能谱纯化技术在泌尿系虚拟平扫成像中的应用价值

Value of CT virtual non-contrast scan in urinary system with tin filter

目的:探讨双源CT能谱纯化技术在CT泌尿系虚拟平扫成像中的应用价值。方法:80例患者随机均分为两组行泌尿系CT扫描,A组采用一代双源CT扫描(140kV/80kV组),B组采用二代双源CT扫描(80kV/Sn 140kV组),两组间在增强扫描动脉期采用双能量扫描的方式,其余期相均采用单源扫描。将两组双能量扫描图像通过软件处理获得虚拟平扫图像。比较两组虚拟平扫图像的CT值、信噪比及噪声,并与常规平扫图像比较病灶的检出情况。结果:B组的图像噪声低于A组,信噪比高于A组;与140kV/80kV组比较,80kV/Sn 140kV组虚拟平扫提高了对小结石(直径<4mm)的显示能力;双能量扫描辐射剂量,80kV/Sn 140kV组比140kV/80kV组低约10%。结论:能谱纯化技术可明显提高对物质的识别能力,提高虚拟平扫的图像质量,真正达到减少扫描次数、降低患者辐射剂量的目的。

Objective：To study the value of CT virtual non contrast scan in urinary system with tin filter. Methods：80 CT contrast scan cases were divided into two groups randomly. One group underwent CT scan with the first generation dual energy CT （140 kV/80 kV）, the other with the second generation dual energy CT （80 kV/Sn 140 kV）. Dual energy scan mode was used with the first generation 140 kV/80 kV and the second generation 80 kV/Sn 140 kV. in the arterial phase, while single source scan in the rest phases. Virtual unenhanced images were obtained through dual energy processing soft- ware. The noise, SNR and radiation close of images of the two groups were compared,and the rate of lesion detection of the two groups were compared with the conventional non-contrast images respectively. Results： The noise of 80 kV/Sn 140 kV group was lower than that of 140 kV/80 kV group,while the SNR of 80 kV/Sn 140 kV group was higher. The stones with diameter less than 4mm were detected better in 80 kV/Sn 140 kV group. Conclusion：Virtual non-contrast scan improves the ability of identifying substances with tin filter,therefore it can not only improved the virtual unenhanced image quality, but also reduce the number of scans to decrease the radiation dose.