ICRP Publication 160
Practical Aspects in Optimisation of Radiological Protection in Digital Radiography, Fluoroscopy, and CT
Recommended citation
ICRP, 2024. Practical Aspects in Optimisation of Radiological Protection in Digital Radiography, Fluoroscopy, and CT. ICRP Publication 160. Ann. ICRP 53(7).
Authors on behalf of ICRP
C.J. Martin, K. Applegate, J. Damilakis, I. Hernandez-Giron,M. Kortesniemi, H. Khoury, K.H. Ng, D. Pekarovic,D.G. Sutton, J. Vassileva
Abstract - Digital radiology is playing an increasingly important role in medicine worldwide. The use of computed tomography (CT) has risen dramatically in recent decades, and makes up approximately half of the population dose from medical exposures in many parts of the world. In addition, ever more complex interventional procedures guided by fluoroscopy are replacing more invasive surgical techniques, thus substituting risks from surgery with lesser ones from radiation. These radiological techniques provide significant health benefits, but the associated radiation dose levels need to be kept commensurate with the benefit accrued. Key factors in achieving this are ensuring that examinations are only carried out when they can contribute to management of a patient’s condition, and that the radiological protection aspects for all exposures are optimised. The latter is the subject of the present publication.Digital imaging data contribute versatility in image acquisition, post-processing, and presentation, and provide opportunities for optimisation. However, unlike their analogue equivalent, images acquired digitally may not provide an indication that a dose is too high or images are not collimated, so there are new problems that have to be addressed. In Publication 154, three fundamental requirements for taking the optimisation process forward were described: (i) the need for collaboration between radiologists, other radiological medical practitioners, radiographers/medical radiation technologists, medical physicists, and managers; (ii) access to the appropriate methodology, technology, and expertise; and (iii) provision of organisational processes which ensure that tasks, such as equipment performance tests, patient dose surveys, and reviews of protocols, are carried out and acted upon. A high-level requirement is the integration and use of decision sciences, and harmonisation of these optimisation processes across multi-specialty clinical teams and equipment types within healthcare systems.This publication contains information on practical methods needed to carry optimization forward for different imaging techniques: radiography, fluoroscopy (and fluoroscopically guided interventional procedures), and CT. Many features of digital equipment allow dose levels to be reduced while still maintaining adequate image quality for the clinical task. Staff need to understand the relationship between the different selectable options to use the features effectively. However, there is a wide range in available equipment and training around the world. Provision ranges from clinics with simple radiographic units to specialist hospitals with complex state-of-the-art equipment. Some countries have established communities of medical physicists, while in other countries, there is little or no medical physics support. This presents challenges in communicating requirements for optimisation. This publication addresses these challenges by providing information for facilities within broad categories linked to optimisation arrangements already in place: Level D – preliminary; Level C – basic; Level B – intermediate; and Level A – advanced. It is hoped that through this approach, radiology teams will be able to plan strategies for introducing optimisation techniques that are appropriate for their own facilities and equipment.
MAIN POINTS
ICRP, 2024. Practical Aspects in Optimisation of Radiological Protection in Digital Radiography, Fluoroscopy, and CT. ICRP Publication 160. Ann. ICRP 53(7).
Authors on behalf of ICRP
C.J. Martin, K. Applegate, J. Damilakis, I. Hernandez-Giron,M. Kortesniemi, H. Khoury, K.H. Ng, D. Pekarovic,D.G. Sutton, J. Vassileva
Abstract - Digital radiology is playing an increasingly important role in medicine worldwide. The use of computed tomography (CT) has risen dramatically in recent decades, and makes up approximately half of the population dose from medical exposures in many parts of the world. In addition, ever more complex interventional procedures guided by fluoroscopy are replacing more invasive surgical techniques, thus substituting risks from surgery with lesser ones from radiation. These radiological techniques provide significant health benefits, but the associated radiation dose levels need to be kept commensurate with the benefit accrued. Key factors in achieving this are ensuring that examinations are only carried out when they can contribute to management of a patient’s condition, and that the radiological protection aspects for all exposures are optimised. The latter is the subject of the present publication.Digital imaging data contribute versatility in image acquisition, post-processing, and presentation, and provide opportunities for optimisation. However, unlike their analogue equivalent, images acquired digitally may not provide an indication that a dose is too high or images are not collimated, so there are new problems that have to be addressed. In Publication 154, three fundamental requirements for taking the optimisation process forward were described: (i) the need for collaboration between radiologists, other radiological medical practitioners, radiographers/medical radiation technologists, medical physicists, and managers; (ii) access to the appropriate methodology, technology, and expertise; and (iii) provision of organisational processes which ensure that tasks, such as equipment performance tests, patient dose surveys, and reviews of protocols, are carried out and acted upon. A high-level requirement is the integration and use of decision sciences, and harmonisation of these optimisation processes across multi-specialty clinical teams and equipment types within healthcare systems.This publication contains information on practical methods needed to carry optimization forward for different imaging techniques: radiography, fluoroscopy (and fluoroscopically guided interventional procedures), and CT. Many features of digital equipment allow dose levels to be reduced while still maintaining adequate image quality for the clinical task. Staff need to understand the relationship between the different selectable options to use the features effectively. However, there is a wide range in available equipment and training around the world. Provision ranges from clinics with simple radiographic units to specialist hospitals with complex state-of-the-art equipment. Some countries have established communities of medical physicists, while in other countries, there is little or no medical physics support. This presents challenges in communicating requirements for optimisation. This publication addresses these challenges by providing information for facilities within broad categories linked to optimisation arrangements already in place: Level D – preliminary; Level C – basic; Level B – intermediate; and Level A – advanced. It is hoped that through this approach, radiology teams will be able to plan strategies for introducing optimisation techniques that are appropriate for their own facilities and equipment.
MAIN POINTS
- Optimisation of radiological protection in diagnostic imaging and image-guided procedures should be built on collaboration between radiologists or other radiological medical practitioners, radiographers/medical radiation technologists, and medical physicists, and developed from the initial level (Level D) when a facility is set up, to the basic requirements (Level C), through the intermediate level (Level B), to the advanced processes of Level A, as set out in this publication.
- Exposure factors for digital radiography should be established for different clinical tasks and patient characteristics, making use of automatic exposure control devices and possible use of different filtration options, especially for paediatric exposures, with exposure indices and image collimation monitored.
- Exposure factor selection programmes for fluoroscopy should be configured to provide the diagnostic information required for the range of clinical tasks at commissioning, and dose and image quality performance should be monitored through regular quality control. Management of occupational protection for interventional procedures should be integrated with patient protection.
- Development of protocols for computed tomography to give a level of image quality that has been agreed among the professionals involved requires consideration of the interdependence of exposure parameters, proper application of automatic tube current modulation, and iterative or deep-learning-based reconstruction to enable appropriate, often lower, dose settings to be used.
- Paediatric protocol optimisation requires an understanding of clinical indications, patient sizes, and the ability of patients to cooperate. Particularly for interventional procedures, occupational protection should be managed in an integrated manner with patient protection. Protocols for pregnant patients require optimisation to reduce doses for both the mother and conceptus.
