枕大池发育异常的影像学诊断

目的：分析枕大池发育异常的影像学表现。加深对本病的认识。方法：本组40例中男22例，女18例，年龄19-62岁，平均41岁。40例均先做CT平扫，其中5例又行强化扫描。35例行脑池造影CT扫描；25例复查时又做MR检查。对CT、MRI表现进行回顾性分析。结果：按病变形态、范围与影像学表现分为二型；（1）对称型；（2）非对称型。其表现各具特点。结论：根据发病部位与影像学表现诊断不难。但应与幕下某些低密度病变进行鉴别。脑池造影CT扫描有助确诊。

Imaging diagnosis of cisterna magna with growth abnormity

Objective:To improve diagnosis value of growth abnormity cisterna magna using CT and MRI. Methods: 40 cases (male 22, female 18, age range 19～62, average 41 ) were studied with CT and MR imaging. in those, all patients were examined by plain CT scan,5 by contrast enhancement,35 by CT cisternography scan,25 by MRI at call back. Results:They can be divided into two types according to the configuration, range and image, i. e. symmetric type and nonsymmetric type. Conclusion: It is not difficult to make a diagnosis of this defect, but this defect should be differential from some showing low density diseases under the tentorium, the CT cisternography may help to make sure diagnosis.