Figure 2. Fraction of adult mAs–slice width product per slice required for a paediatric abdomen CT image with the same noise level plotted against phantom age, using the standard dimensions from Table 2. The curves are spline fits to points for 80 kV, 100 kV, 120 kV and 140 kV at ages neonate, 1 year, 5 years, 10 years and 15 years, and adult placed at age 30 years.