New knowledge about CT usage and dose optimisation in children, but a major question is still unanswered

Abstract

During the last few years, we have seen some worrying articles describing both the significant increase in CT usage in adults and children and estimations of considerable cancer risk from CT in children. The articles by Brenner et al. [1–3] in particular have sparked new awareness and concerns regarding radiation dose. Currently, an article or report on these issues appears in a scientific journal, in a newspaper or on TV almost monthly. This places enormous responsibility on those radiologists who provide CT to children and adolescents. Paediatric radiologists not only have to promote the enormous advances of CT for disease management in childhood, they also need to make every effort to highlight to radiologists, imaging technicians and clinicians in all subspecialties that, before any use of CT in children, two main criteria must be fulfilled: justification, and optimisation of radiation protection. The articles by Pearce et al. [4] and by Goo [5] in this issue of Pediatric Radiology reflect this continuously increasing awareness, and the concerns within and outside the radiological community regarding the increasing number of CT scans in children and the corresponding substantial radiation exposure. While a number of previous publications have described trends in the use of CT primarily in adult populations, very little has been published regarding temporal trends and other patterns of CT usage in young people. The article by Pearce et al. [4] describes patterns in CT usage among young people aged less than 22 years in Northern England from 1993 to 2002. The results show that the number of CT studies increased, in particular in the years 1997–2000. This was around the time of the introduction to clinical practice of helical CT and multidetector CT. These important technical advances improved the overall performance of CT, in particular speed, facilitating large area scans within seconds and multiphase studies. As a result, CT has become an indispensable part of medical imaging. These important technical inceptions and trends in the late 1990s may be the reason for the observed increase in the number of CTs per patient in this study (the median doubled from 1 in 1993 to 2 in 1999). Since we know very little about the utilisation of CT in young populations around the world, it is indeed crucial to report such trends and patterns. Beyond the necessary description of trends in the use of CT in children and young adults, research on optimisation of paediatric CT techniques, particularly of radiation dose, is of major importance. The article by Goo [5] is an example of this important research. This describes an individualised approach that does not rely on age and body weight but rather on cross-sectional area and the mean density of a specific body region to achieve uniform image noise in contrast-enhanced paediatric chest CT. Individualised volume CT dose can thereby be determined. This interesting approach allows a high degree of tailored CT technique in children. On the other hand, it illustrates that paediatric CT is indeed a challenge. The complexity of the technique and approach described leads to a discussion of whether high-quality paediatric CT is perhaps best performed exclusively in dedicated centres R. Fotter (*) Department of Paediatric Radiology, University Hospital, Medical University Graz, Auenbruggerplatz 34, Graz, Styria 8036 Austria e-mail: richard.fotter@medunigraz.at