摘要目的:采用第3代双源CT进行动态负荷CT心肌灌注成像（CTP），探讨定性评估与定量评估对于中重度冠心病风险患者心肌缺血的诊断价值，并分析该项检查的临床应用有效性。方法:2016年12月至2018年4月前瞻性连续纳入北京协和医院具有稳定性心绞痛症状、临床评估为中重度冠心病风险的患者，采用第3代双源CT对入组患者进行动态负荷心肌CTP扫描。针对心肌灌注后处理图像，分别采用定性及定量分析方法对患者进行心肌缺血诊断评估。定量评估基于美国心脏协会（AHA）17段分段法，对左心室心肌牛眼图进行心肌血流数值（MBF）定量测量。以有创冠状动脉造影（ICA）和冠状动脉血流储备分数（FFR）作为心肌缺血诊断参考标准，基于血管水平为分析单位，通过DeLong检验计算ROC曲线下面积（AUC）及灵敏度、特异度、诊断准确度等诊断效能值。结果:60例患者最终入组并完成动态负荷CTP检查，共有151支冠状动脉血管成功接受后续ICA、FFR检查和治疗，其中39例患者的58支冠状动脉血管被诊断为存在血流梗阻性病变伴相应供血区心肌血流灌注减低。定性评估方法AUC为0.65 （95%CI 0.58~0.73），定量评估方法AUC为0.92 （95%CI 0.87~0.97）。2种评估方法诊断效能间差异具有统计学意义（ P<0.05）。入组患者的有效辐射剂量为（3.8±1.2）mSv。 结论:动态负荷心肌CTP定量评估中重度冠心病风险患者心肌缺血的诊断效能显著优于定性评估方法。采用第3代双源CT能够有效实现低剂量CTP检查，具有良好的临床应用价值。

abstractsObjective:The purpose of this study was to investigate the diagnostic performance of qualitative and quantitative analysis methods from dynamic myocardial CT perfusion (CTP) in identifying myocardial ischemia for intermediate-to high-coronary artery disease (CAD) risk patients, and further evaluate the clinical availability.Methods:Consecutive symptomatic patients were prospectively recruited and scanned with adenosine triphosphate (ATP)-stress dynamic myocardial CTP protocol using third-generation dual-source CT. Quantitative and qualitative assessment were performed. For quantitative assessment, the segment-based absolute myocardial blood flow (MBF) values were acquired on the transmural layer of the myocardium for analysis based on the 17-segment AHA myocardial model (bulls-eye plots). The diagnostic performance of yocardial ischemia was assessed using invasive coronary angiography (ICA) and fractional flow reserve (FFR) as the reference standard. Areas under the ROC curves (AUC) and parameters were calculated and compared using DeLong test.Results:Finally sixty patients underwent the CTP examination. Among these patients, there were 151 vessels underwent ICA/FFR examination for analysis in our study. According to the ICA/FFR results, 58 vessels were identified as causing ischemia in 39 patients. The AUC for qualitative and quantitative assessment were 0.65 (95%CI 0.58-0.73) and 0.92 (95%CI 0.87-0.97), respectively. The diagnostic values of quantitative analysis was much higher than that of qualitative method ( P<0.05). The effective dosage was (3.8±1.2)mSv. Conclusions:The quantitative assessment of stress dynamic myocardial CTP for detecting myocardial ischemia in patients with intermediate-to high-risk of CAD was superior to qualitative evaluation. The stress dynamic myocardial CTP with the third generation dual source CT showed great clinical feasibility, which may observably reduce the effective radiation dose of the examination.