双源FlashCT单能谱成像技术减少腰椎金属固定器伪影的研究

Metallic Artifact Reduction with Monoenergetic Imaging Technique of Dual - energy Flash CT Systematic Evaluation of Posterior Lumbar Vertebrae Fusion Implants

目的：研究双源FlashCT单能谱成像技术在去除腰椎内固定金属伪影方面的临床价值，寻求最佳图像质量的光子能量。方法：42例腰椎内固定术后复查的患者行双源FlashCT双能量扫描，获得100、140kV双能图像和120kV混合能量图像，扫描数据用单能谱技术处理，每例患者数据每隔10keV分别重建成60—140keV共9组单能量图像。记录感兴趣区的CT值和噪声值并计算信噪比，采用LSD—t检验比较CT值、噪声值及信噪比。结果：与120KV图像相比，70keV～140keV图像质量改善明显（P〈0．001），不同管电压下单能量图像质量两两比较，60KeV～120KeV之间差异有统计学意义（P〈0．05），120keV～140keV两者差异无统计学意义（P〉0．05）。结论：双源FlashCT单能谱成像技术能有效减少腰椎内固定器金属伪影，明显改善腰椎金属内固定术后的图像质量。

Objective： The aim of the study was to assess the diagnostic value of a dual energy Flash CT approach to reduce metal arti- facts in subjects with lumbar spinal internal fixation. Methods： 42 cases of patient with lumber spinal internal fixation are examinated by dual source Flash CT. 100KV, 140KV and 120KV hybrid energy are collected after one -time scaning. Monoenergetic software was used to post - process, reconstruct 9 monoenergetic image the space of 10 keV between 60 keV - 140 keV energy group, measure CT value and SD value, then recorded, calculated signal -to -noise ratio （SNR） value under different photon energy. LSD t -test was applied to de- termine CT value and noise, SNR. Results： From 70keV to 140keV, there was significant difference among CT value and noise value（ P 〈 0.05）. There was no significant difference among CT value between 120keV to 140keV （P 〉 0.05 ）. Conclusion： Dual -source CT single spectrum technology can significantly reduce metal artifacts of lumbar spinal internal fixation.