双源CT双能量减影体部CTA技术及临床应用

目的 探讨体部DE-CTA的辐射安全性和对体部血管评价的可信度.方法 分别应用64层螺旋CT和双源CT 双能量的体部 CTA 和常规腹部扫描序列对体部模拟人进行扫描,比较同类序列辐射剂量.30例疑体部血管病变者行DE-CTAff(DE组),获得3组彼此匹配的横断面像,将140 kV和80 kV两组图像输入DE后处理程序,获得去骨MIP像和VR像(DE法);将融合图像输入Inspace手动去骨依次获得VR和MIP像(常规法),统计和比较后处理时间.回顾分析另一组30例(64层组),采用64层螺旋CT体部CTA序列,由2位医师对2组血管图像质量进行肉眼观察评价.结果 体部 DE-CTA 辐射剂量不高于单球管CTA;肉眼观察DE组与64层组图像质量无差别;腹部DE法后处理时间短于常规方法,胸腹联合CTA两者时间无差异;体部DE-CTA步骤简化,人为因素少.结论 体部DE-CTA辐射剂量不高于单源 CTA,且能高质量地显示体部血管,与64层组的图像质量无差别,且较常规法节省图像后处理步骤或时间,人为因素减少.

Body artery evaluation of dual energy CTA (DE-CTA) with dual-source CT (DSCT): initial application

Objective To define whether DE-CTA is safe,reliable or not for body artery evaluation. Methods Chest phantom was scanned with standard sequence for body vessel and abdomen of DSCT and 64 spiral CT respectively. The dose-length product (DLP) of each sequence was compared. DE-CTA was done with DSCT on 30 patients who were suspected body vascular disease. Three groups of axial images were acquired, which were 80 kV,140 kV and merged images. MIP, VR image was generated through dual energy postprocessing (DE group, used 140 kV and 80 kV images) and Inspace (non-DE group, used merged images) respectively. Time spending was compared. Another 30 cases (64 group) of body CTA with 64 slice spiral CT were reviewed retrospectively. Image quality of 64 group and DE group were compared by two doctors who were skilled in image postprocessing. Results DLP of DE-CTA was not more than that of 64 spiral CT. There was no difference of image quality between DE group and 64 group. The time spending of acquiring bone removal MIP/VR image of DE-CTA was less than non-DE group for abdominal artery, but no difference for chest-abdominal artery. DE-CTA was simple, with image generated automatically through DE postprocessing and no more manual steps was needed compared to non-DE group. Conclusion DE-CTA was a safe, reliable technique for evaluation of body arteries, as well as 64 spiral CT, additionally DE-CTA needed less postprocessing time or steps than 64 spiral CT.