双源CT低管电压、大螺距头颈部CT血管成像图像质量及辐射剂量的临床研究OA

Objective To evaluate the image quality and effective radiation dose(ED)of third-generation dual-source computed tomography(CT)using low tube voltage and large-pitch scanning mode(Turbo Flash)in head and neck CT angiogra-phy(CTA).Methods A total of 150 patients with suspected vascular diseases underwent head and neck CTA at our hospital be-tween June 2024 and March 2025 were enrolled and divided into three groups by random number table method.Group A underwent conventional scanning at 110 kVp.group B underwent dual-energy scanning(90 kV/Sn 150 kV).group C underwent large-pitch scanning at 80 kVp.The volume of contrast medium was 70 ml for group A and group B,and 50 ml for group C.The CT attenuation values and image noise(SD)of the lumen were measured at the aortic arch,bilateral carotid artery bifurcations,internal carotid ar-tery origins,and proximal middle cerebral arteries.The signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),subjective im-age quality scores,and effective dose(ED)were compared among the three groups.One-way ANOVA or non-parametric Kruskal-Wallis tests were used to calculate intergroup differences for quantitative metrics.Cohen's Kappa test was adopted to evalu-ate the consistency of subjective quality scores between two readers.Results The CT values of target vessels in groups B and C were significantly higher than those in group A(P＜0.05).The CT values in all three groups exceeded 350 HU,meeting diagnos-tic requirements.Statistically significant differences(P＜0.05)were observed among the three groups for SNR and CNR in the aortic arch,bilateral carotid arteries,and internal carotid arteries,as well as for CNR in the bilateral middle cerebral arteries.No significant difference was found for SNR in the middle cerebral arteries(P＞0.05).The mean subjective image quality scores were(3.62±0.60),(3.48±0.61),and(3.50±0.70)for groups A,B,and C,respectively,with no statistically significant difference(P＞0.05).Inter-reader agreement for image evaluation was excellent(Kappa=0.782,P＜0.05).The effective radiation doses were(1.22±0.14)mSv,(0.74±0.08)mSv,and(0.23±0.04)mSv for groups A,B,and C,respectively,demonstrating statis-tically significant differences(P＜0.05).Group C used 20 ml less contrast medium than groups A and B.Conclusion Head and neck CTA with low tube voltage and large-pitch scanning reduces patient radiation exposure and contrast medium volume while maintaining diagnostic image quality,demonstrating its clinical feasibility.