To establish the radiation dose level for single- and dual-source thoracic CT scans in daily practice.

The dose levels delivered during 634 consecutive examinations over a period of 2 months were recorded. The CT scans were performed using: (a) a standard protocol (single source, single energy [group 1]: n=266; dual source, single energy [group 2]: n=276; (b) with prospective ECG synchronisation [group 3]: n=13; or (c) with dual energy [group 4]: n=79. All the acquisitions included kilovoltage selection depending on the weight and automatic milliamperage modulation.

The mean DLP of the standard protocols was 97.12 mGycm (group 2; BMI=23.1kg/m²) and 211.1 mGycm (group 1; BMI=27.3kg/m²), the choice of protocol depending on the diameter of the thorax relative to the diameter of the field of the second source, and therefore on the patient’s morphotype. When imaging included examination of the proximal and middle coronary arteries (group 3), the mean DLP was 105.5 mGycm. Morphological and functional imaging (group 4) was obtained with a mean DLP of 404.3 mGycm.

Depending on the objective of the protocol, the mean DLP varied from 97.12 to 404.3 mGycm.