磁共振相位对比电影对蛛网膜囊肿与蛛网膜下腔扩大的鉴别诊断

Differential Diagnosis of Arachnoid Cyst with Subarachnoid Space Enlargement with Phase-Contrast Cine MRI

目的：应用磁共振相位对比法，揭示脑与脑脊液运动的相互关系，以评价此方法对鉴别蛛网膜囊肿与蛛网膜下腔扩大的诊断价值。材料与方法：运用磁共振相位对比电影和流动分析软件，对10例健康人脑与脑脊液运动规律相关性进行研究和10例影像学疑蛛网膜囊肿或蛛网膜下腔扩大患者的脑脊液运动进行量化分析，绘出一个心动周期不同时相脑脊液流量曲线和时间-信号强度曲线，并进行分析比较。结果：脑脊液流动是由脑运动驱动引起，而脑运动则被认为是在一个心动周期内不同时相内动脉流入与静脉流出量存在流量差所致。基于这一现象和蛛网膜囊肿与蛛网膜下腔扩大的发病机理的不同，两者的相位图、流量曲线图以及时间-信号强度曲线图均有明显差异，各有其特征性。结论：（1）无创性磁共振为研究脑实质运动及脑脊液生理和病理提供可靠、稳定的技术方法；（2）磁共振相位对比电影脉冲序列对鉴别蛛网膜囊肿与蛛网膜下腔扩大有重要价值。

Objective: To reveal the relationShip of brain motion and CSF flow with Phase-contrast cine MRI and to evaluae this technique indifferentiating arachoid cyst with subarachnoid space enlargement. Materials and Methods: Using phase-contrast cine MRI pulse sequence, brainmotion and CSF flow during cardiac cycle were measured in 10 healthy vounteers and 10 patients with MRI-suspected arachnoid cyst or subarachnoidspace enlargement. CSF stroke volume was calculated by flow quantification curve, time-signal intensity curve was traced, and two curves were com-pared. Results: Brain motion was due to the volume difference between arterial and venous blood flow during the cardiac cycles, and was taken for thedriving force for CSF pulsation. Arachnoid cyst and subarachnoid space enlargement carried different curve patterns. Conclusion: (1 ) Phase-contastMRI and flow quantification useful and reliable technique for non-invasive evaluation of brain motion and CSF flow. (2) Arachnoid cyst and suba-rachnoid space eulargement can be differentiated with Phase-contrast cine MRI.