Abstract
There have been a number of major advances in imaging technology in recent years. Here we discuss in detail multislice CT and PET, since these are the two modalities generating the most interest in cancer imaging, but which also have the potential for significantly increasing the radiation burden in the paediatric population. In addition, we focus on the implications of the new Response Evaluation Criteria In Solid Tumours (RECIST) guidelines, which describe a significant new method of tumour size measurement.