updating of diagnostic reference levels (DRLs) for interventional procedures. The aim of this study was to determine doses for patients undergoing TEVAR with mobile Xray systems and hybrid rooms (fixed Xray systems) to obtain national DRLs and to suggest optimisation actions. METHODS: This was a retrospective cross sectional study. The Spanish Chapter of Endovascular Surgery conducted a national survey in 11 autonomous communities representing around 77.6% of the Spanish population (47.33 million inhabitants). A total of 266 TEVAR procedures from 17 Spanish centres were analysed, of which 53.0% were performed in hybrid operating rooms. National DRLs were obtained and defined as the third quartile of the median values from the different participating centres. RESULTS: The proposed national DRLs are: for kerma area product (KAP), 113.81 Gy·cm2 for mobile Xray systems and 282.59 Gy·cm2 for hybrid rooms; and for cumulative air kerma (CAK) at the patient entry reference point, 228.38 mGy for mobile systems and 910.64 mGy for hybrid rooms. CONCLUSION: Based on the requirement to know radiation doses for standard endovascular procedures, this study of TEVARs demonstrated that there is an increased factor of 2.48 in DRLs for KAP when the procedure is performed in a hybrid room compared with mobile C-arm systems, and an increased factor of 3.98 in DRLs for CAK when the procedure is performed with hybrid equipment. These results will help to optimise strategies to reduce radiation doses during TEVAR procedures.

[Radiation protection in endoscopy]. / Protección radiológica en endoscopia.

Endoscopy has evolved from a purely diagnostic technique to a therapeutic procedure. This is possible in many cases thanks to the use of fluoroscopy, which entails exposure to ionizing radiation for both patients and the personnel involved. Endoscopic retrograde cholangiopancreatography (ERCP), which necessarily requires fluoroscopy, is classified by the Food and Drug Administration as an examination with a potential risk of triggering radiation induced injuries. This article reviews the biological effects of radiation, the types of radiological equipment used in ERCP, as well as the magnitudes and dosimetric units, to finally address the radio protection elements in the endoscopy room. The objective is to provide the reader with the information to be able to perform these procedures with the greatest radiological safety for both patients and occupationally exposed personnel.

Notifications and alerts in patient dose values for computed tomography and fluoroscopy-guided interventional procedures.

The terms "notifications" and "alerts" for medical exposures are used by several national and international organisations. Recommendations for CT scanners have been published by the American Association of Physicists in Medicine. Some interventional radiology societies as well as national authorities have also published dose notifications for fluoroscopy-guided interventional procedures. Notifications and alerts may also be useful for optimisation and to avoid unintended and accidental exposures. The main interest in using these values for high-dose procedures (CT and interventional) is to optimise imaging procedures, reducing the probability of stochastic effects and avoiding tissue reactions. Alerts in X-ray systems may be considered before procedures (as in CT), during procedures (in some interventional radiology systems), and after procedures, when the patient radiation dose results are known and processed. This review summarises the different uses of notifications and alerts to help in optimisation for CT and for fluoroscopy-guided interventional procedures as well as in the analysis of unintended and accidental medical exposures. The paper also includes cautions in setting the alert values and discusses the benefits of using patient dose management systems for the alerts, their registry and follow-up, and the differences between notifications, alerts, and trigger levels for individual procedures and the terms used for the collective approach, such as diagnostic reference levels. KEY POINTS: • Notifications and alerts on patient dose values for computed tomography (CT) and fluoroscopy-guided interventional procedures (FGIP) allow to improve radiation safety and contribute to the avoidance of radiation injuries and unintended and accidental exposures. • Alerts may be established before the imaging procedures (as in CT) or during and after the procedures as for FGIP. • Dose management systems should include notifications and alerts and their registry for the hospital quality programmes.

Uncertainties in occupational eye lens doses from dosimeters over the apron in interventional practices.

It is relevant to estimate the uncertainties in the measurement of eye lens doses from a personal dosimeter over the protective apron without using additional dosimetry near the eyes. Additional dosimetry for interventionists represents a difficulty for routine clinical practice. This study analyses the estimated eye doses from dosimeter values taken at chest level over the apron and their uncertainties. Measurements ofHp(0.07) using optically stimulated luminescence dosimeters located on the chest over the apron and on the glasses (in the inner and outer part of the protection) were taken from ten interventionalists in a university hospital, in the period 2018-2019 during standard clinical practice. For a total sample of 133 interventional procedures included in our study, the ratio between theHp(0.07) on the glasses (left-outer side) and on the chest over the apron had an average of 0.74, with quartiles of 0.47, 0.64, 0.88. Statistically significant differences were found among operators using the U-Mann-Whitney test. The average transmission factor for the glasses was 0.30, with quartiles of 0.21, 0.25, and 0.32. Different complexity in the procedures, in the quality of the scatter radiation and in the individual operational practices, involve a relevant dispersion in the results for lens dose estimations from the over apron dosimeter. Lens doses may be between a 64% and an 88% of the over apron dosimeter values (using median or 3rd quartile). The use of 88% may be a conservative approach.

Current status of diagnostic reference levels in interventional cardiology.

Interventional cardiology provides indisputable benefits for patients but uses a substantial amount of ionising radiation. The diagnostic reference level (DRL) is the tool recommended by the International Commission on Radiological Protection to optimise imaging procedures. In this work, a review of studies dealing with radiation dose or recommending DRL values for interventional cardiology since 2010 is presented, providing quantitative and qualitative results. There are many published papers on coronary angiography (CA) and percutaneous coronary intervention. The DRL values compiled for different continental regions are different: the DRL for CA is about 35 Gy cm2for Europe and 83 Gy cm2for North America. These differences emphasise the need to establish national DRLs considering different social and/or economic factors and the harmonisation of the survey methodology. Surveys with a large amount of data collected with the help of dose management systems provide more reliable information with less chance of statistical bias than those with a small amount of data. The complexity of procedures and improvements in technology are important factors that affect the radiation dose delivered to patients. There is a need for additional data on structural and electrophysiological procedures. The analysis of paediatric procedures is especially difficult because some studies present results split into age bands and others into weight bands. Diagnostic procedures are better described, but there is a great variety of therapeutic procedures with different DRL values (up to a factor of nine) and these require a dedicated review.

Strengthening radiation protection education and training of health professionals: conclusions from an IAEA meeting.

In March 2021 the International Atomic Energy Agency (IAEA) organised an online Technical Meeting on Developing Effective Methods for Radiation Protection Education and Training of Health Professionals with attendance of 230 participants representing 66 Member States and 24 international organizations, professional bodies and safety alliances. By means of a pre-meeting survey, presentations by experts, topical panel discussions and post-meeting feedback to the meeting summary, the meeting identified strengths, common weaknesses and possible solutions and actions for improving radiation protection education and training of health professionals. Available guidelines and resources for radiation protection training were also reviewed. The meeting discussion resulted in a strong consensus for the need of: (a) international guidance on education and training in radiation protection and safety for health professionals, (b) an international description of minimum standards of initial and ongoing competence and qualification in radiation protection for relevant professional groups, considering the available recommendations at international and regional levels. The proposed actions include provisions for train-the-trainer credentialing and facility training accreditation, balance betwee the online and face-to-face training, improved on-the job training, as well as improved inclusion in training programmes of aspects related to application of new technologies, ethical aspects, development of communication skills, and use of software tools for improving justification and optimisation. The need for making the ongoing training practical, applicable, and useful to the trainee was highlighted. The international consultation initiated by the IAEA was appreciated as a good approach to understand and promote coordination and collaboration at all levels, for best results in education and training in radiation protection of health professionals. Implementing such a holistic approach to education and training in radiation protection would contribute towards qualification and competence of health professionals needed to ensure application of high standards for quality and safety in medical uses of ionizing radiation.

Dose-reducing fluoroscopic system decreases patient but not occupational radiation exposure in chronic total occlusion intervention.

AIMS: Several novel low-dose fluoroscopic systems (LDS) developed recently, but real practice information of the net benefit for the patient and professionals is scarce. We evaluated separately patient and operator radiation exposure during percutaneous interventions of chronic total occlusions (CTO). METHODS: A total of 116 consecutive CTOs were analyzed (60 in LDS and 56 in standard-dose fluoroscopic system [SDS]). Digital dosimetry of patient and occupational (operator and scatter dose) exposure was prospectively recorded. RESULTS: Biometrics, demographics, CTO variables, and operators were distributed evenly. Patient radiation exposure was effectively decreased in LDS (dose area product [DAP] by 36%, Air Kerma [AK] by 47%). However, occupational data showed no statistical differences between LDS and SDS. The LDS uses less radiation amount but with higher energy (due to additional filtration) compared to SDS, therefore increasing the scatter dose. When comparing the C-arm scatter dose to the DAP we found higher scatter dose with the LDS (0.0139 mSv/gray (Gy)*cm2 vs. 0.0082 mSv/Gy*cm2, p < .001). This was confirmed in a larger dataset comprising 5,221 coronary procedures. CONCLUSIONS: LDS was safer for patients reducing DAP and AK compared to SDS. However, occupational doses were not lower and scatter dose higher. Radiological protection measures must be kept maximized even in LDS.

Cumulative effective dose from recurrent CT examinations in Europe: proposal for clinical guidance based on an ESR EuroSafe Imaging survey.

In recent years, the issue of cumulative effective dose received from recurrent computed tomography examinations has become a subject of increasing concern internationally. Evidence, predominantly from the USA, has shown that a significant number of patients receive a cumulative effective dose of 100 mSv or greater. To obtain a European perspective, EuroSafe Imaging carried out a survey to collect European data on cumulative radiation exposure of patients from recurrent computed tomography examinations. The survey found that a relatively low percentage of patients (0.5%) received a cumulative effective dose equal to or higher than 100 mSv from computed tomography, most of them having an oncological disease. However, there is considerable variation between institutions as these values ranged from 0 to 2.72%, highlighting that local practice or, depending on the institution and its medical focus, local patient conditions are likely to be a significant factor in the levels of cumulative effective dose received, rather than this simply being a global phenomenon. This paper also provides some practical actions to support the management of cumulative effective dose and to refine or improve practice where recurrent examinations are required. These actions are focused around increasing awareness of referring physicians through encouraging local dialogue, actions focused on optimisation where a team approach is critical, better use of modern equipment and the use of Dose Management and Clinical Decision Support Systems together with focused clinical audits. The proper use of cumulative effective dose should be part of training programmes for referrers and practitioners, including what information to give to patients. Radiation is used to the benefit of patients in diagnostic procedures such as CT examinations, and in therapeutic procedures like the external radiation treatment for cancer. However, radiation is also known to increase the risk of cancer. To oversee this risk, the cumulative effective dose (CED) received by a patient from imaging procedures over his or her life is important. In this paper, the authors, on behalf of EuroSafe Imaging, report on a survey carried out in Europe that aims to estimate the proportion of patients that undergo CT examinations and are exposed to a CED of more than 100 mSv. At the same time, the survey enquires about and underlines radiologists' measures and radiology departments' strategies to limit such exposure. Over the period of 2015-2018, respondents reported that 0.5% (0-2.72%) of patients were exposed to a CED of ≥ 100 mSv from imaging procedures. The background radiation dose in Europe depends on the location, but it is around 2.5 mSv per year. It is obvious that patients with cancer, chronic diseases and trauma run the highest risk of having a high CED. However, even if the number of patients exposed to ≥ 100 mSv is relatively low, it is important to lower this number even further. Measures could consist in using procedures that do not necessitate radiation, using very low dose procedures, being very critical in requiring imaging procedures and increasing awareness about the issue. KEY POINTS: • A relatively low percentage of patients (0.5%) received a cumulative effective dose from CT computed tomography equal to or greater than 100 mSv, in Europe, most of them having an oncological disease. • There is a wide range in the number of patients who receive cumulative effective dose equal to or greater than 100 mSv (0-2.72%) and optimisation should be improved. • Increasing the awareness of referring physicians through encouraging local dialogue, concrete actions focused on optimisation and development of dose management systems is suggested.

Radiation dose management systems-requirements and recommendations for users from the ESR EuroSafe Imaging initiative.

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.

Why is radiological protection different in medicine? Sievert Memorial Lecture.

There are many aspects of radiological protection in medicine that are different from other areas of activity using ionising radiation. In this paper, the author presents and justify some of these differences and highlight the reasons for and benefits of this consideration for the medical field. It is important to understand the differences as we are all likely to be patients at some point in our lives and be exposed to ionising radiation for imaging procedures several times and, in some cases, for therapeutic indications. The work done by the International Commission on Radiological Protection and other international organisations to produce and recommend a consistent system of radiological protection in medicine for the safe use of ionising radiation in medical practices must be highlighted. We should understand why we do not apply dose limits and dose constraints to patients, as well as why we have three levels of justification when considering the use of ionising radiation for patients. We highlight the relevance of personalised radiation protection in parallel to personalised medical practice, and the importance of an integrated approach for occupational and patient protection, especially for interventional procedures. We also cover the differences between patients and volunteers in biomedical research, the importance of radiation safety in quality assurance programmes (including the consideration of unintended and accidental exposures) for some clinical practices, and the relevance of education and training in radiological protection for medical and health professionals and information on radiation risks for patients. Finally, the ethical issues with regard to the safe use of ionising radiation in medicine and the impact of new technology will be addressed.

National Diagnostic Reference Levels for Endovascular Aneurysm Repair and Optimisation Strategies.

OBJECTIVE: The International Commission on Radiological Protection (ICRP) has highlighted the large number of medical specialties using fluoroscopy outside imaging departments without programmes of radiation protection (RP) for patients and staff. Vascular surgery is one of these specialties and endovascular aneurysm repair (EVAR) is one of the most challenging procedures requiring RP guidance and optimisation actions. The recent European Directive on Basic Safety Standards requires the use and regular update of diagnostic reference levels (DRL) for interventional procedures. The objective of the study was to know the doses of patients undergoing EVAR with mobile Xray systems and with hybrid rooms (fixed Xray systems), to obtain national DRLs and suggest optimisation actions. METHODS: The Spanish Chapter of Endovascular Surgery launched a national survey that involved hospitals for 10 autonomous communities representing the 77% of the Spanish population (46.7 million inhabitants). Patient dose values from mobile Xray systems were available from nine hospitals (sample of 165 EVAR procedures) and data from hybrid rooms, from seven hospitals, with dosimetric data from 123 procedures. The initial national DRLs have been obtained, as the third quartile of the median values from the different centres involved in the survey. RESULTS: The proposed national DRLs are 278 Gy cm2 for hybrid rooms and 87 Gy cm2 for mobile Xray systems, and for cumulative air kerma (cumulative AK) at the patient entrance reference point, 1403 mGy for hybrid rooms, and 292 mGy for mobile systems. CONCLUSION: An audit of patient doses for EVAR procedures to identify optimised imaging protocol strategies is needed. It is also appropriate to evaluate the diagnostic information required for EVAR procedures. The increase by a factor of 3.2 (for kerma area product) and 4.8 (for cumulative AK) in the DRLs needs to be justified when the procedures are performed in the hybrid rooms rather than with mobile Xray systems.

Percutaneous structural cardiology: are anaesthesiologists properly protected from ionising radiation?

During transcatheter aortic valve implantations (TAVI) and other percutaneous structural procedures, some patients may need close anesthesiological care, thus exposing the anaesthesiologist to x-rays. This work aims to investigate the radiation dose received by anaesthesiologists during these specific procedures in order to improve their radiological protection. Occupational radiation doses were measured prospectively during percutaneous structural procedures in several health professionals using electronic dosimeters worn over the apron at chest level. A sample of 49 procedures were recorded, where the anaesthesiologists' average dose per procedure resulted 13 times higher than that of interventional cardiologists. The average dose per procedure received over the protection apron during TAVIs by the anaesthesiologist was 0.13 mSv, with a maximum value of 0.69 mSv. Taking these figures as a conservative estimation of the eye lens dose, an anaesthesiologist could participate in around 150 procedures before reaching the regulatory annual dose limit for the lens of the eye in Europe (20 mSv). In those clinical procedures where patients need close anesthesiological care, the anaesthesiologists might receive high radiation doses increasing the risk for cataracts and the risk of stochastic radiation effects. The proper use of occupational dosimeters will help identify these situations. It is recommended to use a mobile shielding barrier to reduce radiation exposure to acceptable levels in these situations.

Percutaneous structural cardiology: are anaesthesiologists properly protected from ionizing radiation?

AIM: During transcatheter aortic valve implantations (TAVI) and other percutaneous structural procedures, some patients may need close anesthesiological care, thus exposing the anaesthesiologist to X-rays. This work aims to investigate the radiation dose received by anaesthesiologists during these specific procedures in order to improve their radiological protection. METHODS: Occupational radiation doses were measured prospectively during percutaneous structural procedures in several health professionals using electronic dosimeters worn over the apron at chest level. RESULTS: A sample of 49 procedures were recorded, where the anaesthesiologists' average dose per procedure resulted 13 times higher than that of interventional cardiologists. The average dose per procedure received over the protection apron during TAVIs by the anaesthesiologist was 0.13 mSv, with a maximum value of 0.69 mSv. Taking these figures as a conservative estimation of the eye lens dose, an anaesthesiologist could participate in around 150 procedures before reaching the regulatory annual dose limit for the lens of the eye in Europe (20 mSv). CONCLUSIONS: In those clinical procedures where patients need close anesthesiological care, the anaesthesiologists might receive high radiation doses increasing the risk for cataracts and the risk of stochastic radiation effects. The proper use of occupational dosimeters will help identify these situations. It is recommended to use a mobile shielding barrier to reduce radiation exposure to acceptable levels in these situations.

Correction to: 40th EUROPEAN SOCIETY OF NEURORADIOLOGY Diagnostic and Interventional Annual Meeting.

We note that the following data error was published in regard to patient numbers in the Results section 1.

Strategies to optimise occupational radiation protection in interventional cardiology using simultaneous registration of patient and staff doses.

The International Commission on Radiological Protection recommends that occupational protection and patient protection be managed in an integrated approach. This paper describes the experience and the initial results of a system able to register and to process simultaneously staff and patient doses in interventional cardiology and the practical use of this system in the optimisation of occupational exposure. The system used simultaneously collects and manages patient and staff doses for all radiation events. The personal electronic dosimeters worn over the protective apron of health professionals working inside catheterisation laboratories can send (wireless) doses and dose rate values to an X-hub and provide the operators inside the catheterisation rooms with real-time information. Individual and global reports for all the health professionals may be periodically obtained from the system to help with the optimisation. The results for eight cardiologists, one fellow and four nurses for a total of 2468 interventional cardiology procedures and 3207 occupational dose values collected over one year are presented here. Annual doses Hp(10) measured over the apron for cardiologists ranged from 0.3 to 6.3 mSv. For the cardiologist, the ratio between occupational doses (over the apron) and patient doses ranged from 0.05 to 0.23 µSv Gy-1 cm-2, with a mean value of 0.12 µSv Gy-1 cm-2. The system allows defining optimisation strategies by comparing the results between the different operators while considering the workload and complexity of the procedures (based on the total Kerma Area Product managed by the different operators). The registration of the date and time of the occupational radiation doses allows auditing the use of the personal dosimeters worn by the various operators.

Main problems and suggested solutions for improving radiation protection in medicine in Ibero-American countries. Summary of an International Conference held in Madrid, 2016.

During the International Conference on Radiation Protection in Medicine held in Bonn in 2012, several areas for improvement were identified, including specific actions related with justification, optimization, role of manufacturers, radiation protection education and training, strategic research, data collection on medical and occupational exposures, prevention of incidents and accidents, radiation safety culture, risk-benefit dialogue and implementation of the radiation safety standards. The outcomes of the Bonn Conference were summarized in the so-called 'Bonn Call for Action', identifying 10 priority actions to enhance RP in medicine. Trying to analyse the progress in the implementation of this 'Call for Action' in the Ibero-American region, several international organizations organized the 'Ibero-American Conference on Radiation Protection in Medicine' (Conferencia Iberoamericana sobre Protección Radiológica en Medicina, CIPRaM) held in Madrid, in October 2016. CIPRaM was structured in eight thematic sessions dealing with: diagnostic and dental radiology, image guided interventional radiology, nuclear medicine, radiation therapy, health authorities and radiation protection regulators, professional associations of technologists and nurses, professional associations of medical physicists and radiation protection experts, and universities and researchers in radiation protection in medicine. This paper summarizes the main results of that Conference based on the consensus achieved about main problems, solutions, and indicators to evaluate the implementation of the proposed solutions.

Medical imaging dose optimisation from ground up: expert opinion of an international summit.

As in any medical intervention, there is either a known or an anticipated benefit to the patient from undergoing a medical imaging procedure. This benefit is generally significant, as demonstrated by the manner in which medical imaging has transformed clinical medicine. At the same time, when it comes to imaging that deploys ionising radiation, there is a potential associated risk from radiation. Radiation risk has been recognised as a key liability in the practice of medical imaging, creating a motivation for radiation dose optimisation. The level of radiation dose and risk in imaging varies but is generally low. Thus, from the epidemiological perspective, this makes the estimation of the precise level of associated risk highly uncertain. However, in spite of the low magnitude and high uncertainty of this risk, its possibility cannot easily be refuted. Therefore, given the moral obligation of healthcare providers, 'first, do no harm,' there is an ethical obligation to mitigate this risk. Precisely how to achieve this goal scientifically and practically within a coherent system has been an open question. To address this need, in 2016, the International Atomic Energy Agency (IAEA) organised a summit to clarify the role of Diagnostic Reference Levels to optimise imaging dose, summarised into an initial report (Järvinen et al 2017 Journal of Medical Imaging 4 031214). Through a consensus building exercise, the summit further concluded that the imaging optimisation goal goes beyond dose alone, and should include image quality as a means to include both the benefit and the safety of the exam. The present, second report details the deliberation of the summit on imaging optimisation.

Biplane interventional pediatric system with cone-beam CT: dose and image quality characterization for the default protocols.

The aim of this study was to assess image quality and radiation dose of a biplane angiographic system with cone-beam CT (CBCT) capability tuned for pediatric cardiac procedures. The results of this study can be used to explore dose reduction techniques. For pulsed fluoroscopy and cine modes, polymethyl methacrylate phantoms of various thicknesses and a Leeds TOR 18-FG test object were employed. Various fields of view (FOV) were selected. For CBCT, the study employed head and body dose phantoms, Catphan 504, and an anthropomorphic cardiology phantom. The study also compared two 3D rotational angiography protocols. The entrance surface air kerma per frame increases by a factor of 3-12 when comparing cine and fluoroscopy frames. The biggest difference in the signal-to- noise ratio between fluoroscopy and cine modes occurs at FOV 32 cm because fluoroscopy is acquired at a 1440 × 1440 pixel matrix size and in unbinned mode, whereas cine is acquired at 720 × 720 pixels and in binned mode. The high-contrast spatial resolution of cine is better than that of fluoroscopy, except for FOV 32 cm, because fluoroscopy mode with 32 cm FOV is unbinned. Acquiring CBCT series with a 16 cm head phantom using the standard dose protocol results in a threefold dose increase compared with the low-dose protocol. Although the amount of noise present in the images acquired with the low-dose protocol is much higher than that obtained with the standard mode, the images present better spatial resolution. A 1 mm diameter rod with 250 Hounsfield units can be distinguished in reconstructed images with an 8 mm slice width. Pediatric-specific protocols provide lower doses while maintaining sufficient image quality. The system offers a novel 3D imaging mode. The acquisition of CBCT images results in increased doses administered to the patients, but also provides further diagnostic information contained in the volumetric images. The assessed CBCT protocols provide images that are noisy, but with very good spatial resolution.

The appropriate and justified use of medical radiation in cardiovascular imaging: a position document of the ESC Associations of Cardiovascular Imaging, Percutaneous Cardiovascular Interventions and Electrophysiology.

The benefits of cardiac imaging are immense, and modern medicine requires the extensive and versatile use of a variety of cardiac imaging techniques. Cardiologists are responsible for a large part of the radiation exposures every person gets per year from all medical sources. Therefore, they have a particular responsibility to avoid unjustified and non-optimized use of radiation, but sometimes are imperfectly aware of the radiological dose of the examination they prescribe or practice. This position paper aims to summarize the current knowledge on radiation effective doses (and risks) related to cardiac imaging procedures. We have reviewed the literature on radiation doses, which can range from the equivalent of 1-60 milliSievert (mSv) around a reference dose average of 15 mSv (corresponding to 750 chest X-rays) for a percutaneous coronary intervention, a cardiac radiofrequency ablation, a multidetector coronary angiography, or a myocardial perfusion imaging scintigraphy. We provide a European perspective on the best way to play an active role in implementing into clinical practice the key principle of radiation protection that: 'each patient should get the right imaging exam, at the right time, with the right radiation dose'.