低管电压结合个性化对比剂用量及迭代重建在支气管动脉成像中的应用

Application of Low Tube Voltage Combined with Individualized Contrast Medium Dosage and Iterative Reconstruction in Bronchial Artery Imaging

目的探讨低管电压结合个性化对比剂用量剂及迭代重建在支气管动脉成像中的应用。方法前瞻性将体质量指数<24 kg/m^(2)的60名咯血患者行支气管动脉CT血管造影(Computed Tomography Angiography,CTA)检查,采用随机数字表法分为两个小组(A组、B组),每组各30例。A组管电压120 kV,对比剂用量80 mL;B组管电压80 kV,个性化对比剂用量为1.0 mL/kg×体重(kg);A组和B组分别采用滤波反投影(Filtered Back Projection,FBP)重建及50%ASIR重建,其余扫描参数相同。比较两组图像质量主观评分、客观评价[主动脉CT值、上腔静脉CT值、噪声、信噪比(Signal To Noise Ratio,SNR)、对比噪声比(Contrast to Noise Ratio,CNR)]、辐射剂量[容积CT剂量指数(Volume CT Dose Index,CTDIvol)、剂量长度乘积(Dose Length Product,DLP)和有效剂量(Effective Dose,ED)]及碘摄入量差异。结果两组图像质量主观评分一致性很好,差异无统计学意义(P>0.05)。A组、B组主动脉CT值分别为(342.58±48.93)、(422.20±62.67)HU,差异有统计学意义(P<0.001);A组、B组上腔静脉CT值分别为(213.67±39.68)、(134.05±33.14)HU,差异有统计学意义(P<0.001);两组SNR、CNR差异有统计学意义(P<0.001)。A组、B组的ED分别为(7.61±0.81)、(3.81±0.51)mSv,差异有统计学意义(P<0.001);A组、B组碘摄入量分别为(24.00±0)、(18.06±1.64)gl,差异有统计学意义(P<0.001)。结论采用80 kV低管电压结合个性化对比剂用量及迭代重建行支气管动脉CTA检查可以提升图像质量,同时显著降低辐射剂量和碘摄入量,最大限度地降低患者对比剂肾病的发生概率。

Objective To explore the application of low tube voltage combined with individualized contrast medium dosage and iterative reconstruction in bronchial artery imaging.Methods The bronchial artery CTA examination was prospectively performed on 60 patients with hemoptysis whose body mass index was<24 kg/m^(2),and they were divided into two groups(group A and Group B)by random number table method,with 30 patients in each group.The tube voltage of group A is 120 kV and the dosage of contrast medium is 80 mL;The tube voltage of group B is 80 kV,and the dosage of personalized contrast medium is 1.0 mL/kg×body weight(kg).In group A and Group B,filtered back projection(FBP)reconstruction and 50%ASIR reconstruction were used respectively,and the other scanning parameters were the same.Subjective scores and objective evaluations[aortic CT value,superior vena cava CT value,noise,signal to noise ratio(SNR)and contrast to noise ratio(CNR)],radiation dose[volume CT dose index(CTDIvol),dose length product(DLP)and effective dose(ED)]and iodine intake were compared between the two groups.Results Subjective scores of the image quality of the two groups was very good,and the difference was not statistically significant(P>0.05).The CT values of aorta in group A and Group B were(342.58±48.93)HU and(422.20±62.67)HU,respectively,with statistically significant differences(P<0.001);CT value of superior vena cava in group A and Group B was(213.67±39.68)HU and(134.05±33.14)HU,respectively,with statistically significant difference(P<0.001).The differences in SNR and CNR of the two groups were statistically significant(P<0.001).The effective dose ED of group A and group B were(7.61±0.81)mSv and(3.81±0.51)mSv,the difference was statistically significant(P<0.001);the iodine intake of group A and group B the amounts were(24.00±0)gl and(18.06±1.64)gl.The difference was statistically significant(P<0.001).Conclusion Using 80 kV low tube voltage combined with individual contrast dosage and iterative reconstruction for bronchial artery CTA examination can improve image quality,significantly reduce radiation dose and iodine intake,and minimize the incidence of contrast nephropathy in patients.