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Local diagnostic reference levels in pediatric CT examinations: A survey at the largest children's hospital in Greece.

OBJECTIVES
The increased frequency of pediatric CT examinations and the high radiosensitivity of children entail the need to determine DRLs and optimize CT protocols. The aim of the study was twofold. Firstly, to establish pediatric LDRLs according to age and weight for the most common types of CT examinations at the largest children's hospital in Greece. Secondly, to compare LDRLs with European DRLs.


METHODS
A total of 756 pediatric patients who underwent head, chest and abdomen-pelvis CT examinations were included. Patients were categorized into age groups according to the Hospital's protocols. All CT examinations were performed using iterative reconstruction algorithm and AEC. LDRLs were determined in terms of 75th percentile of CTDIvol and DLP.Values of LDRLs were subsequently regrouped into weight categories and compared with European DRLs.


RESULTS
Gathering all age groups for head CT examinations and all weight groups for body CT examinations, LDRLs were ranged from (22-68, 2-5, 2-10) mGy in terms of CTDIvol; (317-786, 22-168, 58-425) mGy.cm in terms of DLP per acquisition and (324-838, 42-265, 85-498) mGy.cm in terms of total DLP for head, chest and abdomen-pelvis CT examinations, respectively.


CONCLUSION
CTDI LDRLs were comparable to European DRLs for head and either comparable or lower than European DRLs for body CT examinations. DLP LDRLs were higher than European DRLs for head and lower for body CT examinations.


ADVANCES IN KNOWLEDGE
Age- and weight-basedLDRLs for pediatric CT examinations were establishedfor the largest children's hospital in Greece.Further investigations across the country are required for the establishment of national pediatric DRLs in Greece.