双低剂量结合能谱技术在头颈部CTA应用的可行性研究

Application of Dual-Low Dose Spectral CT in Head and Neck CTA

目的:探讨能谱CT低辐射剂量和低对比剂剂量在头颈部CT血管成像(CTA)的可行性。方法:前瞻性收集2023年6月至12月在濉溪县人民医院行头颈CTA检查的200例患者。采用随机数字表法将200例患者分为A组和B组,每组100例。A组为能谱模式的双低剂量扫描,电压80/140 kV瞬切,对比剂注射总量45 mL;B组为正常剂量下的常规CT扫描模式,电压为120 kV,对比剂注射总量为55 mL。图像质量客观评价包括最佳对比度噪声比(CNR)、平均碘摄入量、主要血管CT值;主观评价包括医师评分;并记录2组的有效辐射剂量(ED)。采用独立样本t检验比较客观数据,采用Kappa检验比较主观评分一致性。结果:A组和B组血管CT值均> 300 HU。A组主动脉弓、两侧大脑中动脉、两侧颈内动脉CT值均高于B组,差异有统计学意义(P<0.001);A组基底动脉CT值略低于B组。除主动脉弓外,B组其他血管最佳CNR、信噪比(SNR)均优于A组,差异有统计学意义(P<0.001)。医师主观评分显示2组图像质量无明显差异。A组的平均剂量和人均对比剂碘摄入量低于B组。结论:双低剂量下的头颈部能谱CTA减少了患者接受到的辐射剂量和碘对比剂用量,并且能保证图像质量,满足诊断要求。

Purpose:To investigate the effect of low radiation dose and low contrast agent dose on image quality of head and neck CT angiography(CTA).Methods:A total of 200 patients who underwent head and neck CTA in Suixi County People's Hospital from June to December 2023 were prospectively enrolled,and were divided into group A and group B using the random number table method,with 100 cases in each group.In group A,the low radiation dose was combined with low contrast agent dose scanning in spectral mode,the instantaneous cutting voltage was 80/140 kV,and the total volume of contrast agent was 45 mL.In group B,the conventional CT scanning mode was combined with normal dose,the voltage was 120 kV,and the total volume of contrast agent was 55 mL.The objective evaluation of image quality included the best contrast-to-noise ratio(CNR),average iodine intake,and CT value of main blood vessels.Subjective evaluation included physician's score.The effective radiation dose(ED)of the two groups was recorded.Independent sample t-test was used to compare objective scores,and Kappa test was used to compare subjective scores.Results:CT values of blood vessels in group A and group B were more than 300 HU.The CT values of aortic arch,bilateral middle cerebral artery and bilateral internal carotid artery in group A were higher than those in group B,and the difference was with statistical significance(P<0.001).The CT value of basilar artery in group A was slightly lower than that in group B.The average dose and iodine intake of contrast medium per capita in group A were significantly lower than those in group B.Except for the aortic arch,the best CNR and signalto-noise ratio(SNR)of the other vessels in group B were better than those in group A,and the difference was with statistical significance(P<0.001).The subjective scores of physicians showed no significant difference in image quality between the two groups.The average dose and per capita iodine intake of contrast agent in group A were lower than those in group B.Conclusion:Dual-low dose spectral head and neck CTA can ensure image quality and diagnostic confidence,and greatly reduce the impact of radiation and contrast medium on patients.