目的 探讨优化低剂量CTA方案 在小儿先天性心脏病(CHD)术前检查的临 床价值。方法 CHD患儿139例(年龄1天-6 岁)，根据患儿就诊时间分别采用前门控 和高级混合迭代重建技术(iDose4)、前门 控和滤波反投影重建(FBP)、非门控和FBP 进行CTA检查。采用方差分析及Post-Hoc 双样本T检验对每组患儿有效射线辐射剂 量及图像质量进行对比分析；并以手术 结果为诊断标准，采用CTA诊断结果与超 声心动图(UCG)诊断结果进行符合一致性 分析。结果 1.有效射线辐射剂量：前门 控iDose4组较前门控FBP组降低13.8%、 前门控iDose4组较非门控FBP组降低 23.5%(P＜0.05)。2.图像质量评估：前门 控iDose4 组、前门控FBP组、非门控FBP 组分别为：Ⅲ级36、57、12例；Ⅱ级0、 25、8例，(χ2=15,.879，P<0.05)。3.经 手术治疗的CHD患儿(n=102)，术前CTA、 UCG诊断结果与手术结果对比：CTA总诊 断符合率94.5%(P<0.001)，UCG诊断符合 率90.4%(P<0.001)。结论 低剂量前门控 iDose4 CTA技术在小儿CHD的术前应用具 有重要临床意义。

Objective Evaluate the preoperative clinical value of optimized low-doses CTA examination in children with congenital heart disease (CHD). Methods 139 children with CHD(aged 1 day-6 years) were included in this study, CTA examinations based on 3 different techniques including the front door and high-level mixed iterative reconstruction technique (iDose4), the front door and filter back projection reconstruction place place (FBP) and gate control and FBP were carried out on these children according to the patient's clinical visiting time. Statistical analysis including the analysis of variance and Post Hoc-two sample T test were performed to compare the effective radiation dose and image quality. The results of surgery were taken as the diagnostic criteria, and consistency analysis were used to evaluate the CTA diagnosis and echocardiography (UCG) diagnosis respectively. Results 1.Results on effective radiation dose: the front door iDose4 control group was 13.8% lower than the front door place control FBP group, the front control iDose4 place was 23.5% lower than a non-gate control FBP group (P<0.05).2. Results on image quality assessment: the front door place controlled iDose4 group, the front door FBP group place, non-gate control FBP respectively: Ⅲ level 36, 57, 12 cases, ⅡLevel 0, 25, 8 cases (χ2 =15, 879, P<0.05).3. Results on the consistency with surgical results: 102 children were carried out the surgical treatments, consistencies of preoperative CTA and UCG diagnosis were as follows: CTA total diagnostic coincidence rate 94.5% (P<0.001), the UCG diagnosis coincidence rate 90.4% (P<0.001). Conclusion Low doses of front door control iDose4 CTA technology has important preoperative clinical significance in children with CHD.