Application of adaptive iterative dose reduction 3D and automatic tube potential selection in low-dose CT angiography of craniocervical arteries

ZHANG Li; XU Yan-feng; ZHENG Jing; YU Shu-jing; CHEN Yue-feng; CHE Yan-xu

Abstract：Objective To assess the effect of adaptive iterative dose reduction 3D( AIDR3D) on image quality and radiation dosage in CT angiography of craniocervical arteries.Methods 80 patients who underwent the head and neck CTA examination were divided into Group A and Group B at random.Each group included 40 patients.The patients in group A were scanned using 120 kV, 300 mA, and images were reconstructed using conventional FBP.The other group of patients were scanned using 100 kV, with Auto-mA technology and reconstructed using AIDR3D.All of the images were evaluated on image quality and radiation dose.Results 1) Objective evaluation:The noise level of group B was significant lower than group A in the common carotid ar-tery ( P <0.05), but higher in carotid sinus and internal carotid artery ( P <0.05).Neck artery SNR and CNR of group B were significant higher than group A ( P <0.05).In the evaluation of intracranial arteries(MCA1), the noise level of group A was lower than group B ( P <0.05),but there was no statistical difference in SNR and CNR between the two groups ( P >0.05);2) Subjective evaluation:the image quality score of common carotid artery in group B was higher than group A ( P <0.05), but there was no difference in image quality scoring of carotid sinus and internal carotid artery ( P >0.05).The score of group B was lower than group A in image quality of intracranial artery, but the quality of all the images could meet the require-ments of clinical diagnosis;3) Compared with group A, radiation dose in group B was reduced by 71%.There was significant difference ( P <0.05).Conclusion For CT angiography of craniocervical arteries, AIRD3D reconstruction along with 100 kV and auto-mA modulation produces diagnostic quality images while substantially reducing radiation dose.