高清能谱CT去除金属伪影功能的应用

Application of high definition spectral CT for metallic artifacts reduction function

目的：探讨高清能谱 CT 成像去除金属伪影功能的应用价值；研究在应用去除金属伪影功能中最佳keV 值的范围。方法对42例做过金属异物植入手术的患者行高清能谱 CT 扫描，将原始数据重建以多组单能量（Mono）的图像，对不同质量图像所对应的 keV 的值各做以记录。再通过比较常规 CT 扫描图像和各种不同 Mono 能量级别图像的去伪影功能，进行分析和对比软组织、骨质以及金属植入物图像轮廓的锐利度和残余金属伪影强度；以此来判断高清能谱 CT 在不同患者的相同部位，所得到的去金属伪影的最佳成像能量级和对诊断疾病的有效利用率。结果由金属植入物所形成的伪影大多在90～140keV 的时候减弱或去除，在100～130keV 时减弱就更明显。能谱成像去除金属伪影功能在90～140keV 时，对金属植入物相邻近的骨质及软组织影像清晰度有所提高，在110～140keV 时对骨质及金属植入物的图像显示为最好，在110～130keV 时软组织的图像较好。应用高清 CT 能谱记录选取最佳单能量的条件为90～130keV，在这个能量范围内的图像均能满足阅读要求。结论高清能谱 CT 的能谱扫描，在高能量范围可较好的减除体部植入金属物伪影，四肢略有差别。最佳的能量范围为100～130keV。掌握了有效的能谱范围，可快速有效获得最佳有用图像。

Objective To investigate the application value of high definition spectral CT imaging for metallic artifacts reduction function; study the optimal keV range for metallic artifacts reduction function. Methods 42 cases with metal implanted were underwent high definition spectral CT scan, the original data reconstructed with multi group monochromic （Mono） image, the corresponding image quality for different values of keV, each are done to record. Sharpness and residual metal artifacts strength of soft tissue, bone and metal implants image contour is analyzed and contrasted by comparing the metallic artifacts reduction function of the conventional CT and different Mono image. In order to finding optimal range of keV and the effective diagnosis utilization of high definition spectral CT Image in the same location of different patients. Results Artifacts formed by metal implants are weakened or removed mostly in 90 ~ 140kev, in 100 ~ 130keV decreased more obviously. The diagnosis utilization of adjacent bone and soft tissue imaging is cleared in 90 ~ 140keV, the optimal range was110 ~ 140keV in bone and metal implanted imaging, 110 ~ 130keV in soft tissue imaging. Application of high definition spectral CT, the selection of the optimal Mono range is 90 ~ 130keV, the image in this energy range, can meet the requirement of reading. Conclusion In the high energy range, metallic artifacts reduced better in high definition spectral CT scan. Limb slightly difference the optimal range is 100 ~ 130keV. Master the effective range of the spectrum, which can be quickly and effectively to obtain the best useful image.