64排螺旋CT颈部血管成像低电压扫描初步研究

目的 探讨低管电压(100kV)扫描在颈部CT血管成像(CTA)的临床应用可行性.方法 将55名临床需要做颈部CTA检查的患者(其中男37例,女18例,平均54岁)按随机分配原则编入A、B两组(A组27例,B组28例),分别采用管电压100及120kV,管电流均采用150mAs.比较两组的CT图像质量(包括动脉平均强化...

Study of 64 slice detector carotid CT angiography with low tube voltage

Objective To evaluate the clinical application of carotid CT angiography using a low tube voltage （100kV）. Methods 55 patients requiring carotid CT angiography were randomly assigned to one of the two protocol groups： protocol A（27/55, scanning with 100kV and 150mAs）; protocol B （28/55, scanning with 120kV and 150mAs）. CT image quality including the signal intensity （SI）, signal-to-noise ratio （SNR）, contrast-to-noise ratio （CNR） and the radiation doses （CTDIvol and DLP） were compared between two groups. Kruskal-Wallis test was used for statistical analysis. Results The mean image noise value with protocol A （14.4 HU） was slightly higher （P 〈 0.0001） than that with protocol B （11.5 HU）. The SNR with protocol A was slightly lower than that with protocol B. The mean SI and CNR revealed no significant difference between the two groups （SI： 303.6HU vs 301.7HU,P= 0.873; CNR： 17.8 vs 22.0,P= 0.142）. Image qualitative analysis revealed no significant difference between the two groups. Compared with protocol B, the CTDIvol, DLP and ED of protocol A reduced by 33% （14 mGy vs 22 mGy）, 38% （417mGy-cm vs 669 mGy-cm）, 37% （2.25mSv vs 3.61 mSv） respectively. Conclusion Carotid CT angiography with 100kV in 64 Multi-detector CT can reduce radiation dose and get a good image quality.