128排冠状动脉CTA图像质量与低剂量的研究分析  

Study on 128-detector CT coronary angiography image quality and low-dose

作　　者：华小兰[1] 冯琦[1] 殷焱[1] 朱荣[1] 华佳[1] 杨咏琰[1] 

机构地区：[1]上海交通大学医学院附属仁济医院放射科,上海200127

出　　处：《实用放射学杂志》2011年第10期1570-1573,共4页Journal of Practical Radiology

基　　金：上海交通大学医学院重点学科建设项目;上海市重点学科建设项目（编号：S302030）.

摘　　要：目的 探讨128排螺旋CT低剂量前门控冠状动脉CTA的图像质量。方法研究对象随机分为2组．分别采用前门控（31例）和低剂量后门控（47例）扫描技术，扫描仪为西门子128排螺旋CT。前门控扫描的主要参数包括：管电压100kV．管电流205mAs，70％R—R间期扫描。低剂量后门控扫描的主要参数包括：100kV，40％～70％R—R间期时管电流采用190mAs，其余R—R间期时管电流采用19mAs。螺距0．2～0．5。对每例冠状动脉3支主干：右冠状动脉（RcA）、左前降支（LAD）和左旋支（LCX）的图像质量进行4级评分，测量增强图像的信噪比（SNR），并记录每例患者接受的放射剂量。结果前、后门控2组中的图像质量均没有明显差异。前门控组的平均放射剂量明显低于低剂量后门控组。结论利用前门控冠状动脉CTA扫描可以在大幅度降低患者所受放射剂量的同时，保持良好的图像质量。Objective To evaluate the image quality of low-dose in 128-detector prospective electrocardiogram（ECG）-gated CT coronary angiography（CTA）. Methods 78 cases underwent CTA with prospective （31 cases） and low-dose retrospective （47 cases） ECG -gated CT protocols respectively using Siemens 128-detector CT system. The prospective CTA was performed using following parameters： 100 kV, 205 mAs,70%R-R phase scan. Low-dose retrospective ECG -gated CTA was full dose during 40%-70% of the RR interval and partial dose for the rest of RR interval. The pitch changed from 0.2 to 0.5 depending on the heart rate and patient size. Image quality of CTA was evaluated using four-point grading scale. The signal to noise ratio（SNR） of enhanced arteries and myocardium were also measured and the radiation doses received were recorded. Results There was no significant difference in the image quality between the prospective and the retrospective gating protocols. The mean radiation dose of prospective gating group was significantly lower than that of the retrospective group. Conclusion The prospective CT angiography can achieve lower radiation dose than that of low-dose retrospective CT angiography with preserved image quality.

关 键 词：心脏 冠状动脉 门控 放射剂量 图像质量 

分 类 号：R322.1[医药卫生—人体解剖和组织胚胎学] R814.49[医药卫生—基础医学]