CT机应用质量检测与临床照片图像质量关系

目的：分析CT设备应用质量检测结果与临床照片图像质量之间的关系，探讨检测方法的改进措施。方法：采用Catphan500体模和标准剂量组合头模，依照军队CT机应用质量检测与评审规范，对118台CT设备实施检测；同时随机抽取近期从本各部位临床照片共七张，由专家组评审分级。以图像质量等级为关键字，对各参数进行归类统计。结果：临床照片图像质量与剂量指数、噪声水平、密度分辨经和空间分辨率关系密切。结论：实际检测中，要根据参数之间的相互关系合理安排先后顺序：先测量层厚，并校准直至合格；然后进行照射剂量水平的控制；再继续其它参数的检测。

Relationship between CT scanner quality testing and image quality

Objective:To improve the testing methods by studying the relationship between CT sanner quality testing and image quality.Methods:118 CT scanners were tested by a set of Catphan 500 phantom and a set of standard dose meter. 7 random images associated with different parts of the whole body were evaluated and graded by clinical experts. Then, statistics of the testing results were made corresponding to image quality grade.Results:The qualities of clinical images were closely related to such parameters as CTDI, noise level, density resolution and spatial resolution. Conclusion:It is important in the QA testing to reasonablly arrange the order of parameters: slice thickness and its calibration first,followed by CTDI and other parameters.