64层MDCT冠状动脉成像不同心率扇区重建的应用价值  

The Clinic and Study of Application with Various Heart Rate using Segment Image Reconstruction on 64-MDCT Coronary Angiography

作　　者：缪熙音[1] 陈刚[1] 陈文芳[1] 陆海峰[1] 张利军[1] 陆秀良[1] 曾蒙苏[1] 

机构地区：[1]复旦大学附属中山医院放射科,上海200032

出　　处：《中国临床医学》2011年第4期555-557,共3页Chinese Journal of Clinical Medicine

摘　　要：目的：了解扇区重建技术在冠状动脉CT成像中的应用价值。方法：58例受检者,根据心率分为3组,A组,心率〈75次/min,单扇区重建;B组,心率75~94次/min,双扇区重建;C组,心率95~115次/min,四扇区重建。分别测量冠状窦开口处增强前后CT值的变化,并计算强化率,同时测量受检者的受辐射剂量CTD和DLP值。对三维冠状动脉重建图像质量按5个等级进行主观评分：5分无伪影;4分轻微伪影,仅主干的某一段轻微模糊,诊断不受影响;3分为中等伪影,某一支冠状动脉主干的1/2以上模糊,但可以诊断;2分为严重伪影,某一支冠状动脉主干全长均模糊不清或不连续,诊断受限;1分为冠状动脉主干不能识别,不能作出诊断。其中4分以上因伪影的干扰较少定为优良。结果：①主观评分：A组：共29例,优良率为100%;B组：共20例,优良率为85%;C组：共9例,优良率为56%;②客观评估：3组病例的强化均值、强化率、CTD和DLP值之间均存在显著差异（P〈0.05）,单扇区扫描获得的图像的强化效果最佳,且受检者在检查过程中的所受到的辐射剂量最小。结论：受检者在检查前服用β受体阻滞剂控制心率,并采用单扇区重建技术能获得理想的冠状动脉诊断图像。Objective：To evaluate the effect of different segment image reconstructions for different heart rates（HRs） on 64-multislice computed tomographic（MSCT） coronary angiography.Methods：Fifty-eight patients were categorized into 3 groups based ondifferent sinus rhythms heart rate（HR）.Group A,HR75 beats per minute,single-segment image reconstruction;Group B,HR 75-94 beats per minute,two-segment image reconstruction;Group C,HR 95-115 beats per minute with four-segment image reconstruction.Mean attenuation values of the coronary sinus were measured before and after contrast enhancement and the enhancement ratio were also calculated.Weighted CT dose indexes（CTDI） and dose-length product（DLP）were obtained for all protocols and the image quality were graded on a 5-point confidence scale,Grades 4 and 5 were accepted as good and excellent for the image quality.Results： The ratio of good and excellent image quality were 100%（29/29） for group A,85%（17/20） for Group B and 56%（5/9） for Group C.The values of mean attenuation,enhancement ratio,CTDI and DLP showed significant difference among the 3 groups（P0.05）.The best image quality and the least radiation dose were achieved at single-segment image reconstruction.Conclusions： Oral administration of β-blockers to control patients′ HR and use of single-segment image reconstruction are very important to get the best diagnostic image in 64-MDCT coronary angiography.

关 键 词：体层摄影术 X线计算机 多扇区重建 CT剂量指数 剂量长度乘积 

分 类 号：Q814.42[生物学—生物工程]