Multicentre Audit of Paediatric Brain Computed Tomography Dosage in Hong Kong: the Common Mistakes We Make

Objective: By auditing paediatric brain computed tomography (CT) performed in four Hong Kong centres, dosage values were obtained to address local practice and suggest improvements. Methods: This was a retrospective review of plain CT brain studies on patients aged 16 years or below performed in four Hong Kong hospitals. During the 3-month audit periods in 2010 to 2011, patient demographic data and CT dosage using CT dose index volume (CTDI vol ) and dose-length product (DLP) as measures were recorded for each paediatric brain CT case in each participating centre. Subgroup analyses (age of <1, 1-5, 6-10, 11-16 years) with mean, standard deviation, and third quartile were performed. Results: Altogether 463 CTs from the four centres were studied. Overall mean and third quartile results for CTDI vol and DLP in each age-group were generally comparable to international standards. However, excessive dosages were occasionally noted in individual age-groups or centres. In all, 47 (10.2%) of the CTs entailed excessive dosages, with repeated scanning due to motion artefact being the commonest reason. Incorrect use of adult (instead of paediatric) CT protocols, and excessive scan ranges (outside the region of interest) were also frequent mistakes. In one centre, significantly increased dosages were detected immediately after the installation of a new CT machine. Conclusions: Our results highlight the importance of adequate sedation in the paediatric age-group. Strict adherence to paediatric protocols and narrowing the scan range should also be emphasised. Departmental imaging protocols should be regularly reviewed to monitor dosage, especially after installation of a new CT scanner.