3D磁共振成像与CT诊断腹主动脉瘤的临床价值研究

Study on the Clinical Value of 3D MRI and CT in the Diagnosis of Abdominal Aortic Aneurysm

目的以CT血管造影为参考标准,验证三维磁共振(3D Magnetic Resonance Imaging,3D MRI)定量测量腹主动脉瘤(Abdominal Aortic Areurysm,AAA)直径的准确性,并评价三维高分辨度动态增强磁共振成像表征腔内血栓(Intraluminal Thrombus,ILT)类型分布的分辨度。方法62名AAA患者在两个月内均接受CT和3D MRI检查,由两名影像科医生独立测量AAA直径,并进行Bland-Altman分析,同时测量ILT影像信号与腰大肌影像信号比值。结果3D MRI与CT比较两者在AAA直径测量结果上表现出较强的一致性和重复性,ICCs>0.99,CVs<2.7%。ILT的CT表现为均匀衰减,而MRI显示为丰富的陈旧或新鲜类型分布变化。结论3D MRI不但可以提供准确、可重复的AAA直径测量结果,同时能够显示与AAA病情进展相关的ILT类型分布影像学信息。

Objective To verify the accuracy of quantitative measurement of abdominal aortic aneurysm(AAA)diameter by 3D magnetic resonance imaging(3D MRI)with CT angiography as the reference standard,and to evaluate the resolution of 3D high-resolution dynamic enhanced magnetic resonance imaging to characterize the intraluminal thrombus(ILT)type distribution.Methods A total of 62 patients with AAA received CT and 3D MRI examination within two months were enrolled.The diameter of AAA was measured by two radiologists independently.The Bland-altman analysis was performed,and the ratio of ILT signal to LBP signal was measured.Results The 3D MRI and CT showed strong consistency and repeatability in the measurement results of AAA diameter(ICCs>0.99,CVs<2.7%).CT images of ILT showed uniform attenuation,while MRI showed abundant distribution of old or fresh types.Conclusion 3D MRI can not only provide accurate and repeatable measurement results of AAA diameter,but also display the imaging information of ILT type distribution related to the progression of AAA.