Table 2. Tube voltage/current-induced ranges of changes in SDs, CNRs and EDs for the three age groups.

Tube kVp/mA	Ages	SDs (HU)	EDs (mSv)	CNRs
80/10-250	1-year-old	40.08–7.65	0.04–0.96	0.77–1.31
	5-year-old	61.92–9.50	0.03–0.71	0.27–1.08
	10-year-old	73.47–9.49	0.02–0.52	0.06–1.16
100/10-250	1-year-old	26.43–5.45	0.08–2.12	1.42–1.87
	5-year-old	31.92–6.05	0.06–1.62	1.11–1.64
	10-year-old	33.93–6.33	0.05–1.16	1.10–1.79
120/10-250	1-year-old	19.04–4.36	0.15–3.79	1.69–2.08
	5-year-old	27.13–5.52	0.12–3.00	1.37–1.83
	10-year-old	27.51–5.26	0.09–2.16	1.43–2.09

SD = standard deviation; CNR = contrast-to-noise ratio; ED = effective doses.