低管电压-低碘量技术在冠状动脉CTA中的应用

Application of low tube voltage combined with low dosage of iodine in coronary CT angiography

目的探讨低电压-低碘量扫描方案在冠状动脉CTA(CCTA)中的应用价值。方法纳入90例接受CCTA检查、体质量指数<24kg/m2的患者,随机将其分均为3组:A组管电压120kVp,碘注射总量0.259kg;B组管电压100kVp,碘注射总量0.210kg;C组管电压100kVp,碘注射总量0.150kg。采用前瞻性心电门控触发扫描,管电流200mAs。比较各组图像质量、容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)和有效剂量(ED)的差异。结果 3组CCTA图像质量评分差异无统计学意义(P>0.05);B组图像SNR(17.77±3.90)高于A组(15.79±2.02)和C组(14.63±3.07),差异均有统计学意义(P均<0.05),A组与C组间差异无统计学意义(P>0.05)。CTDIvol、DLP和ED B组[(9.49±0.21)mGy、(121.30±6.12)mGy和(1.70±0.86)mSv]与C组[(9.51±0.22)mGy、(119.64±7.35)mGy和(1.68±0.10)mSv]间差异无统计学意义(P>0.05),均显著低于A组[(23.35±13.74)mGy、(253.53±8.62)mGy和(3.55±0.12)mSv;P均<0.05]。结论采用低电压-低碘量扫描方案进行CCTA可显著降低碘注射总量及辐射剂量,获得较好的图像质量,有重要临床应用价值。

Objective To observe the application value of low tube voltage combined with low dosage of iodine in coronary CT angiography （CCTA）. Method Totally 90 patients whose body mass index ~24 kg/m2 were enrolled and underwent prospective ECG-gating scanning with tube current of 200 mAs. The patients were randomly and equally divided into group A （tube voltage 120 kVp, iodine dosage 0. 259 kg）, B （tube voltage 100 kVp, iodine dosage 0. 210 kg） and C （tube voltage 100 kVp, iodine dosage 0. 150 kg）. The image quality, CT dose index of volume （CTDIvol）, the dose length product （DLP） and effective dose （ED） were calculated and compared among 3 groups. Result No significant difference of image quality was found among 3 groups （P〉0.05）. SNR in group B was 17.77±3.90, significantly higher than that in group A （15.79±2.02） and group C （14.63±3.07）, and no significant difference was found between group A and C. CTDIvol, DLP, EDwas （9.49±0.21）mGy, （121.30±6.12）mGy, （1.70 ± 0. 86 ） mSv in group B and （9.51 ± 0. 22） mGy, （119.64±7.35）mGy, （1. 68±0.10）mSv in group C （P〉0. 05）, respectively, all significantly lower than those in group A （[23.35±13.74]mGy, [253.53±8.62]mGy, [3.55±0.12]mSv, all P〈0. 05）. Conclusion CCTA with low tube voltage combined with low dosage iodine can effectively reduce the iodine and radiation dose with pretty good image quality, therefore having great clinical application value.