Multi-slice computed tomography (MSCT): the dose challenge of the new revolution.

Multislice computed tomography (MSCT) has dramatically increased the flexibility and availability of computed tomography (CT), so that the technique is being used increasingly across a widening range of applications. However CT still remains a technique with high absorbed radiation dose, and contributes an increasingly greater proportion of the total collective dose from man-made sources of radiation. Many, but not all, new applications are supported by clinical benefit. Additionally, the examination technique parameters vary widely but not always with apparent justification. There is currently a weak evidence base for reducing the absorbed dose from CT to the threshold necessary to provide clinically relevant findings and research is needed urgently in this area. In the interim, advice from guidelines such as those published by the European Commission should be followed.