低管电压结合自动毫安技术对降低头颈部数字减影CTA辐射剂量的可行性研究  

Low tube voltage combined with automatic tube current modulation technique for digital subtraction CT angiography of head and neck:a feasibility study

作　　者：华海琴[1] 康德强[2] 徐晓娟[3] 赵晶[1] 彭楠[1] 王玲璞[1] 李超[1] 刘冰[1] 刘明[1] 王志群[1] 

机构地区：[1]北京中医药大学东方医院放射科,北京100078 [2]北京大学北大国际医院放射科,北京102206 [3]北京师范大学医院,北京100087

出　　处：《放射学实践》2016年第8期781-785,共5页Radiologic Practice

摘　　要：目的：探讨低管电压结合自动毫安调制技术降低头颈部数字减影CT血管成像（DscTA）辐射剂量的可行性。方法：将36例患者分为3组进行头颈部DSCTA检查。A组：平扫管电压80kV，增强扫描管电压120kV，管电流固定为400ITIA；B组：平扫管电压80kV、增强扫描管电压120kV，使用管电流调制技术，实际管电流为150～400rnA；C组：平扫管电压80kV、增强扫描管电压100kV，使用管电流调制技术，范围为150～400mA。记录3组的辐射剂量，包括容积CT剂量指数（CTDIv01）、剂量长度乘积（DLP）及有效吸收剂量。对图像质量进行客观及主观分析，客观分析包括测量颈总动脉分叉部及基底动脉中段的cT值、信噪比，主观分析包括对血管进行容积再现、最大密度投影、曲面重组并结合横轴面图像进行评分。结果：三组间cTDlvol、DLP及ED的差异均具有统计学意义（P〉0．05），且各指标值均为A组〉B组〉C组。对DSCTA图像质量的客观评价结果显示，三组间双侧颈总动脉及基底动脉的强化值、图像噪声及信噪比的差异均无统计学意义（P〉0．05）。三组图像质量的主观评分比较，差异无统计学意义（P〉0．05）。结论：采用低管电压蒙片结合自动毫安技术能明显降低头颈部DSCTA检查的辐射剂量，并能保证图像质量。Objective： To explore the feasibility of low tube voltage combined with automatic tube current modulation （ATCM） technique in the examination of head and neck digital subtraction CT angiography （DSCTA）. Methods： A total of 36 patients were randomly and equally divided into three groups to undergo DSCTA of head and neck using three scan pro- tocols ： in group A, 80kV for plain scan and 120kV for contrast enhanced （CE） scan, tube current was 400mA; in group B, 80kV for plain scan and 120kV for CE sean,ATCM technique was used with actual tube current of 150~400mA;in group C： 80kV for plain scan and 100kV for CE scan,ATCM technique was used with actual tube current of 150〉400mA. The ra- diation dose in the three groups was calculated and compared. Both objective and subjective analysis of image quality were made. The objective evaluation included CT value of common carotid artery and basilar artery, the background noise and sig- nal-to-noise ratio （SNR）. The subiective analysis included assessing the image quality by volume rendering （VR） ,maximum intensity projection （MIP）,curve planar reconstruction （CPR） and axial images. Results：There were significant differences of radiation dosage including CTDIvoI,DLP and ED among the three groups, which presented as group A〉group B〉group C. No significant differences in enhanced CT value of the cervical and basil arteries,noise and signal noise ratio were found among the three groups （P〉0.05）. There were no significant differences of visualization scores among the three groups. Conclusion：By combination of super lower KV mask and low KV,ATCM technique in the examination of head and neck DSCTA can significantly reduced the radiation dosage and guarantee the imaging quality for diagnostic purpose.

关 键 词：颈动脉 体层摄影术 x线计算机 血管成像 低剂量 

分 类 号：R816.1[医药卫生—放射医学]