| Objective To discuss and investigate the MRI features of cerebellum cystica tumours in order to improve the accuracy of diagnosis. Methods Twenty-three cases of cerebellum cystica tumours with MRI proved by surgery and pathology were analyzed retrospectively. The main evaluation index are cystic extent, diseased region, size, periphery, surrounding edema, mass effect, noncommunicating hydrocephaly and so on. Results Among the 23 cases of cerebellum cystica tumours, there were 12 cases of medulloblastoma(53%), 8 cases of hemangioblastoma(35%), and 3 cases of pilocytic astrocytoma(13%); among these tumours, medulloblastoma with cystic was in eight cases, but the scope was small, hemangioblastoma cystic became large but with small nodules in 8 cases, and astroastrocytoma had larger cystic components and larger nodules than hemangioblastoma. Enhancement scanning showed cystic part of medulloblastoma was not enhanced, solid part showed moderate to severe enhancement, cystic part of hemangioblastoma and pilocytic astrocytoma was not strengthened, nodules were obviously improved, hemangioblastoma capsule wall had no enhancement, while pilocytic astrocytoma capsule wall was strengthened in two cases. Three kinds of tumor boundary was clear, with no or only one degree edema, the placeholder effect was lighter, and the larger tumor size easily caused obstructive hydrocephalus. Conclusion MRI images have important diagnostic value since they can clearly show the tumor location, cystic change degree and the placeholder effect, and so on. Medulloblastoma can be seen more in cerebellar vermis, capsule occurs more but in smaller scale. Hemangioblastoma and pilocytic astrocytoma can be seen more in cerebellar hemispheres, with more cystic change and bigger area; hemangioblastoma has typical MRI feature, with large cystic and small nodule, and rare reinforcement in capsule wall; pilocytic astrocytoma has a typical big cystic and big nodule and frequent reinforcement of capsule wall. |
