Jerrold Bushberg, Ph.D.
Director of Health Physics Programs
Clinical Professor
Department of Radiation Oncology
University of California, Davis

“Justification, Optimization and Communication in Medical Imaging: Recent Improvements and Persistent Challenges”

It would be difficult to overestimate the value and impact CT has made to the diagnosis and treatment injuries and illnesses since its clinical début in 1971. The use and capability of medical imaging has increased rapidly worldwide during the past decade, and the rise in the use of pediatric CT was one of the main contributors. CT is currently the modality of choice for assessing a number of pediatric disorders and the introduction of new technology has expanded the spectrum of its applications in pediatric imaging. On a global scale the use of computed tomography (CT) accounts for about 34% of the collective dose and is a major source of medical radiation exposure in children. While the use of x-rays for medical imaging help millions of patients worldwide, inappropriate use may result in unnecessary and preventable radiation risks. A balanced approach is needed that both recognizes the multiple health benefits that can be obtained from the use of x-rays in medical imaging, while addressing and minimizing health risks. Radiation protection in medical exposures is based on two principles: (i) justification of the procedures and (ii) optimization of the procedure to manage the radiation dose commensurate with the medical objective. CT remains a powerful tool in the diagnosis of pediatric illness and there is little doubt that the benefits of its use vastly outweigh potential risks when it is appropriately prescribed and properly performed (i.e. justified and optimized). During the last few years, advocacy campaigns to promote appropriate use of radiation in pediatric imaging have been conducted by several organizations. The Image Gently Campaign, created by the Alliance for Radiation Safety in Pediatric Imaging (http://www.pedrad.org/associations/5364/ig/), is likely the most widely recognized educational and awareness campaigns. Among themany attributes of this program is its comprehensive web site that allow users to access information where the scope and readability of the content is tailored to the intended audience (e.g., parents, technologists, medical physicists, radiologist and referring physicians). Recent data indicated a declining volume of pediatric CT studies in some high income countries. This finding hopefully reflect a reduction in the number of unnecessary/unjustified procedures. However, the wide spread (and too often unbalanced) media coverage of the potential risk from CT have led to a reluctance on the part of some parents to allow CT examinations of their children (even when they are clinically justified). Opportunities for optimization by reducing unnecessary radiation dose in pediatric CT include individual “child size” adjustments of exposure parameters (kVp and mA), minimizing the use of multi-phase exams, and limiting the scan length to only the area indicated by the exam objectives. In addition to the traditional equipment performance checks, a comprehensive quality assurance and improvement program should include a periodic sampling and retrospective assessment of how well CT procedures met appropriateness guidelines and evaluation of the patient dose relative to existing diagnostic reference levels or ranges. Data published in the last few years indicate that radiation dose for many medical imaging procedures have decreased and this trend was also reflected in the radiation dose in pediatric CT. Multiple opportunities to reduce patient dose and improve communication about radiation risk in pediatric x-ray imaging still exist. While many of the tools necessary to support improvements in justification and optimization exist, their integration into the daily practice of many imaging facilities has not been fully realized. Dialogue and collaboration among all those involved in providing healthcare can help to identify and take advantage of these opportunities. Greater and more effective communication between referrers, and radiologic medical practitioners would facilitate the optimization process. One document, to be published this year by the WHO entitled Communicating radiation risks in pediatric imaging to support risk-benefit dialogue will hopefully further serve this effort.

Location
1005 GBSF