磁共振3D-CISS序列检查在三脑室造瘘术前后的意义

目的 探讨三脑室的MR3D—CISS（three dimensional constructive inference in steady state）序列扫描对梗阻性脑积水病人诊断分析意义，及其在内镜三脑室底造瘘（endoscopic third ventriculostomy ETV）手术前后的临床血用价值。方法采用回颐性分析方法，对本组46例梗阻性脑积水在1．5T超导MRI仪行3D—CISS序列扫描，通过对MRI图像的观察、测量来分析三脑室扩大程度与三脑室底厚度、脑积水程度的相关程度：对本组中行单纯神经内镜下ETV手术的12例病人作手术前后3D—CISS序列扫描的较为详细的影像学评价。结果梗阻性脑积水三脑室扩大程度与三脑室底的厚度、脑积水程度均具有明显的相关性。3D—CISS三脑室底清晰显示率达96％（44／46），基底动脉（BA）显示率达91％（42／46）：ETV术前可根据矢状位3D—CISS扫描，作切口的体表定位，充分了解三脑室扩大程度与三脑室底厚簿即穿刺造瘘的难易，可了解基底动脉的方位并通过确定造瘘点避免其损伤；术后行3D—CISS可测量瘘口大小、观察CSF的流动方向、评价手术效果。结论3D—CISS序列技术在显示三脑室方面敏感精确，为ETV手术前后评价提供了可靠依据。梗阻性脑积水三脑室扩大程度决定三脑室底的厚度与术中造瘘的难易。

Evaluation of 3D-CISS sequence MRI before and after the endoscopic third ventriculostomy

Objective To analyze the diagnostic value of obstructive hydrocephalus by three dimensional constructive inference in steady state (3D CISS) sequence MRI in third ventricle, and to evaluate its clinical value before and after endoscopic third ventriculostomy (ETV) . Methods With retrospective analysis, 3D CISS sequences were performed in 46 cases on a 1.5 T superconductive MR unit. The correlative degree between enlargement of third ventricle and thickness of third ventricle floor and degree of hydrocephalus were analyzed through observation and measure of the MR image. Detailedly evaluate the 3D-CISS sequence scanning for 12 cases in the group before and after ETV operations. Results There is an obvious correlation between enlargement of third ventricle and thickness of third ventricle floor, and degree of hydrocephalus. 96% of third ventricle floor and 91% of basal artery (BA) can be shown in 3D-CISS. With 3D-CISS scanning we can mark the incision on the scalp, find out the enlargement degree of third ventricle and the degree of difficulty of puncturing third ventricle floor, and find out orientation of BA to avoid injury in operation. After operation, with 3D-CISS scanning we can measure size of fistula, observe CSF flowing direction, and evaluate outcome of operation. Conclusion 3D -CISS can display third ventricle more easily and accurately, provide a credible method for evaluating ETV before and after operation. In obstructive hydrocephalus, the enlargement degree of third ventricle decides the thickness of third ventricle floor and degree of difficulty of puncturing.