光子探测器双源CT70kV联合低对比剂在冠状动脉CTA中的应用

目的：探讨 Stellar 光子探测器双源 CT 70 kV 管电压联合30 mL 低对比剂前瞻性大螺距扫描在冠状动脉 CTA 中的应用价值。方法60例体质量指数(BMI<24.9 kg/m2)正常行冠状动脉 CTA 检查者,随机分为2组(A 组：管电压70 kV、对比剂30 mL；B组：管电压100 kV、对比剂50 mL),每组30例,2组均采用 Stellar 光子探测器双源 CT 前瞻性大螺距螺旋式扫描技术进行扫描。A组采用 SAFIRE 迭代重建技术,B 组采用滤过反投影(FBP)技术重建；客观评价包括测量 CT 值、计算信号噪声比(SNR)、对比噪声比(CNR)及记录有效辐射剂量(ED),并用4分法对图像质量评分。组间对比采用独立样本 t 检验。结果冠状动脉图像质量评分分别为(3.38±0.942)分、(3.50±0.682)分,组间差异无统计学意义(t =-0.562,P >0.05)；A 组患者冠状动脉各节段 CT 值高于B 组(P 均<0.01),2组间 SNR、CNR 差异无统计学意义(P >0.05)。A 组患者辐射剂量为(0.19±0.023)mSv ,B 组患者辐射剂量为(0.81±0.101)mSv,A 组较 B 组下降76.5%,差异有统计学意义(P <0.01)。结论光子探测器双源 CT 70 kV 管电压联合30 mL低对比剂在正常 BMI 患者冠状动脉 CTA 检查中,在获取满足诊断要求图像质量的同时显著降低 ED 及对比剂用量。

Application of 70 kV with 30 mL contrast medium by dual-source CT with Stellar photon detector in coronary angiography

Objective To investigate the value of prospectively electrocardiogram (ECG)-triggered high-pitch coronary computed tomography angiography at 70 kV and 30 mL contrast medium with Stellar detector dual-source CT.Methods 60 patients with the BMI<24.9 kg/m2 were randomized into two groups:Group A (30 cases)with the tube voltage of 70 kV and 30 mL contrast medi-um.Group B (30 cases)with the tube voltage of 100 kV and 50 mL contrast medium.All the patients were performed with a Stellar detector dual-source CT using a prospectively ECG triggered high-pitch spiral technique.The images of Group A were reconstructed with SAFIRE technique,while Group B were with FBP technique.The objective image quality includes CT attenuation,SNR, CNR.And radiation dose was also calculated.The subjective was evaluated by 4-scale point.Independent sample t test was used.Re-sults There was no difference for subjective image quality between the groups,A:(3.38±0.942),B:(3.50±0.682),(t=-0.562, P >0.05).The CT attenuation of the 70 kV group were higher than that of the 100 kV group for all the segments(P <0.01).The SNR and the CNR have no statistically significant difference between the groups (P >0.05).Compared with the 100 kV group,the radiation dose of the 70 kV group was reduced by 76.5% (A:0.19±0.023 mSv,B:0.81±0.101 mSv,P <0.01).Conclusion Using 70 kV with 30 mL contrast medium in Stellar detector dual-source CT coronary angiography for the patients with a normal BMI could obtain qualified diagnostic image with low radiation dose and contrast medium.