Background: The growth of rib cartilages closely related to age determines the feasibility and results in auricular reconstruction.A prospective study would involve elective radiation that is not otherwise clinically indicated.Direct firm data such as rib cartilage growth preoperation is required.The aim of this study is to evaluate a method for rib cartilage assessment with reduced radiation dose.Methods: A total of 43 children with microtia in age from 5 to 7 years were included with Low-dose in coronary scan technique,17 childen selected randomly in age from 6 to 7 years were examined with routine axial scan manner as a control.Differences in terms of image quality and the radiation dose of the two groups were compared.Results: In the coronal scanning group, there were 42 image(98%) in quality above good(good and excellent) and 1(3%) in poor quality;in the routine axial scanning group, there were 15 image(89%) in quality above good(good and excellent) and 2(12%) in poor quality;the same or slightly better image quality was achieved by coronal scanning compared with axial scanning(x2=6.33,p<0.05).The noises in the two groups were similar(F=1.88,p>0.05).DLP was 19.44±3.25 mGy*cm in the coronal scanning group,68.00±12.36 mGy*cm in the axial scanning group;dose of coronal scanning group was significantly lower than that of axial scanning(t=15.98, p<0.001).Conclusions: The coronal scanning technique offered a better choice for assessment of rib development in younger microtia children requiring ear reconstruction.