Multislice CT: update on radiation and screening.

With ever-expanding applications, increasing availability, and accessibility of CT scanners, concerns have been raised about radiation exposure associated with CT scanning. Global statistics and projections suggest increasing use of CT scanning and its contribution to radiation exposure is a cause for concern. Several strategies based on modulation of scanning parameters and technologic improvisations have been developed in an effort to reduce associated radiation dose. This article discusses the basis for rising concern regarding radiation dose associated with CT scanning. The fundamentals of CT dose estimation are described along with strategies that aim to reduce radiation dose associated with CT scanning based on patient characteristics, study indications, and technological innovations.