双流技术调节对比剂浓度联合迭代重建在冠状动脉成像中的应用研究

目的：探讨双流技术调节对比剂浓度联合迭代重建在低管电压冠状动脉成像中的可行性及对图像质量的影响。方法选取120例疑似冠心病患者行冠状动脉 CT 血管成像(CCTA)检查,采用随机数值表法分成 A、B 2组,30 kg/m2>体质量指数(BMI)≥25 kg/m2为A1和B1组各30例；BMI<25 kg/m2为A2和B2组各30例。A组管电压为120 kV,使用碘普罗胺(350 mg I/mL)和滤波反投影(FBP)算法重建；B组管电压为80 kV或100 kV(BMI≥25 kg/m2),使用双流技术调节对比剂浓度为245 mg I/mL 或280 mg I/mL,迭代算法(AIDR 3D)重建图像。比较同 BMI 值范围内 A、B 2亚组之间升主动脉对比噪声比(CNR)及信噪比(SNR)、胸主动脉(升主动脉、降主动脉、肺动脉)及冠状动脉(左主干、左前降支、左回旋支、右冠支)各近段强化 CT 值(SI)、噪声(SD)、主观图像质量评分及辐射剂量。结果高BMI值2亚组间图像质量得分、SD及升主动脉SNR、CNR均有统计学意义(P<0.05),血管 SI值无统计学意义(P>0.05)。低BMI值2亚组间图像质量得分均无统计学意义(P>0.05),图像噪声、血管 SI值及升主动脉SNR、CNR均有统计学意义(P<0.05)。同范围亚组之间BMI值与主动脉强化 CT 值均有显著的负相关性(r=-0.66、-0.441, P<0.05),体质量与主动脉强化CT值均无相关性(P>0.05)。各亚组之间辐射剂量差异均有统计学意义(P<0.05)。结论使用双流技术按BMI配比245 mg I/mL对比剂依然可以保证血管对比强化效果且不降低图像质量。

Application research of contrast material for coronary CT angiography by a combination of iterative reconstruction and double inj ection technology

Objective To evaluate the feasibility of contrast material on image quality of coronary CT angiography (CCTA)by using double injection technology and iterative reconstruction.Methods 120 patients with suspected coronary heart disease who underwent CCTA were randomly divided into two groups.Then,60 patients with 30 kg/m2>BMI≥25 kg/m2 were averagely divided into A1 and B1 groups,and other 60 ones with BMI<25 kg/m2 were also averagely divided into A2 and B2 groups.The patients in group A were scanned with 120 kV tube output and iolromide 350 mg I/mL,and the images were reconstructed using filtered back projection (FBP).Meanwhile,the patients in group B were scanned with 80 kV or 100 kV tube output and 245 mg I/mL or 280 mg I/mL of contrast media (BMI≥25 kg/m2 )using double injection technology,and the images were reconstructed using adaptive iterative dose reduction 3D (AIDR 3D).The effective radiation dose (ED)of each patient was also calculated.CT attenuation of the main proximal vessels (ascending or descending aorta,pulmonary artery,RCA,LM,LAD and LCX)and the obj ective image quality (SD,CNR and SNR)were measured,and the subj ective evaluation was also assessed by an experienced radiologist.Results There was significant differences in mean image quality scores,SD,SNR and CNR of ascending aorta between group A1 and B1(P<0.05),but no difference in the SI of values (P>0.05).There was no significant difference in mean image quality scores between group A2 and B2 (P>0.05), however,there were significant differences in the SI,SD of values and SNR,CNR of ascending aorta (P<0.05).The values of BMI were negatively related to the values of CT in ascending aorta between two subgroups (r=-0.66 and -0.441,P<0.05).The values of weight were not related to the values of CT in ascending aorta (P>0.05).There was significant difference in effective dose between subgroups (P<0.05).Conclusion The method with a combination of iterative reconstruction and a contrast material of 245 mg I/mL using double inj ection technology can improve the contrast enhancement without impairing image quality.