全模型迭代重建技术对低剂量CT冠状动脉支架显示的初步研究

A preliminary study of iterative model reconstruction technique combined with low-dose CT in coronary artery stent

目的:评价低剂量冠状动脉CT结合全模型迭代重建技术(IMR)对冠状动脉支架图像质量的影响。方法:招募临床PCI术后拟行冠状动脉CT复查者46例,共计71枚支架。扫描参数:前瞻性心电门控扫描,管电压100 kV,采用自动管电流调试技术。对患者CT扫描的原始数据分别进行滤波反投影法(FBP)、高级混合迭代(iDOSE^4)及IMR重建。三组重建图像分别进行主、客观评价。结果:所有患者均顺利完成检查。IMR组噪声(26.9±3.6)、信噪比(16.5±2.9)显著优于iDOSE^4组(54.6±9.2,8.2±1.8)及FBP组(78.9±11.4,5.6±1.1)(P<0.01);支架腔内显示方面,IMR组支架腔内信噪比、对比噪声比最高,FBP组最低;组间比较具有统计学差异(P<0.01)。IMR组主观评分最高;在诊断可行性方面,IMR组与iDOSE^4组无显著性差异(P=0.08)。结论:低剂量冠状动脉CT结合IMR具有更低的噪声及更高的信噪比有利于冠脉支架内腔的显示。

Objective:To evaluate the effect of low-dose the image quality of coronary artery stent.Methods:Forty-six coronary CT combined with Iterative Model Reconstruction on patients with PCI were recruited to undergo coronary CT angiography,with a total of 71 stents.CT scan parameters:Prospective ECG-gated scan,tube voltage 100 kV,tube current using automatic tube current debugging technology.The original data of the patient CT scan were reconstructed by filtered back projection(FBP),advanced mixed iteration(iDOSE4)and IMR.Three groups of reconstructed images were subjectively and objectively evaluated.Results:All patients were successfully completed.The noise(26.9±3.6)and the signal-to-noise ratio(16.5±2.9)of the IMR group were significantly better than those in the iDOSE4 group(54.6±9.2,8.2±1.8)and FBP group(78.9±11.4,5.6±1.1) (P<0.01).In the stent cavity display,the signal-to-noise ratio and contrast noise ratio in the IMR group were the highest,and those in the FBP group were the lowest.There was statistical difference between the two groups (P<0.01).IMR group had the highest subjective score.There was no significant difference between the IMR group and the iDOSE4 group in terms of diagnostic feasibility (P=0.08).Conclusion:Low-dose coronary CT combined with IMR has lower noise and higher signal-to-noise ratio,which is beneficial to the display of coronary stent cavity.