四维MR血流成像在肾透析患者自体动静脉瘘血流动力学研究中的应用价值

Application of four-dimensional flow MRI in hemodynamic study of autogenous arteriovenous fistula in renal dialysis patients

目的·探讨利用四维MR血流成像(four-dimensional flow MRI,4D flow MRI)评估肾透析患者前臂自体动静脉瘘(autogenous arteriovenous fistula,AVF)血流动力学的可行性。方法·选择上海交通大学医学院附属仁济医院肾脏科的血液透析患者45例,接受前臂AVF血管超声检查及磁共振成像。利用配对t检验对2名放射科医师经4D flow MRI测量的血流动力学参数的一致性、4D flow MRI与血管超声在AVF相同层面血流动力学参数的一致性进行分析;利用磁共振黑血序列获取AVF形态学参数,并就该参数与4D flow MRI血流动力学参数进行Pearson相关分析。结果·42例患者成功完成了前臂AVF血管超声检查及磁共振成像。配对t检验结果显示,2名放射科医师利用4D flow MRI测量的血流动力学参数重复性较好(均P=0.000);除了吻合口峰流速(r=-0.078,P>0.05)外,4D flow MRI与血管超声的血流动力学参数一致性较好(r=0.292～0.569,均P<0.05)。经Pearson相关分析显示,AVF头静脉流量与静动脉管径比、吻合口面积均相关(r=-0.671,r=0.482,均P<0.05);吻合口附近剪切力与吻合角度、管壁厚度均相关(r=0.530,r=0.462,均P<0.05)。结论·利用4D flow MRI可以获取肾透析患者前臂AVF的血流动力学参数,对进一步研究AVF功能障碍有一定的参考价值。

Objective · To investigate the feasibility of four-dimensional flow MRI (4D flow MRI) in evaluating the hemodynamics of forearm autologous arteriovenous fistula (AVF) in renal dialysis patients. Methods · Forty-five patients from Renal Division of Renji Hospital, Shanghai Jiao Tong University School of Medicine were included. Patients with forearm AVF underwent ultrasonography and MRI. The consistency of 4D flow MRI hemodynamic parameters measured by two radiologists and hemodynamic parameters at the same plane of AVF by 4D flow MRI and ultrasonography were analyzed by paired t test. The morphological parameters of AVF were acquired from black blood sequence, and they were used for Pearson correlation analysis with the hemodynamic parameters obtained from 4D flow MRI. Results · Forty-two patients completed the forearm AVF ultrasonography and MRI successfully. Paired t test showed that the consistency of 4D flow MRI hemodynamic parameters by two radiologists was good (all P=0.000), and all hemodynamic parameters measured by 4D flow MRI and ultrasonography were in good agreement (r=0.292-0.569, all P<0.05) except for the peak flow velocity at anastomosis (r=-0.078, P>0.05). Pearson correlation analysis showed that the cephalic venous flow volume of AVF was correlated with the diameter ratio of the cephalic venous to radial artery and the anastomosis area ( r=-0.671, r=0.482, both P<0.05), and the wall shear stress (WSS) near the anastomosis was correlated with the anastomosis angle and wall thickness (r=0.530, r=0.462, both P<0.05). Conclusion · 4D flow MRI can be used to evaluate the hemodynamic parameters of forearm AVF in renal dialysis patients, which can provide a reference for further study of AVF dysfunction.