Computed tomographic scanning in children: II. An updated comparison of radiation dose and resolving power of commercial scanners

Surface and internal radiation doses for abdominal CT of children were determined using child-sized phantoms and seven commercial models of CT body scanners. High contrast resolving power and low contrast discrimination for each scanner were determined simultaneously with radiation dose measurements and the results were compared with those from a similar study conducted in 1977 with earlier CT models. The average circumferential surface doses for simulated pediatric CT body examinations were 31% lower in this study compared to 1977 results, with a mean of 1.5 rad (0.015 Gy) vs. 2.2 rad (0.022 Gy) respectively. At the same time, resolving power for high (12%) contrast improved by 31% to a mean of 1.38 mm from 2.00 mm. All scanners in the present study could resolve low contrast differences of 1/4% for a 5 mm object.