目的 :测量CT的层厚 ,探讨与层厚相关的各项参数。方法 :采用 3种不同的方法对 10台CT进行测试 ,计算出CT的层厚并测量了不同层厚条件下CT的噪声和空间分辨力。结果 :3种测试方法各有优缺点 ,有多种因素影响CT层厚。结论 :必须通过测试校准来确保CT设备层厚的准确性 Objective: To measure the layer thickness of CT and discuss the parameters related to layer thickness. Methods: Three different methods were used to test 10 CTs. The layer thickness of CT was calculated and the CT noise and spatial resolution were measured under different slice thicknesses. Results: The three methods have their own advantages and disadvantages, there are many factors that affect CT thickness. Conclusion: The accuracy of the CT device layer thickness must be ensured by test calibration