多层螺旋CT Flash Spiral模式老年冠状动脉成像的图像质量及影响因素分析

The Image Quality and its Influence Factor of High-Pitch Dual-Source Coronary Angiography Using Flash Spiral Mode in Senile People

目的：探讨老年多层螺旋CT Flash Spiral模式和Spiral模式的冠状动脉动脉成像质量及其影响因素。方法：选择我院2010年1月-2012年12月行多层螺旋CT冠状动脉成像老年患者186例，根据心率和心律将患者分为两组：A组98例行Flash Spiral模式扫描；B组88例行Spiral模式扫描，对两组扫描的冠状动脉分别做图像后处理。比较两组患者的一般情况、图像质量评分及辐射剂量，并统计分析心率变异性对图像质量的影响。结果：两组患者在年龄、性别构成、体重指数（BMI）、钙化积分方面差异无统计学意义（均P〉0．05）；在心率、心率变异性方面，A组明显低于B组，差异有统计学意义（均P〈0．05）；两组患者图像质量评分、图像噪声及对比信噪比（cNR）相比较，差异均无统计学意义（均P〉0．05）；不可诊断节段基于血管节段评价A组和B组分别为1．98％和2．21％，基于患者评价分别为8．16％和6．82％，差异无统计学意义（均P〈0．05）；A组扫描时间、容积CT剂量指数（CTDIv01）、剂量长度乘积（DLP）、单位有效剂量（ED）小于B组，差异有统计学意义（均P〈0．05）；心率变异性〉10次/min患者冠状动脉图像质量明显低于心率变异性5-10次/min和≤5次/min（P〈0．05）。结论：采用多层螺旋CT Flash Spiral模式扫描老年冠状动脉成像质量与Spiral模式接近，但有效辐射剂量明显减少。心率变异性是影响老年患者Flash Spiral模式扫描图像质量的重要因素。

Objective： To explore the image quality of high-pitch coronary angiography by flash spiral mode and to analyze the influence factors for the senile patients. Methods： One hundred and eighty-six senile patients with suspected coronary artery disease who were undergoing coronary angiography in our hospital from January 2010 to December 2012 were prospectively selected in this study and were divided into two groups by the rate and rhythm of the heart. Group A （98 cases） were performed the coronary angiography by flash spiral mode, while group B （88 cases） were conducted by spiral acquisition mode to acquire data. Then the general characteristics, image quality scores and effective radiation dose of patients in the two groups were assessed, and effects of heart rate variability on image quality were analyzed statistically. Results： There were no significant differences about the age, gender, body mass index （BMI） and calc ium scores between two groups （all P〉0.05）; the heart rates and heart rate variability of groups A were significantly lower than that of the group B（P〈0.05, respectively）; there were no significant differences about the image quality scores, the image noise, contrast-to-noise ra tio （CNR） between two groups （all P〉0.05）; there were no significant differences about the non-diagnostic coronary artery segments between two groups （segment-based analysis 1.98% vs 2.21%, patients-based analysis 8.16% vs 6.82%, all P〉0.05）; the scan time, volume CT dose index （CTDIvol）, dose length product （DLP） and effective dose （ED） of groups A were significantly lower than those of the group B （all P〈0.05）; the coronary artery image quality in patients with heart rate variability 〉 10 times/min were significantly lower than that heart rate variability 5 ~ 10 times/min and 5 times/min or less （P〈0.05）. Conclusion： The image quality of high-pitch coronary angiography detected by the flash spiral mode is similar with spiral acquisition mode, while being associated with significant reduction ofradiation exposure in senile patients. The heart rate variability is a considerable factor which affects the image quality of high-pitch dual-source coronary computed tomography angiography in senile patients.