Evaluation of Low-dose Multi-slice CT Scanning in Children Chest Examination

Objective: To evaluate the application effect and value of low-dose kV and mA for chest examination in children by multi-slice CT. Methods: 120 children underwent chest CT were enrolled and divided into six groups according to different kV and mA values. Average CT dose index (CTDIvol, mGy) and dose length product (DLP, mGy* cm) in each group were recorded. Effective dose (ED, mSV) was calculated by DLP, ED= kxDLP [k value =0.039]. Image quality analysis was independently conducted by two experienced doctors. Radiation dose and image quality were compared among six groups. Peripheral blood cells of each child were respectively detected before and after test (2 hours, 1 day, 1 week and 4 weeks). Results: Radiation doses in each group (CTDIvol, DLP and ED) were decreased to the control group, in which the combined reduction group dropped approximately 50%. There was no significant difference in image quality among each group and all meet the diagnostic requirements. No significant change was observed in peripheral blood cell counts of children before and after test. Conclusions: Low-dose multi-slice CT scanning for chest examination combined reduction of kV and mA value may effectively reduce hazards of radiation to children, with the image quality meeting the diagnostic requirements.