扰相梯度双回波序列与3D-TOF-MRA及SWI在显示正常颅内主要动、静脉的比较

目的探讨磁共振扰相梯度双回波序列（dual-echo sequence）同时获得动脉成像及静脉成像的能力。方法选取11例健康志愿者行双回波序列、3D-TOF-MRA及SWI序列检查。将双回波序列所获得的动脉成像对大脑前、中、后动脉各段显示效果与3D-TOF-MRA成像效果比较；同时所获得的静脉成像对脑深部静脉的显示效果与SWI成像效果比较。结果双回波与3D-TOFMRA序列对双侧大脑前动脉A1～A4段、大脑中动脉M1～M2段、大脑后动脉P1～P3段显示效果无明显差异（P〉0．05）。两成像方法对双侧大脑前动脉A5段、大脑中动脉M3段、M4段、M5段及大脑后动脉P4段显示效果具有明显统计学差异（P〈0．05），31）-TOFMRA序列对以上动脉段的显示效果优于双回波序列。双回波序列与SWI序列对大脑大静脉、双侧大脑内静脉、双侧透明隔静脉、双侧丘纹上静脉的显示效果无明显差异（P〉0．05）。而两成像序列对双侧脉络膜静脉的显示效果具有明显统计学差异（P〈0．01），SWI序列对其显示效果优于双回波序列。结论双回波序列适合于检出多数大脑内动、静脉，但对小的动脉远端检查以常规31）一TOF—MRA为好；双回波序列亦适合检出多数脑深部静脉，但对于微小静脉的检出以常规SWI更好。

Comparison of FLASH T2 dual-echo MRI sequence with 3D TOF MRA and SWI for evaluation of the cerebral circulation

Objective To compare the FLASH T2 dual-echo MRI sequence with 3D TOF MRA and susceptibility-weighted imaging （SWI） for evaluation of the cerebral circulation. Methods Eleven healthy volunteers underwent FLASH T2 dual-echo sequence, 3D-TOF-MRA and SWI. The visibility of the cerebral arteries and deep cerebral veins was compared. Results Most of the cerebral arteries and deep cerebral veins were equally well seen on the dual-echo sequence in comparison with the 3D TOF MRA and SWI, respectively （P 〉 0.05）. The 3D-TOF-MRA was significantly better than the dual-echo sequence for demonstrating the A5 segment of the anterior cerebral artery, M3-M5 segments of the middle cerebral artery and P4 segment of the posterior cerebral artery （P 〈 0.05）. The SWI was significantly better than the dual-echo sequence for demonstrating the venae chorioidea （P 〈 0.05）. Conclusions FLASH T2 dual-echo can depict most cerebral arteries and deep cerebral veins. Visualization of A5, M3-MS, P4 segments of the anterior, middle and posterior cerebral arteries is better on 3D-TOF-MRA and the venae chorioidea on SWL