Table 4. Estimated effective doses for typical paediatric CT examinations according to the International Commission on Radiological Protection (ICRP) 60 [13] and ICRP 103 [32] definitions of effective dose.

Examination	Age group	Effective dose (mSv) ICRP 60	Effective dose (mSv) ICRP 103
CT brain	0–6 months	2.4	1.6
	6 months to 3 years	1.9	1.3
	3–6 years	1.7	1.2
	6–10 years	1.9	1.3
	>10 years	1.4	1.0
CT chest	<5 years	1.5	1.8
	5–10 years	4.6	5.6
	>10 years	10 (5.4)a	13 (6.6)a
CT abdomen/pelvis	<5 years	2.7	2.5
	5–10 years	6.7	6.3
	>10 years	11 (5.1)a	10 (4.7)a

^aAll values of effective dose have been estimated from the mean DLP₁₆ (dose–length product relative to the 16-cm phantom) values, except those shown in brackets, which have been estimated from the mean DLP₃₂ (dose–length product relative to the 32-cm phantom) values. These have been included for comparison as some of the patients in the >10 years age group will be closer in size to an adult than to a child.