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of reducing the effective dose for routine abdomen and pelvis CT from 10 mSv to less than 1 mSv. Despite the benefits of optimization tools, addressing the need to select and implement optimized protocols across numerous hospitals and CT imaging centers arises a significant challenge.
This challenge extends to interventional procedures, where sophisticated machines offer preset examination protocols for ease of use, while proper implementation is not guaranteed. Even assuming optimal protocol settings for clinical tasks, understanding their practical application is essential for efficient utilization of manufacturer-offered tools and successful optimization. Unfortunately, universal implementation remains elusive( Housni et al., 2023).
3.3 Steps towards successful optimization process 3.3.1 Quality Assurance program
Numerous international or national organizations have proactively proposed distinct quality assurance protocols customized to various modalities within the realm of medical physics. Consequently, the responsibility lies with medical physicists to orchestrate a comprehensive quality assurance program that aligns with the criteria for optimized procedures in radiology. This imperative task is necessary in addressing the factors contributing to excessively high patient doses, which are commonly attributed either to suboptimal equipment performance or inadequately optimized examination protocols( IAEA, 2012).
In the pursuit of successful optimization processes, the foundational step involves the establishment of a robust quality assurance program. The World Health Organization( WHO) defines a quality assurance program as an organized effort. Its primary objective is to ensure that images generated during X-ray imaging procedures exhibit consistently high quality, providing sufficient diagnostic information at the most economical cost and with the minimal possible patient’ s radiation dose. This highlights the significance of balancing between patient dose and image quality, while considering various clinical factors, including the judicious use of contrast agents( WHO, 1982; IAEA, 2012).
A wealth of knowledge and guidance is available through reports disseminated by authoritative bodies such as the International Atomic Energy Agency and the European Commission( EC) on matters pertaining to quality assurance and dosimetry in diagnostic radiology. Professional medical physics societies, including the American Association of Physicists in Medicine( AAPM), the European Federation of Organizations for Medical Physics( EFOMP), and the French Association of Medical Physics, actively contribute to the discourse by generating guidance documents on quality control. The creation of a strong quality assurance program is the primary requirement, regardless of the particular procedure or guidelines followed.. This foundational step is imperative for ensuring the efficacy of patient dose optimization efforts, thereby reinforcing the important role played by medical physicists in upholding the highest standards in radiological practices( AAPM, 2002; IAEA, 2007, 2011; EC, 2012; Greffier et al., 2017; EFOMP, 2015).
3.3.2 Optimization team and attributions
The optimization team, comprising radiologists, medical physicists, and radiation technologists, collaborates synergistically to integrate clinical expertise, technical proficiency, and practical considerations. This multidisciplinary approach is essential for achieving an optimal balance in image quality and radiation dose across diverse radiological procedures. Establishing an optimization team is paramount for refining radiological procedures. Each member of this collaborative unit contributes distinctively, ensuring a comprehensive approach to harmonizing image quality and radiation dose, as reflected in literature( IAEA, 2013; Tahiri et al., 2022; Gingold, 2017).
The radiologist assumes a key role within the optimization team, offering invaluable insights to ensure whether taskspecific image quality is adequately maintained. Their clinical expertise is essential in optimization efforts with the clinical requirements of specific tasks, safeguarding diagnostic accuracy. The medical physicist leads the optimization process by implementing various methodologies as detailed in existing literature. In many instances, their active involvement extends to the actual optimization of examination protocols, leveraging their technical capacity to balance between optimal image quality and radiation doses. This requires a comprehensive understanding of the technical intricacies of radiological equipment and the strategic application of optimization techniques. As for the radiation technologist, their role is to check if the modified( optimized) protocol is appropriate within the clinical workflow. Their responsibility encompasses careful execution to ensure alignment with the intended goals of achieving optimal image quality at the designated radiation dose. Practical considerations, efficiency, and adherence to established protocols constitute integral aspects of their contribution( IAEA, 2013; Tahiri et al., 2022; Gingold, 2017; Sensakovic et al., 2017).
The optimization team engages in collective decisionmaking to identify critical clinical tasks, examination types, and X-ray modalities necessitating optimization in terms of radiation exposure. Given the substantial variability across medical institutions in modalities, examination types, and frequencies, these determinations are appropriately made at the institutional local level. Upon identification of relevant examination types, collaborative efforts with clinicians ensure establishing clinically appropriate image quality requirements, ensuring optimization aligns precisely with institutional diagnostic needs.
3.3.3 Establishing diagnostic reference levels( DRLs)
DRLs, endorsed by organizations like the ICRP, are crucial for optimization, indicating dose levels above which exposures are inappropriate. DRL values depend on specific exposure circumstances.
Establishing DRLs is essential for evaluating doses and examination quality. This involves comparing local dose values with DRLs or benchmarks and understanding their complexities. The optimization team plays a pivotal role in managing these difficulties to ensure that radiological procedures achieve the optimal balance between diagnostic efficacy and patient safety( El Mansouri et al., 2022; Talbi et al., 2022).