Congress:
EuroSafe Imaging 2020
Keywords:
Performed at one institution, Cross-sectional study, Retrospective, Dosimetric comparison, Safety, Dosimetry, CT, Radioprotection / Radiation dose, Paediatric, Abdomen, Action 7 - Radiation protection of children
Authors:
H. F. L. Verelst, M. Aertsen, H. Bosmans
DOI:
10.26044/esi2020/ESI-02153
Background/introduction
The radiation dose a patient receives in CT imaging is mainly determined by the used tube current and tube voltage, and dose optimisation requires an ideal relationship between these two while keeping in mind technical limitations.[1]
In the era of multidetector CT imaging, Automated Exposure Control (AEC) became one of the most important tools in dose reduction. This technique adapts the tube current to the size of the patient. However, using lower tube currents inevitably leads to an increase in noise.[2]
In Siemens' CT scanners multiple tube current modulation techniques are used. A z-axis modulation is applied after determining patient size by taking a topogram. During scanning, an online helical modulation is used, which adjusts tube current to the slice acquired in the previous rotation. All settings are adjusted to maintain the same quality as would be obtained in a reference patient of 70-80kg, with a corresponding reference tube current.[3]
It is known that pediatric patients are more susceptible to the malignant potential of X-rays. This is partially due to their difference in size, but also in morphology. Tissues are still developing and growing in children, which also increases their vulnerability, and because of their long projected life expectancy, long term effects will play a bigger role.[4] The currently used tube current modulation techniques do not seem to specifically cater to these differences.
This study assesses if tube current modulation techniques do indeed lower the used dose in pediatric patients adequately while still maintaining good image quality in CT-imaging of the abdomen, as this does not seem to have been investigated thus far.