第3代双源CT低剂量Turbo Flash成像图像质量与诊断效能的临床研究

Study of image quality and diagnostic accuracy of low-dose coronary angiography using third-generation dual-source CT with free breathing and heart rate

目的探讨第3代双源CT大螺距前瞻性心电门控扫描模式(TurboFlash)冠状动脉CT成像(CCTA)评价冠状动脉狭窄的准确性、图像质量及有效辐射剂量。方法前瞻性收集2016年4月至2017年4月接受第3代双源CCTA检查的患者1003例,其中有70例患者在CCTA检查后30d内行冠状动脉造影(CAG)。对冠状动脉各节段图像质量进行评分,计算有效辐射剂量。以CAG结果为“金标准”,计算CCTA显示冠状动脉病变的灵敏度、特异度、阳性预测值和阴性预测值;CCTA与CAG评价冠状动脉狭窄分级的一致性采用Kappa值并进行U检验。结果(1)图像质量:右冠状动脉不可诊断血管节段为0,左冠状动脉主干及前降支不可诊断血管节段为0,左冠状动脉回旋支不可诊断血管节段为0.04%(3/835)。(2)准确性评价:基于节段水平分析,ForceCT诊断冠状动脉狭窄的灵敏度为97.0%(289/298)、特异度为98.3%(706/718)、阳性预测值为96.0%(289/301)、阴性预测值为98.7%(706/715);基于血管分析,灵敏度为97.5%(159/163)、特异度为85.1%(40/47)、阳性预测值为95.8%(159/166)、阴性预测值为90.9%(40/44);基于患者分析,灵敏度、特异度、阳性预测值、阴性预测值均为100%。CCTA与CAG显示的冠状动脉狭窄部位高度一致(U=2.4,P=0.008)。(3)辐射剂量:有效辐射剂量为(1.17±0.29)mSv。结论第3代双源CTTurboFlash模式可以在自然呼吸、无心率干预下进行冠状动脉成像,扫描成功率高,图像质量佳,评价冠状动脉狭窄的准确性高,有效辐射剂量低。

ObjectiveTo prospectively investigate the diagnostic accuracy, image quality, and radiation doses of electrocardiogram (ECG)-triggered high-pitch acquisition (turbo flash) coronary computed tomography(CT) angiography(CCTA) using third-generation dual-source CT compared with coronary angiography(CAG) for the diagnosis of significant coronary stenoses.MethodsProspectively collected 1003 patients who received the third-generation dual-source CCTA examination from April 2016 to April 2017. Among them, 70 patients underwent coronary angiography(CAG) 30 days after CCTA examination to score the image quality of each segment of coronary artery and calculate the effective radiation dose. The sensitivity, specificity, positive predictive value and negative predictive value of CCTA for coronary artery lesions were calculated using CAG results as the gold standard. The consistency of CCTA and CAG in grading coronary artery stenosis was evaluated by Kappa value and U test.Results(1) Image quality:no non-diagnostic image quality was observed in the right coronary artery nor left anterior descending artery. The rate of coronary segments with non-diagnostic image quality reached 0.04% in the left circumflex artery. (2) Diagnostic accuracy:the sensitivity, specificity, and positive and negative predictive values totaled 97.0%(289/298), 98.3%(706/718), 96.0%(289/301), 98.7%(706/715) for segment assessment and 97.5%(159/163), 85.1% (40/47), 95.8%(159/166), 90.9%(40/44) for vessel assessment, and all the values are 100% for patients assessment. CCTA was highly consistent with the site of coronary artery stenosis shown by CAG(U=2.4, P < 0.05). ⑶ Radiation doses:the effective radiation dose was(1.17±0.29) mSv on average.ConclusionsCCTA using the prospectively ECG-triggered high-pitch mode (turbo flash) of the third-generation dual-source CT system is associated with high diagnostic accuracy for the assessment of coronary artery stenoses at low doses.