1.5T磁共振TWIST技术在主动脉夹层的应用研究

Application of 1.5T magnetic resonance using TWIST technique in patient with aortic dissection

目的探讨磁共振(time-resolved angiography with interleaved stochastic trajectories,TWIST)技术在主动脉夹层诊断中的应用价值。方法分析30例主动脉夹层病例,实验组15例MRA采用TWI ST技术扫描,对比剂注射与MR扫描同时进行,无需屏气,60s内共采集15个动脉期数据;对照组15例MRA采用冠状面超快速三维梯度回波序列扫描,屏气18s采集一期数据。数据传输至工作站并进行MPR、MIP重组。采用双盲法分别对两种检查在增强图像对比度、图像灰阶清晰度及图像细节方面进行图像质量对比,并进行统计学分析。结果实验组A型2例,B型13例;对照组A型1例,B型14例,原始图像结合MPR重组均能清晰显示破裂口、真假两腔及分支血管受累情况。两种检查方法的影像质量差异没有统计学差异(P>0.05)。实验组无需患者屏气配合,亦无须估计扫描起始点,不同时相的增强图像能提供额外的血流动力学信息,直观反映真假二腔的关系。结论磁共振TWIST扫描技术在不降低图像质量前提下,降低对患者及检查操作者的要求,更准确显示真假腔的位置,值得临床推广应用。

Objective To discuss the value of application of 1. 5 T magnetic resonance using TWIST（ Time-resolved angiography with interleaved stochastic trajectories） technique in patient with aortic dissection. Methods 30 patients suspected with aortic dissection underwent MR scanning were divided into a control group and a research group. 15 cases in research group were examined with TWIST skill,which were scanning at the time of injection and without breath holding,15-arterial phase data were collected in 60 seconds. 15 cases in control group presented with bolus track DCE-MRA,breath holding in 18 s to gain an arterial phase data. All data were sent to workstation for reconstruction using MIP and MPR. Then,two observers evaluated the quality,including contrast of enhanced scan image,gray scale clarity,matrix and detail of image,then,analyzed them by statistics. Results 2 cases were type A and 13 cases were type B in research group,1 case was type A and 14 cases were type B in control group. The original images combined with MPR can clearly show the rupture,true and false cavity and involved branch of vascular. There was no statistically significant different of image quality with two types of technique（ P〉0. 05）. Patients in research group were not needed breath holding and estimated the scanning starting point. The enhanced images of all arterial phase data can provide additional hemodynamic information,which can directly show the relationship between true and false cavities. Conclusion Magnetic resonance using TWIST can reduce the requirements of patients and operators while do not reduce the image quality. It can more accurately display the location of the true and false cavities and is an effective method for screening and evaluation of aortic dissection,which is worth to populate and apply.