目的探讨双低冠状动脉CT血管 造影术(CCTA)在经皮冠状动脉介入治疗 (PCI)术后随访中的临床应用价值。方 法 选取行PCI的128例(143枚可评估支架) 冠心病患者为研究对象，均予以常规冠 状动脉造影(CAG)检查；根据随机数字表 法将受试患者分为A、B两组，各64例； A组患者接受双低CCTA检查(100kv电压 +270mgI/mL碘对比剂)，B组接受常规CCTA 检查(120kv电压+350mgI/mL碘对比剂)。 详细记录检查结果，以CAG为“金标准” 评估双低CCTA检查对支架再狭窄(ISR)的 特异性、敏感性、准确性差异；记录双低 CCTA检查及常规CCTA检查方案图像质量主 观评分、辐射剂量(ED)、碘用量差异。 结果 ①此次受试的A组患者72枚可评估 支架中经CAG诊断为ISR共9枚(12.5%)， 非ISR共63枚(87.5%)；其中双低CCTA正 确诊断ISR8枚，正确诊断非ISR57枚， 对ISR诊断的准确性、特异性、敏感性 分别为90.3%(65/72)、90.5%(57/63)和 88.9%(8/9)；②双低CCTA及常规CCTA检查 在图像质量主观评分对比上均无统计学意 义(P>0.05)；双低CCTA检查ED及碘用量 均显著低于常规CCTA检查，差异具有统计 学意义(P<0.05)。结论 双低CCTA检查可 作为PCI患者术后随访复诊的首选检查方 案，对ISR诊断准确性较高，具有图像清 晰、碘摄入量少、辐射剂量低等优势，值 得临床推广。

Objective To investigate the clinical application value of double low coronary CT angiography (CCTA) in the follow-up after percutaneous coronary intervention (PCI). Methods 128 patients (143 measurable stents) with coronary heart disease who underwent PCI were selected as the research subjects. All the patients were given cinventional coronary arteriography (CAG) examination. According to the random number table method, the objects were divided into A, B of two groups with 64 cases in each group. Group A received double low CCTA examination (100kv voltage and 270mgI/mL iodinated contrast agent) while group B received routine CCTA examination (120kv voltage and 350mgI/mL iodinated contrast agent). The results were recorded in detail. CAG was taken as the golden standard to evaluate the specificity, sensitivity and accuracy differences of the double low CCTA in the examination of in-stent restenosis (ISR). The differences in subjective score of image quality, the radiation dose (ED) and the dosage of iodide between double low CCTA and routine CCTA were recorded. Results ①Among the 72 measurable stents in group A, there were 9 stents (12.5%) with ISR and 63 stents (87.5%) without diagnosed by CAG. 8 stents with ISR and 57 cases without were correctly diagnosed by double low CCTA. The accuracy, specificity and sensitivity in the diagnosis of ISR were 90.3% (65/72), 90.5% (57/63) and 88.9% (8/9), respectively. ②The comparison of subjective score of image quality between double low CCTA and routine CCTA was not statistically significant (P>0.05). ED and dosage of iodide in double low CCTA were significantly lower than routine CCTA and the differences were statistically significant (P<0.05). Conclusion Double low CCTA can be used as preferred examination scheme for follow-up and subsequent visit of patients after PCI. The accuracy in the diagnosis of ISR is higher, with clear image, low intake of iodine and low radiation dose, etc. which is worthy of clinical promotion.