kV assist技术联合自动管电流调制技术及ASIR重组算法在头颈CTA成像的可行性研究

Feasibility Study of Head and Neck CT Angiography Using KV assist Combined with Auto Modulation Tube Current Technique and ASIR Reconstruction Algorithm

目的探讨k V assist技术联合自动管电流调制技术及自适应迭代重组（ASIR）算法在降低头颈CT血管成像（CTA）检查辐射剂量的可行性。方法将临床疑诊头颈动脉病变而行头颈CTA检查的60例患者随机分为两组,A组（30例）,采用常规扫描方案：管电压100 k Vp,350 m A,30%ASIR;B组（30例）,采用k V assist技术联合自动管电流调制技术,50%ASIR;两组对比剂均为碘克沙醇（270 mg I/ml）。采用两独立样本t检验（非正态分布采用Mann-Whitney U检验）来比较两组的临床资料、CT辐射剂量以及图像质量主、客观评价指标。结果 A、B两组患者的性别、年龄、身高、体重和身体质量指数（BMI）的差异均无统计学意义（P〉0.05）。两组的CT有效辐射剂量（ED）差异具有显著统计学意义（P〈0.05）,B组[（1.18±0.26）m Sv]较A组[（2.50±0.96）m Sv]减少约52.8%。两组图像主观评分的差异无统计学意义（P〉0.05）。图像的客观评价：两组头颈动脉主干及其主要分支的CT值均〉300 HU,噪声、信噪比（SNR）、对比噪声比（CNR）差异有统计学意义（P=0.000）,B组低于A组。结论 k V assist技术联合自动管电流调制技术及ASIR重组算法行头颈CTA检查,在保证图像质量的同时,可以有效减低辐射剂量。

Objective To explore the feasibility of head and neck CT angiography using KV assist combined with auto modulation tube current technique and ASIR reconstruction algorithm in reducing the radiation dose.Methods 60 patients with clinically suspected head and neck arterial lesions and underwent head and neck CT angiography were divided into two groups（group A and B）.Group A（n = 30 cases） applied with 100 k Vp,350 m A and 30% ASIR.Group B（n = 30 cases） applied KV assist combined with auto modulation tube current technique and 50% ASIR.Iodixanol（270 mg I/ml）was used in two groups as contrast medium.The clinical information,CT radiation dose,objective and subjective assessment of image quality between two groups were retrospectively analyzed by independent test or Mann-Whitney U test.Results The difference of sex,age,height,weight and body mass index（BMI） of two groups were not statistically significant（P〉0.05）.The difference of radiation dose between two groups was statistically significant（P〈0.05）.ED of group B was less than that group A by around 52.8%.The difference of CT subjective assessment score of image quality in two groups was not statistically significant（P〉0.05）.The average CT values of the carotid artery trunk and its major branches in two groups were higher than 300 HU（P〉0.05）.There is statistical difference between two groups in SD,SNR and CNR（P =0.000）.Group B was lower than that of group A.Conclusion On the premise of obtaining good quality of image for diagnosis,k V assist combined with auto modulation tube current technique and ASIR reconstruction algorithmin head and neck CT angiography will reduce radiation dose effectively.