Shunsuke Nosaka, M.D.

Division of Pediatric Imaging, Department of Radiology, National Center for Child Health and Development

　　This special comment will summarize ; recent articles mentioning the estimation of cancer risks from diagnostic X-rays especially concerning CT, reports as“front page news”by mass media, and the official response of the Japan Radiological Society. This special comment will also deal with ; the basic principles of low dose radiation based on linear extrapolation, the issue of unlimited medical radiation dose, the current status of CT in the Japanese health care system, and the future announcement regarding pediatric CT which will be made by the Japan Radiological Society.

Keywords：Pediatric CT，Radiation dose，Dose reduction，Estimated cancer risk，
Mass media