Abstract：Objective To explore the differences in radiation doses in infants and young children by comparing body size-specific
dose estimates (SSDE) based on effective diameter (De) and water equivalent diameter (Dw) and volume CT dose index(CTDIVOL)
in cardiac CTA examinations, and to explore the reasons. Methods The cardiac CTA examination images of 217 children were
retrospectively analyzed and divided into 3 groups according to different examination conditions: Group A 0 to 1 years old,
Group B 1 to 3 years old, and Group C 3 to 6 years old. The size-specific dose estimate (SSDE) values and conversion factors of
the three groups were analyzed. Results SSDE of effective diameter (SSDEDe) and SSDE of water-equivalent diameter (SSDEDw)
were 128.27% (3.04/2.37) and 132.49% (3.14/2.37), higher than CTDIVOL in Group A, 111.34% (2.65/2.38) and 114.29% (2.72/2.38)
higher than CTDIVOL in Group B and 98.73% (3.10/3.14) and 105.41% (3.31/3.14) higher than CTDIVOL in Group C. In three groups,
SSDEDe were 1.85% , 1.39% and 3.37% lower than SSDEDw. The fDe and fDw were highly positively correlated with De (R2=0.998,
0.803, P<0.01). CTDIVOL underestimated its radiation dose, and the smaller the body diameter, the more serious the underestimation.
Conclusion SSDEDw takes into account the differences of body type and tissue, so it is more accurate to evaluate the radiation dose
of Cardiac CTA in Infants. SSDEDw considers the differences in body size and tissue of infants and young children when measuring
the radiation dose of the cardiac CTA examination, and the evaluation of the radiation dose is more accurate.
张见，张晓军，刘鹏. 婴幼儿心脏CTA检查不同辐射剂量衡量方法的对比分析[J]. 中国医疗设备, 2022, 37(7): 72-75.
ZHANG Jian, ZHANG Xiaojun, LIU Peng. Comparative Analysis of Different Dosimetry Methods in Cardiac CTA Examination of
Infants and Young Children. China Medical Devices, 2022, 37(7): 72-75.