髓母细胞瘤的CT和MRI诊断

目的：提高非典型髓母细胞瘤的CT和MRI的诊断准确率。材料和方法：经手术及病理证实的髓母细胞瘤40例，年龄5～35岁。CT检查34例，其中28例同时作增强扫描。MRI检查38例，30例作增强扫描。32例同时作CT和MRI检查。结果：CT和MRI对髓母细胞瘤的定位诊断正确率为100％，定性诊断正确率为87．5％（35／40）。肿块位于小脑蚓部25例，小脑半球9例，四脑室内6例。肿瘤囊变26例，钙化3例，有例增强不明，3例出现转移，转移沿脑脊液播散。结论：非典型髓母细胞瘤可以发生在四脑室内，小脑半球，可以出现大的囊变、钙化，也可以增强不明显，掌握这些征象是CT和MRI诊断非典型髓母细胞瘤的关键。

CT and MRI Diagnosis of Medulloblastomas

To promote the diagnostic accuracy of atypical medulloblastomas with CT and MRI. Materials and Methods: 40patients proved by pathologic result, the age ranged from 5 to 35 years. 34 cases were examined with CT and 38 cases with MRI, amongof them, 28 cases and 30 cases were examined with contrast studies by CT and MRI, 32 patients had done CT scan as well as MRI. Results: The loclization of medulloblastomas diagnosed by CT and MRI was 100%, the diagnostic accuracy was 87. 5 % (35/40). 25 caseswere located at cerebellar inferior vermis, 9 cases were located at the cerebellar hemisphere and 6 cases at the fourth ventricle. 26 cases hadcystic component and 3 cases had calcification, 2 cases had no enhancemene. Metastasis were found in 3 cases, which were spread along thecerebrospinal fluid. Conclusion: Atypical medulloblastomas could growth in the fourth ventricle and cerebellar hemisphere. The tumor mightdevelop cystic degeneration, calcification and also might present without significant contrast enhancement. Recognizing the characteristic features are important in diagnosis atypical medullblastomas with CT and MRI.