Optimization of a protocol in pediatric Computed tomography with automatic exposure control

Objective: The aim of this work is to describe the optimization of a posterior fossa protocol in pediatric computed tomography (CT) by using an Automatic Exposure Control (AEC) system, named Flex-mA (SHIMADZU Corp., Kyoto, Japan). Materials and methods: The calculation of the CT dose index over the entire volume, C-vol, and the kerma-length product in air, P-KT,P-CT, was based on the C-vol reported by the CT unit, with slice thickness and tube current being taken from metadata of patient's DICOM files. The estimated mean dose levels were compared between each other and with respect to Dose Reference Levels (DRLs) by multiple comparison of means. Results: Significant dose reductions were obtained for all age ranges from 1 year to 19 years old, with minimum reductions up to 31% for the C-vol and 25% for the P-KT,P-CT, compared with DRLs from developed countries in a range from 10 to 14 years old. Conclusions: The use of the AEC function, Flex-mA, allows both the average value and the dispersion of C-vol and P-KT,P-CT for pediatric patients to be evaluated, preserving an acceptable level of the diagnostic image quality according to international criteria of quality of head imaging protocols in general. (C) 2013 ACTEDI. Published by Elsevier Espana, S.L. All rights reserved.