Paediatric CT made easy

Abstract

Paediatric computed tomography (CT) imaging has always been associated with challenges. Although the technical background of CT imaging is complex, it is worth considering the baseline aspects of radiation exposure to prevent unwanted excess radiation in paediatric patients. In this review, we discuss the most relevant factors influencing radiation exposure, and provide a simplified and practical approach to optimise paediatric CT.

Keywords: ALARA; Children; Computed tomography; Image Gently; Imaging; Radiation protection.

Fig. 1

The graphic depicts the imaging chain. This review focuses on the first three columns (planning the examination, image acquisition and image reconstruction)

Fig. 2

Brooks formula, where D stands for patient dose, B for attenuation factor of the object, µ for mean attenuation coefficient of the object, d for diameter of the object, σ for standard deviation of Hounsfield units within a region of interest (image noise), a for sample increment, b for sample width and h for slice thickness

Fig. 3

A computed tomography scan in the trauma setting without (a) and with (b) gantry tilting

Fig. 4

Modulation of radiation exposure with automated exposure control (AEC). The red line represents the attenuation profile of the body. The light blue line represents the selected minimum value for AEC. If the blue line is not set sufficiently low, as in this case, then there is an excess radiation exposure in thoracic region, indicated by the blue area (adapted from [10])

Fig. 5

The half-slice thickness approach. CT computed tomography