Purpose or Case Report: The use of pediatric abdominal CT has been increasing rapidly. However increased radiation exposure is a public health concern for children because of children are more sensitive to radiation than adults. The purpose of this study is to estimate which patient-related factors affect radiation dose, to pediatric patients undergoing abdominal CT
Methods & Materials: The data evaluated had been recorded for 434 pediatric abdominal CT between November 2013 and May 2015. Of these exams, 284 (153 boys, 131 girls; mean age 7.1±4.8 years) were included in this study and retrospectively reviewed. The patients were divided according to their age (0-2, 3-5, 6-10 and 11-15 years old) at the time of performing abdominal CT and we calculated the size-specific dose estimates (SSDE). In each age groups, the patients who have the highest 25% of SSDE value were classified as Group 1 and the patients who have the lowest 75% of SSDE value were classified as Group 2. The age, BMI, arm positioning (both arms up, both arms at sides, right arm up, and left arm up), leg positioning (both legs down, both legs at sides, right left down, and left down) and patient centering (distance between data collection center and reconstruction target center) were evaluated and compared between two groups. The factors influencing increased radiation dose were evaluated by univariate and a multivariate logistic regression model
Results: Seventy patients included in Group 1 and 214 patients included in Group 2. The average of SSDE was statistically significant differences between the two groups (5.68±2.39 in Group 1 and 3.80±1.47 in Group 2, P< 0.001). BMI was statistically significantly higher in the Group 1 than Group 2 (P < 0.001). In 12 cases (17%) and 6 cases (2%) in Group 1 and 2 respectively, both or one arms were at sides. Statistically significant differences in arm positioning were found between the two groups (P < 0.001). Age, leg positioning and patient centering did not show significant differences between two groups. Arm positioning and BMI were significant risk factors for an increased radiation dose, as confirmed by univariate and multivariate analyses
Conclusions: Children have the higher radio-sensitivity compared with adults. For children, it is important to reduce the radiation dose. We evaluate the patient-related factors affecting radiation dose for pediatric abdominal CT. The patient BMI and arm positioning are important factors of radiation dose for pediatrics