Purpose or Case Report: 1. To compare the effective dose of dual energy CT with plain films in the pediatric population.
2. To compare effective dose using Turbo Flash scanning technique with that of standard scanning technique on single energy CT.
Methods & Materials: Patients were scanned on a SOMATOM Force Dual Energy scanner using either Dual Energy or Turbo Flash scanning modes. The dose length product (DLP) of chest, abdomen and pelvis scans were recorded and the effective doses were calculated from conversion factors derived from published data. The effective doses for the CT of the chest, abdomen and pelvis scans were then compared with the effective doses of plain films from published data.

A further analysis was made of patients scanned using Turbo Flash scanning technique only. Retrospective dose-length products were recorded from patients receiving scans using single energy CT on a Lightspeed VCT scanner for comparison.
Results: A CT chest, abdomen and pelvis scan of a 1 year old patient gave a DLP of 90.7 with a total effective dose of 5.0 mSv for the entire study. This dose was approximately 47 times higher than the combined doses from radiographs of a chest and abdomen. An 8 day old patient receiving a chest CT with contrast had an effective dose of 0.5 mSv, which is approximately 26 times higher than the dose of 0.019 mSv derived from a single chest radiograph. A 13 day old patient had an effective dose of 1.7 mSv from a CT of the abdomen and pelvis, which is equivalent to 27 abdominal radiographs.

In the patients who were scanned using Turbo Flash, effective doses ranged from 1.9 to 5.7 mGy using dual energy CT and from 3.2 to 14.3 mGy using single energy CT. Early data shows that the patients scanned using dual energy had about three times lower the effective dose in the newborn patient group and half the effective dose in the 3 year old patients. The effective dose in the dual and single energy CT groups became similar at 5 years old.
Conclusions: With the advent of faster scanning techniques such as Turbo Flash mode on Dual Energy CT, pediatric patients can now be scanned in under a second, diminishing the total effective dose when compared to single energy CT. When CT is neccessary in the pediatric age group, having references dose ranges are necessary to help facilitate discussions with referring providers and patient families.