PET／CT图像基于CT衰减校正伪影的实验研究

目的：研究不同浓度泛影葡胺溶液在不同CT扫描条件下对PET／CT图像质量的影响。方法：向5个乳胶容器中分别注入体积分数为5％、10％、15％、20％和40％的1：7服泛影葡胺溶液，依次将其密闭置于圆柱形水模内进行PET／CT成像。利用CT扫描数据对PET图像进行衰减校正，并比较不同管电压CT扫描条件下PET图像的差异。结果：体积分数为15％、20％和40％的泛影葡胺充盈区在经CT衰减校正的PET图像上表现为高浓聚伪影．标准摄取值比本底均有不同程度的升高，而体积分数为5％、10％的泛影葡胺充盈区则无明显伪影，反映了随着泛影葡胺浓度的升高CT衰减校正伪影随之增强；对于体积分数为40％的口服泛影葡胺溶液，随着CT扫描所使用的管电压的升高．经CT衰减校正的PET图像上的伪影随之减弱．标准摄取值降低。结论：体积分数大于15％的泛影葡胺溶液在PET／CT成像中标准摄取值升高，图像表现出伪影；PET／CT成像中CT扫描所采用的管电压越高，高浓度泛影葡胺溶液产生的伪影越弱。

PET/CT Images Based on CT Attenuation Correction Artifact

Objective To study the influence of different concentrations of meglumine solutions on PET/CT image quality with different CT protocols. Methods Meglumine solutions with concentrations of 5%, 10%, 15%, 20% and 40% were injected into five latex vessels, then were sealed into a cylindrical water phantom. The phantom was scanned by PET/CT with different CT tube voltages, followed by a conventional attenuation correction procedure. Comparison was finally made among the images of different tube voltages. ~ There were artifacts in the areas filled with meglumine solutions with the concentrations Of 15%, 20% and 40%. Standard Uptake Value （SUV） grew higher than the background with varying degrees. However, there were no apparent ar- tifacts when the concentration of the meglumine solution was 5% or 10%. It＇s could be concluded that CT attenuation correction artifact became apparent with the increased concentration of meglumine solutions. For the meglumine solution with the concen- tration of 40%, as CT voltage rose the CT attenuation correction artifacts on PET images became much less apparent, and the SUV decreased. Conclusion The SUV on the PET/CT images of meglumine solutions with concentrations of more than 15% is higher than the background, and there are artifacts on the images. The artifact for high-concentration meglumine solution gets less apparent with the increase of the CT voltage, when PET/CT scanning performed.