ABSTRACT
Objective To evaluate the radiation dose in both low radiation dose and to conventional radiation dose mode in multislice spiral CT scan for children with embedded teeth,and explore the lowest conditions of exposure in multislice spiral CT scan for children embedded teeth.Methods Eighty cases of children with embedded teeth examined by 16 slices spiral CT were divided into 5 ,25,125 and 250 mAs scanning groups.The scanned pictures of four groups were evaluated by two chief physicians and three associate chief physicians in the radiological department with double blind method.The CTDI_w and DLP in different radiation dose mode were recorded and analyzed with statistics.Results All the four groups scanned pictures in different radiation dose mode could accurately show the structure and the adjacency relation of embedded teeth.Even though the resolution of scanned pictures in S mAs group were inferior to the other three groups on bone trabecula,gingiva and their surrounding soft tissue,it still could meet the requirements of examination.The average DLP in 5 mAs group was only 2% of value in 250 mAs group.Conclusions MSCT in 5 mAs group can not only meet the requirements of examination,but also reduce the radiation dose to patients to the greatest extent.