Abstract: On the premise of keeping other parameters or conditions unchanged, the effects of scanning dose, layer thickness, and tube voltage on the low contrast detectability of CT images were studied. This study will provide data support for testing and standard revision of standardized CT equipment quality control. The results of this study suggests that when detecting the low contrast detectability of CT equipment, the CTDI_w should be as close as possible to 50 mGy, and the minimum should not be less than 40 mGy; 10 mm layer thickness should be selected, and the minimum should not be less than 5 mm; The voltage of a single tube is not significant for the detection results, and clinical commonly used tube voltages above 100 kV can be selected.

Key words: CT quality control, Low contrast detectability, Dose, Layer thickness, Radiation quality