共轭采集技术在头颈联合CTA中的应用

The Application of Conjugate Acquisition Technology in CT Angiography of Head and Neck Joint

目的研究头颈联合CTA成像采用64排128层共轭采集技术改善图像Z轴分辨率,显示细微结构的能力。资料与方法连续选取行头颈联合CTA检查的患者200例,随机分成两组。A组100例,采用128层40 mm的容积数据采集。B组100例,采用64层40 mm的容积数据采集。其他扫描参数不变。由两名有经验的影像医师以双盲法对两组图像质量进行评分,同时记录空腔、血管腔内和软组织的图像噪声值,有效剂量,计算各组数据的均值及标准差并进行统计学分析。结果 (1)两组图像质量评分分别为3.57±0.50和3.17±0.59,差异有统计学意义(t=7.40,P<0.05),A组图像质量明显优于B组。(2)A、B两组图像空腔、血管腔内和软组织的图像噪声值分别为14.21±1.37和16.48±1.62、10.43±0.57和14.06±1.03、20.79±1.01和24.26±1.79。组间差异有统计学意义(P均<0.05)。(3)两组图像的有效剂量分别是(4.02±0.58)mSv和(4.09±0.60)mSv,差异无统计学意义(t=1.18,P>0.05)。结论头颈联合CTA成像中,采用共轭采集技术,在没有增加辐射剂量的情况下,可以有效地提高Z轴分辨率,清晰地显示组织的细微结构,整体图像质量得到明显改善。

Objective To research the ability of head and neck joint CTA by using conjugate acquisition technology to improve image z-axis resolution and depict the fine structures.Materials and Methods 200 patients with head and neck joint CTA were consecutively selected in our hospital,who randomly divided them into group A and group B.Group A was of 100 patients with 40 mm volume data by using level 128.Group B was of the other 100 patients with 40 mm volume data by using level 64,other scan parameters were the same.Two experienced rdiologists evaluated the image quality with double-blind method,simultaneously recorded the image noise value of cavity,lumen and soft tissue,measured the effective dose by dose length product which was generated by the machine,calculated the mean and standard deviation,and statistical analysis was performed.Results（1）The image quality score for two groups were 3.57±0.50 and 3.17±0.59 respectively,which had statistical significance（t=7.40,P〈0.05）,image quality of group A was better than that of group B.（2）The noise value of cavity,lumen and soft tissue for group A were 14.21±1.37,10.43±0.57,and 20.79±1.01 respectively,the noise value of cavity,lumen and soft tissue for group B were 16.48±1.62,14.06±1.03,and 24.26±1.79,which had statistical significance（average P〈0.05）.（3）ED value for two sets of images were 4.02±0.58mSv and 4.09±0.60 msv respectively,which had no statistical significance（t=1.18,P〈0.05）.Conclusion On the CTA image of head and neck joint,using conjugate acquisition could significantly improve the z-axis resolution,clearly show the fine structure of the organization without increasing the radiation dose,the overall image quality can be significantly improved.