YU Xikun1,2, ZHAO Jingxia3, ZHANG Zhenming1, QIAO Yue1, LIU Shizhu2, ZHANG Jian4, LIU Jingxin1,2
1. Department of Radiology, China-Japan Union Hospital, Jilin University, Changchun Jilin 130033, China; 2. Jilin Province
Engineering Research Center of Medical Imaging, Changchun Jilin 130033, China; 3. Experimental Teaching Center of College of
Nursing, Jilin University, Changchun Jilin 130021, China; 4. Changchun City Metrology and Testing Technology Research Institute,
Changchun Jilin 130012, China
Abstract：Objective To explore the minimum threshold of milliampere in low-dose chest CT examination under the premise of
meeting the quality of diagnosis. Methods The dose threshold of low-dose chest CT was determined through a variety of quality
control model scans, and the simulation model was used to obtain the dose threshold of low-dose chest CT, which ensured the
diagnostic value of image. Results While fixing the tube voltage was 120 kV and changing the tube current was less than 50 mAs,
the low contrast resolution and noise of CT images could no longer meet the diagnostic requirements in the national metrological
verification regulation JJG 961-2017 Medical Diagnostic X-ray Radiation Source for Spiral Computed Tomography (CT).
Conclusion The condition of the tube voltage of 120 kV and the tube current of 50 mAs can be used as the minimum threshold for
low-dose chest screening.
