Application of low tube current combined with lower contrast agent in the head and neck dual-source CT angiography / 中华老年医学杂志

ABSTRACT

Objective To investigate the application value of low kilovolt technique combined with lower contrast in the head and neck angiography by the second-generation dual source CT.Methods From October 2013 to January 2015,120 patients undergoing head and neck computed tomography angiography (CTA) were randomly divided into groups A,B,C,D.Each group was given a different tube current and different dose of contrast agent and saline solution 50 ml.Group A received current 100 mA and contrast agent 50 ml,group B received current 100 mA and contrast agent 40 ml,group C received current 80 mA and contrast agent 50 ml,and group D received current 80 mA and contrast agent 40 ml.CT values of aortic arch,bilateral common carotid artery bifurcation,double sided M1 segment of middle cerebral artery,basilar artery enhanced degree of the straight sinus were measured in each group.Residual artifacts caused by contrast agent in brachiocephalic vein and subclavian vein were observed.5-score method was used to assess the quality of reconstructed image,and the radiation exposure dose was calculated.Results The mean effective dose was reduced by 29％ in group C as compared with group A [(0.53±0.17) mGy vs.(0.74±0.04) mGy].There was no significant difference in developing strength in cerebral arteries angiography between group C and group A (P=0.247),but the inage noise was slightly larger in group C than group A,without significant differences (P=0.203).The average effective dose in group A was almost the same as that in group B [(0.74 ± 0.04) mGy vs.(0.73 ± 0.05) mGy].Structure display of cerebral arteries on CT volume rendering (VR) and multiplane reformation (MPR) images had no significant differences between group A and group B (P=0.114).The average effective dose in group C was almost the same as that in group D[(0.53 ± 0.17) mGy vs.(0.53 ±0.01) mGy].Structure display of cerebral arteries on CT volume rendering (VR) and muhiplane reformation (MPR) images had no significant differences between group C and group D (P=0.109).The mean effective dose was reduced by 28％ in group D as compared with group B[(0.53±0.01)mGy vs.(0.73±0.05) mGy].There was no significant difference in developing strength in cerebral arteries angiography between group C and group A (P=0.236),but the image noise was sligbtly larger in group C than group A (P =0.212).Conclusions Application of low tube current combined with low concentration of contrast agent in the head and neck dual-source CT angiography is feasible in clinical diagnosis,with good clinical value.It can not only get better image quality,but also meet the needs of clinical diagnosis.