可变螺距技术对头颈部CT血管造影辐射剂量及图像质量影响  

Impact of variable helical pitch technique on radiation dose and image quality of head and neck CT angiography

作　　者：张进慧 裴锦奎 唐启瑛 徐如林 刘豪 周建军 ZHANG Jinhui;PEI Jinkui;TANG Qiying;XU Rulin;LIU Hao;ZHOU Jianjun(Department of Radiology,Zhongshan Hospital,Fudan University,Xiamen 361015,China;Department of CT Scientific Research Collaboration,Canon Medical SystemsCo.,LTD,Guangzhou 510623,China;Department of Radiology,Zhongshan Hospital,Fudan University,Shanghai 200032,China)

机构地区：[1]复旦大学附属中山医院厦门医院放射科,福建厦门361015 [2]佳能医疗系统(中国)有限公司CT科研合作部,广东广州510623 [3]复旦大学附属中山医院放射科,上海200032

出　　处：《中国医学影像技术》2022年第12期1872-1876,共5页Chinese Journal of Medical Imaging Technology

摘　　要：目的探讨可变螺距(vHP)技术对头颈部CT血管造影(CTA)辐射剂量及图像质量的影响。方法纳入120例接受头颈部CTA检查的患者,并随机分为3组,每组40例。各组以不同参数进行扫描,A组采用常规螺旋扫描,头颈部噪声指数(NI)=5;B组采用vHP技术,头部NI=5,颈部NI=10;C组采用vHP技术,头部NI=5,颈部NI=15;其余扫描参数一致。比较组间辐射剂量及主、客观图像质量评价结果差异。结果B、C组CT容积剂量指数、剂量长度乘积及有效剂量均低于A组(P均<0.01),且C组低于B组(P均<0.01)。3组CTA图像中主动脉弓及颈总动脉分叉噪声(SD)、信噪比(SNR)及对比噪声比(CNR)差异均有统计学意义(P均<0.05),其中A组SD值最低、而SNR及CNR最高,C组SD值最高、而SNR及CNR最低,B组各值均位于A、C组中间。3组大脑中动脉M1段CT值、SD值、SNR及CNR差异均无统计学意义(P均>0.05)。3组头颈CTA各重建图像均可满足诊断需求,主观评分差异无统计学意义(P=0.241)。结论vHP技术可在保证图像质量的情况下显著降低头颈部CTA检查辐射剂量。Objective To observe the impact of variable helical pitch(vHP)technique on radiation dose and image quality of head and neck CT angiography(CTA).Methods Totally 120 patients who underwent head and neck CTA were divided into 3 groups randomly,each consisting of 40 cases.Each group was scanned with various parameters:Group A underwent the conventional helical scan with noise index(NI)of 5 in head and neck;group B used vHP technique with NI of 5 in head and 10 in neck;and group C with NI of 5 in head and 15 in neck.Other scan parameters in each group were consistent.The results of the subjective and objective image quality evaluations and the radiation dose were compared between the groups.Results The volume CT dose index,dose length product and effective dose in groups B and C were lower than those in group A(all P<0.01),and those in group C were lower than those in group B(both P<0.01).There were significant differences in the noise(SD),signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)of the aortic arch and common carotid artery bifurcation among 3 groups(all P<0.05).Group A had the lowest SD value and the highest SNR nor CNR,while group C had the highest SD value and the lowest SNR and CNR,and the values in group B falls in the middle of groups A and C.There was no significant differences in CT value,SD value,SNR and CNR of the M1 segment of the middle cerebral artery in 3 groups(all P>0.05).All of the head and neck CTA reconstructed images in 3 groups could meet diagnostic requirements,and there was no significant different in subjective ratings(P=0.241).Conclusion vHP technique could significantly reduced effective radiation dose while maintaining the image quality.

关 键 词：头颈部 CT血管造影术 螺距 管电流 

分 类 号：R543.5[医药卫生—心血管疾病] R816.2[医药卫生—内科学]