多层螺旋CT血管成像技术诊断主动脉夹层的临床价值

目的:评价多层螺旋CT血管成像对主动脉夹层的临床诊断价值。方法:对29例主动脉夹层患者行多层螺旋CT平扫和增强扫描,将获得的容积数据进行表面覆盖法(SSD)、实时3D(RT-3D)、多平面重组(MPR)及曲面重组(CPR)等多种方式重组。16例经手术证实,8例经造影证实,其中2例术后进行了复查。结果:SSD能直观地显示主动脉夹层的全貌,病变与分支血管的关系,但显示管腔内的情况欠佳;RT-3D图像优于其它方法的重组图像,可清楚显示主动脉壁的钙化、测量各径线参数以及多角度动态观察病变,但重组时间较长。MPR能保留有助于定性诊断的密度CT征象,多方位地显示附壁血栓、真假腔,并能显示主动脉旁血肿等合并症,但缺乏病变与周围解剖结构的立体观。CPR可连续地显示主动脉夹层的范围,弥补MPR的不足。结论:多层螺旋CT血管造影可直观地显示主动脉夹层的特异性征象,综合应用多层螺旋CT的各种重组技术,为临床提供了一种安全可靠的诊断手段。

The Clinical Value of 3D Reconstruction with Multi-spiral CT in Aortic Dissection

Objective:To study the clinical diagnostic value of 3D reconstruction with multi-spiral CT in aortic dissection.Methods:29 cases of aortic dissection were performed by multi-spiral CT.Surface shaded display(SSD),real time volume rendering(RT-3D),multiplanar reconstruction(MPR) and curve planar reconstruction(CPR) were used.16 cases were confirmed by surgery,8 by angiography and 2 cases were followed up after surgery.Results:SSD stereoscopically showed panorama of aortic lesion and the relation with arterial branches,display of intra-aortic condition was defective.(Reconstruction) pictures of RT-3D were better than the pictures of other methods.It clearly showed the wall calcification,measured any diameter and observed the lesion in any desired angle,but the reformation time was longer.MPR could keep the density features and help to diagnosis.In any desired orientation it could display mural thrombus,true and false lumen,collection of blood outside the aorta,but the image was lack of stereoscopical view of the anatomic relationship between the lesion and surrounding structures.CPR could consecutively show the scope of aorta lesion,making up the shortage of MPR.Conclusion:Multi-spiral CT can stereoscopically show the particularity appearance of aortic dissection.Application of combined reconstruction techniques of multi-spiral CT can provide more reliable modality in clinical diagnosis of aortic dissection.