Review articleSecuring safe and informative thoracic CT examinations-Progress of radiation dose reduction techniques

- Various techniques have led to substantial radiation dose reduction of chest CT.
- Automatic modulation of tube current has been shown to reduce radiation dose.
- Iterative reconstruction makes significant radiation dose reduction possible.
- Processing time is a limitation for full iterative reconstruction, currently.
- Validation of diagnostic accuracy is desirable for routine use of low dose protocols.

The increase in the radiation exposure from CT examinations prompted the investigation on the various dose-reduction techniques. Significant dose reduction has been achieved and the level of radiation exposure of thoracic CT is expected to reach the level equivalent to several chest X-ray examinations. With more scanners with advanced dose reduction capability deployed, knowledge on the radiation dose reduction methods has become essential to clinical practice as well as academic research. This article reviews the history of dose reduction techniques, ongoing changes brought by newer technologies and areas of further investigation.