Experimental Research for Quality Control and Detection of Low-dose CT Imaging
JIAO Long1,2, YU Xikun2, LIU Shizhu2, ZHANG Jian3, ZHANG Futian2, LIU Jingxin1,2
1. Department of Radiology, China-Japan Union Hospital of Jilin University, Changchun Jilin 130033, China; 2. Jilin Province
Engineering Research Center of Medical Imaging, Changchun Jilin 130033, China; 3. Changchun City Metrology and Testing
Technology Research Institute, Changchun Jilin 130012, China.
Abstract：Objective To determine the low dose threshold that meets the national standard via performing quality control tests on the
performance of the CT equipment. Methods A total of 126 CT machines of various brands and models applied in clinical practice were
selected. The parameters such as CT value, noise, spatial resolution and low-contrast detectability were tested by referring
to GB17985-2011 Specifications for quality assurance test for computed tomography X-ray scanners. Finally, the data were
statistically analyzed. Results The experimental results showed that the CT value, uniformity and spatial resolution of the tested CT
equipment were all qualified under 120 kV and normal mA. The mean ± standard deviation of CT value of the tested equipment was
(-1.17±0.97) to (-1.33±0.67) HU. The mean ± standard of homogeneity was (1.17±0.17) to (1.33±0.67) HU. The noise
qualification rate of CT equipment was 93.65%. The qualified rate of low contrast resolution of CT equipment was 96.03%. The
noise and low contrast resolution could not meet the standard requirements under the condition of 120 kV and lower than 40 mAs.
Conclusion For national standards, the numerical standards of CT value and uniformity are too loose, the noise detection interval is
too long and the numerical standard of CTDIw is too strict. With the development of the times, 8 to 10 mm thick layer is no longer in
clinical use. Under the condition of 120 kV, 40 mAs is recommended as the dose threshold for low-dose CT examination.
焦龙1,2，于喜坤2，刘师竺2，张健3，张鳆天2，刘景鑫1,2. 低剂量CT成像质量控制检测实验研究[J]. 中国医疗设备, 2019, 34(4): 21-24.
JIAO Long1,2, YU Xikun2, LIU Shizhu2, ZHANG Jian3, ZHANG Futian2, LIU Jingxin1,2. Experimental Research for Quality Control and Detection of Low-dose CT Imaging. China Medical Devices, 2019, 34(4): 21-24.
