低浓度对比剂在冠状动脉CTA检查中的可行性研究

目的：探讨低浓度碘对比剂（270 mgI/mL）配合低管电压在冠状动脉CTA检查中的可行性。材料与方法：将90例行冠状动脉CTA检查的患者随机分为A组和B组。A组60例应用270 mgI/mL碘对比剂同时使用迭代算法重建，再将A组根据体质量指数（BMI）分为A1组（25例）及A2组（35例），A1组（BMI〈24 kg/m2）管电压为80 kV，A2组（BMI≥24 kg/m2）管电压为100 kV；B组30例应用370 mgI/mL碘对比剂，120 kV管电压。两组均采用前瞻性心电门控扫描。记录扫描辐射剂量，并对图像质量进行主、客观分析。结果：平均有效辐射剂量（ED）A1组为（2.00±0.56） mSv，A2组为（2.35±0.74） mSv，B组为（3.98±1.78） mSv，A1组与B组间及A2组与B组间均有统计学差异（t值分别为-5.34和-4.95，P〈0.05）。图像质量方面，A1组与B组间及A2组与B组间主观评价优秀率无统计学差异（χ2值分别为1.10和2.04，P值均〉0.05）；客观评价图像噪声（SD）、信噪比（SNR）、对比噪声比（CNR）亦均无统计学差异。结论：应用尽可能低浓度的碘对比剂（270 mgI/mL）配合低管电压在冠状动脉CTA检查中是可行的，超重人群（BMI≥24 kg/m2）亦可应用，同时显著的降低了辐射剂量和碘注射量。

Feasibility of low concentration contrast medium in coronary CT angiography

Objective： To explore the feasibility of using low concentration contrast medium（270 mgI/mL） with the low tube voltage in coronary artery CTA. Materials and Methods： Ninty patients with coronary CTA examination were divided into group A and group B randomly. Group A （n=60） used contrast medium of 270 mgI/mL with sinogram-affirmed iterative reconstruction（SAFIRE）. Group A was further divided into group Al（n=25） and A2（n=35） according to body mass index（BMI）. Group Al（BMI〈24 kg/m2） 80 kV was used for scanning, group A2（BMI≥24 kg/m2） 100 kV. The concentration of contrast medium and the tube voltage of group B （n=30） were 370 mgI/mL and 120 kV. All groups were scanned in prospective ECG-trigger gated. Radiation dose was recorded and image quality was analysed subjectively and objectively. Results： The effective dose （ED） of group A1, A2 and B were （2.00±0.56）mSv, （2.35±0.74）mSv and （3.98±1.78）mSv respectively, between group A1 and B, group A2 and B there were statistically significant（t=-5.34 and -4.95, P〈0.05）. In image quality, there were no statistical differences between each groups in the excellent rate （x2=l.10 and 2.04, P〉0.05）. The SD, SNR and CNR of images also showed no sta- tistical differences by objectively evaluated. Conclusion： Using low concentration contrast medium （270 mgI/mL） with low tube voltage in coronary artery CTA is feasible, especially in overweight（BMI≥24 kg/m2） population. At the same time, the radiation dose and concentration of iodine injection are reduced significantly.