冠状动脉病变自身因素对CTA评价冠状动脉狭窄准确性的影响

The Study of Intrinsic Properties of Coronary Arteries and Their Impact on the Evaluation of Vascular Stenosis by CT Angiography

目的探讨冠状动脉病变自身因素对CTA评估血管狭窄程度准确性的影响。资料与方法60例临床拟诊疑为冠状动脉狭窄的患者同期行冠状动脉CT血管造影(CTA)和冠状动脉血管造影检查(CAG)。CTA扫描采用64层螺旋CT及回顾性心电门控技术,以CAG结果为金标准,采用双盲法评价CTA诊断冠状动脉狭窄的准确性,并分析各种冠状动脉病变自身因素对评价狭窄准确性的影响。结果CTA诊断冠状动脉轻、中、重度狭窄的敏感性分别为76.47%、77.97%和85.71%,钙化斑块是导致64层螺旋CT评价冠状动脉狭窄假阳性最重要的自身因素(18/28,占64.29%),对于冠状动脉和其分支的狭窄程度的低估占假阴性结果的66.67%(20/30),壁冠状动脉和心肌桥的漏诊占假阴性结果的23.33%(7/30)。结论64层螺旋CT诊断冠状动脉重度狭窄具有较高的准确性,钙化斑块、心肌桥和小血管的狭窄病变本身均影响CTA评价狭窄的准确性,而非钙化斑块和支架/冠状动脉旁路移植术(CABG)后狭窄的诊断准确性较高。

Objectives To discuss the impact of intrinsic properties of coronary arteries on the evaluation of vascular stenosis by CT angiography. Materials and Methods 60 patients received both CTA and CAG in our hospital during May to November in 2006. CTA was performed using Phillips 64 slices spiral CT with retrospective electrocardiogram gated technique. CAG was set as the gold standard and double blind trial technique was applied in assessing the diagnostic accuracy of CTA. In addition, the impacts of intrinsic properties of coronary arteries were evaluated. Results The sensitivity of CTA in diagnosing mild, moderate and severe stenosis was 76.47%, 77.97% and 85.71% respectively. Calcified plaque was found to be the primary intrinsic property leading to false positive （64.29% , 18/28）. The stenosis of distal branches was under evaluated in 66.67% false negative cases （20/30）. Mural coronary artery and myocardial bridges accounted for 23.33% false negative cases （7/30）. Conclusions 64 slices spiral CT has a high diagnostic accuracy in evaluating severe stenosis. Calcified plaque, myocardial bridges and distal branches are the intrinsic properties affecting the diagnostic accuracy. In contrast, noncalcified plaque, PCI and CABG rarely affect the diagnostic accuracy.