Santos, JoanaJoanaSantosFoley, Shane J.Shane J.FoleyPaulo, GracianoGracianoPauloMcEntee, Mark F.Mark F.McEnteeRainford, Louise A.Louise A.Rainford2016-02-112016-02-112013 the A2013-09Radiation Protection Dosimetryhttp://hdl.handle.net/10197/7486The aims of this study were to investigate the frequency of Portuguese computed tomography (CT) examinations, identify protocol application and establish diagnostic reference levels (DRLs). CT departments (n=211) were surveyed nationally (June 2011–January 2012) and CT protocol information and dose data were collected, as were retrospective age-categorised paediatric CT data from three national paediatric centres. The proposed national CT DRLs (CTDIvol) for adults were 75, 18, 14, 18, 17, 36, 22, 27 and 16 mGy for head, neck, chest, abdomen, pelvis, cervical, dorsal, lumbar and joints, respectively. The levels for paediatric head and chest examinations were as follows: 48 and 2 mGy (newborns), 50 and 6 mGy (5 y olds), 70 and 6 mGy (10 y olds) and 72 and 7 mGy (15 y olds). A limited number of current paediatric protocols aligned to recommended international age categorisations. Portuguese DRLs were generally higher than European recommendations, suggesting potential for optimisation. The need for greater standardisation of age-categorised paediatric protocols was identified.enThis article has been accepted for publication in Radiation Protection Dosimetry ©: 2013 the Authors. Published by Oxford University Press. All rights reserved.Computed tomography (CT)Radiation dosageRadiation protectionJournal Article158330731710.1093/rpd/nct2262015-11-16https://creativecommons.org/licenses/by-nc-nd/3.0/ie/