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Computed Tomography Dose in Paediatric Care: Simple Dose Estimation Using Dose Length Product Conversion Coefficients
Mohd Tap, Nor Hanani; Jaafar Sidek, Mohamed Ariff; Mohd Ridzwan, Siti Farizwana; Selvarajah, S. Elavarasi; Mohd Zaki, Faizah & Abdul Hamid, Hamzaini
Abstract
Background: The use of multislice computed tomography (MSCT) is increasing
worldwide; at the same time, there is a growing awareness of the future risk of cancer associated
with greater exposure to radiation. Therefore, there is a need for an accessible method of effective
dose estimation. This study aims to estimate the effective doses (EDs) of a variety of paediatric
computed tomography (CT) examinations in five age groups using recently published age- and
region-specific dose length products (DLPs) as effective dose conversion coefficients.
Methods: A retrospective review was performed over a 12-month period. Patients were
assigned to one of five age groups: neonatal, 1-, 5-, 10- and 15-years-old. Age- and region-specific
conversion coefficients were applied to the DLP data displayed on the CT console in order to
estimate the ED.
Results: Over the 12-month period, there were a total of 283 CT scans, 211 of which were
selected for study. The ED estimates for plain CT brain scans in neonatal, 1-, 5-, 10- and 15-year-olds
were 2.5, 1.5, 1.4, 1.3 and 0.8 mSv, respectively. For the corresponding CT abdominal scans,
the results were 18.8, 12.9, 7.8, 8.6 and 7.5 mSv; these were the highest values recorded. High-resolution
CT (HRCT) temporal scans showed EDs of 2.9, 1.8, 1.5 and 1.1 mSv in 1-, 5-, 10- and
15-years-old, respectively. CT scans of the helical thorax had an estimated ED of 4.8, 4.2 and 7.0
mSv in 5-, 10- and 15-years-old, respectively.
Conclusion: An inverse relationship between age and effective dose was demonstrated
in CT scans of the brain and abdomen/pelvis. In general, our study showed lower overall EDs
compared to other centres.
Keywords
simple dose estimation; conversion coefficient; paediatric CT; dose length product; effective dose
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