CT系统高级扫描方式的图像质量测量方法

A measurement method for image qualities of advanced scanning techniques of CT systems

目的:设计椭圆体模,对X射线计算机断层扫描(CT)系统中的高级扫描方式的图像质量进行评估。方法:制作兼容Catphan的椭圆体模,在3个不同品牌的CT扫描系统上使用自动曝光控制(AEC)、低剂量扫描和双能扫描3种高级扫描模式,对图像的CT值准确性和均匀性及层厚进行测量;在其中的两个支持双能的CT扫描系统上进行双能物质分解准确性的测量。结果:应用椭圆体模在各高级扫描模式下测量的图像质量无明显下降,能够满足国家的强制图像质量标准;两个CT扫描系统的双能扫描的物质分解准确度在±20%以内。结论:所设计的椭圆体模能够对CT系统的高级扫描条件下图像进行质量评估,并可为CT系统的临床应用和质量控制提供参考依据。

Objective:To design a oval phantom to assess the image qualities when advanced scanning techniques were applied on X-ray computed tomography(CT)system.Methods:The produced oval phantom which was compatible with Catphan was scanned on 3 kinds of advanced scanning models,included automatic exposure control(AEC),low dose scan and dual energy scan,of CT scan system of 3 various brands,and the accuracy of CT value,homogeneity and slice thickness of images were measured.The measurement of the accuracy of dual energy decomposition was implemented on two CT scan systems which supported dual energy.Results:The image qualities of the oval phantom that was measured under variously advanced scanning model didn't have obvious decline,and they could meet the national mandatory standard for image quality.And the accuracy of material decomposition of dual energy scanning of CT scan system was within±20%.Conclusion:The oval phantom can implement quality assessment for image under advanced scanning technique of CT system,and it can provided references for clinical application and quality control of CT system.