第二代双源CT前门控冠状动脉成像与冠状动脉造影比较的初步研究

目的:探讨第二代双源CT前门控冠状动脉成像(CTCA)对冠状动脉狭窄病变的诊断价值。方法:连续44例同期行第二代双源CT前门控CTCA(其中前门控序列扫描35例,前门控大螺距螺旋扫描9例)及选择性冠状动脉造影(SCA)检查的患者,按冠脉病变狭窄程度分为:无狭窄;轻度狭窄(狭窄≤50%);中度狭窄(狭窄50%～75%);重度狭窄(狭窄≥75%);闭塞(狭窄100%),将中度及中度以上狭窄定义为有意义狭窄。以SCA为金标准,分析第二代双源CT前门控CTCA诊断冠状动脉狭窄的敏感性、特异性、阳性和阴性预测值及准确度,同时计算第二代双源CT前门控CTCA的辐射剂量。结果:44例患者冠脉直径2mm以上的节段共570个,其中12段图像质量较差,无法评估,可评估节段占97.89%。第二代双源CT前门控CTCA按冠脉节段计算,诊断冠状动脉狭窄的敏感度、特异度、阳性和阴性预测值、准确度分别为90.18%、93.05%、76.52%、97.42%、92.47%,诊断冠状动脉有意义狭窄的敏感度、特异度、阳性和阴性预测值、准确度分别为90.14%、95.69%、75.29%、98.52%、94.98%。第二代双源CT前门控CTCA与SCA比较对冠状动脉狭窄评价的差异无统计学意义(χ2=2.10,P>0.05),对冠状动脉有意义狭窄评价的差异无统计学意义(χ2=1.46,P>0.05)。第二代双源CT前门控CT-CA的平均辐射剂量为(3.36±1.59)mSv,其中前门控序列扫描的平均辐射剂量为(3.99±1.18)mSv,前门控大螺距螺旋扫描的平均辐射剂量为(1.11±0.44)mSv。结论:第二代双源CT前门控成像对诊断冠状动脉狭窄的准确度稍低于SCA,但其阴性预测值较高,同时其辐射剂量较低,可作为临床冠心病筛查的无创性检查手段。

Comparison of coronary artery imaging with prospectively ECG-triggered acquisition on the second generation of Dual-source CT and coronary angiograph~

Objective： To explore the clinical value of prospective acquisitions in coronary CT angiography （CCTA） using the 2nd generation of dual-source CT by comparing with selective coronary angiography. Methods：Forty-four patients with suspec-ted coronary heart disease underwent prospective ECG-triggering CCTA（thirty-five patients on prospective sequential acquisi-tions and nine on prospective high pitch spiral mode）and selective coronary angiography （SCA）. These two examinations were performed within one month to evaluate the stenosis of coronary artery. CCTA was diagnosed by two experienced radiologists by consensus, and SCA by two cardiologists respectively. The diagnostic sensitivity, specificity,positive and negative predictive value,accuracy of CCTA were determined with SCA as standard of reference. Radiation dose values were measured. Results.. Based on coronary stenosis segmentary analysis, the sensitivity, specificity, positive and negative predictive value, accuracy of CCTA were 90.18 %, 93.05%, 76.52%, 97.42% and 92.47%. For significant coronary stenosis, the sensitivity, specificity, positive and negative predictive value,accuracy were 90. 14%, 95.69%, 75. 29%,98.52%and 94.98% . There was no signifi-cant difference in evaluating the stenosis and significant stenosis of coronary artery between CCTA and SCA（ P 〉0.05）. The mean effective radiation dose was（3.36±1.59） mSv per patient with CCTA. Conclusion：The prospective ECG-triggering coro-nary CT angiography on the 2nd generation of dual-source CT can provide a high diagnostic accuracy of coronary artery stenoses with a low radiation dose.